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Standard Methods for the Examination of Water and Wastewater
... For the physicochemical characterization of FVW and digestates, pH was determined according to Fernández [24]. Moisture content, total solids (TS), fixed solids (FS), and volatile solids (VS) were estimated according to standard methods [25]. Nitrogen content was determined using the Kjeldahl method according to NMX-AA-026- SCFI-2001 [26]. ...
... The chemical oxygen demand (COD) and carbohydrates were quantified using colorimetric techniques reported by Eaton et al. [25] and Goel et al. [27], respectively. These analyses were applied to a 1 g·L −1 suspension of dried FVW. ...
... The ranges were established so that one (∅3) included the particle size of 391 µm, where methanogenic inhibition due to intermediate accumulation during the AD of food waste was observed [18], along with two larger ranges (∅1 and ∅2) and one smaller (∅4). The smallest interval was selected to analyze the AD of particles at the threshold (0.45-2 µm) between suspended and dissolved solids [25]. ...
This study examines the anaerobic digestion (AD) of fruit and vegetable waste (FVW) and digestates to assess the effect of particle size on anaerobic biodegradability (AB) and process rate at different stages of digestion progress. Batch assays were conducted with FVW mixtures and digestates from 5, 10, and 15 days of digestion, using four particle size ranges: Ø1 < 1.8 µm, 1.8 < Ø2 < 500 µm, 500 < Ø3 < 1000 µm, and Ø4 > 1000 µm. While AB and specific methanogenic activity (SMA) showed no significant differences among FVW mixtures, particle size significantly influenced these variables. Methane yields were 298.2 and 309.8 mL CH4·g−1VS for Ø4 and Ø3 particles, exceeding the 186.7 and 161.8 mL CH4·g−1VS obtained for Ø2 and Ø1, respectively. These results indicate that particle size reduction enhanced methane production; however, reducing the particle size below 500 µm inhibits methanogenesis due to intermediate accumulation. Compared to FVW, digestates exhibited a 23% reduction in AB, a 73.9% decrease in SMA, and methane yields of 55.8–294 mL CH4·g−1VS. Additionally, the surface-based kinetic constant (KSBK) decreased from 0.4523 g·dm−2·d−1 for FVW to 0.0437 g·dm−2·d−1 for digestates. These differences are attributed to the rapid consumption of easily biodegradable fractions within the first 5 days of digestion.
... To reflect the cell growth of S. platensis, the OD 560 value was measured once every two days for a total of seven days (on days 1, 3, 5, 7), using a 721G spectrophotometer at the wavelength of 560 nm. This OD 560 value represents the algae concentration in the fluid (17). ...
... Subsequently, the TN, TP, and COD levels of the SAW were measured before and after treatment to evaluate pollutant removal efficiency. The TN level was determined using the alkaline potassium persulfate digestion UV spectrophotometric method, which involves digesting samples with alkaline potassium persulfate under high temperature (120-124°C), followed by measuring absorbance of the resulting solution with a UV spectrophotometer at a wavelength of 220-275nm (17). The TP level was measured using the ammonium molybdate method. ...
... Samples were digested with potassium peroxydisulfate at 120°C. Absorbance was measured at 700 nm, and TP was quantified via a calibration curve (17). The COD level was determined using the dichromate method, which uses acid-dichromate solution to digest oxidizable substances in the presence of silver sulfate catalyst and determines the COD concentration spectrometrically by measuring the absorbance of the Cr 3+ formed at a wavelength of 600-610nm (17). ...
The contamination of water bodies by untreated agricultural wastewater is a major global issue. Traditional centralized treatment methods, including sedimentation tanks and photocatalytic degradation modules, which are commonly employed in economically developed areas such as Shanghai, present significant challenges for implementation in remote regions due to cost and technological limitations. Consequently, there is a pressing need for cost-effective alternatives in these less accessible areas. In this study, we hypothesized that Spirulina platensis, a species of cyanobacterial microalgae, has the potential to thrive in and purify agricultural wastewater, as has been previously reported for other cyanobacterial microalgae. Firstly, we conducted a comparative analysis of S. platensis growth in simulated agricultural wastewater (SAW) and a standard medium, Zarrouk’s medium, to assess its adaptability to the growth conditions of SAW. Subsequently, utilizing total nitrogen, total phosphorus, and chemical oxygen demand as indicators for the purification of agricultural wastewater, we examined the efficacy of S. platensis in treating SAW. Our findings indicate that S. platensis is capable of reducing the concentration of each pollutant. However, the S. platensis–based treatment methods may be constrained by the potential toxicity of SAW with elevated nitrogen levels, necessitating additional research and development. This research offers a novel approach to cost-effective agricultural wastewater purification.
... Hal ini dikarenakan kelebihan sisa klorin yang terlalu tinggi dapat menimbulkan penyakit yang lebih parah. Penambahan kaporit harus sesuai dengan hasil yang didapat dari Break Point Chlorination (BPC) karena bila kurang dari hasil yang didapatkan akan mengakibatkan mikroorganisme yang ada di dalam air kolam renang tidak dapat tereduksi sempurna dan bila kelebihan penambahan kaporit bisa menyebabkan rasa gatal pada kulit akibat reaksi dari kalsium hipoklorit yang berlebih [10] dan menyebabkan bau yang sangat menyengat dari phenol [11]. ...
... Biasanya, es yang dibuat dari air mentah adalah es Balok. Es batu ini jelas-jelas tidak baik dikonsumsi, terlebih lagi jika airnya diambil dari air sungai yang tercemar [11]. Sejalan dengan pendapat tersebut bahwa penggunaan air es batu yang tidak diolah terlebih dahulu memiliki bahaya bagi konsumennya. ...
Water is one of the necessities of life and is the basis for life on earth. Water can be in the form of solids, liquids, and gases. Ice cubes are a food product that is well known to the general public and is considered safe for consumption. But prone to contain chlorine. The presence of chlorine in water is considered to have a high correlation to cause diseases, one of which is bladder cancer. Determine the content of chlorine levels in ice cubes required laboratory examination. The purpose of the study was to determine the level of chlorine in ice cubes on Jalan Prof. Dr. Soepomo, Yogyakarta City. The type of research is descriptive qualitative. Taking 30 samples of ice cubes from beverage traders then conducting laboratory tests to identify the phenomena and characteristics that exist in ice cubes and conducting interviews with 5 representatives of beverage traders to strengthen laboratory results. The results of the analysis showed that the chlorine content in ice cubes from thirty samples taken from Jalan Prof. Dr. Soepomo Yogyakarta City was <0.03 mg/L. All of them are under the standard of the Regulation of the Minister of Health of the Republic of Indonesia Number 492/MENKES/PER/IV/2010 concerning the requirements for the quality of clean water or drinking water that has been set at 0.2-0.5 mg/L. The results of the interview that the source of water used by the ice cube maker is direct PDAM water and refilled water. The water is directly processed in ice cube packs without going through the first procprocessanwhile, the source of mineral water refills for ice cube makers first buys refilled water that is ready for consumption. This will make the ice cubes not free from disease and bacteria contained in the ice cubes. There is a chlorine content of < 0.03 mh/L in ice cubes on Jalan Prof. Dr. Soepomo, Yogyakarta City.
... 1) Spectrophotometric method (Clesceri et al., 1998). Dissolved ozone in organic-free water can be measured by UV-Visible spectrophotometer. ...
