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Subsurface flow and free water surface flow constructed wetland with magnetic field for leachate treatment
Abstract and Figures
This study conducted using two-stage lab-scale Subsurface Flow (SSF) and Free Water Surface (FWS) constructed wetland under influence of magnetic field to treating the leachate. The leachate samples were pre-treated with magnet circulation with strength 0.55T. The constructed wetlands were planted with Limnocharis flava (yellow bur-head) and Eichhornia crassipes (water hyacinth). The performance of the system determined by suspended solid, nutrient (ammonia and phosphate), heavy metal (Iron and Manganese) removals and uptake by root and leaves of constructed wetland plants. From the analysis, planted system shows higher removal compared to unplanted system. The result shows great removal efficiency with 98.7% NH3-N, 90.2% PO43-, 98.7% Fe, 92.5% Mn and 94.3% SS removal. At the end of study, the plants harvested and analyzed for heavy metals uptake by plants. The results showed that Fe uptake on leaves greater than on roots while Mn uptake on roots is greater than in leaves. For Limnocharis flava for example, 54% Fe uptake by leaves while 44% uptake by roots and Mn uptake by roots was 51% while 34% by leaves. This study concludes that SSF-FWS constructed wetland with magnetic field can improve the leachate quality.
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... (Kamariah, 2006) . 60 Table 3.4 Application of the simplified statistical wetland filter set-up design (Table 3. ...
... Schematic representation of free water surface flow constructed wetland(Oki and White, 2011) Plants for free water surface flow constructed wetlands(Kamariah, 2006) ...
Wetlands have long played a significant role as natural purification systems. Textile industry processes are among the most environmentally unsustainable industrial processes, because they produce coloured effluents in large quantities polluting water. The aim of this study is to assess the performance of VFCWs to treat two different azo textile dyes with and without artificial wastewater for long periods of time through different operation modes such as contact and resting times, and loading rates, which has rarely been considered in previous research works. The corresponding key objectives are (a) to assess the role of gravel (as a control wetland) and plants on dye reduction and other pollutants; (b) to determine the influence of two groups of dyes (acid (AB113) and basic (BR46)), each dye having a different molecular weight and chemical structure, at two different concentrations (7 mg/l and 215 mg/l); (c) to evaluate the impact of the mixture of both dyes on the performance of vertical-flow constructed wetlands in terms of dye reduction with/without artificial wastewater; (d) to determine the annual and seasonal reduction; and (e) to assess the influence of operational parameters such as contact time (48h and 84h), resting time and mass loading rate on dye reduction and other pollutants for a long period.
The first phase dealt with treating the two azo textile dyes only during the period between 1 June 2015 and 31 May 2016, while the second phase dealt with artificial wastewater containing the two azo textile dyes during the period between 1 June 2016 and 31 May 2017. According to the first phase, for the low concentration of BR46, there was no significant (p≥0.05) difference between the wetlands in terms of dye reductions. However, for chemical oxygen demand (COD), the reduction percentages were 50%, 59% and 67% for the control and for the wetlands with short and long contact times, respectively. All reductions were statistically significant (p<0.05). For the high concentration of BR46, the reduction percentages for the dyes were 94% and 82%, and for COD, they were 89% and 74% for the long and short contact times, correspondingly. A good reduction was noted for total suspended solids for long and short contact times. For the low concentration of AB113, the percentage reductions for the dye were 71%, 68% and 80%, and for COD, they were 5%, 7% and 16% for the control, and the short and long contact times, respectively. For the high concentration of AB113, the percentage reductions for the dye were 72% and 73%, and for COD, they were 54% and 55% for the 48 h and 96 h contact times in this order. Regarding ortho-phosphate-phosphorous for the low concentrations of BR46 and AB113, the reduction percentages for wetlands, which have high contact times, were significantly (p<0.05) better than those of the control wetlands, as well as wetlands, which have low contact times. In the case of high concentration regarding BR46, the reduction percentages of wetlands with low loading rates were significantly (p<0.05) better than wetlands with high loading rates, while for AB113, the reduction percentages of wetlands with high loading rate were significantly (p<0.05) better than those for wetlands with low loading rates. In the case of ammonia-nitrogen for the high concentration of dyes, there were no significant (p≥0.05) differences between wetlands. Regarding nitrate-nitrogen reduction for low and high concentration of BR46 and AB113, the reduction percentages for wetlands with long contact times were better than those for wetlands having short contact times.
