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Nutrient Removal from Farm Effluents
Abstract
The objectives of the study were: (i) to examine the efficiency of nutrient removal during the treatment of dairy farm effluent in a two-pond system, and (ii) to produce an inexpensive but effective nutrient trap which could be recycled as a nutrient source or soil mulch. The concentration of chemical oxygen demand (COD), biological oxygen demand (BOD), nitrogen (N), phosphorus (P) and potassium (K) in a two-pond system used to treat dairy farm effluent was monitored over a period of 7 months. The retention of nutrients by two porous materials was examined both in the laboratory batch (zeolite and bark) and pilot-scale field (bark) experiments. The results indicated that biological treatment of farm effluents using the two-pond system was not effective in the removal of nutrients, which are likely to become pollutant when discharged to waterways. Both the bark and zeolite materials were effective in the removal of N, P and K from effluent. These materials can be placed in the second (i.e., aerobic) pond to treat effluents, which can then be discharged to streams with minimum impact on water quality. The nutrient-enriched porous materials can be recycled as a source of nutrients and soil conditioner.
... Ballantine and Tanner (2010) suggested a filtration method to treat agriculture runoff, by adding natural tree bark which has the potential to act as a filter material in CWs, and enhance their ability to remove NG contaminants before returning water to the rivers (Ballantine and Tanner, 2010). Even though tree bark has an adsorption capability for many nutrients, e.g. total phosphorus, it has low capture efficiency for cations such as NH + 4 (Bolan et al., 2004). ...
... Aeration can also be used for reducing contaminants in farming water. Bolan et al. (2004) showed that during an intermittent aeration technique, denitrification may occur while aeration is suspended, eventually transferring nutrients from agricultural runoff to gaseous nitric oxide (NO) and nitrous oxide (N2O) which in turn emits volatiles to the atmosphere, thus changing the problem from water to air pollution (Greenhouse effects). ...
... Some scientists have add porous materials as a filter to CWs. These materials include tree bark (Pinus radiate) and zeolite to promote adsorption (Bolan et al., 2004). ...
... Ballantine and Tanner (2010) suggested a filtration method to treat agriculture runoff, by adding natural tree bark which has the potential to act as a filter material in CWs, and enhance their ability to remove NG contaminants before returning water to the rivers (Ballantine and Tanner, 2010). Even though tree bark has an adsorption capability for many nutrients, e.g. total phosphorus, it has low capture efficiency for cations such as NH + 4 (Bolan et al., 2004). ...
... Aeration can also be used for reducing contaminants in farming water. Bolan et al. (2004) showed that during an intermittent aeration technique, denitrification may occur while aeration is suspended, eventually transferring nutrients from agricultural runoff to gaseous nitric oxide (NO) and nitrous oxide (N2O) which in turn emits volatiles to the atmosphere, thus changing the problem from water to air pollution (Greenhouse effects). ...
... Some scientists have add porous materials as a filter to CWs. These materials include tree bark (Pinus radiate) and zeolite to promote adsorption (Bolan et al., 2004). ...
Anthropogenic activities such as industrial discharge and agricultural run-off can negatively impact surface water quality. Agricultural run-off contaminants, other than soil particles and suspended solids are mainly nitrogen-based, phosphorus, sourced primarily from fertilisers and pesticides. Currently, available treatment methods include biological treatments, aeration and filtration, however, these methods are restricted by their removal capacity, land requirement and cost. Very little research has been done on the application of capacitive deionisation (CDI) coupled with biochar in agricultural settings. This project is dedicated to investigating the capacity of this combination for removal of nitrate as a commonly existing contaminants in agriculture runoff. The application of CDI to multi-media filter layers of biochar (BC) is a promising technology to improve the nutrient adsorption capability of the BC and thus remove nutrients from the water media. The ability to easily rejuvenate the CDI-BC layers, allows for incorporation into simple backflush cycles in line with current industrial practice, whilst the increased capacity allows for a reduced number of such cycles.
This study tested the natural abilities of in-house prepared BCs sourced from agricultural waste biomass source i.e. Macadamia or as it is more traditionally known Bauple nutshells, in batch and column experiments targeting nitrate removal. The macadamia biochar (MBC) samples were pyrolysed at 900°C and 1000°C respectively, then characterised using standard techniques such as functional group identification using Fourier Transform Infrared Spectroscopy (FTIR) and physical structures analysis with a Scanning Electron Microscopy (SEM). Batch experiments found that 1000°C pyrolysed MBC achieved better nitrate removal around double than those of MBC pyrolyzed at 900°C.
Column test with upward flow removed more nitrate compared to downward flow, largely due to their longer contact time. Three concentrations of 5, 10 and 15 mg/L and 3 flow rates of 2, 4 and 10 ml/min were tested applying the factorial design. The lowest flow rate of 2 ml/min with the highest concentration at 15 mg/L was found to be the most effective settings for nitrate removal. A laboratory-scale in-house designed CDI-MBC unit was used to assess the
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relative improvement to contaminant removal capacity of natural MBC. The results of these laboratory-scale tests can be used to aid the future design of a pilot-scale unit, suitable for handling typical agricultural nutrient and pesticide contamination on-farm. The CDI assisted MBC tests found that with the addition of CDI, the filter can remove around three times the natural MBC capability. Incorporating CDI also prolonged effective usability of the filter. CDI-MBC reached filter saturation after 72 hours usage, compared to 5.5 hrs usage of natural MBC.
Nitrate desorption was carried out after the column was saturated by being backflushed with deionised and/or tap water, using the so-called ‘degaussing method’. The name is derived from the approach used to remove magnetism from test equipment by applying a strong alternating voltage. In the case of CDI, we applied a square waveform of frequency 100 Hz, amplitude 0.5 V and current 0.06 A during backflush to desorb nitrate. These experiments found that the ‘degaussing’ technique recovered around 80% of nitrate in 30 minutes, while 48% and 35% of nitrate was recovered after one hour for the backflush with deionised water and tap water respectively. The CDI- MBC regenerated filter was tested for three cycles. It was found that the fresh column was exhausted after 72 hours and the regenerated filters for cycle one and two were exhausted after 60 and 48 hours, respectively.
... These types of farm waste are often treated biologically using a two-stage system (Bolan et al., 2004; Guo et al., 2013). The first stage involves a settlement or sedimentation pond; and the second aerobic stage is usually stratified with an aerobic top layer over an anaerobic base layer. ...
... In many countries including New Zealand and Australia, discharge of farm wastewaters to surface waters currently requires legal consent; the concentration of effluent nutrients needs to be minimized before entering surface waters. Various approaches involving either disposal to land or tertiary treatments are commonly used (Bolan et al., 2004Bolan et al., , 2009). p0025 Some countries such as New Zealand encourages land disposal of effluents, because this is generally less harmful to water quality than discharge directly into water bodies. ...
... p0025 Some countries such as New Zealand encourages land disposal of effluents, because this is generally less harmful to water quality than discharge directly into water bodies. However, land disposal of farm wastewaters has some challenges (Bolan et al., 2004; Guo et al., 2013): o0010 1. soil moisture and climatic conditions are critical because they may not be favorable for operating the treatment processes o0015 2. free land is essential for holding wastewater when land application is not possible owing to unfavorable environmental conditions o0020 3. land can be waterlogged, which makes treatment operations difficult o0025 4. groundwater and surface water can be contaminated by leaching and runoff, respectively o0030 5. odor nuisance may occur when spreading the effluent (eg, piggery wastewater) p0055 Removal of contaminants should engage cost-effective technologies. A variety of techniques have been developed in past decades for wastewater treatment. ...
Many countries including New Zealand, Australia, and South Korea discharge of farm effluents containing large reserves of plant nutrients into surface waters. Such discharge is currently considered a discretionary activity and requires legal consent that demands the effluent nutrient concentration to be minimized before entering surface waters. This can be achieved by land disposal or nutrient stripping of the effluent by tertiary treatment. Although the pond system (ie, biological treatment) is effective in removing suspended solids and carbon, there has been some debate about its efficiency in removing nutrients. Porous materials such as zeolite, a naturally occurring and electrically charged aluminosilicate material, can be used to adsorb nutrients from effluents. Then the nutrient-enriched material can be recycled as a soil conditioner or nutrient source. This chapter examines the potential of zeolite in nutrient stripping from wastewater streams and its value as a nutrient source.
... Ion exchange is another widely st udied ammonia removal and recovery technology because of its ability for handlin g shock loads and wide ran ges of operating (Pansini 1996). According to experim ents, the affinity sequence of common ions to clinop tilolite and chabazite is: K + > (Bolan et al. 2004). ...
... After ion exchange, the ammonium saturated zeolite can be applied to th e field as nitrogen fertilizer (Bolan et al. 2004), used for ammonia recovery by ammonia stripping and acid absorption followed by chem ical regeneration, or regenerated by converting the ammonia to nitrate using biological re generation (reactions 10 and 11) (Dim ova et al. ...
... W ith protecting filtration coal layer, periodical backwash was needed to avoid clogging even the suspended solid (S S) was less than 20 mg/L (Booker et al. 1996 ). Because of the clogging problem was difficult to solve, Bolan et al., (2004) directly applied the ammonium saturated zeolite as nitrogen fertilizer. Ammonia stripping is a potenti al technology for ammonia rem oval from digested dairy manure. ...
... Algal treatment of wastewater has been tried previously by several authors (Gantar et al. 1991;Chevalier et al. 2000;De-Bashan et al. 2002;Garcia et al. 2006;Carlsson et al. 2007;Queiroz et al. 2007;Guzzon et al. 2008;Woertz et al. 2009;Park et al. 2011). To compensate for the capital investment and the operational costs of the conventional treatment system, the treatment process by algae should be co-integrated with other advantages like bio-utilization of CO 2 from flue gas (1 kg algal biomass utilizes approximately 2 kg CO 2 ) (Herzog and Golomb 2004;Packer 2009;Kumar et al. 2011), photosynthetically produced oxygen (O 2 ) for treatment wastewater by aerobic process (1 kg CO 2 consumed by the algae generates approximately 0.73 kg O 2 ), production of neutraceuticals (x3 fatty acids) (Lee 2001;Costa et al. 2003;Olaizola 2003), sustainable energy sources (biodiesel, ethanol and methane) (Chisti 2007;Milledge 2011), animal food supplements (Mulbry et al. 2008), commercially high-valued products (Bolan et al. 2004;Muñoz and Guieysse 2006;Cardozo et al. 2007). ...
... Hence, algae uptake phosphorus as inorganic orthophosphate, preferably in the form of H 2 PO 4 or HPO 4 2-, through an active process requiring energy (Becker 1994). A report by Bitton (1990) also indicated that phosphorus is utilized by algae in the form of polyphosphate granules co-transported together with potassium and magnesium. ...
Axenic culture of microalgae Chlorella vulgaris ATCC® 13482 and Scenedesmus obliquus FACHB 417 were used for phycoremediation of primary municipal wastewater. The main aim of this study was to measure the effects of normal air and CO2-augmented air on the removal efficacy of nutrients (ammonia N and phosphate P) from municipal wastewater by the two microalgae. Batch experiments were carried out in cylindrical glass bottles of 1L working volume at 25oC and cool fluorescent light of 6500 lux maintaining 14h/10h of light/dark cycle with normal air supplied at 0.2 L min-1 per liter of the liquid for both algal strains for the experimental period. In the next set of experiments, the treatment process was enhanced by using 1%, 2% and 5% CO2/air (vol./vol.) supply into microalgal cultures. The enrichment of inlet air with CO2 was found to be beneficial. The maximum removal of 76.3% and 76% COD, 94.2% and 92.6% ammonia and 94.8% and 93.1% phosphate after a period of 10 days was reported for C. vulgaris and S. obliquus, respectively, with 5% CO2/air supply. Comparing the two microalgae, maximum removal rates of ammonia and phosphate by C. vulgaris were 4.12 and 1.75 mg L-1 d-1 respectively at 5% CO2/air supply. From kinetic study data, it was found that the specific rates of phosphate utilization (qphsophate) by C. vulgaris and S. obliquus at 5% CO2/air supply were 1.98 and 2.11 d-1 respectively. Scale-up estimation of a reactor removing phosphate (the criteria pollutant) from 50 MLD wastewater influent was also done.
... Effluents from secondary domestic and agricultural wastewater treatment plants contain high concentrations of inorganic nitrogen and phosphorus that may lead to eutrophication of the water bodies that they discharge (Martínez et al., 2000;Mallick, 2002;De-Bashan et al., 2004).Microalgae offer a low cost and effective approach to remove the excess nutrients and other contaminants because of a high capacity for inorganic nutrient uptake for tertiary wastewater treatment, while producing potentially valuable biomass (Martínez et al., 2000;Muňoz and Guieysse, 2006;Bolan et al., 2004;García et al., 2006;Chevalier et al., 2000). However, one of the major drawbacks of using microalgae in wastewater purification is the harvesting of biomass from the treated effluent (Mallick, 2002;Aslan and Kapdan, 2006). ...
... The above-discussed nitrogen and phosphorus removal methods normally consume significant amounts of energy, chemicals and carbon source, and therefore are cost intensive. Furthermore, chemical based treatments often lead to the contamination of the sludge by-productfirstly, nutrients can be removed more efficiently; secondly, secondary pollution in the by –product caused by chemical additives is avoided, so it does not generate additional pollution; thirdly, when the biomass is harvested, it generates recycling of nutrients; and fourthly, the system is less expensive Microalgae offer a low cost and effective approach to remove the excess nutrients and other contaminants because of a high capacity for inorganic nutrient uptake for tertiary wastewater treatment, while producing potentially valuable biomass (Bolan et al., 2004;García et al., 2006;Chevalier et al., 2000;Abdel-Raouf et al., 2012). However, one of the major drawbacks of using microalgae in wastewater purification is the harvesting of biomass from the treated effluent (James, 1998;Mallick, 2002Calcium alginate is the most commonly employed system for its easiness in gel formation. ...