... This method was also cited by Bader et al. (1988) as well. 4) Indigo titration method (Clesceri et al., 1998). This method is similar to the DPD colorimetric method in the sense that it is also primarily used to measure the chlorine levels, but the reagents react with an oxidizer present. ...
This report contains the progressing of my PhD study.
... Ammonia, total nitrogen, and COD t were measured via spectrophotometry (absorbance measurement) using a Hach DR3900 spectrophotometer and Hach high-range test kits for ammonia, total alkalinity, volatile acids, COD, total nitrogen (TN) and total Kjeldahl nitrogen (TKN) (Hach Company, London, ON, Canada). The total solids (TS) and VS of the effluent, as well as the elemental analysis of feedstock, including C, H, N, O, and S, were determined following standard protocols [36]. Physicochemical analyses were performed on digesters' liquor samples one hour before feeding. ...
Anaerobic digestion (AD) has gained broad interest as a sustainable organic waste management and resource recovery method. However, the complexity of the AD process could pose serious risks in real-scale applications. One of the most critical phases in the operation of AD systems is the start-up phase, including the seeding strategy of the digesters. This study aims to assess the effect of digestate post-treatment before seeding on the start-up of thermophilic AD systems. Two anaerobic digesters (R1 and R2) were started using two different thermophilic inocula and were kept operational for 17 weeks under identical conditions. Lab digesters were seeded with digestates sampled from a thermophilic full-scale reactor (R2) and a post-treatment mesophilic tank (R1). The start-up strategies exhibited satisfactory stability and high productivity, achieving mean weekly methane-based biodegradability rates of 61 and 64% of the feed’s theoretical biomethane potential (BMP), respectively, in R1 and R2. However, R2 showed greater resilience to high and sudden organic loads applications, making it more suitable for rapid and aggressive start-ups. These results are expected to assist full-scale anaerobic digester operators in selecting an appropriate inoculum based on the characteristics of its source.
... Titrimetric approach (5220-C; closed-reflux) was applied for measurement of chemical oxygen demand (COD) as reported in the standard methods 25 . Also, BOD 5 (5210-D; Respirometric Method), TOC (5310-B; High-Temperature Combustion Method), total nitrogen 26 and phosphorus 27 measured based on previous studies. ...
Improving the quality of biologically treated effluent could encourage the reuse of wastewater. It is uncommon to use enhanced electrochemical oxidation techniques to improve effluent. Using hydrothermal reaction with complicated precipitation, the work generated FTO-TiO2/Ni anodes and analyzed them with the following methods: TEM, FESEM, EDS, elemental mapping, XRD, FTIR, and CV analysis. A 500 mL sono-electrocatalyst process reactor was used with central composite design in order to achieve the greatest decrease in COD. The reaction kinetics, synergistic effect of mechanisms, physicochemical properties of wastewater after the process, energy efficiency, and toxicity of wastewater were all investigated under ideal conditions. The anode electrode analyses indicate that the synthesis is sufficient. The quadratic model is noteworthy because of the P-value (0.0001) and the F-value (600.39). The correlation coefficients were much greater than the values obtained for the other model. The experimental settings were pH 7.1, 74.4 mA/cm² DC power, 15 mW/cm² applied USI, and a reaction time of 112 min (COD reduction = 81.5%). Chemical reactions follow first-order kinetics (R² = 0.99). The synergistic coefficients for the pathways were 1.6 for COD, 2.2 for BOD5, and 1.5 for TOC. After 300 min, the energy efficiency was 1.07 kWh/m³, and the toxicity of the effluent was reduced to 5%. The above technique was shown to be a feasible advanced treatment that can improve effluent discharge, according to this study.
... The TS and VS were determined according to the standard methods [29]. Cellulose, hemicellulose, and lignin content were analyzed following protocols established by the National Renewable Energy Laboratory (NREL) [30]. ...
... The samples collected (extracts from filter samplers and collection liquid from BioSamplers) after specific tests were cultivated using the standard spread plate technique (Greenberg et al. 1992) to determine the culturable count of the sample, and these data were then used to calculate bacterial culturability. For the culture-based analysis, an aliquot of 0.1 mL collection liquid from BioSampler was spread onto the TSA plates after 100-, 1000-, and 10,000fold dilution, while the 10-and 100-fold dilutions of filter extracts were applied. ...
Background
Airborne pathogenic bacteria sampling is critical for microbial risk assessment. The stress induced by sampling methods such as filtration and liquid impingement can affect the bioactivity and integrity of collected microbial samples, but the roles of sampling time, media, and replenishment strategies remain unclear.
Methods
This study evaluated the culturability, viability, and DNA loss percentage (DLP) of collected Escherichia coli using two common sampling techniques: filter-based sampling (Button Sampler) with two filter types (mixed cellulose ester (MCE) and polycarbonate (PC)) and liquid impingement-based sampling (BioSampler) with three collection media (DI water, PBS, and a Tween mixture (TM)). Sampling times ranged from 0 to 120 minutes. Replenishment effects were assessed for liquid impingement-based sampling.
Results
Longer sampling times significantly reduced bacterial culturability and viability across all methods. MCE filters showed better performance than PC filters, with lower DLP. TM as the impingement medium with replenishment preserved the highest viability (89.91%) and culturability (69.64%) at 120 min, with the lowest reaerosolization loss (0.12%) and DLP (36.27%). DLP was negatively correlated with viability (r = –0.762, p 0.01) and culturability (r = – 0.638, p 0.01).
Conclusions
Sampling media, replenishment, and time substantially affect the bioactivity and DLP of collected microbial sample. TM-based BioSampler with replenishment is preferable for environmentally sensitive bacteria. Sampling time should be minimized to reduce DNA loss and ensure microbial viability and culturability.
Graphical abstract
... The total Cr (VI) content was calculated according to the colorimetric method of Clesceri et al. (1998), as described by Bouhadi et al. (2024a). Briefly, a 0.5 g dry plant material sample was incinerated in an oven at 600 °C for 5 h and the ash was recovered in 3 ml hydrochloric acid (6 N), then diluted in distilled water and filtered. ...
The expression of genes coding for stress proteins in plants, plays a very important role in the enhancement of tolerance, resistance and efficiency of defense system in plants under various types of stress (biotic or abiotic) especially the antioxidant system. The aim of our work was to study and evaluate the effect of chromium (VI) on the expression of some stress genes such as Hsp70.1 (Heat-shock-proteins), MT2 (Metallothionein-2), GR1 (Glutathione-reductase), Cu-ZnSOD (Superoxide-dismutase) and Cat (Catalase), in the roots of Vicia faba L. The results shown that chromium (VI) negatively affects Vicia faba L. root growth by reducing length and fresh biomass. On the other hand, it induces the overproduction of H 2 O 2 , MDA and stimulates the expression of stress-related genes. However, we noticed that the accumulation of Cat, GR, and Cu ZnSOD transcripts was maximal for a short duration of exposure, but after 24 h the accumulation starts to decrease, it is assumed that there is a threshold where the accumulation can be maximal (low chromium (VI) dose and short duration of exposure).
... After incubation, aliquots were collected every 48 h (equivalent to one cycle) for six cycles and then centrifuged at 7000 rpm for 10 min. The elimination of hexavalent chromium in the supernatant was determined by monitoring the decrease in its concentration over time using S-diphenylcarbazide (DPC 0.25% (w/v) (Greenberg et al. 1992). The DPC-Cr(VI) complex in an acidic medium produces a purple color, which was measured at 540 nm. ...