In the case of phase two, the presence of plants had no effect on the dye and COD reductions. For the low concentration of BR46, the percentage reductions for the dye were 92%, 89% and 91%, and for COD, they were 69%, 82% and 70% for the control, and the short and long contact times, respectively. All reductions were statistically significant (p<0.05). For the high concentration of BR46, the reduction percentages for the dyes were 73% and 33%, and for COD, they were 56% and 39% for the long and short contact times, respectively. For the low concentration of AB113, the percentage reductions for the dye were 85%, 77% and 82%, and for COD, they were 76%, 81% and 62% for the control, and the short and long contact times in this order. For the high concentration of AB113, the percentage reductions for the dye were 44% and 54%, and for COD, they were 40% and 56% for the 48 h and 96 h contact times, correspondingly. Regarding ortho-phosphate-phosphorous for the low concentrations in the case of AB113 and BR46 and the mixture of both dyes, the reduction percentage in wetlands with high contact time was significantly (p<0.05) better than those of the control wetlands and wetlands with low contact time. For the high concentration of BR46, AB113 and the mixture of both of them, wetlands with high resting and contact times had lower ortho-phosphate-phosphorous effluent concentrations when compared with wetlands with low resting and contact times. Regarding ammonia-nitrogen reduction percentages for low concentrations of BR46 and AB113 and the mixture of both dyes, wetlands with high resting times had better reduction percentages (p<0.05) when compared with the control wetlands as well as wetlands with low resting times. In the case of high concentrations for BR46, AB113 and the mixture of both of them, wetlands with low loading rates had a better reduction percentage when compared with wetlands with a high loading rate. Regarding nitrate-nitrogen reductions for low and high concentrations of BR46, AB113 and the mixture of both of them, the reduction percentages for all wetlands were in the range from 75 to 100%. Regarding aromatic amine compound reductions, wetlands with long contact times showed significant (p<0.05) differences when compared with the control and wetlands with short contact times for the low concentrations of BR46 and AB113. For the high concentration of BR46 and AB113, wetlands with low loading rates showed a significant difference (p<0.05) when compared with wetlands with a high loading rate. The researcher recommended that using HPLC combined with FTIR to investigate the reduction in aromatic amines and working on modelling of the results should help the designer in improving the construction of wetlands on an industrial scale.
... Average influent concentration and removal efficiency of pollutants in this hybrid CW collected in the Table 11. Two series of lab-scale planted and unplanted hybrid CW including a HSSF at the first and a FWS at the second stage were applied to treating landfill leachate by a recirculation line under influence of magnetic field (Saat and Kamariah, 2006). Average influent concentrations of NH 3 , PO 4 3-, Fe, Mn and TSS in landfill leachate were 73.4, ...
... Eckhardt et al. in 1998 have studied on landfill leachate treatment by a FWS-HSSF hybrid CW which showed removal efficiency about 98% for Fe and 99% for TP (Eckhardt, 1998). (Saat and Kamariah, 2006). ...
... It was believed that plant litter, providing additional organic material and thereby new sites for phosphorus adsorption was responsible for a better mass removal performance of the planted systems [25]. The average percentage removal for five trials in R3 was higher than R2 because the phosphorus was taken up by the cattail plant and the phosphorus adsorption capacity increases as the size of the gravel is smaller as compared to the size of the granite in R2 [26]. In R4 which was filled with the sand and charcoal and planted with cattail plant showed the highest average percentage removal, 67.7 %. ...
... Microbial uptake of phosphorus had been claimed that biotic processes have a considerable effect on the phosphorus removal which was influenced by the bioavailable carbon source in the sediment [28]. Results show that the availability of adsorption sites due to smaller media sizes which provided higher surface area that gave bigger capacity for the phosphorus binding site [26]. ...
Performance of vegetated horizontal subsurface-flow constructed wetland was evaluated for the removal of ammoniacal nitrogen (AN), total reactive phosphorus (TRP), and soluble reactive phosphorus (SRP) from landfill leachate. Four reactors were used, namely RI (granite without vegetation), RII, and RIII which consists of granite and gravel with different sizes respectively and RIV contained sand and 67.5 L of charcoal. RII, RIII, and RIV were planted with cattails. The leachate obtained from the site of Pulau Burung Sanitary Landfill, Penang was introduced into RI at flow rate of 18 mL/min which was continuous to flow through another three reactors. The leachate was analyzed for AN, TRP, and SRP before and after the treatment in each reactor by standard methods. The overall average removal efficiency of AN, TRP, and SRP were 86.7, 86.2, and 90.0%, respectively. Reactor IV performed the best for removal of all the parameter studies. Index Terms—Ammoniacal nitrogen, landfill leachate, total phosphorus, vegetated constructed wetland.