... However, since the introduction of the Resource Management Act (1991), land application is the preferred treatment option. As effluent contains a large reserve of nutrients (Di et al., 1998;Silva et al., 1999;Bolan et al., 2004), it is expected that it will boost soil biological activity and nutrient levels (Degens et al., 2000;Brussaard et al., 2007;Wall et al., 2008). In spite of this, a review of effluent studies in New Zealand reports a reduction of soil biochemical properties in response to effluent application (Speir, 2002). ...
... The objective of this study was to determine the effect of irrigation, effluent dispersal and farm conversion on soil property changes and whether these changes can be predicted from earthworm measurements. Because effluent contains a large reserve of nutrients (Bolan et al., 2004) and water application improves soil structure, porosity and hydraulic characteristics (Borda and Siddall, 2004), we hypothesised that irrigation and effluent dispersal will enhance the soil's water content, total carbon, nitrogen and phosphorus but reduce its bulk density (Hypothesis 1). In New Zealand, dairy farming has a high intensity and pasture turnover compared to sheep farming (Carey et al., 2010, through increased use of abiotic inputs sourced outside the farm (Macleod and Moller, 2006) and increased use of nitrogenous fertiliser (Ledgard et al., 2003). ...
Application of water and effluent to boost agricultural production is increasing in New Zealand, particularly in the Waimate District; a drought prone region traditionally associated with extensive sheep farming, but now converting to dairying. To determine how this intensification affects soil properties, we sampled soil from 615 locations across 41 farms in the District between April and September 2012. Effluent applied soils had between 8% and 15% higher amounts of soil carbon, nitrogen and phosphorus, while application of water alone increased these nutrients by between 17% and 35%. Soils where both effluent and irrigation water were applied had the highest amounts than the untreated “control” locations. Irrigation and effluent dispersal affected soil structure by reducing bulk density in the range of 14% to 26% but increased soil water content by 29% to 100%. The effect of water application was more pronounced in cattle grazed soils. For example, phosphorus increased by 63% in dairy compared to a decrease of 5% in sheep farms when irrigated. When compared with untreated locations, total earthworm density was higher by 42% in effluent locations and 72% in irrigated locations. Maximum density and biomass occurred where both effluent and irrigation were applied. Earthworm densities and biomasses were higher on sheep farms than on dairy farms. Soils with a lower abundance of Lumbricus rubellus earthworms, had higher total carbon and nitrogen whereas those with greater earthworm biomass had a higher water holding capacity. The study however failed to find evidence of linear and directly proportional relationships between earthworm measurements and other soil properties.
... Bioremediation with microalgae is particularly effective because of their capabilities converting solar energy into useful biomasses and assimilate nutrients such as phosphorus and nitrogen which cause eutrophication in the process of photosynthesis (De la Noüe and De Pauw 1988). In tertiary wastewater treatment, microalgae offer effective low cost approach to remove contaminants and excess nutrients and produce potentially valuable biomass, because of its high ability for inorganic nutrient uptake (Bolan et al. 2004;Munoz and Guieyssea 2006). Zhang et al. (2008) found that Scendesmus sp. ...
... The phosphorus, which is used in the algal cells mainly for production of phospholipids, adenosine triphosphates (ATP) and nucleic acids, gets assimilated as inorganic orthophosphate and the uptake process is active, i.e. it requires energy (Becker 1994). Microalgae are able to assimilate phosphorus in excess, which is stored in the cells as polyphosphate granules, and magnesium and potassium are co-transported along with phosphate (Bitton 1990). ...
The present investigation was attempted to reduce the toxic pollutants from the different mixtures of water samples (sewage, sea and well) using the freshwater alga, Chlorella vulgaris and the marine alga Chlorella salina. The results revealed that both algae species were highly efficient and having a potential to reduce pH, total dissolved solids (TDS), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrate, ammonia, phosphate, sulphate, calcium, magnesium, sodium, potassium, heavy metals (Zn, Cu, Mn, Ni, Co, Fe and Cr) and the number of total Coli-form bacteria after 10 days of treatment compared to the untreated water samples. The removal efficiency of heavy metals was 13.61–100 %. In general, C. vulgaris shows higher removal efficiency in most of parameters than C. salina.
... En tal sentido, son referentes países como Nueva Zelanda, Australia y Estados Unidos, donde se ha trabajado en comités integrados por productores, empresas y políticos que colaboran en este tema. Se destacan los trabajos referidos al análisis y características de los efluentes de tambo y las alternativas de tratamientos, en particular provenientes de Nueva Zelanda (Bolan, et al., 2009;Bolan, et al., 2004; Wallace y Johnstone, 2010) y de Estados Unidos (US-EPA, 1999;Knutson et al., 1993). ...
El ordeñe bovino en tambo es una de las principales actividades económicas primarias de Argentina. Regionalmente, los tambos se agrupan en ‘cuencas lecheras’, según particularidades productivas en común. La cuenca “Mar y Sierras”, en el sudeste de Buenos Aires, es una de las más importantes con el 7% de los establecimientos de la provincia. A partir de una estrategia económica que buscó promover la renovación y reconversión tecnológica, se logró una intensificación y concentración de la producción. No obstante implicó un aumento en el volumen del agua consumido por establecimiento y del caudal de efluentes y residuos generados. Esto significa un riesgo potencial tanto para el medio natural como para la propia producción y comercialización del producto. El objetivo general del presente trabajo fue evaluar la situación ambiental de los Tambos de la cuenca lechera Mar y Sierras (Provincia de Buenos Aires), en el período 2017-2019. Para ello el trabajo se dividió en dos etapas. La primera consistió en la caracterización con un enfoque integral de la producción en tambo de la cuenca, en un marco socioeconómico y físico natural. En la segunda etapa, se seleccionaron 5 establecimientos donde se aplicó una auditoría ambiental diagnóstica. En cada sitio se describieron los procesos productivos, se midieron caudales de efluentes y se tomaron muestras para su caracterización fisicoquímica. Especialmente se describió el medio físico natural, enfatizando en el aspecto hídrico.
Dentro de la cuenca lechera se identificó un circuito “informal” con un gran número de PyMEs en su mayoría destinadas a un consumo local y regional. Aunque se evidenció diversidad de instituciones, ninguna de ellas nuclea a la totalidad de los productores. Se identificaron condiciones hidrológicas que influyen en el aspecto cuali-cuantitativo de la gestión y uso del agua. Predialmente, se pudieron identificar los puntos críticos ambientales de la actividad, principalmente la necesidad de grandes volúmenes de agua y la generación, tratamiento y disposición de efluente generado. El principal uso de agua está destinado al refresco de la leche y a la limpieza de maquinarias e infraestructura. La presencia de altas concentraciones de nitratos y cloruros evidenció la contaminación orgánica por actividad antrópica. Se identificaron dos momentos de importancia en la generación de efluentes: etapa de ordeñe y etapa de lavado. Los caudales totales varían de acuerdo a la infraestructura, al método de lavado de corrales, y recirculación o no del agua de refresco. En los tambos a escala familiar no se contaba con sistemas de tratamiento. En dos de los establecimientos de mayor tamaño, el sistema de tratamiento fue diseñado por el propio dueño, aunque no cumplía con los requerimientos de la normativa. Uno de ellos, ha intentado el uso agronómico de los purines aunque limitado por cuestiones económicas y del medio físico donde se ubican. Como conclusión, la situación ambiental de los tambos seleccionados como representativos de la cuenca lechera Mar y Sierras, presenta deficiencias que deben ser corregidas de forma integral y para cada sector en particular. La implementación de herramientas de gestión, tal como las auditorías ambientales, basadas en una perspectiva holística, son de gran utilidad para el monitoreo, seguimiento y manejo de la situación ambiental en los establecimientos.
... In conjunction with CEC variations, pH can potentially affect the absorbency rate of NH + 4 -into the woodchip matrix, where an increase in pH would result in lower adsorption rates (Özacar and Sengil, 2005 as supported by Shukla et al., 2002). In addition, studies have suggested microbial immobilisation plays a large role in removing N from leachate (Bolan et al., 2004). ...
Intensive pastoral farming has been linked to adverse environmental effects such as soil degradation and increased fluxes of nitrogen, phosphorus, sediments, and pathogens into waterways, resulting in their degradation. Stand-off pads are engineered structures covered with bedding materials, available for occupation by stock to minimise those adverse effects to soil and water bodies. Wood chips are ideal for bedding due to their low cost, high water holding capacity, and stock preference as resting areas. While they reduce the mobility of both nutrients and pathogens, their effectiveness depends on the type of wood, size of the chips, pH, pad design, and feeding management used. Dissolved organic carbon, present in wood residue, may slow nitrogen mineralisation thereby decreasing loss via leachate. This effect depends on plant tannins and nutrients already stored within the plant tissue. Poplar and willow have high concentrations of tannins in leaves and bark with potential nitrification-inhibiting properties. When grown on-farm, these deep-rooted trees also reduce nitrogen leaching and prevent soil erosion. This review addresses the use of temporary stand-off pads within poplar or willow silvopastoral systems. Harvested trees can provide suitable wood chips for constructing the stand-off pad, while the deep rooting systems of the trees will reduce the moisture content of the pad, preventing waterlogging. A key objective is to discuss the feasibility and establishment of multiple temporary stand-off pads that allow for stock rotation from pad to pad, and subsequent on-site composting of wood-wastes into fertiliser, reducing both nutrient inputs and losses in agricultural systems. The review highlights the potential suitability of poplar and willow tree species for such a system.
... These species have high nutrient removal capabilities combined with a fast growth rate, making them good candidates to treat wastewater. At the same time, due to their high capacity for inorganic nutrient uptake (Bolan et al., 2004;den Haan et al., 2016) microalgae could produce potentially valuable biomass (Al-Jabri et al., 2021). Some of the multiple benefits that can be derived from microalgae biomass include amongst others, biofuel (Alam et al., 2012;Hannon et al., 2010), biogas (Debowski et al., 2013, and biofertilizer (Baweja et al., 2019;Guo et al., 2020). ...
The development of the local end-use market for waste plastic is crucial to increasing South Africa’s plastic recycling rates, especially for low-value, problematic plastic fractions, such as polyolefins consisting mainly of polyethylene and polypropylene. The use of recycled and/or alternative materials such as plastics in road construction is beneficial not only in terms of sustaining the environment, since naturally occurring materials will be conserved but as a means of reducing construction costs. Recycled plastics are being investigated worldwide not only as a green investment, but also for improved pavement durability (Milad et al., 2020). The objectives of the study were to screen, evaluate and implement existing international technologies in line with South African design standards and specifications for materials in road construction. The main research question was whether low value waste plastics can be optimised as alternative road construction materials in South Africa.
... Mg 2+ did not change significantly (Table 2). Bolan et al. (2004) also found that the content of potassium in the soil and in the crop leaves increased following long-term terrestrial FDE applications. ...
... This reduces the potential to use the precipitate, e.g., as a fertilizer. There are also other methods for phosphate removal, such as adsorption, ion exchange, electro-coagulation, and electro-Fenton treatment [12][13][14]. Nitrogen is typically present in the form of ammonium nitrogen. Ammonium ions are not easy to precipitate and are therefore removed in the biological process by nitrification and denitrification [15]. ...
Batch electrocoagulation (BEC), continuous electrocoagulation (CEC), and chemical precipitation (CP) were compared in struvite (MgNH4PO4·6H2O) precipitation from synthetic and authentic water. In synthetic water treatment (SWT), struvite yield was in BEC 1.72, CEC 0.61, and CP 1.54 kg/m3. Corresponding values in authentic water treatment (AWT) were 2.55, 3.04, and 2.47 kg/m3. In SWT, 1 kg struvite costs in BEC, CEC, and CP were 0.55, 0.55, and 0.11 €, respectively, for AWT 0.35, 0.22 and 0.07 €. Phosphate removal in SWT was 93.6, 74.5, and 71.6% in BEC, CEC, and CP, respectively, the corresponding rates in AWT were 89.7, 77.8, and 74.4%. Ammonium removal for SWT in BEC, CEC, and CP were 79.4, 51.5, and 62.5%, respectively, rates in AWT 56.1, 64.1, and 60.9%. Efficiency in CEC and BEC are equal in nutrient recovery in SWT, although energy efficiency was better in CEC. CP is cheaper than BEC and CEC.
... In Australia, for example, 520,238 × 10 3 kL of dairy effluent and 29,194 × 10 3 kL of piggery effluent, which contain 18,729 and 4233 P/year, respectively, are generated yearly (Karunanithi et al. 2015). Bolan et al. (2004) discovered that in New Zealand, dairy farm effluents contain 120 g m _3 N and 28 g m _3 P. ...
Nutrient recovery from wastewater and recycling nutrients as soil fertilizers is a major challenge for the future circular economy. This is motivated by unregulated discharge of wastewater, poor access to fertilizers in developing countries and high fertilizer costs. Here, we review protocols of nutrient recovery from major wastewater sources such as agriculture, domestic and industrial wastewater. We provide an update on the reuse of the recovered nutrient as fertilizers in agriculture. Many effective strategies have been developed for nutrient recovery from wastewater. The reuse potential of the recovered nutrient as fertilizer is often based on postulations. Plant growth and yield potentials with recovered nutrients are either similar or better than that of the conventional fertilizer, in few experimental cases. Evaluation of reuse potentials of the recovered nutrient should involve field trials and not just pot experiments. The contamination of the recovered nutrient with toxic compounds should be avoided.