The microbial reduction of hexavalent chromium (Cr(VI)), particularly by bacteria, has been extensively studied, revealing varying removal mechanisms among different strains. This investigation identified a novel bacterial strain, Staphylococcus succinus subsp. Succinus AMG-D1, which was isolated from mining soil and Cr(VI)-resistant. This strain demonstrated the capability to completely remove a high concentration of 200 mg/L Cr(VI) within 120 h at pH 7 and 35 °C. Moreover, it effectively reduced repeated contamination of 100 mg/L Cr(VI). Scanning electron microscopy analysis confirmed the strain's high resistance to Cr(VI), coupled with the secretion of a viscous material, possibly metal-adsorbing exopolysaccharides. Energy dispersive X-ray peaks analysis revealed characteristic chromium peaks, indicating the presence of adsorbed Cr(VI) and/or precipitated species of reduced chromium (Cr(III)). Further investigations into Cr(VI) removal mechanisms have revealed a detoxification process involving adsorption, accumulation, and enzymatically mediated biological reduction. This reduction predominantly occurs through constitutive cytoplasmic proteins. Moreover, a protein with a molecular weight of approximately 30 kDa was identified on an SDS-PAGE gel, potentially responsible for Cr(VI) reduction. The remarkable resistance and substantial reduction capabilities of Staphylococcus succinus position it as a promising strain for bioremediation applications.
... The aquarium water was aerated through stone diffusers connected to a mechanical air compressor continuously. Throughout the study period water temperature was maintained between 25±2 C. W ater quality parameters were kept sustained according to American Public Health Association (APHA) standards (Clesceri et al., 1989). Fishes were fed with commercial fish pellets during the acclimatized period. ...
Background: Most industrial toxic effluents and human-made discharges eventually find their way into aquatic ecosystems (No, 2021; OECD, 2024). With rapid global economic development, the large-scale emission of heavy metals has become particularly concerning (Kumar et al., 2018; Shao et al., 2014). The frequent release of these excessive pollutants into water bodies has detrimental effects on aquatic life. To assess fish toxicity, contemporary and standardized acute toxicity tests are frequently employed, proving highly effective in environmental risk assessment. For example, the lethal concentration (LC50) is widely recognized worldwide as a valuable tool for studying environmental toxicology. The test for quantifying the diversified effects of this toxicant is thus immensely essential to maintain the water quality standard and to assume the effects of toxicant to the aquatic organism. Method: In this study, two ornamental fishes i.e., Pethia, commonly called as rosy barb that belongs to order- cypriniformes and Hyphessobrycon commonly known as Buenos Aires Tetra that belongs to order-characiformes were used as test organisms. They were exposed to different concentrations of lead. Rosy barb was exposed to 250, 275, 300, 325, 350 mg/L of lead and 365, 375, 385, 395 and 405 mg/l in case of tetra along with control in both the species having no metal toxicant and with all the conditions constant. Results: The 50% lethal concentration (LC50) was 565mg/l after 24h, 525mg/l after 48h and 389mg/l after 72h for Rosy Barb and 380 mg/l after 24h, 355 mg/l after 48h and 347 mg/l after 72h for BA Tetra. Rosy Barb was detected with higher LC50 values and showed higher resistance than BA Tetra. Presence of more keratinized structure and having larger body size than tetras may be the possible cause behind this.
... The MC, TS, VTS, pH, EC, TA, and VFA were determined following the American Public Health Association (APHA) standard procedures [34]. COD and N-NO 3 analyses were conducted using a DR3900 spectrophotometer (Hach, Loveland, CO, USA), with test kits supplied by Alfakit. ...
Aquaponics integrates aquaculture and hydroponics, promoting circularity through the recirculation of water and nutrients. However, waste management remains a challenge. This study aimed to evaluate the anaerobic digestion (AD) of aquaponic effluent (AE) combined with cattle manure (CM) for biogas production. An Indian model biodigester was fed with AE, CM and 1:1, 1:3, and 3:1 W (Water):CM, under anaerobic mono-digestion (MoAD) and 1:1, 1:3, and 3:1 AE:CM under anaerobic co-digestion (CoAD) conditions. The chemical characteristics of the substrates and digestates were assessed, as well as the potential for biogas production over 19 weeks. Overall, CoAD provided better results regarding the chemical characterization of the substrates aimed at biogas production. Notably, the 1:3 AE:CM ratio resulted in the most promising outcomes among the tested conditions. This ratio demonstrated higher efficiency, initiating biogas production by the third week and reaching the highest accumulated volume. It is probable that AE increased the dissolved organic load, optimizing the conversion of organic matter and eliminating the need for additional water in the process. Thus, the CoAD of AE and CM emerged as a promising alternative for waste valorization in aquaponics, contributing to renewable energy generation, agricultural sustainability, and the promotion of the circular economy.
... TS, VS, pH, chemical oxygen demand (COD), and ammonia nitrogen (NH 3 -N and NH 4 + -N) were analyzed using standard methods [81,82]. NH 4 + -N measurements were conducted under constant temperature conditions. ...
Anaerobic digestion (AD) is a preferred method for food waste (FW) treatment due to its sustainability and potential for production of renewable bioenergy. However, the accumulation of volatile fatty acids (VFAs) and ammonia often destabilizes the AD process, and managing the digestate byproduct poses additional challenges. This study investigates the use of co-pyrolysis biochar synthesized from digestate and rice straw (DRB) to enhance methane production and AD efficiency. DRB addition increased cumulative methane yield by 37.1%, improved VFA conversion efficiency, and achieved a 42.3% higher NH3-N-removal rate compared to the control group. The COD-removal rate was 68.7% throughout the process. Microbial analysis revealed that DRB selectively enriched Fastidiosipila and Methanosarcina, promoting direct interspecies electron transfer (DIET) and methane yield. These findings highlight DRB’s potential to enhance AD efficiency and support closed-loop resource utilization.
... Water samples were taken from the majority of springs along both sides of the Alice Tableland (outcrop and artesian), as close as possible to the discharge vent, and analysed for major ions following procedures in Clesceri et al. (1998). Analytical uncertainties are ± 5 % or less. ...
... Total Kjeldahl Nitrogen (TKN) was determined for the liquor following APHA 4500-N org -B method (Clesceri et al., 1999). Phosphorus, phosphate, ammonium, and nitrate contents were determined through spectrophotometric methods using Hach® DR6000™ UV-Vis Spectrophotometer. ...
... For water quality monitoring, ten sites along the Awash irrigation schemes diversion points across the low, medium, and high flow seasons were collected following Guidelines: NSW-EPA (2022); NSW-EPA-2 (2022); Rice et al. (2017); Greenberg et al. (1992) to be used for generation and analyses of various quality metrics. ...