... Until recent, magnetic field has been implemented for several common wastewater treatment processes. For instance, magnetic field were applied for the removal of heavy metals [4], turbidity and suspended solids [4,5,6], organic compounds [7,8,9], nutrients consisting of nitrogen and phosphorus compounds [10,11] and toxic chemicals [12]. Generally, most of the treatment processes shown improvement in their performances under specific magnetic conditions. ...
... Until recent, magnetic field has been implemented for several common wastewater treatment processes. For instance, magnetic field were applied for the removal of heavy metals [4], turbidity and suspended solids [4,5,6], organic compounds [7,8,9], nutrients consisting of nitrogen and phosphorus compounds [10,11] and toxic chemicals [12]. Generally, most of the treatment processes shown improvement in their performances under specific magnetic conditions. ...
In this study, activated sludge was exposed by magnetic field exhibited from NdFeB – type of permanent magnets. The exposure was aimed to improve the physical properties of the activated sludge used in treating wastewater. Hence, it was hypothesized that the magnetically-exposed activated sludge is potential in enhancing the efficiency of removal performances of the wastewater treatment processes. The influence of magnetic field, exposure time, biomass concentration and mixing intensity on turbidity reduction, aggregation and settling velocity was thoroughly investigated. Response surface methodology (RSM) was applied for experimental design, analysis and optimization. Based on the results, magnetically-exposed activated sludge displayed certain trends showing that its properties were positively affected by magnetic field. At the optimum conditions of magnetic field of 88.0 mT, exposure time of 38.5 hrs, biomass concentration of 3380 mg/L and mixing intensity of 345 rpm achieved 68.3%, 60.1% and 0.0104 cm/s of turbidity reduction, aggregation and settling velocity, respectively.
... En otro estudio, se mejoró el desempeño de los humedales artificiales en el tratamiento de lixiviados con aplicación magnética (Kamariah, 2006) Se utilizó un imán permanente de 550 mT para pretratar el lixiviado del influente antes de que atraviese el humedal. los rendimientos indicaron que la remoción de sólidos en suspensión fue tan alta como 94,3%. ...
Como resultado de este trabajo de investigación, se evidencia que a partir de
las características físico-químicas presentadas por las aguas analizadas, con la
aplicación del tratamiento magnético, se obtienen variaciones para la
conductividad, el pH, la turbidez y la DQO. Se confirma que hay respuestas en
los resultados y que las mismas son significativas, ya que el tratamiento magnético interviene positivamente en el ahorro de coagulantes y constituye un ahorro económico para el país.
... In wastewater treatment, magnetic fields were applied to aid in the separation of heavy metals (Cd and Zn, Flores López et al. (2018); Cu and Ni, Rajczykowski and Loska (2018); Pb and Cu, Szatylowicz and Skoczko (2018); Cr IV, Dias et al. (2020)). Removal of suspended solids from wastewater treatment was also investigated under magnetic field exposure (Sa'at and Kamariah 2006;Tomska and Wolny 2008;Lu et al. 2020;Zaidi et al. 2014), as well as the elimination of contaminants like dyes (Hu et al. 2007;Wang et al. 2021;Tan et al. 2020). Magnetic field effect has been studied in denitrification processes (Benyoucef et al. 2021;Liu et al. 2008) and total nitrogen removal from wastewater (Liu et al. 2008;Łebkowska et al. 2018;Xu et al. 2020). ...
The present study reports on the effect of magnetic field (MF) intensity on the biofiltration of hexane vapors. MF ranging from 0 to 30 mT (millitesla) was used to evaluate the biofiltration of hexane for 191 days under a fixed inlet load of 40 g m⁻³ h⁻¹. A homogeneous MF generated by Helmholtz coils was used. The performance of the reactors was evaluated in terms of removal efficiency (RE), elimination capacity (EC), biomass content, and exopolysaccharide (EPS) production. Maximal removal efficiencies of 25%, 36%, and 40% were found for the control (H0), 10 mT (H10), and 30 mT (H30) reactors, corresponding to ECs of 14.2, 15, and 18 g m⁻³ h⁻¹, respectively. In the last period (days 94 to 162), H10 and H30 showed 40% of RE improvement compared with Ho. Also, the removal occurred all along the bioreactor height for biofilters exposed to MF. Reactors achieved a total biomass content of 152, 180, and 147 mg VS (volatile solids) g⁻¹ dry perlite for H0, H10, and H30, correspondingly, associated with EPS production of 30, 30, and 40 mg EPS g⁻¹VS. The main components of EPS affected by the MF were carbohydrates and glucuronic acid; proteins were slightly affected. Experiments with MF pulses of 4 and 2 h confirmed that MF exposure improved the removal efficiency of hexane, and after the pulse, removal enhancement was maintained for 5 days. Thus, the MF application by pulses could be an economically and friendly technology to improve the RE of volatile organic compounds (VOCs).