... Traditionally, phosphorus is removed by chemical precipitation using calcium, aluminum or iron salts or by a biological process [7,8]. Currently, different kinds of methods for phosphate removal, such as adsorption [9,10], ion exchange [11], electro-coagulation [12,13], and electro-Fenton treatment [14], have also been used. Nitrogen is typically present in the form of ammonium ion that is not easy to precipitate because ammonium volatilizes into the air as ammonia gas under alkaline conditions as a function of pH [15]. ...
Currently, recycling and re-use of materials is extremely important due to the diminishing of natural resources. The objective of the European Union's circular economy strategy is to increase recycling and the use of industrial waste materials and side streams as secondary raw materials. In this study, a chemical precipitation method to simultaneously remove ammonium nitrogen and phosphate from the liquid phase of anaerobic digestate using calcined paper mill sludge was studied. Papermill sludge is a waste material that forms in the paper-making process. In addition, commercial calcium oxide (CaO) was used as a reference precipitant. The suitability of the formed precipitate's composition for recycled fertilizer use was also considered. The study results indicated that calcined paper mill sludge was as effective precipitant as commercial CaO in the removal of ammonium nitrogen and phosphate from the synthetic wastewater. In addition, the results indicated that calcined paper mill sludge removed efficiently phosphate from the liquid phase of anaerobic digestate, which led to the formation of hydroxyapatite, Ca 5 (PO 4) 3 (OH). In this research we have shown, that calcined paper mill sludge can be used to produce recycled, slow-release, solid fertilizer. Another possible reaction, such as adsorption was also considered.
... In addition, beside the traditional organic fertilizers, new kinds, such as granular rivers, etc. Pollutants such as nitrates, salts, pathogens can easily pollute not only surface but also groundwater. Intensive livestock farms can face a number of environmental problems, such as soil degradation or water pollution (Abelha et al., 2003;Bolan, Wong, & Adriano, 2004). ...
In recent years, the European countries recycle only 5−7% of bio-waste. One activity of the biological waste disposal is granulation. The production of fertilizer from animal manure with supplement represents an important area of environmentally friendly bio-fertilizer production. This paper presents an investigation of estimation manure compost physical-mechanical properties for reuse of organic waste − cattle and cow manure, sugar production waste − molasses through new technology pellets production and of granulated fertilizer impact on soil. The experimental manure samples produced by industrial methods and samples produced in the laboratory from the time period of 2014 to 2017 were investigated. The following physical – mechanical characteristics were estimated: biometric indicators (dimensions, mass), volume and density of raw material and pellets, material and pellet’s humidity and pellets strength. Experiments results have shown that the difference in limit strength between experimental and industrial organic compost pellets was about 5%. Experiments of fertilizers on the impact on soil shown that the amount of nutrients added to the soil depends on the rate of the granulated compost fertilizer. As the norm increases, organic carbon, humus, mobile phosphorus and potassium increase in soil. Increases in soil fertility, improved agrochemical properties, soil organic matter accumulation and humus increase. Granulated compost fertilizers have no effect on soil acidity. The presented results could be helpful to the development of the fertilizing process by the granulated compost fertilizer for improvement of soil quality in small farms.
... Currently, phosphorus is removed by collateral precipitation using aluminum or iron precipitant before the biological process, which reduces the potential to use the precipitate, for example, as a fertilizer. There are also various methods for phosphate removal, such as adsorption [12,13], ion exchange [14], electro-coagulation (EC) [15,16], and electro-Fenton treatment [17]. Nitrogen is typically present in the form of ammonium. ...
The European Union's circular economy strategy aims to increase the recycling and re-use of products and waste materials. According to the strategy, the use of industry waste material should be more effective. A chemical precipitation method to simultaneously remove phosphorus and nitrogen from synthetic (NH 4) 2 HPO 4 solution and the liquid phase of anaerobic digestate using fly ash as a precipitant was tested. Fly ash is a waste material formed in the power plant process. It mainly contains calcium oxide (CaO) and magnesium oxide (MgO). Saturated precipitant solution was prepared from fly ash, which was added in small proportions to (NH 4) 2 HPO 4 solution during the experiment. Fly ash's effectiveness as a precipitant was compared with that of commercial CaO and MgO salts, and it can be observed that fly ash removed as much ammonium and phosphate as commercial salts. Fly ash sufficiently removed ammonium nitrogen and phosphate from the liquid phase of anaerobic digestate, which led to the formation of ammonium magnesium hydrogen phosphate hydrate, struvite (NH 4 MgPO 4 ·6H 2 O), and calcium hydroxide phosphate, monetite, CaPO 3 (OH). In this study, we have shown for the first time that fly ash can be used to manufacture recycled, slow-release fertilizers from anaerobic digestate.
... Phycoremedation involves the use of microalgae and macro algae for the removal or biological transformation of contaminants in wastewater [4]. Algae are inexpensive and have high efficiency in removing contaminants and nutrients when used as a third treatment [5].in other side, The use of Cyan bacteria in the treatment may be due to several reasons, including the requirements of its simple growth and not need highenergy compounds such as other microorganisms that are not capable of photosynthesis. ...
The current study examined the susceptibility of three types of algae, including Oscillatoria sp., Westiellopsis prolifica, Stigonemasp in reducing the values of some heavy metals in industrial wastewater. These algae were used as unialgal culture and the wastewater was used from the industrial wastewater disposed by the State Company for Textile Industries as a growth culture for the development of these algae by cultivating each algae alone in wastewater under constant laboratory conditions at 25 ± 20 ° C and in a light system 16: 8 hours Illumination: Darkness. The results showed that the Oscillatoria sp has the ability to reduce heavy metals in high ratios reduction of (100.3%) for Iron and (29.1%) for Copper and (66.2%) for Zinc and (33.5%) for Cadmium and (99.5%) for Lead. The results also indicated that W. prolifica showed the ability to reduce heavy metals by (99.7%) for Iron and (29.1%) for Copper and (56.4%) for Zinc and (40.2%) for Cadmium and (99.5%) for lead. Stigonemasp showed higher efficiency than the rest of algae in reduction of some heavy metals with ratio of (100%) for Iron and (44.3%) for Copper and (73.8%) for Zinc and (22.3%) for Cadmium and (100%) for lead .As for the current algae physiological status, Glutathione (GSH) content in Oscillatoria sp was decreased after treatment, while its content was increased in W. prolifica, Stigonema sp. after treatment. The content of the Cytochrome p450 in the algae appears to have decreased after treatment in Oscillatoria sp. And W. Prolific and increased in Stigonema sp. The results indicate that the Metalothionine content has not increased significantly and the values remain similar to the algae shown for control. On the other hand, bioremediation showed a clear effect on molecular properties of algae, this was demonstrated by the high values of Comet assay indicators, which include tail length, Comet length, tail moment which indicate the effect of treatment on DNA after completion of the treatment.
... These studies observed their removal capacity by either increasing NO 3 - -N removal form leachate by enhancing N 2 O losses via denitrification (biochar as carbon source for denitrifiers) or by decreasing NH 4 + -N in leachate through adsorption to negatively charged sites. However, not much research has been undertaken to study adsorption and desorption of NH 4 + -N by fresh woodchip materials ( Airaksinen et al., 2001;Bolan et al., 2004). ...
The aim of this study was to determine the effectiveness of wood residues in the removal of nutrients (ammonium-N; NH4-N) from nutrient-rich (NH4-N) waters. The water holding capacity of the wood materials was also determined. Carried out at Rothamsted Research, North Wyke, UK, this controlled laboratory experiment tested two wood residues; in length, one being 1-2cm and the other from 150 µm (microns) to 9.5mm. Although a wide range of studies have shown the effectiveness and performance of various absorbent materials as animal beddings, such as straw (cereal straw), woodchip (sawdust, bark or wood shavings), bracken and rushes, only few have focused on the NH4-N sorption/desorption capacity. The depuration capacity of wood residues from nutrient-rich effluents such as those from cattle bedded on woodchip or straw will be controlled by processes such as sorption (adsorption-absorption) and desorption of nutrients. Studies have reported the nitrogen removal capacity of woodchip materials and biochar from woodchip as well as removal of NH4+-N from domestic and municipal wastewater, farm dirty water, landfill and industry effluents. These studies have observed that the mechanism of removal of nitrogen is by either increasing NO3--N removal form leachate by enhancing N2O losses via denitrification (biochar as carbon source for denitrifiers) or by decreasing NH4+-N in leachate through adsorption to negatively charged sites. Results showed that although the cation exchange capacity (CEC) and surface area (SA) are both fundamental properties of adsorbent materials, no correlation was found with CEC and adsorption or desorption. Nor did changes in pH appear to be sufficiently important to cause changes in CEC. For this reason, osmotic pressure appeared to be a more predominant parameter controlling processes of adsorption and desorption of NH4+-N in both wood residues. Thus, wood residues high in NH4+-N should be avoided, as they could have an opposite effect in the adsorption of nutrients from nutrient-rich effluents. The results also showed that some wood residues (G30) had great capacity to adsorb NH4+-N to levels up to nearly 90% whilst demonstrating low desorption capacity of NH4+-N (less than 1%). These are ideal relevant features for an adsorbent material for the removal of nutrients (or heavy metals) from contaminated waters such us farm o industrial effluents, or for the depuration of eutrophic watercourses. This could help reduce the concentration of farm effluents making them more manageable, subsequently contributing towards the compliance of new environmental regulations. Keywords: nutrients, nitrogen, ground and surface water
... Water sample collected from industrially polluted region was analyzed for different physio chemical parameters (Subramanian E et al., 1999). The parameters under study were Total solids (TS), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), pH, Sodium, Potassium, Chloride (Argenometric method), Sulphate, Residual Chlorine, phosphate, dissolved oxygen (DO), Biological Oxygen Demand (BOD), Nitrogen, Sulphite and Chromium (Bolan NS et al., 2004) Statistical Analysis: ...
The textile industry is one of the fast growing industries in India, and the number one polluter of clean water. More than 80,000 tons of dyes used mainly in food industries, cosmetics, paper mills and especially in textile industries which absorb alone more than 70% of the produced total quantity. Phycoremediation is a novel, low cost, effective, continuous treatment technique that uses algae to clean up the polluted water. Textile dye industry effluents were collected from Tirupur district for three periodic intervals (September 2011, December 2011 and February 2012). Effluents were taken in five concentrations such as 100:400, 200:300, 250:250, 300:200, and 400:100. In this studies two fresh water Microalgae such as Chlorella vulgaris and Scenedesmus obliquus were treated separately to the different effluent concentrations which can tolerate the extreme condition and the consortium of these algal species were also taken in to account for the Effluent Treatment System. The Physico Chemical Parameters were recorded in different intervals of treated effluents such as 7 th day, 14 th day and 21 st day. In our results proved the equal concentration of algae and effluent system showed the highest reduction of TDS in all the treatment flasks. About 32.16%, 51.40%, and 61.71% of reduction in Chlorella vulgaris treated effluents on 7th, 14th and 21st days respectively. Scenedesmus obliquus showed 21.91%, 49.17% and 61.38% reduction whereas above all 35.22%, 54.35% and 64.00% reduction were recorded in the consortium of these algae. Initial pH of the raw effluent was 7.11, increased steadily to 9.89 in 21 days after the addition of C. vulgaris and 9.05 in S. obliquus culture. In our study, C. vulgaris was able to reduce all forms of nitrogen substantially, and ammonia and nitrate levels, in particular, were drastically reduced. Hence the use of algae in waste-water treatment could be beneficial in different ways since they bring about oxygenation and also mineralization in addition to serving as a food source for some aquatic species.
... In addition to the waste landfill context, the study of NH4 + intercalation has particular importance in other environmental issues. For example, ammonium concentrations up to 40 mg/L were regularly found in domestic wastewater (Kim et al., 2014;Kim et al., 2015;Paing et al., 2015) and even higher in farm effluent (Bolan et al., 2004;Bouwman et al., 2013). Clays can be used to remove ammonium from aqueous solution (Çelik et al., 2001;Eturki et al., 2012;Zadinelo et al., 2015). ...
The percolation of water through waste landfills produces leachates with high concentrations of NH4+ which can generate NH4+-exchanged clays within geochemical barriers. These leachates also contain several volatile organic compounds (VOCs) which can interact with the clay barrier. The aim of the present study was to characterize the sorption of eight short-chain VOCs (acetonitrile, methyl tert-butyl ether, dichloromethane, benzene, phenol, ethanol, acetone and aniline) on NH4+-smectite, and to identify their sorption mechanisms. The samples treated were characterized by carbon and nitrogen elemental analysis, infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analysis. For acetonitrile, methyl tert-butyl ether, dichloromethane and benzene, no sorption was detected. Phenol, ethanol and acetone were sorbed very weakly, through Van der Waals interactions. Aniline molecules were sorbed strongly on NH4+-smectite mainly with hydrogen bonds between aniline and interlayer water molecules. However, aniline sorption decreased the hydrophilic character of the NH4+-smectite, which may increase the permeability of the clay barrier.
... The influence of biochar application rate on NH 4 + adsorption was investigated by treating 20 mL of NH 4 + -N solutions (40 mg N L −1 ) at different biochar application rates (1, 2, 3, 5 and 7 g L −1 ); the initial NH 4 + concentration of 40 mg N L −1 is typical of municipal wastewaters (Bolan et al. 2004). The pH was adjusted to 7.0 for consistency and the samples were shaken for 24 h in a mechanical shaker. ...