Article history: Recent data on the water quality and suitability dynamics of the Awash River, Ethiopia's most heavily used river for irrigated agriculture, with water that spatiotemporally varies in the transport pathways, is scarce. Increasing anthropogenic activities and the effects of climate change are exacerbating concerns about salinity and water quality degradation, presenting significant challenges for the sustainable management of the Awash River This study addresses these issues by using big data analytics and Geo-spatial Sci-tech to assess water quality in a robust framework, enabling precise, timely insights essential for sustainable irrigation management. The vast volume, high velocity, and complex variety of big data including pH, EC, and ion concentrations align well with these demands. Leveraging geospatial analysis, this research valorized extensive data from ten water quality monitoring stations over a period of twenty years for tracking and visualizing water quality trends across time and space. A slightly to moderately alkaline pH, between 7.4 and 8.4, was observed in the results, while EC ranged from 0.209 to 1.161dS/m between 2004 and 2019. Ion concentrations generally followed the northward sequence of Ca²⁺ > Na⁺ > Mg²⁺ > K⁺, HCO₃⁻ > Cl⁻ > SO₄²⁻, and Na⁺ > Ca²⁺ > Mg²⁺ > K⁺. Spatial trend analysis demonstrated a positive progression of ECw, SAR, RSC, and other ionic constituents, with temporal variations indicating a progressive decline in water quality, largely due to human activities. The findings also indicated slight to moderate sodicity hazards across samples. These spatio-temporal variations underscore the importance of using updated water quality evaluations and spatiotemporal analysis to inform water management strategies.
... According to Hargreaves (2013), Imhoff or settling cones are a simple means of indexing suspended solid concentration. Biofloc density measurements were conducted using Imhoff cones, following the methodology described by Eaton et al. (1995) and adapted by Avnimelech (2007). Solids were also measured using a turbidity meter (Hargreaves 2013). ...
Three recirculation systems – aquaponics (Aqua), aquaponics with bioflocs (AquaFloc), and hydroponics (Hydro) – were established to evaluate lettuce production (floating) over 45 days. Juveniles of hybrid tambacus kept in aquaponic tanks were fed commercial feed. Water quality was monitored and vegetable growth was assessed. Metrics of lettuce, such as head diameter, height, fresh matter, dry matter, number of leaves, and chlorophyll concentration, were significantly higher (p < 0.05) in the Hydro system than in the AquaFloc system even after 60 days. The AquaFloc system exhibited 62% fish survival, significantly lower (p < 0.05) ammonia and nitrite concentrations than Hydro, and an absence of nitrate. Electrical conductivity and total dissolved solids concentration were significantly lower (p < 0.05) in AquaFloc than in Hydro, while pH levels were significantly higher (p < 0.05) in both Aqua and AquaFloc, resulting in reduced nutrient availability for plant growth. The Aqua system showed no lettuce growth and experienced complete fish mortality. The fish-to-vegetable ratio used did not meet the nutritional demands of lettuce. Further studies are needed to determine an appropriate fish-to-vegetable ratio that provides sufficient nutrients to plants in aquaponics, along with the maintenance of optimal pH control.
... The samples collected (extracts from lter samplers and collection liquid from BioSamplers) after speci c tests were cultivated using the standard spread plate technique (Greenberg et al., 1992) to determine the culturable count of the sample, and these data were then used to calculate bacterial culturability. For the culture-based analysis, an aliquot of 0.1 mL collection liquid from BioSampler was spread onto the TSA plates after 100-, 1000-, and 10000-fold dilution, while the 10-and 100-fold dilutions of lter extracts were applied. ...
Sampling stress due to impingement and filtration on bioaerosols has been previously evaluated. However, how changes in sampling time, sampling media, and the refilling of liquid during impingement sampling affect the viability, culturability, and DNA concentrations of collected airborne bacteria remains largely unknown. This information is crucial for air sampling of pathogenic bacteria and subsequent analysis by molecular methods during microbial outbreak in communities. This study aimed to address these knowledge gaps by testing Escherichia coli collected over 15 to 120 minutes on filters of Button Samplers and in the liquid media of BioSamplers, with the collection liquid either replenished at 15-minute intervals or not replenished. The results indicate that changes in simulated sampling times, media, and the replenishment of media in impingement sampling can significantly influence the recovered quantity of viable and culturable bacteria, as well as DNA concentrations. It was found that using a BioSampler with Tween mixture (TM) solution replenishment can lead to a reaerosolization loss of 0.12% at a sampling time of 120 minutes. For filter-based sampling, the results show that both mixed cellulose ester (MCE) and polycarbonate (PC) filters imposed high stress on bacterial cells, leading to greater DNA losses. However, MCE filters were found to be more suitable for 120-minute sampling, as they achieved better bacterial viability and culturability, with a DNA loss percentage (DLP) of 61.16%. The DLP was found to be negatively correlated with viability (r = -0.762, p < 0.01) and culturability (r = -0.638, p < 0.01), respectively. This indicates that cell membrane damages occurred during filter- and liquid impingement-based sampling, resulting in significant DNA losses for microbial analysis. Comparing filter- and liquid impingement-based methods across different sampling times, the results suggest that a BioSampler with TM solution is preferable for sampling E. coli and similar environmentally sensitive pathogenic bacterial species. Additionally, the sampling time should be kept as short as reasonably possible to minimize stress on the collected bacteria.
... Chromium-contaminated soil samples were digested with HNO 3 and HClO 4 (10:1 ratio) on a hot plate as per the standard process (Eaton et al., 1995). Consequently, digested soil samples were filtered using filter paper to obtain filtrates. ...
The present investigation aimed to isolate and identify a novel bacterium from chromium (VI)-contaminated soil samples collected from the Gorbi mine area, Singrauli coalfield, evaluates its potential for Cr(VI) reduction to Cr(III) and enhances environmental and operational conditions to apply this in bioremediation of Cr-contaminated soils. A bacterium was newly isolated from contaminated soils of coal mines for chromium (VI) reduction and identified as Klebsiella sp. (BH-A1) using 16S rRNA gene sequencing. Calcium chloride and sodium alginate solutions were used to immobilize the bacterial cells of isolated Klebsiella sp. Bacteria beads (Klebsiella sp. BH-A1) were tailored to reduce 10 µg/g Cr(VI)-contaminated soil under varied environmental factors such as bead biomass (200–1000 mg), pH (5–8), temperature (25–35 °C), and nutrient sources. Beads of Klebsiella sp. (BH-A1) (1000 mg/g) were efficient for 87% reduction of 10 µg/g Cr(VI) present in the soil at pH 7, 30 °C, within a six-hour contact period. Fourier transform infrared spectroscopy analyses reveal varied functional groups like –OH, –NH, and –COOH in Cr-treated bacterial beads. Functional groups corroborate their involvement in Cr(VI) and Cr(III) absorption on the cell surface of bacteria. Chromium-treated Klebsiella sp. (BH-A1) cell size was wider due to chromium absorption than the non-treated bacterial cells after SEM analyses. The energy dispersive X-ray plot has proven the 0.41 weight percent chromium accumulation inside the bacterial cells. Moreover, XPS analyses of Cr-treated bacterial cells indicate reduced Cr(VI) into Cr(III). The finding further suggests that Klebsiella sp. (BH-A1) might be a new prospect for potential application in Cr detoxification from Cr-contaminated soil. The limitations of this research include the accumulation of hazardous metabolic products due to low diffusion rates, the formation of thick biofilms blocking bead pores, and interrupted substrate transport from the bulk liquid to immobilized cells.
... Chloride was extracted from the ground plant tissue using water at 85°C. The determination of Clin both the plant tissue extracts and the nutrient solutions was performed by titration with AgNO 3 in the presence of K 2 CrO 4 (EATON et al. 1995). The nutrient concentrations aimed at monitoring the nutrient supply were measured as described previously (SAVVAS and GIZAS 2002). ...