... The bulk magnet system achieved performance values of 100% removal, showing a higher separation for Fe(II); Mn(II) Removal: Fe (98.7%); Mn (92.5%) [15], [16]. ...
Human society and environment are based on water resources. Hard water with iron and manganese excess is spread across the world and softening of drinking water is widely applied for reasons of public health, client comfort, economic and environmental benefits. Also, from industrial or commercial point of view, using it produce scale deposits in water systems and equipment often result in ample technical and economic problems. Solutions of reducing its hardness and iron/manganese excess exists on the market, even with the substances presented in the work. The novelty this study brings comes from using high intensity permanent magnets arrangements and CO2 nanobubbles treatment that increased the speed, the volume of treatment, while decreasing the energy and complexity of the installation, also decreasing the pollution mark of the system. The detrimental contributions of softening, in particular the use of chemicals and energy, are taken into account in the carbon footprint of the drinking water companies. The beneficial contributions have not been included in the carbon footprint. For carbon capture in the crystallized calcite and dissolution of CO2 into the softened water, the carbon footprint is compensated by the net carbon benefit of softening.
... N with maximum removal of 97.35%.Sa'at (2006) explained the proportional relationship between the magnetic field and the removal efficiency as the magnetic field strength increases the magnetic force, which subsequently enhances the removal efficiency. The magnetic field enhances the movement of particles and aggregation process subsequently large flocs are produced. These heavy an ...
Leachate produced from sanitary landfill should be treated before discharge into the environment, whereas it contains high concentrations of organic pollutants and high counts of pathogenic microorganisms. A bench-scale treatment unit was designed to study the effects of low-strength magnetic field on the physicochemical and bacterial properties of landfill leachate using three different magnetic intensities (120, 240 and 360 μT). Also, the effect of contact time was examined. Characterization of raw leachate showed high concentrations of organic pollutants and conductivity as well as high counts of both total bacterial count and total coliforms. The results showed the ability of magnetic force to improve the quality of leachate. Moreover, it was observed that, by increasing the magnetic intensity, the removal percent of pollutants increased. The magnetic force of 360 μT showed the maximum removal percent of 38.2, 30.5, 16.0, 32.7, 16.0, 45.2 and 41.2% of Biological Oxygen Demand, Chemical Oxygen Demand, Total Suspended Solids, ammonia-nitrogen, conductivity, total bacterial count, and total coliforms, respectively. Depending on the obtained results, the magnetic force can be used as a clean, cheap and eco-friendly pre-treatment technology for the improvement of physicochemical and bacterial properties of landfill leachate.
Adsorption studies of zinc (Zn2+), cadmium (Cd2+) and nickel (Ni2+) from aqueous solutions on corncob (CC) and granular activated carbon (GACC) were carried out. A batch pattern was used to determine the kinetics as well as the adsorption isotherm parameters. The obtained results using either CC or GACC separately were found to be matched with the Langmuir isotherm model. Furthermore, the breakthrough study was conducted using CC, and GACC. This study was extended with wetland technology for the purification of greywater. The main objective of this study the enhancement of the sedimentation tank by coagulants materials (ferric chloride aided with lime) was followed by a hybrid-constructed wetland. The evaluation three hydraulic retention times (HRT) were 24, 48, and 72 h. The obtained results showed the quality of the effluent at 72 h was found to be complying with the EEAA limits (2nd) for treated effluent reuse. Keywords; Heavy metals; corncob; activated carbon; adsorption, agricultural waste, subsurface constructed wetland; free water surface; sedimentation tank; coagulants materials.
Water pollution is a global problem. During current study, ammonia, phosphate, phenol, and copper(II) were removed from aqueous solution by subsurface and surface flow constructed wetland. In current investigation, distilled water was polluted with four contaminants including ammonia, phosphate, copper (Cu), and phenol. Response surface methodology and central composite design were applied to optimize pollutant removal during treatment by subsurface flow constructed wetland (SSFCW). Contact time (12 to 80 h) and initial pollutant concentration (20 to 85 mg/L) were selected as independent factors; some upper and lower ranges were also monitored for accuracy. In SSFCW, water hyacinth transplanted in two substrate layers, namely zeolite and cockle shell. SSFCW removed 87.7, 81.4, 74.7, and 54.9% of ammonia, phosphate, Cu, and phenol, respectively, at optimum contact time (64.5 h) and initial pollutant concentration (69.2 mg/L). Aqueous solution was moved to a surface flow constructed wetland (SFCW) after treating via SSFCW at optimum conditions. In SFCW, Typha was transplanted to a fixed powdered substrate layer, including bentonite, zeolite, and cockle shell. SFCW could develop performance of this combined system and could improve elimination efficacy of the four contaminants to 99.99%. So this combined CW showed a good performance in removing pollutants.