Ammonium (NH4⁺) is a common form of reactive nitrogen in wastewater, and its discharge to water bodies can lead to eutrophication. This study was conducted to understand NH4⁺ adsorption mechanisms of pine sawdust and wheat straw biochars in aqueous solutions and the factors affecting NH4⁺ removal. Biochars were produced by pyrolysing pine sawdust at 300 °C (PS300) and 550 °C (PS550) and wheat straw at 550 °C (WS550). Pseudo-second-order and Redlich-Peterson models best fitted the adsorption data. The PS300 showed the highest NH4⁺ adsorption capacity (5.38 mg g⁻¹), followed by PS550 (3.37 mg g⁻¹) and WS550 (2.08 mg g⁻¹). Higher H/C and O/C ratios of PS300 (0.78 and 0.32, respectively) indicated the greater presence of functional groups on the biochar’s surface as compared to PS550 (0.35 and 0.10, respectively) and WS550 (0.36 and 0.08, respectively), resulting in different NH4⁺ adsorption through electrostatic interactions. The dominant mechanism for NH4⁺ adsorption by the biochars was likely chemical bonding and electrostatic interaction of NH4⁺ with the surface functional groups. Lower pyrolysis temperature resulted in a higher NH4⁺ adsorption capacity by the pine sawdust biochar. At the same pyrolysis temperature (550 °C), the biochar made with pine sawdust as the feedstock had a higher NH4⁺ adsorption capacity than biochar made from wheat straw. We conclude that biochars can be efficient absorbents for NH4⁺ removal from wastewater, and the removal efficiency can be optimised by selecting different feedstocks or the pyrolysis condition for biochar production.
... In the case of solids, reduction was achieved by the process of precipitation, flocculation, filtration, gravity sedimentation and microbes assisted biodegradation present around the rhizospheric area of the plants. [37] Similar results were also reported in macrophyte E. crassipes and P. stratioites. [38] In CW, aquatic plants play an important role in nutrient removal either directly through assimilation or indirectly through the influence of plants on oxygen and microbial activity in the matrix. ...
A simulated horizontal flow constructed wetland (CW) has been designed with gravel medium and aquatic plants Typha latifolia and Polygonum hydropiper to assess its performance efficiency for sewage treatment. Monitoring of fully developed CW revealed a high removal of nutrients and metals from sewage after treatment at varying retention times. The percent (%) removal of biological oxygen demand, total dissolved solids, total suspended solids, PO4-P and total nitrogen in CW planted with T. latifolia were 88.20, 61.9, 72.12, 74.23 and 66.78%; however, with P. hydropiper, reductions were 79.47, 53.47, 55.46, 60.40 and 52.87%, respectively, at 8 d retention time. In addition, T. latifolia and P. hydropiper accumulated substantial amount of metals in their tissues particularly in roots. T. latifolia root accumulated maximum amount of Zn (40.44 µg/g dw) followed by Cu (39.24 µg/g dw), Pb (37.78 µg/g dw) and Cr (19.95 µg/g dw) as compared to P. hydropiper, which was 17.85, 33.43, 36.19 and 9.67 µg/g dw, respectively. Further, plant-specific high translocation factor (>1) of metals were observed at different retention times. Results suggest that simulated CW may be applied as an ecofriendly and low-cost tool to treat sewage before discharge into a fresh water body.
... Utilization of biofuel C (e.g., that from maize or sugar cane) instead of fossil fuel can reduce CO 2 emissions, because biofuel C is mainly derived from the atmosphere via current photosynthesis (fossil fuels result from photosynthesis millions of years ago). [59] Production of CO 2 due to various anthropogenic [208]]. ...
Greenhouse gas (GHG) emissions from agricultural operations continue to increase. Carbon (C) enriched char materials like biochar have been described as a mitigation strategy. Utilization of biochar material as a soil amendment has been demonstrated to provide potentially greater soil GHG suppression due to its interactions in the soil system. However, these effects are variable and the duration of the impact remains uncertain. Various (nano) materials can be used to modify chars to obtain surface functionality to mitigate GHG emissions. This review critically focusses on the innovative methodologies for improving char efficiency underpinning GHG mitigation and C sequestration.
... As microalgae utilize CO 2 as a carbon source, they can grow photoautotrophically without the adding an organic carbon source. Microalgae propose a cheap and competent approach for removing extra nutrients and other pollutants in tertiary wastewater treatment, when creating possibly valuable biomass, owing to a high inorganic nutrient uptake capacity [19,20]. Algae deliberated as green-cell factories are not only good scavengers of poisonous chemicals but are also engaged in oxygenation of the atmosphere and CO 2 sequestration, thus creating them a better applicant among bioremediation systems. ...
Provision of clean drinking water remains a global requirement, so for arsenic-affected areas where various physico-chemical methods are used. These methods require regeneration of media requiring non-stop arsenic checking and it requires skilled operation. Otherwise arsenic contaminated water has to be discarded into the environment. This study examined the probability of using living microalgae Chlorella pyrenoidosa for phycoremediation of arsenic contaminated water (either As(III) or As(V). DO and pH cycles in presence of arsenic (either As(III) or As(V)) ions in the culture did not significantly differ from the control (pure media) indicating that the algae were still growing and photosynthesizing in presence of arsenic ions. As(V) was more noxious than As(III), particularly at pH 7.0, but it was opposite at pH 9.0. Phycoremediation efficiency of As(V) at pH 9.0 by algal cells was greater than that As(III). Monod model has been employed for demonstrating growth kinetics of microalgae in pure media containing various concentrations of nitrate ions. Maximum specific growth rate and saturation constant have been found to be 0.146 d− 1 and 8.29E–4 g/L, respectively. With the increase in concentration of phosphate in growth medium the growth of microalgae increased. Media with 1.0 g/L NaCl indicated the highest algal growth. Addition of NaHCO3 (1 g/L) resulted in higher maximum biomass concentration.
... Phosphate removal by electocoagulation is also possible method (Vasudevan et al. 2009). Adsorption onto porous materials such as zeolites is suitable way to remove phosphates from aqueous solution (Biswas et al. 2008, Bolan et al. 2004). ...
Gasification is an energy conversion method for the utilisation of biomass for obtaining energy (heat and power). In the gasification process carbon residue is formed as a waste. For improving the cost-effectiveness of the gasification process the utilisation of this waste is important and the present legislation also creates requirements for the utilisation of waste material.
Activated carbon is typically used for purification of water, for example, wastewaters as well as gaseous emissions. Consequently, commercial activated carbon is fairly expensive and its preparation is energy consuming. However, this inhibits sometimes its widespread use in wastewater treatment and therefore there is a need to develop cost-effective adsorbents from alternative biomass-based low-cost raw materials to remove harmful substances from aqueous solutions.
The first aim of this thesis was to determine physical and chemical properties of carbon residues from wood gasification, and fly ashes from burning processes were used as reference samples. The properties are essential to known when evaluating the potential utilisation applications for unknown carbon residue samples. Properties of carbon residue indicate that it would be suitable adsorbent due to the high carbon content but its activation or modification is needed. The second aim was to modify this industrial carbonaceous by-product by physical and chemical activation and chemical modification methods to maximise the adsorption capacity of material. Based on our results, adsorption properties can be enhanced by using zinc chloride as a chemical activating agent, carbon dioxide as a physical activating agent and ferric chloride in the chemical modification and adsorbents with specific surface areas 285, 590 and 52 m2 g-1 were produced, respectively. The third aim was to test produced adsorbents to anions removal. Chemically activated carbon residue removes phosphate well and physically activated carbon residue removes phosphates and nitrates. Chemically modified carbon residue was observed to be suitable sorbent for sulphate removal. Optimal initial pH and concentration were determined and effect of time was studied and kinetic calculations and isotherm analysis was done for studied adsorbents.
... The most productive materials are usually found among various industrial by-products, waste materials and among natural materials (Mateus et al., 2012). The application of proficient solid materials as adsorbents, involving synthetic materials (Bolan et al., 2004;Halajnia et al., 2013;Hamoudi and Belkacemi, 2013;Jiang et al., 2013;Sowmya and Meenakshi, 2013;Taleb et al., 2008;Yadav et al., 2015), natural materials (Akosman and Özdemir, 2010;Hamoudi et al., 2007;Kilpimaa et al., 2015;Rout et al., 2014Rout et al., , 2015bRouta et al., 2014;Saad et al., 2008), agricultural by-products (Hale et al., 2013;Namasivayam and Höll, 2005;Namasivayam et al., 2007;Xu et al., 2010) and industrial byproducts (Ji et al., 2015;Olgun et al., 2013;Wendling et al., 2013), in nutrient removal from aqueous solutions has been widely inspected in recent times. ...
The viability of utilizing sponge iron industry based waste ‘dolochar’ as a proficient adsorbent for nutrient (phosphate and nitrate) removal and subsequent slow release of nutrient from the spent dolochar has been undertaken in this study. The efficacy of dolochar has been explored in both single and binary adsorption systems containing nutrients. The proposed experimentally obtained quadratic models for both the phosphate and nitrate removal were substantiated by analysis of variance (ANOVA) with high R2 values of 0.99 and 0.98, respectively. Response surface methodology (RSM) based optimization followed by experimental validation resulted in phosphate removal efficiency of 96.7% and nitrate removal efficiency of 57.1%. Single component adsorption equilibrium data fitted well to pseudo-second order kinetic and Langmuir isotherm models with Langmuir maximum adsorption capacity, qm of 327.7 and 6.51 mg g−1 for phosphate and nitrate, respectively. Out of non-modified Langmuir, modified Langmuir, extended Langmuir and extended Freundlich, multi component isotherm models, binary adsorption equilibrium data fitted well to the extended Freundlich model. Thin layer funnel analytical test results reveals the slow nutrient release nature of spent dolochar.The results suggest that the dolochar has the potential to serve as a sustainable adsorbent for nutrient removal from wastewater along with the scope of utilizing spent dolochar as a slow release nutrient supplier.
... For example, annually Australia produces 520 Â 10 3 megaliter (ML) of dairy effluent and 291 Â 10 3 ML of piggery effluent which contains, apart from other nutrients, 18,729 and 4233 kt P year À1 , respectively. For New Zealand dairy farms, effluents contained 120 g m À3 N, 28 g m À3 P, 320 g m À3 Total Suspended Solids (TSS), 950 g m À3 COD, and 210 g m À3 BOD (Bolan et al., 2004). Accordingly, the use of effluents in agriculture can provide a point source of P. ...
Phosphorus (P) is a macronutrient essential for all living organisms. Regrettably, it is a finite resource since phosphate rock (PR) is the main material used for production of P fertilizers. Globally, the demand for quality PR is escalating due to many factors including increasing human population. Inevitably, the demand for PR will exceed its supply capacity. This condition will be very difficult to manage as living systems have no alternative for P. Moreover, P use efficiency is low; only 15-20% of applied P is used by crops and animals. Globally, the remaining P is shunted into various waste streams. These waste streams include large quantities of effluents rich in P from both municipal and industrial wastewater treatment systems and manure from livestock production. The P present in these waste streams poses a threat to the environment by nutrient enrichment resulting in serious ecological issues such as eutrophication of waterways. However, P in these waste streams, if economically recovered, can contribute to a sustainable management of P resources. This review covers the following aspects: global importance of P as an essential nutrient; efficient and sustainable utilization of P; waste stream production, their suitability for P recovery, and limitations; current and emerging technologies for recovery of P; and the use of recovered P material. Finally, future research needs are identified associated with P recovery from waste streams and reuse in agriculture.
... Farm effluents such as those emanating from dairy sheds and piggeries are being increasingly employed as sources of irrigation water and nutrients (Bolan et al., 2009;McDonald, 2007). For example, in New Zealand, dairy and piggery effluents generate annually about 9000Mg of N, 1250Mg of P and 14,000Mg of K (Bolan et al., 2004a). Effluents from farms differ in their composition depending on the animal production system from which they are derived (chicken, pigs, beef, dairy). ...
With pressure increasing on potable water supplies worldwide, interest in using alternative water supplies including recycled wastewater for irrigation purposes is growing. Wastewater is derived from a number of sources including domestic sewage effluent or municipal wastewater, agricultural (farm effluents) and industrial effluents, and stormwater. Although wastewater irrigation has many positive effects like reliable water supply to farmers, better crop yield, pollution reduction of rivers, and other surface water resources, there are problems associated with it such as health risks to irrigators, build-up of chemical pollutants (e.g., heavy metal(loid)s and pesticides) in soils and contamination of groundwater. Since the environment comprises soil, plants, and soil organisms, wastewater use is directly associated with environmental quality due to its immediate contact with the soil-plant system and consequently can impact on it. For example, the presence of organic matter in wastewater-irrigated sites significantly affects the mobility and bioavailability of heavy metal(loid)s in the soil. Wastewater irrigation can also act as a source of heavy metal(loid) input to soils. In this chapter, first, the various sources of wastewater irrigation and heavy metal(loid) input to soil are identified; second, the effect of wastewater irrigation on soil properties affecting heavy metal(loid) interactions is described; and third and finally, the role of wastewater irrigation on heavy metal(loid) dynamics including adsorption and complexation, redox reactions, transport, and bioavailability is described in relation to strategies designed to mitigate wastewater-induced environmental impacts.
... Regardless of ISSN: 2321 -8371 the operating system or the level of wastewater treatment concerned, the success of an algal system relies on the ability to take up inorganic nutrients such as N and P from the wastewater and assimilate them for their growth. Microalgae offer a low-cost and effective approach to remove excess nutrients and other contaminants in tertiary wastewater treatment, while producing potentially valuable biomass, because of a high capacity for inorganic nutrient uptake (Bolan et al., 2004;Muñoz and Guieyssea, 2006). ...