Four different NaCl concentrations (0.8, 5.0, 10 and 15 mM) in the irrigation water were applied to cucumber (Cucumis sativus cv. Camaron) grown in a closed hydroponic system. These treatments were attained by automatically injecting the required amounts of NaCl into irrigation water containing 0.8 mM NaCl, whenever water was mixed with fertilizers and drainage solution to prepare fresh irrigation solution. Initially, the Na⁺ and Cl⁻ concentrations increased rapidly in both the fresh nutrient solution supplied to the crop and the drainage water, but they were stabilized to maximum levels depending on the treatment at 45-55 days after initiation of solution recycling. It was concluded that the Na⁺ and Cl⁻ concentrations in the root zone were maximized as soon as the Na/water and Cl/water uptake ratios reached equal levels with the NaCl concentration in the irrigation water. Based on these data, relationships between the Na/water or Cl/water uptake ratios and the NaCl concentration in the root zone were established. The leaf Na⁺ and Cl⁻ concentrations were influenced by both the external Na⁺ and Cl⁻ concentrations and the season. The Cl:Na uptake ratio (mol basis) was higher than 1 at low external NaCl concentrations but decreased below 1 as salinity increased, thereby indicating a more rapid decline in the ability of the plant to exclude Na⁺ from the leaves as compared to that for Cl⁻.
... Measurements of some of the physico-chemical properties of the water were done at each sampling site such as the water temperature, velocity, pH, turbidity, total dissolved solids (TDS), conductivity and dissolved oxygen (DO). The values of BOD5, ammonium nitrogen, nitrate nitrogen and soluble reactive phosphorus (SRP) were determined in the laboratory by the azide modification, the nesslerization, the cadmium reduction and the ascorbic acid methods, respectively [22]. The trophic status of the water quality was then evaluated from the main parameters such as conductivity, DO, BOD5, ammoniumnitrogen, nitrate nitrogen and soluble reactive phosphorus according to Leelahakriengkrai and Peerapornpisal [24] The differences in the physical and chemical water properties among sampling sites were tested by using the analysis of variance (ANOVA) and Least Significant Difference (LSD). ...
The distribution of freshwater algae in Mae Ram Stream in Mae Rim District, Chiang Mai Province, Thailand was investigated in June and October of 2019. Benthic diatoms and macroalgae were collected from nine sampling sites located along a stream in the upstream to downstream areas. The physical and chemical water properties at each sampling sites were analysed and classified for the trophic status. The results show that the water temperature ranged between 22.0-30.0 °C, Velocity 0.28-0.79 m/s, Turbidity 2.98-182.33 NTU, pH 7.01-8.02, Total Dissolved Solids 91.93-162.01 mg/l, Conductivity 131.33-249.35 µs/cm-1, DO 4.88-8.02 mg/l, BOD5 0.27-3.47 mg/l, Nitrate 0.29-1.29 mg/l, Ammonium 0.09-0.61 mg/l and Soluble reactive phosphorus 0.27-0.96 mg/l. The trophic status of the water at each sampling site was classified as the oligotrophic to mesotrophic. A total of 111 benthic diatoms were found. The most abundant species were Eolimna minima, Nitzschia sp.1, Achnanthes pusilla, Gomphonema lagenula and Nitzschia palea, respectively. The highest species abundance was recorded for Eolimna minima which was found at all sampling sites, whereas Nitzschia palea was found as a majority group only at the downstream sampling sites. A total of 14 species of macroalgae were found and they were classified into four divisions, Chlorophyta, Cyanophyta, Charophyta and Rhodophyta. The most abundant group was Chlorophyta and the least abundant group was Rhodophyta. Furthermore, Compsopogon spp. (Rhodophyta) was found to be a common species at the downstream sites, whereas Nitella sp. and Chara sp. (Charophyta) were only found at the upstream sampling sites.
... Different water quality parameters, i.e. water temperature, dissolved oxygen (DO), pH, conductivity, transparency and total dissolved solids (TDS), were directly assessed in the field using suitable digital instruments. Simultaneously, analyses of ammonia, nitrite, nitrate, chlorophyll a, phosphate and silicate were performed in a laboratory, adhering to the standard procedures outlined by APHA [19]. ...
Zooplankton diversity serves as a widely utilised ecological indicator of aquatic ecosystems due to the plankton's capacity to promptly adapt to environmental alterations. This study investigates the influence of environmental factors on zooplankton diversity in Al-Asfar Lake, Saudi Arabia. Zooplankton and water samples were seasonally collected from three distinct locations in the lake at different depths: station 1 (intermediate), station 2 (deep) and station 3 (shallow). A total of 39 zooplankton species were identified, comprising 16 Rotifera, 8 Cladocera, 8 Copepoda and 7 Ostracoda. The abundance of Rotifera was found to be highest at 88%, followed by Ostracoda at 6%, Cladocera at 4% and Copepoda at 2%. There was a notable difference in the average density of the zooplankton across seasons and study sites. The total density of zooplankton species showed positive correlations with salinity, chlorophyll a, temperature and transparency while negative correlations were observed with pH, dissolved oxygen, silicates, phosphate, total dissolved solids, nitrate and conductivity. Station 2 had the highest average density of zooplankton while station 3 had the lowest. The ecological status, as determined by various hydrological parameters, indicates that the stations under investigation exhibit either eutrophic or hypereutrophic characteristics. These findings indicate that the discharge of sewage and other domestic pollutants into the lake may lead to a decline in zooplankton diversity.
... For example, decreases in Spartina alterniflora productivity and biomass have been reported at sulfide concentrations of 1-3 mM (30-100 μg mL −1 ) (Koch & Mendelssohn, 1989;Koch et al., 1990), whereas negative impacts on marine organisms (e.g., oyster, clam, shrimp, mussel, and amphipods) and some seagrasses have been reported at even lower (0.05-0.4 mM; 3-13 μg mL −1 ) sulfide concentrations (Abel, 1976;Caldwell, 1975;Carlson et al., 1994;Goodman et al., 1995;Knezovich et al., 1996;Koch, 2001;Michael Kemp et al., 2004;Vismann, 1996). The most common methods for measuring sulfide concentration in porewater involve sampling with suction (sippers) and semipermeable membrane equilibrium (peeper) apparatus (Hesslein, 1976;Keller et al., 2009;Marsh et al., 2005;Teasdale et al., 1995) followed by analytical determination in the lab, either by chemical, colorimetric, or potentiometric titration using a sulfide specific electrode (Cline, 1969;Eaton et al., 1995;Environmental Protection Agency, 1996). Peepers may provide a vertical resolution of 2-3 cm, but with sippers, the vertical resolution may only be 5-10 cm. ...
Soluble sulfide is toxic to many plants and animals and is especially problematic in brackish environments of the coastal zone (e.g., marshes and benthic environments). In addition to traditional techniques for measuring porewater sulfide in marsh and subaqueous systems (peepers, sippers, and centrifugal extraction), over the last decade or so, Indicator of Reduction in Soils (IRIS) has been added to the arsenal of available methods. Soluble sulfide reacts with the Fe oxide coatings on IRIS devices to form gray to black iron monosulfide (FeS) stains and coatings, the color of which is a function of both the concentration of the sulfide and the time of exposure. Challenges in using IRIS for sulfide analysis stem from the fact that the dark FeS colors fade quickly over a period of minutes to hours. During the last few years, significant advances in IRIS technology, as well as recent advances in digital image acquisition and image analysis, have allowed us to develop an IRIS approach for quickly and effectively collecting and quantifying porewater sulfide levels in coastal environments (e.g., subaqueous areas and marshes). This article will introduce new tools for deploying IRIS in subaqueous settings and will also demonstrate the utility of the new digital technology for image acquisition and analysis, as sulfide data from two marsh sites and four subaqueous soil sites are presented and discussed.