Graphical abstractWetlands arrangement for treating aqueous solution in current study
Sanitary landfills are the most widely utilized method of solid waste disposal around the world. With increased use and public awareness of this method of disposal, there is much concern with respect to the pollution potential of the landfill leachate. Depending on the composition and extent of decomposition of the refuse and hydrological factors, the leachate may become highly contaminated. As leachate migrates away from a landfill, it may cause serious pollution to the groundwater aquifer as well as adjacent surface waters. There is growing concern about surface and groundwater pollution from leachate. Better understanding and prediction of leachate generation, containment, and treatment are needed. This book contains a literature review of various methodologies that have been developed for prediction, generation, characterization, containment, control, and treatment of leachate from sanitary landfills. The contents of this book are divided into nine chapters. Each chapter contains theory and definition of the important design parameters, literature review, example calculations, and references. Chapter 1 is devoted to basic facts of solid waste problems current status and future trends towards waste reduction and recycling. Chapter 2 provides a general overview of municipal solid waste generation, collection, transport, resource recovery and reuse, and disposal options. The current status of sanitary landfill design and operation, problems associated with the landfilling, and future trends are presented in Chapter 3. Methods of enhanced stabilization, recycling landfill space, methane recovery, and above grade landfilling, and closure and post closure care of completed landfills are also discussed in detail. Chapter 4 provides a general overview of Subtitle D regulations and its impact upon sanitary landfilling practices. Chapter 5 is devoted entirely to moisture routing and leachate generation mechanisms. Examples of calculation pr.
Leachate poses a number of environmental problems. This is due primarily to the extreme variability of sources of this material, and, therefore, the heterogeneity of its composition. Operating and closed landfills generate leachate whose quality and quantity depend on how the landfill was constructed, operated and ultimately closed. Currently, a number of options exist for the containment and treatment of this type of wastewater. The methodology presented here utilizes surface-flow constructed wetlands for treatment and disposal of leachate and leachate-contaminated groundwater at the Chunchula, Alabama closed landfill. The final goal was to provide effluent water quality standards to conform to Federal National Pollution Discharge Elimination System (NPDES) guidelines.
Several pilot wetlands have been constructed in Queensland to treat municipal wastewater. The wetlands are in tropical, subtropical and arid geographical locations. Most wetlands are free water surface and contain a variety of macrophyte types and species. A total of 49 native and 11 exotic species of wetland plants have been identified. This paper examines tissue nutrient content in different species and plant components from 7 wetlands.
Most species translocated to the constructed wetlands flourished indicating their ability to tolerate nutrient enriched waters, and tended to have higher tissue nutrient concentrations than their controls in natural wetlands. Submerged and free floating species exhibited higher nutrient concentrations than floating leaved and emergent species. Maximum dry weight nutrient concentrations (mg.g−1) were recorded in duckweed 18 mgP.g−1; 58 mgN.g−1; Ceratophyllum 14 mgP.g−1, 35 mgN.g−1; Monochoria cyanea (a native relative of the water hyacinth) 13 mgP.g−1, 30 mgN.g−1; waterlilies: Nymphoides indica 16 mgP.g−1, 40 mgN.g−1; aquatic vines Ipomoea diamantinensis 10 mgP.g−1, 53 mgN.g−1, I. aquatica 9.5 mgP.g−1, 53 mgN.g−1; Ludwigia peploides 10 mgP.g−1, 52 mgN.g−1; and the water ferns Ceratopteris thalictroides 10 mgP.g−1, 31 mgN.g−1,Marsilea 10 mgP.g−1, 43 mgN.g−1. Emergent species with the highest nutrients (P or N) were Eleocharis sphacelata 9.4 mgP.g−1, 31.7 mgN.g−1, Baumea articulata 8.7 mgP.g−1, 24 mgN.g−1,Typha domingensis 7.2 mgP.g−1, 51.8 mgN.g−1 and Cyperus involucratus 7 mgP.g−1, 44.6 mgN.g−1.
Pooled data showed no significant difference between tissue nutrient content in plant components, though nitrogen was highest in the leaves and phosphorus highest in the roots of most species. There was some evidence of spatial variation in tissue nutrient content between different wetlands but it has not been possible to correlate this with nutrient loadings or removal efficiencies.
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