The leather industry represents an important economic sector in many countries especially in India. On the other hand, it generates large amounts of wastewater containing ammonium ion, sulphides, surfactants, acids, dyes, sulfonated oils and organic substances including natural or synthetic tannins agents. However treatments of these effluents using physical and chemical methods are quite expensive technology. Most leather industries construct a number of shallow evaporation ponds or Central Effluent Treatment Plant (CETP) to manage the effluent despite there is still a considerable amount of pollution load to be dealt. Hence the present work is focused on biological treatment to reduce the pollutants of tannery effluents through microalgal treatment process taken from the leather industries central treatment plant, Madhavaram, Chennai District, Tamil Nadu, India. The effluent samples were characterized before and after the treatment by measurements of Physico – chemical properties. In our findings we observed that the consortium of Microalgal species such as Chlorella vulgaris LS120 and Scenedesmus obliquus LS121 at various concentrations effectively reduces the TDS, COD and BOD levels of effluents as confirmed by the Physico – Chemical measurements at regular interval of 7 days for a period of 21 days. The concentration of algal consortium and effluent 250: 250 was found to effectively reduce TDS, BOD and COD levels when compared to individuals. Hence this green remediation technology avoids use of chemicals and the whole process of effluent treatment is simplified and eco – friendly.
... Ammonia removal can be accomplished biologically by converting ammonium into non-reactive nitrogen gas through nitrification/denitrification [4][5][6][7] or anaerobic ammonium oxidation (Anammox) [8]. Ammonia recovery processes, which allow for production of potential agricultural fertilizers, include ammonia stripping-absorption [9][10][11][12][13], struvite precipitation [14,15], and membrane (gas permeable and reverse osmosis (RO)) separation [16,17]. ...
... Tokie teršalai, kaip nitratai, druskos, patogenai, gali nesunkiai užteršti ne tik paviršinius, bet ir požeminius vandenis. Intensyvios gyvulininkystės fermose gali kilti nemažai su aplinkosauga susijusių problemų, tokių kaip dirvų pertręšimas ar vandens tarša (Abelha et al. 2003;Bolan et al. 2004). ...
Biodegradable agricultural wastes such as manure, has long been used as an organic fertilizer that improves soil structure, enriches the soil with micro-organisms and micro-elements necessary for plants and promotes humus formation. Manure can also be successfully used as a renewable energy source directly combusting and extracting energy. The carried out investigation showed that the incineration of manure remaining in ashes could also be used as a fertilizer. Waste combustion reduces its volume to 80–90%. Also, the investigation revealed that the amount of chemical elements (Na, Mg, Si, P, K, Ca, Ti, Mn, Fe) decreased after combustion. However, the concentration of these elements in ashes is higher than that in raw manure. Article in Lithuanian
... 2004). Dairy industry is often treated biologically (Arnaud, 2008, Bolan, 2004, Djelal, 2009, Ghoualem ,2009). Our study aims to analyze the feasibility of a biological treatment of a food processing sewage resulting from a cheese B-347 dairy in order to reduce wastewater pollution, to protect and to maintain the quality of the receiving environment (river). ...
Wastewaters emanating from the food industry typically contain elevated levels organic matter, nitrogen and phosphorus. Several types of processes are currently in use for removal organic matter and nutrient, including processes designed such as biological treatment to remove both nitrogen and phosphorus. Factors affecting the treatability of dairy wastewater for biological nutrient removal were investigated. Average COD, BOD and PO 4 3-concentrations were 7738, 938, 17,2 and 51,24 mg/l, respectively. The biological wastewater treatment at the laboratory scale was achieved through digesters. The digesters are placed at mesophilic temperature 35°C.The influence of pH (6 and 9,5) and agitation was investigated. The best results were obtained with agitation, at pH equal to 9,5 removal efficiencies of 58, 66, 83 and 63% were obtained for COD, BOD, NH 4 + and PO 4 3-respectively. However at pH 6, the obtained results of elimination from COD, BOD, NH 4 + and PO 4 3-parameters have reached 62, 69, 90 and 69% respectively. The agitation has helped to improve the performance of eliminating studied COD, BOD, anions and cations. The obtained results showed that the pH 9.5 has played an important role in reducing of the Mg 2+ , Ca 2+ parameters which reached 71 and 79.8% respectively. This work showed that biological nutrient removal could be successfully applied to treatment of dairy industry wastewaters.
... Some applied excreta N was not accounted for (Table 2), which was probably largely due to sampling and measurement errors. The effects of natural materials in retaining N (Table2) can be attributed to enhanced microbial N immobilisation and/or direct absorption of ammonium ions (Bolan et al. 2004;Luo & Lindsey 2006).have also demonstrated that treatment of farm effluent with pine bark achieves a considerable reduction in the N concentration, which they attributed to immobilisation of N by the C-rich bark material (C:N ratio = 265:1). ...
Farmers are increasingly using management systems such as moving cows out of paddocks onto stand-off pads to protect wet soils from damage during winter. Studies were carried out to investigate nutrient and faecal bacterial retention or loss from stand-off pad materials. A preliminary laboratory study found that a range of natural materials, including crushed pine bark, wood chips, zeolite and soil can retain between 66% and 76% of applied cows' excreta nitrogen (N). Zeolite was found to be particularly good at reducing ammonia (NH3) volatilisation losses from the columns. A field-scale standoff pad study at a Waikato dairy farm, in the winter season of 2005, indicated that carbon (C)-rich materials including both bark and sawdust can be used as standoff pad materials with effective retention of N and faecal bacteria. Both bark and sawdust pads retained about 60% of deposited excreta N. Substantially more Escherichia coli were recovered in the drainage from the bark pad (total yield 3.1 x 1011 E. coli) than from the sawdust pad (total yield 7.5 x 109 E. coli) demonstrating that sawdust was more effective than bark in retaining these faecal bacteria. Keywords: stand-off pads, winter management, dairy, nitrogen, faecal bacteria, natural materials
The present investigation was carried out to treat industrial effluents containing heavy metals and other toxic compounds using freshwater lake isolated algae. In the current study, two freshwater algal species C. vulgaris and Scenedesmus abundances were immobilized by encapsulation with sodium alginate with a measured pore size. These immobilized algae were subjected to industrial effluents for bioremediation. Parameters like temperature pH turbidity nitrates sulphates and heavy metals such as iron aluminum and copper were determined initially at day zero and on the 30th day of inoculation. Artificial wastewater with known parameters was used as a standard. Among the species studied C. vulgaris possessed the greater affinity for adsorption resulting in the higher uptake. C. Vulgaris showed more positive values reducing the concentration of nitrates, sulphates, metals like iron, aluminum, and copper which were seen to be treated in both the water samples i.e. industrial effluent and artificial wastewater. Scenedesmus abundans also showed positive results but lesser when it is compared with C. vulgaris.
The development of technology for nitrogen removal from swine wastewater is necessary to meet the effluent standards of nitrogen for water pollution prevention. However, because the composition of swine wastewater differs among various farms, it is necessary to select a nitrogen removal method based on the wastewater conditions present. Depending on the organic matter/nitrogen ratio in the influent wastewater in activated sludge treatment, it is necessary to select nitrification-denitrification, nitritation-denitritation, or anammox treatment strategies. In particular, the practical application of anammox treatment technology to treat wastewater with a low organic matter/nitrogen ratio is expected to be productive. Many cases of natural accumulation of anammox bacteria have been reported in full-scale activated sludge treatment facilities installed on pig farms under various conditions. It is thought that anammox can flexibly adapt to changes in the environmental conditions such as water temperature or changes in the influent composition. Additionally, stable nitrogen removal is possible by controlling the facility. This study outlines the characteristics of swine wastewater and nitrogen removal technology, with a focus on anammox treatment.
The eutrophication of water bodies due to excessive amounts of nutrients is an ongoing issue that coincides with the depletion of the commercial and affordable phosphorus reserves that are required for food production. This paper presents the development of Advanced Green Environmental Media (AGEM) for nutrient removal and recovery, in stormwater runoff or agricultural discharge, via a laboratory-scale fixed-bed column study. The water filtration media mix of AGEM was compared to existing Iron-filings Based Green Environmental Media (IFGEM) for performance assessment. Synergistic effects among iron, aluminum, and clay resulted in different capacities for removal and recovery of ammonia, nitrate, and phosphate simultaneously in IFGEM and AGEM due to their different sorption functionalities. Research findings indicate that AGEM and IFGEM removed 52% and 42% of the nitrate load, respectively, while both filtration media exhibited elevated phosphate removal, with 98% and 96% of the total phosphate load removed by IFGEM and AGEM, respectively. The discovery that the AGEM mix exhibited synergy among clay, iron, and aluminum particles with higher application potential on a long-term basis is the first of its kind in water filtration media. In this process, optimal phosphate removal was achieved by utilizing ammonia, a byproduct of nitrate reduction, which precipitated to form ammonium-phosphate salt. Finally, the synergistic effects of iron, aluminum, and clay for promoting urban farming, stormwater treatment, and hydrogen gas production simultaneously was confirmed in an urban food-energy-water nexus.
This study describes the feasibility for treatment of waste waters in batch cultures by using selected strains of green microalgae Chlorella sp. A5. To investigate the role of algae in wastewater treatment algal samples were collected from polluted water. These samples were used to isolate most dominant and pollution tolerant algae and used for the treatment. The wastewater samples used in this study was prepared in laboratory synthetically having composition of Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Kjeldahl Nitrogen (TKN) and Total Phosphorus (TP) of 398, 705, 38 and 25 mg/L respectively further reduced by ~98.5%, 97.8%, 92.6% and 99.2% by the algal treatment respectively at the end of the process. The experiments were carried out in the laboratory of Food Technology and Biochemical Engg, Jadavpur University using synthetic medium. Chlorella sp. A5 was found to be the most dominant one. Synthetic Dairy Waste Water (SDWW) was prepared in such proportion that could mimic the original Dairy wastewater. Those isolated species of Chlorella was then added to the prepared SDWW. A control sample (C-SDWW--sample without the algal species) was also prepared. Both the SDWW and C-SDWW was analyzed periodically for the waste water quality parameters in an interval of 3 days to evaluate the performance of the algae. At the end of our experiment the nutrients and BOD, COD removal rate was found to be sufficiently high especially the phosphate removal.
Environmental context: Glyphosate is a non-selective and widely used herbicide commonly found as a contaminant in water. This work reports the use of functional graphene aerogels prepared with carboxymethyl chitosan and graphene oxide for the efficient adsorption and removal of glyphosate present in water samples. The procedure has potential to successfully treat water bodies contaminated with glyphosate. Abstract: Three-dimensional carboxymethyl chitosan (CM-CS)-graphene aerogels ([email protected]) were prepared through an integration strategy of a carboxylation process and freeze drying technology for efficient glyphosate removal from water. The structure, surface properties, morphology and crystal phase of the prepared [email protected] composites were characterised using SEM, TEM, XRD, FT-IR and BET. The adsorption behaviour of glyphosate in aqueous solution on [email protected] was systematically investigated. The results show that with the advantages of high surface area, and abundant hydroxyl and carboxyl groups of [email protected], glyphosate can be easily and rapidly extracted from the water. The adsorption equilibrium of [email protected] for glyphosate correspond to a Langmuir isotherm, the maximum adsorption capacity can reach to 578.0 mg g⁻¹, and the novel adsorbent exhibited a better glyphosate removal efficiency in solutions with low pH. The exhausted [email protected] composites could be regenerated by NaOH solution for repeated use without any significant capacity loss, where the adsorbed glyphosate was effectively desorbed into the solution. These results provide evidence to further validate that [email protected] composites would be of considerable potential in the removal of glyphosate from contaminated waters.
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A zeolite porous filter (ZPF) was prepared using mixed raw zeolite, cement, and aluminum powder through steam curing and used as a novel filter medium in biological aerated filter (BAF). The performances of ZPF and commercially available ceramsite (CAC) in two laboratory scale upflow BAFs were compared. Results showed that the interconnected porous structure of ZPF was conducive to microbial biofilm growth. ZPF featured a total porosity of 29.55%, a compressive strength of 41-47N, and a specific surface area of 59.53m2/g. BAF containing ZPF showed more effectively the removal of organic carbon, ammonia nitrogen, nitrogen, and phosphorus compared to BAF containing CAC. The hydraulic retention time (HRT) was 7h at an air/water (A/W) ratio of 3:1. The amounts of total nitrogen removed were 59.89% with ZPF and 35.96% with CAC. Moreover, the amount of phosphorus removed was 83.80% with ZPF, whereas that of CAC was only 31.50%. ZPF was more suitable for the attached growth of heterobacteria and nitrobacteria to attain simultaneous nitrification and denitrification performance in the BAF. Therefore, ZPF is a novel suitable filter medium for simultaneous removal of nitrogen and phosphorus in BAFs.
The contamination of aqueous systems with phosphates has considerable environmental concerns and here, we present a new method for phosphate removal based on graphene aerogel composites. 3-dimensional graphene aerogels decorated with goethite (αFeOOH) and magnetite (Fe3O4) nanoparticles were synthesised and their application for capturing phosphates in water was successfully demonstrated. The prepared aerogels showed superior capacity to remove up to 350 mg/g at an initial phosphate concentration of 200 mg/L from water. The Freundlich model was suitable to describe the adsorption mechanism of phosphate removal by the graphene-iron nanoparticle aerogels through both mononuclear and polynuclear adsorption onto the nanosized αFeOOH and Fe3O4 nanoparticles. These new phosphate adsorbents can be produced in different forms and dimensions, using a simple, green and scalable process, and have potential to be applied for practical applications for phosphate management of waste and storm waters.
In the anaerobic digestion (AD) process, a considerable fraction of organic nitrogen is converted to inorganic nitrogen, producing an effluent with higher concentrations of ammonium as well as elevated temperatures, both of which can be useful in downstream processing of N recovery via ammonia stripping. Unfortunately, release of the ammonia also requires a suitable increase in pH to convert ionic ammonium to free ammonia. Chemical dosing for pH elevations at or above 10 is possible but economically problematic. On the other hand, the supersaturated CO2 and high concentration of bicarbonate present as a result of the digestion process is an important resource for elevating pH by stripping out the acid gas CO2. Our research has demonstrate that limited aeration is an effective way to elevate pH of the AD effluent because of intriguing chemical shifts strongly related to the high levels of carbon dioxide, bicarbonates and carbonates present in digested effluent. These chemical shifts, ultimately release carbon dioxide and raise the pH of the effluent to levels near 10, which combined with elevated operating temperatures (from waste engine heat in commercial scenario), can lead to 70-90% shift from ionic to free, gaseous form of ammonia and subsequent recovery of the ammonia through acid contact. Moreover, the removal of supersaturated CO2 and elevated pH could further enhance the phosphorus-rich solids precipitation, resulting a better total suspended solids (TSS) and total phosphorus (TP) removal. This manuscript is a summary of laboratory results with dairy manure wastewater, with particular emphasis on the chemical relationships and equilibrium shifts associated with the aeration process and its subsequent release of gases.