... A modified version of the classical ascorbic acid method (Greenberg et al. 1992) was adopted as described here. Following filtration, 15 mL of the water samples were measured and mixed with 2.5 mL of molybdate antimony solution + 1m of ascorbic acid in 20 mL vials and allowed to stand for 10 min to allow for color development (phosphomolybdenum blue reaction). ...
Environmental pollution exacerbates global freshwater scarcity. In Harare, sewage pollution drives freshwater pollution, compromising its quality and security. Here, we uniquely explored the dual role of Lemna aequinoctialis as a phytoindicator and phytoremediator of freshwater quality. Using a purposive sampling strategy targeting common household freshwater abstraction sites in selected communities of Harare (Tafara and Manyame), 12 water samples and an L. aequinoctialis culture were collected from the field and incubated in the laboratory. Biochemical oxygen demand (BOD), electrical conductivity (EC), and potential hydrogen (pH) were determined by probes, while total suspended solids (TSS) and turbidity were analyzed by UV‐Vis Spectrometry. Chemical oxygen demand (COD), nitrates (NOˉ₃), nitrites (NOˉ 2 ), and orthophosphates were analyzed by colorimetric techniques. An analytical balance measured the plant fresh weights and root lengths were measured via microscopy. Akin to ⁺ raw sewage, River B (Tafara) exhibited the highest initial pollutant load; BOD (3.8 mg/L), COD (38 mg/L), TSS (96 mg/L), NOˉ₃ (0.134 mg/L), NOˉ 2 (0.058 mg/L), orthophosphates (0.524 mg/L), turbidity (87 FTU), with notably reduced mean fresh biomass (2.9 g) and root length (7.3 mm) which were moderately and negatively correlated with NOˉ 2 and orthophosphates, respectively. Only EC failed to improve after L. aequinoctialis incubation significantly. Despite spatial‐temporal limitations, we present limited evidence suggesting a potential real‐time, dual utility role that can help track, redress pollution, and suppress algal blooms enhancing public health and transcending the typical role of duckweeds. Long‐term applicability of this phytotechnology requires further attention for sustainable freshwater management in resource‐limited regions like Zimbabwe.
... The filtrates' P 1 concentrations were determined by colorimetry with a continuous flowing analyzer (AA3, Seal, Norderstedt, Germany). The total P concentration was determined by ICP-AES (7000DV, PerkinElmer, Waltham, MA, USA) after concentrated HNO 3 -H 2 SO 4 autoclave digestion [43]. Meanwhile, based on the adsorption isotherm results, the adsorption equilibrium solutions at the initial concentrations of 50, 100, and 300 mg P L −1 were selected to measure the separation and quantification of P species using IC (ICS-600, Thermo scientific, Waltham, MA, USA) [40]. ...
The growing use of ammonium polyphosphate (APP) fertilizer requires an understanding of its soil transformation for sustainable phosphorus (P) management and environmental protection. This study investigated the adsorption characteristics of APP1 (two P species) and APP2 (seven P species) in six soils, comparing them with monoammonium phosphate (MAP). Results revealed that APP adsorption was greater than MAP under low P soil and/or low P addition condition, but was lower under high P soil and high P addition conditions. Generally, APP1 showed greater adsorption than APP2, except in laterite soil rich in iron (Fe) and aluminum (Al) oxides. Polyphosphates in APP, especially pyrophosphate, mainly contributed to total P adsorption and promoted the release of native orthophosphate in soil. Compared to MAP, APP’s chelation altered soil pH and released Fe, Al, and organic carbon, impacting P adsorption. Redundancy analysis indicated that Fe oxide and Olsen-P in acidic soils accounted for 54.5% of the variance in adsorption differences between APP and MAP, while pH and organic matter in calcareous soils explained 49.7%. In conclusion, the adsorption differences between APP and MAP depended on P concentration, APP’s P species distribution, and soil properties, providing valuable insights for optimal P management in sustainable agriculture.
... An AquaSensors DataStick Dissolved Ozone Measurement System was used to record DO 3 values for each trial. The DO 3 concentration reported digitally was verified using the Indigo Method as within 0.1 mg/L [87]. The DO 3 value reported by the probe seemed to change as air or ozone accumulated in its flow cell throughout testing, which caused swings up to 2 ppm after shaking the bubbles free from the flow cell. ...
This paper seeks to evaluate the effect of reaction parameters on iron electrolysis-catalyzed ozonation (ECO) performance as a promising approach for micropollutant removal. ECO is proposed to be an environmentally and economically suitable technology for the removal of biologically recalcitrant organics in wastewater. In this process, iron ions generated via electrolysis of low-carbon steel react with dissolved ozone to produce hydroxyl radicals. The removal of tert-Butyl alcohol (TBA) was selected as a performance indicator based on its significant resistance to direct ozonation compared to hydroxyl radicals, such that TBA removal denotes catalytic breakdown of ozone. TBA removal was measured with an HS-SPME-GC-MS method for precise quantification. ECO performance ranged from 7 to 77% TBA removal (from 0.73 mM initial concentration), varying depending on the tested levels of initial pH of 5, 7, and 9, applied current between 0.065 and 0.470 A, and ozone supply rate between 3.9 and 6.4 g/h. Performance was generally increased by pH, applied current, and ozone generation, converging at high applied current rates. The most efficient use of ozone was observed at pH 9 and 0.323 A, removing 32.2% of TBA per gram of ozone supplied.
... Some physico-chemical parameters as pH and temperature were assessed in-situ using a Hach pH-meter (model HQ11d). Conductivity, salinity and Total Dissolved Solid (TDS) were analysed in the laboratory with a Hach Conductimeter (model HQ14d) according to the standard methodology of the American Public Health Association [12]. ...
Introduction
The management of pig manure in sub-Saharan Africa poses significant challenges. Typically, pig manure is indiscriminately disposed of in urban areas without prior treatment, resulting in adverse environmental consequences such as greenhouse gas (GHG) emissions, and biosecurity risks associated with improper handling. To address these issues, the development of low-cost biodigester systems for pig manure management can ameliorate these negative impacts. The objective of this study was to assess the operational efficiency of a low-cost tubular digester system in the urban area of Yaoundé.
Methodology
Over a period of three months, the digester with a total volume of 2 m³ and a continuous daily organic loading rate (ORL) of 3.945 kg VS/m³ of pig slurry was monitored. Weekly biogas production measurements were taken and data on physico-chemical and microbiological parameters were collected and analysed.
Results
Data obtained during the monitoring period revealed that the digester operated consistently without any risk of inhibition. Biogas production exhibited variations over time, ranging from 0.1 to 0.4 m³ of biogas/Kg VS/D. Furthermore, significant reductions of 82 ± 10.55%, 88 ± 12%, and 83 ± 19% were observed in the levels of volatile solids (VS), chemical oxygen demand (COD), and biochemical oxygen demand (BOD5), respectively. Notably, the process resulted in the significant reduction of certain microbial groups (faecal Coliforms, Escherichia coli, Faecal streptococci, Faecal enterococci, Balantidium coli, Entamoeba coli, Hookworms, Entamoeba histolytica, Trichostrongylus), while others remained unaffected (Gardia spp., Trichuris trichuira, Ascaris sp., Cryptosporidium spp., Strongeloides larva).
Conclusion
This management by anaerobic digestion of pig manure has a double advantage because it not only makes it possible to have an organic fertilizer but also to have an alternative source of energy for cooking within households. However, it is important to note that digestate requires post-treatment before being applied to fields, due to the presence of pathogens.
Graphical Abstract
... Samples were collected into plastic bottles and were transported to the mobile laboratory at the accommodation place, where some of them were filtered by Whatman GF/F glass microfiber filters. Both filtered, and non-filtered samples were stored for further chemical laboratory measurements to be done by standard methods as: Na + , Ca 2+ , Mg 2+ , K + , Cl − , SO 4 2− , HCO 3 − , CO 3 2− ion concentration (Eaton et al., 2005). ...
... Anions and cations were determined according to procedures of ICARDA, (2013). Clesceri et al. (2005) evaluated the soluble levels of Zn, Cu, Ni, Cd, and Pb. Inductively coupled plasma was used to identify the water-soluble components (ICP-JYULTIMA). ...
... The published version will differ from this one as a result of linguistic and technical corrections and layout editing. 3 fecal contamination and water pollution (8,9). Thus, irrigation water contaminated with E. coli supplied to crops is a potential source of contamination of fresh fruits and vegetables (9,10), by coming in contact with the plant foliage or wounds (11) through bioaerosols generated by sprinkler irrigation (12). ...
Research background
Food safety is threatened by the contamination of fresh fruits and vegetables by pathogenic bacteria, among which the particularly widespread ones are coliform bacteria. Due to the continuous increase in the incidence of severe diseases caused by the consumption of fresh (tomato) fruits contaminated with Escherichia coli, antimicrobial postharvest measures are needed. The problem is that many active antimicrobial compounds have a weak and short-lasting effect and/or are not environmentally friendly. Recently, the antibacterial and antifungal activity of environmentally friendly agent phenylboronic acid (PBA), including on two tomato pathogens, has been reported.
Experimental approach
The aim of this study is to determine the antibacterial effect of PBA on E. coli and three enteropathogenic Enterobacterales, and to check its ability to serve as a bacterial decontaminant of fresh tomato fruits.
Results and conclusions
The minimum inhibitory concentration (MIC) of PBA against E. coli, as well as Shigella sonnei, Salmonella enteritidis and Yersinia enterocolitica was 1.0, 1.2, 1.0 and 0.8 mg/mL, respectively. In addition, we have shown that PBA has a bacteriostatic effect on E. coli at lower concentrations and a bactericidal effect at higher (>3.0 mg/mL) concentrations. Importantly, the study found that an E. coli strain resistant to seven commonly used antibiotics, as well as strains producing extended-spectrum beta-lactamases (ESBL), is as sensitive to PBA as the wild-type strain without any resistance, suggesting that the mechanism of action of PBA differs from that of all these antibiotics. Finally, we have shown that washing and incubating contaminated tomato fruits in PBA solution reduces the growth of E. coli washed from fresh tomato fruits in a concentration- (0.5–3.0 mg/mL) and time-dependent manner, while having no adverse effect on the tomato fruits.
Novelty and scientific contribution
This is the first report on the antibacterial effect of PBA on medically important bacteria E. coli, S. enteritidis, S. sonnei and Y. enterocolitica. Moreover, we show that PBA kills multidrug-resistant E. coli, including those producing ESBL, making it a promising agent against such bacteria. Finally, PBA is shown to be an effective decontaminant of E. coli on fresh tomato fruits.
This study focuses on the use of vinasse in agriculture. The study was carried out during the 2022-2023 first agricultural season. Vinasse and soil characterisation were conducted using standard methods. Plant morphological parameters were measured. The results of the physicochemical parameters of the vinasse indicated an effluent with a deep colour (4757±2139.46 Pt/co) ; with an acid pH (5.46±1.07). Three forms of nitrogen were measured in the vinasse: Ammonium (NH4+) with a concentration of 32.49±7.17 g/l; Nitrites (N02-) 0.69±0.38g/l and Nitrates (N03-) 151.13±57.82g/l. The available phosphorus content (PO43-) was 16.62±8.93 g/l in the effluent. The average Chemical Oxygen Demand (COD) content was 81.13±78.94 g/l, while the Biological Oxygen Demand (BOD5) content was 11.53±6.85 g/l. Potassium ion (K+) was 2.12±0.78 g/l. Soil characteristics according to each treatment showed a pH variation from 3.65±0.071 to 5.73±0.70 in all treatments. Nitrogen concentrations were high in treatments T3 and T5. The carbon to nitrogen ratio was high in treatments T01, T1 and T3. Cation exchange capacity was higher in treatment T5. Vinasse treatment increased phosphorus concentrations in the T4 treatments soils. There were major differences for each parameter. Morphological parameters showed a high emergency rate at T2 (87%). The highest values for plant height, collar diameter, number of leaves and leaf area were obtained with treatment T4 (8L/m2). The amount of potassium in the soil increased with doses of vinasse. The C/N ratio decreased as soil organic matter reduced. Compared with chemical fertilisers, vinasse can be a sustainable alternative for organic farming.
O monitoramento de parâmetros físico-químicos e microbiológicos da água são realizados para se medir, avaliar e gerir as condições do estado de equilíbrio estático ou dinâmico natural em ecossistemas aquáticos. Este estudo consite em identificar os fundamentos científicos analisando as principais tendências de aplicabilidade tecnológica ao utilizar biossensores como instrumento de coleta dos dados neste monitoramento, com o foco na gestão da conservação dos ecossistemas aquáticos, contudo obtendo um panorama dos indicadores da QA. Para sintetizar os dados obtidos, tais informações são descriminadas por região e períodos de coletas, tópicos estratégicos e suas especificidades, leitura identificando vantagens, limitações no que tange o nível de incerteza, robustez, acurácia com destaque nos tipos de sensores mais utilizados em sistemas de monitoramento físico-químicos e microbiológicos nos ecossistemas aquáticos do bioma Amazônia. Logo, para embasar as pesquisas realizou-se a obtenção de arcabouço teórico acerca do tema, considerando o recorte geográfico das aplicações em nível tropical global, sobretudo na Amazônia brasileira. A revisão na nomenclatura documental consistiu inicialmente em consulta sistemática nas principais bases científicas de dados, tais como: web of science, scopus, scielo, google scholar, abrangendo diversas as fontes de periódicos da literatura internacional e seu contexto geográfico-temporal. Os principais resultados da pesquisa apontam uma tendência de crescimento da demanda para o uso das tecnologias e aplicapilidade dos biossensores no monitoramento on line e remotamente (telemetria). Contudo, é notória a carência desse tipo de estudo em literatura, com o foco sobre em suas especificidades e demandas, além de analises demonstrativas direcionadas para a otimização funcional de tais sistemas.
The present research was designed to assess the potential effect of SNP to alleviate salinity stress injury in fig transplants cv. Conadria. One-year-old transplants irrigated with saline water (6.25 ds/m) were treated with sodium nitroprusside (SNP) at four concentrations (0, 50, 100 and 200 µM); untreated transplants exposed to salt stress represent the positive control, while the non-stressed transplants represent the negative control. Salt stress showed a considerable increase in lipid peroxidation, proline, sodium, chloride content and antioxidant enzyme activity and reduced vegetative growth parameters, photosynthetic pigments, phenolic content and K/Na ratio. SNP reduced salt stress injury in fig transplants through maintaining higher values of growth parameters and photosynthetic pigment content, reducing sodium accumulation and maintaining the integrity of cell membrane lipids. SNP-treated transplants accumulated higher amounts of potassium ions and a higher K/Na ratio. SNP at 100 µM was the most efficient treatment in enhancing the response to salt stress. Overall, the results show that SNP application is a promising practice for alleviating salt stress on fig transplants.