Bibliography to accompany the report 'Nutrient Management Science - state of knowledge'
Carbon residue obtained as a by-product from wood gasification process was employed as a precursor for preparing adsorbent by physical activation. Adsorbent with BET surface area 590 m2 g−1 and pore volume of 0.335 cm3 g−1 was prepared and used as an adsorbent for phosphate and nitrate removal. The optimal pH and initial concentrations for phosphate and nitrate removal were determined. The kinetics showed that the adsorption data followed pseudo-second-order kinetics. The isotherm analysis indicated that the adsorption data can be represented by the Langmuir model. Results showed that activated carbon residue is suitable adsorbent for phosphate removal.
Four deciduous ornamental shrubs [`Coral Beauty' cotoneaster (Cotoneaster dammeri C.K. Schneid); Tartarian dogwood (Cornus alba L.); `Lynwood' forsythia (Forsythia × intermedia Zab.); `Variegata' weigela (Weigela florida Bunge A.D.C.)] were grown in trickle-fertigated containers. There were eight media consisting of 25% or 50% sphagnum peat or composted pine bark, 25% sand, and the remainder one of two sources of spent mushroom compost; four media with 509″ peat or bark mixed with 50% spent mushroom compost; and a control medium of 10070 pine bark. Initially, higher than desirable salt levels in all compost-amended media were leached quickly (within 2 weeks of planting) and not detrimental to the species tested. Unlike cotoneaster, which showed no difference in growth (shoot dry weight) due to medium, dogwood, forsythia, and weigela grew significantly better in all compost-amended media than in the control. Growth of these three species was 20% greater in peat-based than in bark-based, compost-amended media. Dogwood and forsythia grew slightly more (+8%) with spent mushroom compost based primarily on straw-bedded horse manure than with one based on a blend of straw-bedded horse manure, wheat straw, and hay. The addition of sand (25%) to a mixture of 50% peat or bark and 25 % spent compost produced a medium with minimal compaction.
INTRODUCTION In 1994 Environment Waikato introduced rules to regulate farm dairy effluent management in the Waikato Region through the Dairy Shed Effluent Operative Plan (Environment Waikato, 1994). This paper discusses the policy and implementation processes.
The effluent characteristics of 11 dairy shed oxidation ponds designed to national specifications were examined. Measurements covering a wide range of parameters were made monthly over at least 1 year in ponds from two regions (Manawatu and Southland) and covering two types of farms: town milk supply (non‐seasonal) and daily factory (seasonal). There was considerable variation in effluent composition within ponds with time and between different ponds. Biochemical oxygen demand (BOD) concentrations (overall median 98 g m; 3‐fold range of individual pond medians) showed less variation between ponds than suspended solids (SS) concentrations (median 198 g m; 9‐fold range). Available nutrient levels were very high (e.g., an overall median of 12.2 g m for dissolved reactive phosphorus and 75.0 g m for ammonium (NH4‐N)). The ammonia represents a 4‐fold higher level of potential oxygen demand than the measured BOD. Faecal coliforms (median 70 000 (100 ml)) showed large variability both within and between ponds, with higher levels in town milk supply ponds. Differences in pond effluent characteristics could not be attributed to influent loading as apercentage of design or to the significant temperature difference between regions. Maintenance of receiving waterconcentrations below existing criteria for 95% of the time would require > 2 700‐fold dilution for faecal coliforms (bathing criterion), > 67‐fold dilution for coliforms (post treatment drinking criterion), and > 2700‐fold dilution to prevent nuisance levels of algal proliferations below discharges. Most uses are accommodated provided dilution exceeds 250‐fold requiring a minimum stream flow of 0.058 m s for a 220‐cow herd.
The performance of biofiltration to remove odours from animal rendering plant's gaseous emissions was investigated using pilot-scale biofilters containing different media (sand, sawdust, bark, barkhoil mixture). Biofilter influent and effluent gases were characterised using a gas chromatograph-mass spectrometer (GC-MS) and a GC fitted with an odour "sniffing" port. Overall odour-removal performance of the biofilters was determined using a forced-choice dynamic-dilution olfactometer. The biofilter influent gases contained about 300 organic compounds, of which approximately 40 were odorous. The odorous compounds included alkanes, alkenes, ketones, hydrocarbons, alcohols, alkyl halides, fatty acids, amines, aromatics, aldehydes and epoxides. The biofilters reduced the concentrations of the odorous compounds, often to levels that were undetectable by the GC. Some of the odorous compounds in the biofilter effluent gas came from the biofilter medium or were the result of biological or chemical transformations within the biofilter. Biofilter odour removal efficiencies of between 75% and 99% were measured at influent odour concentrations of between 490,000 and 1,100,OOO odour units m-3, and various air loading rates (0.074-0.057 m-3 gas m3 medium mid ) and medium moisture contents. Biofilters with new media, low air loading rates, or high medium moisture contents generally gave the best odour removal. Different biofilter media gave similar odour reductions at the gas loading rates examined.
The toxic concentration for un-ionized ammonia (NH3) was assessed for nine native New Zealand invertebrate species. The 96-h EC50 values at 15C and pH 7.6 and pH 8.2 ranged from 0.18 to >0.8 g/m3 NH3. The rank of species sensitivity was: shrimp (Paratya curvirostris) (least) mayfly (Zephlebia dentata) stonefly (Zealandobius furcillatus) < oligochaeta="">Lumbriculus variegatus) < fingernail="" clam="">Sphaerium novaezelandiae) < mayfly="">Deleatidium spp.) < a="" snail="">Potamopyrgus antipodarum) < caddis="">Pycnocentria evecta) < crustacean="">Paracalliope fluviatilis) (most). Surprisingly, the more sensitive species were those which would normally be associated with lowland streams (the snail and crustacean) rather than the normally accepted sensitive species (mayflies and stoneflies). Temperature had no significant effect on the acute toxicity of un-ionized ammonia with snails tested at 15, 20, and 25C. The invertebrates were more sensitive than the native fish species tested (inanga, EC50 1.60 g/m3 NH3; Richardson 1991). A final acute value (FAV) calculated for these species was 0.15 g/m3 NH3. This compares with the FAV value of 0.52 g/m3 NH3 derived by the US Environmental Protection Agency (EPA) as the basis for the ammonia criterion for salmonid containing waters. Thus EPA criteria may not provide adequate protection for New Zealand species. These data suggest that chronic studies would be particularly desirable on native New Zealand species to better determine their sensitivity to long term ammonia exposure.
A rapid adsorption process, which utilises the ammonium ion selectivity of a natural Australian zeolite, is being developed for removal of ammonia from sewage. The study reported in this paper claims not to have invented nor discovered this technique of ammonia removal from wastewater, but aims to realise the value of this natural Australian resource as an efficient alternative to existing treatment processes. An understanding of the equilibrium and kinetic behaviour of this material provided insight into its expected capacity as an adsorption media. Favourable results led to pilot scale trials, which revealed excellent performance of the zeolite under continuous column operation. The zeolite adsorption process has proved effective, at pilot scale, in reducing ammonium ions in sewage from concentrations ranging from 25 to 50 mg NH4-N/L down to levels below 1 mg NH4-N/L. Under optimised operating conditions, the adsorption capacity of the zeolite for this range of influent ammonium concentrations was about 4.5 mg NH4-N/g. The rate of treatment by the pilot zeolite column makes it ideally suited as a retrofit to high rate secondary sewage treatment processes, for removal of the soluble ammonium component.
A new concept for ammonium removal from secondary effluent by zeolite followed by bio-regeneration has been studied. In contrast to other studies of hybrid biological-ion exchange multireactor systems, the proposed process uses the ion exchange material, zeolite, as the carrier for the nitrifying biomass. This enables the two mode process to be carried out in a single reactor.
In the first mode (ion exchange), secondary effluent is passed through an ion exchange column where ammonium is concentrated in the zeolite. During the second mode (bioregeneration), the absorbed ammonium is released gradually and converted to nitrate by the active biomass residing on the zeolite. Nitrification is carried out batchwise and in a small volume reactor where optimal conditions can easily be maintained. Moreover, the addition of chemicals for the desorption of ammonium is minimal due to regenerant reuse during several cycles of nitrification. As a result, operational costs and production of large volumes of brine are minimized.
Batch and breakthrough experiments showed that the amount of ammonium adsorbed on the chabazite is strongly affected by the presence of competing cations present in secondary effluent. A reduction of about 75% was observed when using a typical Israeli sewage ion composition. The attached biomass did not significantly effect the efficiency of the ion exchange column.
Ammonium desorption experiments showed that regeneration with 10,000 mg/L Na+ is much faster than with 2440 mg/L (more than 90% ammonium recovery after 40 and 70 bed volumes, respectively).
A nitrification rate of 6 g NH4-N/(L reactor *day) was obtained in a fluidized bed reactor with chabazite as the carrier. Although this rate is in the high range of reported values for biofilm reactors, desorption experiments proved that nitrification will be the process's rate limiting step, rather than the desorption rate when regenerant solutions as low as 2440 mg/L Na+ are used.
A new biotechnology of immobilization of nitrifying bacteria is developed to improve the effect of nitrification, in which a concentrated enriched culture of nitrifiers is entrapped into a special biomass carrier and immobilized by sodium alginate to form spherical pellets with diameters ranged from 1 to 2 mm. In addition, zeolite, which is a natural ion exchanger of ammonium, was co-immobilized into the pellets to enhance the efficiencies of transferring ammonium into the pellets as nitrifiers' substrate. The system was operated under five different initial applied ammonia concentration levels. The experimental results showed that physical air stripping effect was stronger than both chemical ion exchange and biological nitrification effects occurring in the system applied with initial ammonia concentration levels of both 10 and 20 mg N/I. In the experiments applied with initial ammonia concentration levels of 50, 70, and 100 mg N/I to the system, due to high nitrite concentrations detected in the effluents, it was inferred that both ion exchange and nitrification effects were dominant over air stripping effect. The reasons might be due to higher ammonium concentrations existing in the system causing stronger effects of ion exchange by zeolite entrapped inside the pellets. Hence, this new ammonia removal biotechnology appeared to be suitable to treat the wastewaters containing higher ammonia concentrations.
A single solution reagent is described for the determination of phosphorus in sea water. It consists of an acidified solution of ammonium molybdate containing ascorbic acid and a small amount of antimony. This reagent reacts rapidly with phosphate ion yielding a blue-purple compound which contains antimony and phosphorus in a 1:1 atomic ratio. The complex is very stable and obeys Beer's law up to a phosphate concentration of at least 2 μg/ml.The sensitivity of the procedure is comparable with that of the stannous chloride method. The salt error is less than 1 %.
Struvite (MgNH4PO4·6H2O) solution chemistry was studied in order to understand a struvite scaling problem which exists in the pipe network of a series of 4 effluent lagoons at a piggery.
The conditional solubility constant (PS=SMG·SNH3−N·SPO4−P, equilibrium S values (M)) was determined over a range of pH values (6.8-8.5) and solution concentrations of Mg, NH3−N and PO4−P close to field conditions, and at a temperature of 30°C.
A comparison of field and laboratory data indicates struvite precipitates from the second lagoon onwards. The solubility data obtained also indicate potential for precipitation as a method of nutrient removal from wastewaters.
A facultative waste stabilization pond treating anaerobically pre-treated dairy shed (milking parlor) wastewater was studied in order to investigate the oxygen demand transformation ability of the pond, the oxygen demand distribution between total and soluble components and to assess nutrient removal performance. Total BOD5 levels entering the pond averaged 159 g/m3 and effluent soluble BOD5 levels averaged 18 g/m3, representing an 89% removal of the total incoming BOD5. On a soluble BOD5 only basis the removal through the pond averaged 81%. These data represent a reasonably good level of oxygen demand transformation performance for a facultative pond system. The proportions of soluble BOD5 to total BOD5 averaged 0.61 for influent to the pond and 0.25 for effluent from the pond. Total COD concentrations entering and leaving the pond were relatively high, averaging 884 g/m3 and 618 g/m3 respectively, yielding COD:BOD5 ratios of 5.6:1 and 8.5:1. Suspended solids were associated with 41% and 75% of the total effluent COD and BOD5, respectively. Ratios of insoluble BOD5:SS averaged 0.20 and 0.27 for influent and effluent, respectively, whilst biodegradable fractions were estimated at 0.21 g-BSS/g-SS and 0.28 g-BSS/g-SS. Nitrogen removals were relatively low, at 25% for total kjeldhal nitrogen, giving an average effluent concentration of 129 g/m3, while for ammonia the figures were 30% and 100 g/m3, respectively. Nitrogenous oxygen demand was not typically exerted in the pond. A low degree of total and dissolved reactive phosphorus removal occurred, with effluent concentrations averaging 23.9 g/m3 and 12.7 g/m3, respectively. At an estimated applied total organic loading rate of 30 kg-BOD(u)/ha·d the pond was well underloaded in relation to both conventional design practice and maximum theoretical algal oxygen production. Tertiary treatments able to remove suspended solids offer the potential for substantial reduction in effluent BOD concentrations. In order to meet proposed water quality criteria in New Zealand, effluent dilutions of up to 1850:1 were indicated from this study, with dissolved inorganic nitrogen (DIN) and dissolved reactive phosphorus (DRP) identified as the key parameters. Future research into the reduction of dissolved inorganic nitrogen and dissolved reactive phosphorus in dairy shed wastewaters is recommended.
Green waste compost (GWC) was examined for its suitability as an ingredient in soilless growing media by measuring nutrient content, nutrient retention and physical properties. Growing media were formulated from GWC, composted pine bark and pumice, with suitable additions of lime and fertilizer. Nutrient concentrations, electrical conductivity and pH were measured in the media, which were used to grow tomato plants. Plant dry weight was used to assess media performance. Mixes with 30% (by volume) GWC, 50% composted pine bark, 20% pumice, 3g/l dolomite lime and 3 - 4g/l controlled release fertilizer performed as well as conventional barkpumice mixes.
Zeolite clinoptilolite is a natural mineral with ionexchange and gas-adsorption properties. Ammonium- and ammonia-adsorption processes were studied in the zeolite clinoptilolite and zeolite-like sepiolite minerals. Maximum adsorption capacities of both ammonium and ammonia were determined by fitting the experimental results of the adsoption isotherm to Langmuir and first-order models. Ammonium-adsorption capacities of the zeolites were from 8·149 to 15·169 mg N g−1; up to 10·3 times higher than that of sepiolite. Ammonium-adsorption capacity increased with the surface charge density of the material, due to the readily available exchange sites in the surface.Ammonia-adsorption capacities of the zeolites were between 6·255 and 14·155 mg N g−1. Because of its large surface area, sepiolite had a capacity of ammonia adsorption three times higher than that of the ammonium ion. The complexity of the ammonia-adsorption process meant that no individual characteristics of the materials influenced directly the adsorption capacity. However, ammonia adsorption was enhanced on the ammonium adsorption in zeolites with relatively low surface charge density.
A new biotechnology of immobilization of nitrifying bacteria is developed to improve the effect of nitrification, in which a concentrated enriched culture of nitrifters is entrapped into a special biomass carrier and immobilized by sodium alginate to form spherical pellets with diameters ranged from 1 to 2 mm. In addition, zeolite, which is a natural ion exchanger of ammonium, was co-immobilized into the pellets to enhance the efficiencies of transferring ammonium into the pellets as nitrifiers' substrate. The system was operated under five different initial applied ammonia concentration levels. The experimental results showed that physical air stripping effect was stronger than both chemical ion exchange and biological nitrification effects occurring in the system applied with initial ammonia concentration levels of both 10 and 20 mg N/I. In the experiments applied with initial ammonia concentration levels of 50, 70, and 100 mg N/I to the system, due to high nitrite concentrations detected in the effluents, it was inferred that both ion exchange and nitrification effects were dominant over air stripping effect. The reasons might be due to higher ammonium concentrations existing in the system causing stronger effects of ion exchange by zeolite entrapped inside the pellets. Hence, this new ammonia removal biotechnology appeared to be suitable to treat the wastewaters containing higher ammonia concentrations.
A new concept for ammonium removal from secondary effluent by zeolite followed by bio-regeneration has been studied. In contrast to other studies of hybrid biological-ion exchange multireactor systems, the proposed process uses the ion exchange material, zeolite, as the carrier for the nitrifying biomass. This enables the two mode process to be carried out in a single reactor. In the first mode (ion exchange), secondary effluent is passed through an ion exchange column where ammonium is concentrated in the zeolite. During the second mode (bioregeneration), the absorbed ammonium is released gradually and converted to nitrate by the active biomass residing on the zeolite. Nitrification is carried out batchwise and in a small volume reactor where optimal conditions can easily be maintained. Moreover, the addition of chemicals for the desorption of ammonium is minimal due to regenerant reuse during several cycles of nitrification. As a result, operational costs and production of large volumes of brine are minimized. Batch and breakthrough experiments showed that the amount of ammonium adsorbed on the chabazite is strongly affected by the presence of competing cations present in secondary effluent. A reduction of about 75% was observed when using a typical Israeli sewage ion composition. The attached biomass did not significantly effect the efficiency of the ion exchange column. Ammonium desorption experiments showed that regeneration with 10,000 mg/L Na+ is much faster than with 2440 mg/L (more than 90% ammonium recovery after 40 and 70 bed volumes, respectively). A nitrification rate of 6 g NH4-N/(L reactor *day) was obtained in a fluidized bed reactor with chabazite as the carrier. Although this rate is in the high range of reported values for biofilm reactors, desorption experiments proved that nitrification will be the process's rate limiting step, rather than the desorption rate when regenerant solutions as low as 2440 mg/L Na+ are used. Copyright (C) 1996 IAWQ.
+ from 1500 mg/l to 300–400 mg/l and anaerobic digestion in UASB and UASB-AF reactors to remove organics. The ion-exchange pre-treatment by zeolite leads to a reduction of toxicity of wastewater towards anaerobic microbial population and improves the UASB and UASB-AF reactors yields in organics reduction and gas production. The laboratory plant in this configuration reaches a COD removal range of 60–80% and a good reduction of effluent nutrients concentration whereas the use of a anaerobic second stage gave modest results in organics removal because of low applied organic load. A treatment cycle composed of a pre-treatment with zeolites, anaerobic digestion in UASB-AF reactor and a final treatment in an aerobic activated sludge plant is giving very good preliminary results.
Ammoniacal nitrogen (ammonia and ammonium) in agricultural wastewaters can promote eutrophication of receiving waters and be potentially toxic to fish and other aquatic life. Zeolites, which are hydrated aluminum‐silicate minerals, have an affinity for ammonium ions (NH4 ) and are, therefore, potentially useful in removing this contaminant from wastewaters. The major objectives of this study were to evaluate the capacity of two natural New Zealand zeolites (clinoptilolite and mordenite) to remove NH4 from a range of wastewaters under both batch and flow‐through conditions. Effects of two zeolite particle size ranges (0.25–0.50 mm and 2.0–2.83 mm) on NH4 removal performance were also investigated. Results obtained from the batch adsorption experiments indicated that both zeolites tested, regardless of their particle sizes, were equally effective (87–98%) at NH4 removal from domestic wastewaters or synthetic solutions containing NH4 concentrations of up to 150 gNH4‐N m. However, mordenite showed more effective NH4 removal than clinoptilolite for dairy and piggery waste‐waters, and for synthetic solutions containing high NH4 concentrations (350–750 g NH4‐N m). At all equilibrium NH4 concentrations tested (0.2–300 g NH4‐N m), NH4 removal by both mordenite and clinoptilolite was significantly (P < 0.0001) reduced by the presence of competing sodium (Na) cations in the synthetic solutions. The maximum amounts of NH4 removed by coarse and fine clinoptilolite and coarse and fine mordenite, calculated by the Langmuir model, were 5.77 and 5.74, and 8.09 and 8.28 g NH4‐N kg, respectively. In the slow flow‐through experiment (0.47 mm min), NH4 breakthrough (>1.2 g NH4‐N m) for both zeolite sources (regardless of their particle sizes) did not occur even after receiving 40 bed volumes (BV) of wastewaters containing 100 g NH4‐N m. The NH4 removal at this breakthrough was approximately 99 g NH4‐N m of wastewater throughput, which equates up to 5.8–6.5 g NH4‐N kg zeolite. In contrast, at a faster loading flow rate (15.9 mm min), the breakthrough was almost immediate (1 BV) for coarse zeolites and after 22 BVs for fine zeolite. The NH4 breakthrough capacity for fine mordenite was 2.0–4.4 g NH4‐N kg zeolite. Fine zeolites were more effective than coarse zeolites in removing wastewater NH4 (95% and 55% removal, respectively), even after receiving 64 BV of wastewater.
The effect of pH of the buffered saturating solution on the cation-exchange capacity (CEC) of 60 Wisconsin soils was determined within the pH range 2.5 to 8.0. The relative contributions of clay and organic matter to total CEC were measured using multiple regression analyses; the independent variables were clay and organic matter contents and the dependent variables, CEC at pH 2.5, 3.5, 5.0, 6.0, 7.0, and 8.0. The average CEC of the organic matter at each pH value was 36, 73, 127, 131, 163, and 213 me. per 100 g., respectively; while that of the clay was 38, 46, 54, 56, 60, and 64 me. per 100 g. Within the limits of the standard errors of the regression coefficients, CEC of both clay and organic matter increased linearly with pH. The regression equations indicated that the mean relative contribution of organic matter to total soil CEC in this group of soils varied from 19% at pH 2.5 to 45% at pH 8.0; the mean organic matter and clay contents of the soils studied were 3.28% and 13.3% respectively. Coefficients of multiple correlation varied from 0.927 at pH 3.5 to 0.959 at pH 8.0.
Increased concern about environmental degradation and a move towards sustainable farming systems has lead to closer attention being paid to farm dairy effluents (FDE). Treatment of FDE in New Zealand is mainly through land application, or through oxidation ponds. Since the introduction of the Resource Management Act, 1991, regional councils require dairy farmers to be more accountable for the management of effluent from their dairy farms. Regulations have been imposed to limit the application of nitrogen (N) to land from FDE, and these limits range from 150 to 200 kg N ha yr. Farmers, consultants, and regional councils require information on the chemical composition, particularly N content, of effluents, so that land effluent application systems can be designed and managed within the guidelines or regulations imposed. Data gathered from previous investigations on effluents in New Zealand found an average solids content of 0.9% dry matter. Between 1977 and 1997 the mean N content of FDE doubled from approximately 200 to 400 mg N I. The trend for higher N concentrations is likely to continue as dairy herd numbers increase. The most likely reason for the increase in N is that volume of washwater used per cow has proportionately decreased as herd size has increased, thus, FDE has become more concentrated with levels above 400 mg N I increasingly common. Average values of phosphorus (P) and potassium (K) in FDE were 70 and 370 mg I, respectively. Slurries obtained from anaerobic ponds, which require periodic de‐sludging about every 5 years, had average nutrient concentrations of 1650, 290, and 510 mg 1 for N, P, and K, respectively, representing an accumulation of minerals over the 5 years.
Philadelphus mexicanus, Cuphea hyssopifolium ’Violet’ and Viola wittrockiana ’Blue Angel’ (pansy) were grown in mixtures of peat and Pinus radiata bark with Nitrogen Drawdown Index (NDI75) values ranging from 1.1 to 0 (NDI150 value of 0.36). Nutrients were provided via liquid feeds containing 150–700 mg/L N or via coated fertilizers added at 3–9 g/L medium. Growth responses covered the full spectrum from N deficiency to growth reduction through excessive salinity. Some of the controlled‐release fertilizers used released nutrients at considerably higher rates than that nominated by the manufacturer.At the lowest levels of N application, growth generally graded down from a maximum in medium with the highest NDI value to a minimum in medium with the lowest NDI value. Calculations based on growth response indicated that N immobilisation was at a weekly rate of 1.5 to 2.9 mg/L for each 0.1 NDI unit fall below 1, with a mean of about 2.5 mg/L.
Removal of copper from aqueous solutions containing 100-1000 ppm, using different indian bark species, was performed on laboratory scale. The percentage removal of metal ions depends on the solution pH, bark species and time. The efficiency of copper removal by the used raw barks increases with a rise of solution pH and reaches a maximum of about 65-78% around pH 4-5. However, the decontaminated aqueous solutions were colored due to the dissolution of soluble organic compounds contained in the raw bark. This increases the biological and chemical oxygen demand (BOD and COD) of the solutions as well as the total organic carbon content (TOC). For this reason, raw bark should be treated either by chemical or biological means. Such treatment will allow the extraction of the soluble organic compounds and increase the chelating capacity and efficiency of the treated bark. Depending on the pH value, the chelating efficiency of treated barks is about 1.2-2.2 times that of the raw ones. Moreover, the retention capacity of the Indian treated bark varies from about 42 experiments that allow recovery of about 99% of the contained copper. The retention capacity of the treated bark is almost constant after five cycles of chelation-elution, suggesting that the 'life time cycle' is sufficiently long for continuous industrial application. The spent copper loaded barks can either be incinerated or pyrolysed. It generates solids containing either ~ 80% of CuO or ~ 14% of Cu(o), respectively. Such materials can be used either in the secondary or primary copper production, thus offering a friendly environmental solution of effluents' treatment. The suggested process can be used as an alternative to the classical technologies for effluent decontamination. It is also efficient for polishing effluents treated by other methods.
Porous treatment walls are increasingly used for remediating contaminated groundwater. These walls are constructed below the water table and perpendicular to the groundwater flow. Successful nitrate removal from groundwater has been demonstrated in porous walls amended with sawdust but the mechanism responsible has not been identified. The objective was to determine whether denitrification rates in such a wall were high enough to account for observed nitrate removal. During a year-long field trial, the rate of nitrate removal from groundwater was measured as it passed through a 1.5 m wide wall. Concurrently, denitrification rates were measured in samples taken from the wall using an acetylene-inhibition technique. Denitrification rates (0.6–18.1 ng cm−3 h−1) were generally high enough to account for the nitrate losses in groundwater (0.8–12.8 ng N cm−3 h−1), except on one occasion, when nitrate loss in groundwater was greater than 50 ng N cm−3 h−1. When the water table dropped below the wall, nitrate inputs were decreased, and there were concurrent declines in denitrification rates. Rates subsequently increased once the water table rose. Laboratory incubations also demonstrated that denitrification was highly responsive to nitrate inputs. Denitrification rates increased by an order of magnitude within 7 h of nitrate addition. This treatment wall has removed nitrate from groundwater for more than 2.5 years and denitrification rates were high enough to account for nitrate removal.
Kjeldahl nitrogen (N), total N and forms of inorganic N (ammoniacal (NH4)-N, nitrate (NO3)-N and nitrite (NO2)-N) were measured in a range of animal manures. The manures include fresh samples of poultry manure, sheep manure, horse manure, dairy slurry and pig slurry and composted poultry manure. Kjeldahl N was measured by standard micro-Kjeldahl digestion. For total N measurements, NO3-N and NO2-N were recovered during Kjeldahl digestion by pretreatments with various oxidizing and reducing agents. Inorganic forms of N were measured by extraction with 2M KCl solution.Kjeldahl digestion alone allowed measurement only of organic N and NH4-N. Amongst various modifications to the Kjeldahl, pretreatment with either acidified (H2SO4) Zn-CrK(SO4)2 or acidified (H2SO4) reduced Fe achieved complete recovery of NO3-N. Nitrite N was only recovered by first oxidising the NO
2
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to NO
3
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with KMnO4 followed by reduction to NH4-N with acidified (H2SO4) reduced Fe.More than 95% of the total N in fresh animal manure was present as organic N and NH4-N which were recovered by the standard Kjeldahl digestion. In the case of fresh manures there was no difference between the amount of total N measured by the Kjeldahl digestion and its modified methods. However composting of poultry manure or drying of poultry manure, pig slurry and dairy slurry resulted in an increase in NO3-N which was not recovered during Kjeldahl digestion alone. Under these conditions the total N could be measured by pretreating the samples with KMnO4 and reduced Fe prior to Kjeldahl digestion.Drying of animal manures caused a decrease in organic N and NH4-N, especially in poultry, pig and dairy manures. There was a slight increase in NO3-N; but most of the decrease in N content with drying was attributed to the volatilization loss of ammonia (NH3). Amongst various drying methods examined air drying caused maximum loss of N as NH3 whereas freeze drying caused minimum loss of N. This suggests that fresh animal manures can be freeze dried for analysis of N which causes minimum loss of N.
The removal of toluene from an experimental gas-stream was studied in an industrial biofilter filled with poplar wood bark. Toluene degradation, approximately 85% through the operating period, resulted in low levels of toluene in the off-gas effluent. For a toluene load of 6.7 g m-3 h-1 the elimination capacity of the biofilter was found to be 6.0 g m-3 h-1. Toluene removal was due to biodegradative activity of microorganisms in the filter bed; the most probable number counts of toluene degraders increased from 2.4102 to 6.4107 MPN/g dry packing material in about seven months of air-toluene supply. The degradative capacity of a Burkholderia (Pseudomonas) cepacia strain, isolated from the biofilter material, as an example of the effectiveness of microbial toluence removal was tested in batch culture. The microorganism degraded completely 250 ppm of toluence supplied as sole carbon source in 24 hours. The high performance demonstrated for a long period and the mechanical and physico-chemical stability of the biofilter favour its use in industrial full-scale off-gas control.
The electroplating industries generate large volumes of industrial effluent containing hexavalent chromium ions. The classical treatment of these effluents is via the reduction of Cr6+ to Cr3+ before precipitation. This produces a significant amount of calcium sulfate and chromium hydroxide. Due to environmental regulations, high waste disposal costs and the necessity to recycle these heavy cations, research on a new approach has been initiated. This paper describes the preliminary results of a low cost process dedicated to the decontamination of these industrial effluents by chemically treated barks.Decontamination of solutions containing hexavalent chromium by this organic support has been studied on the laboratory scale. Experiments conducted with the main European tree species have shown that the metal removal percentage, from synthetic solutions, depends upon pH, initial concentrations and the tree species. More than 95% of Cr6+, contained in a 10, 100 or 1000 ppm solution, can be recovered at pH 3.80. The ashes obtained by the incineration of the saturated bark contain up to 50% of chromium metal, which could be recycled by the traditional metallurgical processes. Spectroscopic analysis of the saturated bark is used to investigate the type of ligand between the treated bark and the chromium.Pilot plant trials were successful in eliminating about 90% of Cr6+ from industrial effluents containing 5000 ppm.
Laboratory columns were used to determine the treatment capacity of Sphagnum spp peat and Pinus spp bark and woodchips to treat primary (unsettled) domestic sewage by percolation. Bark and peat were found to be applicable materials, woodchips seemed inadequate because of poor CODtot removal and lack of disinfection. Matured percolator columns containing a layer of 50 cm bark packed at a density of 0.150 g/cm3 and supplied with 10 cm wastewater per day gave the following reductions: SS, 72%; CODtot, 63%; BOD5, 97%; NH+4 -N, 64%; and Ntot-N, 35%. The effluent had a pH of 7.5. The bark percolator had, however, a poor disinfecting capacity: faecal indicator organisms were reduced by only 1 log unit. The peat percolator (operated at 0.075 g/cm3 and 10 cm/d) had a good disinfecting capacity for faecal bacteria, reducing them by 3–4 log units. The effluent had a low pH (pH = 4.5) during the first 3 months of operation. Once matured, the following average reductions were obtained: SS, 91%; CODtot, 50%; BOD5, 99%; NH+4 -N, 93% and Ntot-N, 38%. The treatment capacity was not significantly (α = 0.05) affected by the applied densities of a percolator layer (0.075 and 0.100 g/cm3 for peat and woodchips; 0.150 and 0.175 g/cm3 for bark) and the hydraulic loading rates (2.5 or 10.0 cm/d). Combining two or three materials by mixing (equal volume) or by applying them in layers (equal layer thickness) gave similar effluent qualities, though percolators containing a layer of peat were more effective in the removal of faecal bacteria. The temporary presence of a biocide in the wastewater and a prolonged period of drought (14 days) disturbed NOx-N formation but did not influence SS, CODtot and NH+4-N removal.
A single solution reagent is described for the determination of phosphorus in sea water. It consists of an acidified solution of ammonium molybdate containing ascorbic acid and a small amount of antimony. This reagent reacts rapidly with phosphate ion yielding a blue-purple compound which contains antimony and phosphorus in a 1:1 atomic ratio. The complex is very stable and obeys Beer's law up to a phosphate concentration of at least 2 μg/ml.The sensitivity of the procedure is comparable with that of the stannous chloride method. The salt error is less than 1 %.RésuméUne méthode spectrophotométrique est décrite pour le dosage du phosphate dans l'eau de mer, an moyen de molybdate d'ammonium, en présence d'acide ascorbique et d'antimoinc. Il se forme rapidement un composé violet bleu, renfermant antimoine et phosphore dans un rapport atomique de 1:1.ZusammenfassungBeschreibung einer Methode zur Bestimmung von Phosphat in Mecrwasser mit Hilfe von Ammoniummolybdat in Gegenwart von Ascorbinsäure und Antimon. Der gebildete blau-violette Komplex wird spektrophotometrisch gemessen.
A rapid adsorption process, which utilises the ammonium ion selectivity of a natural Australian zeolite, is being developed for removal of ammonia from sewage. The study reported in this paper claims not to have invented nor discovered this technique of ammonia removal from wastewater, but aims to realise the value of this natural Australian resource as an efficient alternative to existing treatment processes. An understanding of the equilibrium and kinetic behaviour of this material provided insight into its expected capacity as an adsorption media. Favourable results led to pilot scale trials, which revealed excellent performance of the zeolite under continuous column operation. The zeolite adsorption process has proved effective, at pilot scale, in reducing ammonium ions in sewage from concentrations ranging from 25 to 50 mg NH4-N/L down to levels below 1 mg NH4-N/L. Under optimised operating conditions, the adsorption capacity of the zeolite for this range of influent ammonium concentrations was about 4.5 mg NH4-N/g. The rate of treatment by the pilot zeolite column makes it ideally suited as a retrofit to high rate secondary sewage treatment processes, for removal of the soluble ammonium component.
Two 200-L fixed-bed bioreactors, containing porous-medium material of coarse sand and organic carbon (tree bark, wood chips and leaf compost), were used to treat NO3 contamination from agricultural runoff. Flow from a farm-field drainage tile containing NO3-N concentrations of 3–6 mg L−1 was successfully treated in the reactors (NO3-N < 0.02 mg L−1) at a rate of 10–60 L day−1 over a 1-yr period. Treatment occurs by anaerobic denitrification promoted by the added solid-phase organic carbon. Because the reactor design is simple, economical to construct and maintenance free, it may provide a practical solution to the problem of treating redox-sensitive contaminants, such as NO3, in agricultural runoff.
In manure disposal systems, denitrification is a major pathway for N loss and to reduce N transport to surface and ground water. We measured denitrification and the changes in soil N pools in a liquid manure disposal system at the interface of a pasture and a riparian forest. Liquid swine manure was applied weekly at two rates (approximately 800 and 1600 kg N ha-1 yr-1) to triplicate plots of overland flow treatment systems with three different vegetation treatments. Denitrification (acetylene block technique on intact cores) and soil N pools were determined bimonthly for 3 yr. The higher rate of manure application had higher denitrification rates and higher soil nitrate. Depth 1 soil (0-6 cm) had higher denitrification, nitrate, and ammonium than depth 2 soil (6-12 cm). The vegetation treatment consisting of 20 m of grass and 10 m of forest had lower denitrification. Denitrification did not vary significantly with position in the plot (7, 14, 21, and 28 m downslope), but nitrate decreased in the downslope direction while ammonium increased downslope. Denitrification ranged from 4 to 12% of total N applied in the manure. Denitrification rates were similar to those from a nearby dairy manure irrigation site, but were generally a lower percent of N applied, especially at the high swine effluent rate. Denitrification rates for these soils range from 40 to 200 kg N ha-1 yr-1 for the top 12 cm of soil treated with typical liquid manure that is high in ammonium and low in nitrate.
Denitrification, the anaerobic microbial conversion of nitrate (NO3-) to nitrogen (N) gases, is an important process contributing to the ability of riparian zones to function as "sinks" for NO3- in watersheds. There has been little analysis of riparian zones in urban watersheds despite concerns about high NO3- concentrations in many urban streams. Vegetation and soils in urban ecosystems are often highly disturbed, and few studies have examined microbial processes like denitrification in these ecosystems. In this study, we measured denitrification potential and a suite of related microbial parameters (microbial biomass carbon [C] and N content, potential net N mineralization and nitrification, soil inorganic N pools) in four rural and four urban riparian zones in the Baltimore, MD metropolitan area. Two of the riparian zones were forested and two had herbaceous vegetation in each land use context. There were few differences between urban and rural and herbaceous and forest riparian zones, but variability was much higher in urban than rural sites. There were strong positive relationships between soil moisture and organic matter content and denitrification potential. Given the importance of surface runoff in urban watersheds, the high denitrification potential of the surface soils that we observed suggests that if surface runoff can be channeled through areas with high denitrification potential (e.g., stormwater detention basins with wetland vegetation), these areas could function as important NO3- sinks in urban watersheds.
The choice of management practices for the treatment of piggery effluent prior to its disposal to waterways or land is governed by the desire to simultaneously minimise the cost of treatment whilst minimising pollution of the environment. Laboratory experiments were conducted to compare the removal of total and total filterable phosphorus (P) (<0.45 microm) from ortho-phosphate solutions or piggery effluent by hydrated lime or lime kiln dust alone, or from recycled piggery effluent by lime and physico-chemical treatment methods. In addition, the ability of lime to remove P from recycled piggery effluent at an intensive piggery was assessed. Most P in lime treated effluent was present in the >0.45 microm fraction because of the presence of unsettled flocs of P impregnated lime. The efficiency of total P removal by hydrated lime and lime kiln dust decreased as effluent quality declined. The efficiency of removal of total filterable P by hydrated lime or lime kiln dust was not affected by effluent quality. Hydrated lime was more efficient in removing P from effluent or ortho-phosphate solutions, but lime kiln dust was more cost effective. More than 95% of total P was removed from recycled piggery effluent when physico-chemical treatment followed settling with or without lime. The physico-chemical treatment decreased total P mainly by decreasing the number of suspended particles in the effluent and by precipitating some total filterable P as iron, aluminium or calcium compounds.
Methods for chemical analysis of soils
- L L Blakemore
- P L Searle
- B K Daly
Blakemore, L.L., Searle P.L., Daly, B.K., 1987. Methods for chemical
analysis of soils. New Zealand Soil Bureau Scientific Report 80,
Wellington, New Zealand.
Lagoon performance treating livestock waste
- D J Warburton
Warburton, D.J., 1983. Lagoon performance treating livestock waste.
In: McFarlane, P.M. (Ed.), Proceedings of the 15th Biotechnology
Conference on Waste Stabilization Ponds. Massey University,
Palmerston North, New Zealand, pp. 89-128.
Impact of animal manure manage-ment on ground and surface water quality Animal Waste Utilization: Effective Use of Manure as a Soil Resource
- A Sharpley
- J J Meisinger
- A Breeuwsma
- J T Sims
- T C Daniel
- J S Schepers
Sharpley, A., Meisinger, J.J., Breeuwsma, A., Sims, J.T., Daniel, T.C., Schepers, J.S., 1998. Impact of animal manure manage-ment on ground and surface water quality. In: Hatfield, J.L., Stewart, B.A. (Eds.), Animal Waste Utilization: Effective Use of Manure as a Soil Resource. Ann Arbor Press, Chelsea, MI, pp. 92– 102.
Characterisation of fluidised bed boiler ash as potential source of liming material
- H Wang
- M J Hedley
- N S Bolan
Wang, H., Hedley, M.J., Bolan, N.S., 1994. Characterisation of
fluidised bed boiler ash as potential source of liming material. N.Z.
J. Agric. Res. 38, 225-249.
Nutrient recycling from farm effluent
- N S Bolan
Bolan, N.S., 2001. Nutrient recycling from farm effluent. Water Waste
NZ 117, 32-35.
Standard Methods for the Examination of Water and Wastewater
- Awwa Apha
- Wpcf
APHA, AWWA, WPCF, 1995. Standard Methods for the Examination of Water and Wastewater, 14th ed. American Public Health
Association, Washington, DC.