Climate change is expected to drive significant alterations in rainfall patterns, which will pose considerable threats and pressures on aquatic ecosystems. Phytoplankton, as a critical component of these ecosystems and a reliable biological indicator of environmental health, may respond variably to such climatic changes. However, our understanding of how phytoplankton communities respond to climate change remains limited. In this study, we investigated the response of phytoplankton functional groups to rainfall patterns and their relationships with environment factors in a subtropical eutrophic lake (Changhu Lake, China) from May 2020 to April 2022. Our findings indicate that changes in phytoplankton functional structure over time were influenced by rainfall patterns. A total of 119 genera, 21 functional groups, and 15 dominant functional groups were identified, with the dominant functional groups exhibiting strong seasonal variations. Notably, shifts in rainfall patterns led to a transition in dominant phytoplankton functional groups: from taxa tolerant of mixing and low nitrogen levels (e.g., H1, J, and S1) during the rainy season to taxa that thrive under eutrophic and stratified conditions (e.g., X2, C, N, and W1) during the dry season. The use of phytoplankton functional approaches simplifies identification and reflects environmental conditions effectively. Redundancy analysis (RDA) revealed strong correlations between changes in phytoplankton functional groups and environmental factors such as water temperature, precipitation, water level, and nutrient availability. The insights from this study improve our understanding of how aquatic ecosystems shift under climate change and demonstrate the potential of phytoplankton functional responses as a valuable tool for water management and conservation.
To foster public trust in water reuse and develop solutions for future water scarcity, the B-WaterSmart project piloted water reclamation for artisanal beer production, providing scientific evidence on the safety of direct potable reuse (DPR) in industry. The demonstration took place at the Beirolas Water Resource Recovery Facility in Portugal, where four advanced treatment technologies were tested: ultrafiltration (UF), ozonation (O₃), biologically active granular activated carbon (BAC) filtration, and reverse osmosis (RO). Four RO-based reclamation schemes were continuously piloted (24/7) to assess water quality and operational performance: (1) UF + O₃ + RO, (2) UF + RO, (3) UF + O₃ + BAC + RO, and (4) O₃ + BAC + RO. Water quality was monitored weekly for E. coli, organic matter and nutrients, and, once per scheme, for trace compounds, including 54 pharmaceutical compounds (PhCs), 2 hormones, oxidation by-products (N-Nitrosodimethylamine (NDMA), bromate, chlorate, 4 trihalomethanes (THMs), 9 haloacetic acids (HAAs)), 20 per- and polyfluoroalkyl substances (PFAS), 10 alkylphenols, and toxicity (Daphnia magna, Vibrio fischeri). EU Drinking Water Directive 2020 parameters and pathogen indicators (Clostridium perfringens, enteric viruses, protozoa) were also assessed. All treatment schemes produced water meeting EU and Portuguese drinking water standards, with no pathogen indicators and with trace contaminants below quantification limits (PFAS <2 ng/L, 5 HAAs <1 µg/L, bromate <3 ng/L, PhCs <0.3 µg/L) or below international regulations or guidelines (total THMs <2 µg/L, NDMA <8 ng/L). Operational monitoring showed lower energy demand for the UF + RO scheme, corresponding to 1.0 kWh/m3. Furthermore, a craft beer company used the produced water to brew 1,000 litres of beer, which received a positive organoleptic evaluation from its producer.
The unfettered discharge of untreated pharmaceutical effluent into water bodies poses severe menace to aquatic ecosystem. The conventional approaches found to be ineffectual in treating pharmaceutical effluent due to certain issues such as lack of eco-friendliness, cost extensive, also sludge is formed which further increases the expenditure for processing. In context of developing nations, the cost effectiveness and environmental sustainability of vermifiltration technology make it an ideal alternative to conventional wastewater treatment techniques. The current exploration was devised to appraise the effect of untreated and vermifiltration treated effluent in fish Channa punctata through biochemical, histopathological, ultrastructural and ATR-FTIR analysis. Considerably augmented alterations in biochemical parameters (MDA, SOD, CAT and GST) in liver, gill and kidney tissues were scrutinized in untreated group. After 45 days of exposure, 4.35, 4.19 and 3.89 folds hike in MDA content were noticed in liver, gill and kidney tissues of untreated group respectively in contrast to control group. Histopathological examination in fish unveiled to untreated effluent exhibited numerous distortions in liver (necrosis, vacuolization, hepatocyte degeneration), gill (disintegration of primary lamellae, upliftment of gill epithelial layer, fusion of secondary lamellae) and kidney (necrosis, degenerated and constricted glomerulus) tissues. Scanning electron microscopy examination further reiterated the anomalies perceived in histopathological investigation. Further, ATR-FTIR analysis presented more biomolecular alterations in exposed tissues. On contrary, fewer biochemical, histopathological, ultrastructural and biomolecular alterations were noticed in treated effluent exposed fish implies its less toxic nature. The outcomes of the study concluded that vermifiltration technology is trustworthy, economic and sustainable technology for treating different industrial effluents.
The elimination of absorbance of excess dye by selective oxidation was first proposed for analytical methods using the formation of ion-association complexes (IAs). On this basis, a new sensitive and selective spectrophotometric method for the determination of phosphate in the form of the IA of 11-molybdovanadophosphate with diindodicarbocyanine (DIDC) was developed. Symmetric diindodicarbocyanine and diindotricarbocyanine dyes can be completely oxidized by sufficiently strong oxidizing agents such as permanganate, dichromate, cerium (IV), and vanadate. Of the three dyes investigated (DIDC, N,N’-dipropyldiindodicarbocyanine, and diindotricarbocyanine), the best results were obtained with DIDC. A mixture of molybdate, vanadate, and nitric acid was preferably used as an oxidizing agent. Selective decolorization of only free dye ions, as well as changes in the IA spectrum compared to the dye spectrum, were explained by the isolation of the dye due to the formation of poorly soluble IA nanoparticles and changes in the redox potential of the dye due to its aggregation. The following optimal conditions for phosphate determination were found: 0.3 M nitric acid, 0.43 mM sodium molybdate, 0.041 mM sodium vanadate, 0.015 mM DIDC, and 18 min for the reaction time. The molar absorptivity of the IA was 1.86 × 10⁵ mol⁻¹·L·cm⁻¹ at 600 nm, and the detection limit for phosphate was 0.013 µM. The developed method was applied to the determination of phosphate in natural water samples.
The purpose of all oil and gas production systems is to produce safely and economically, dehydrated crude oil and natural gas condensate, dehydrated natural gas, and clean disposable water. Successful corrosion inhibition systems must be designed and applied to alleviate corrosion effectively and reliably without adversely affecting the production system. This paper details the process, including test results, to develop, apply and monitor a successful corrosion inhibition system for subsea oil and gas wells.
Intermittent rivers are hydrologically extreme freshwater systems that periodically cease to flow. Such habitats occur worldwide, but they are most common in semi-arid regions of the world, such as the Mediterranean region. Trichoptera are frequently used in biomonitoring programmes worldwide. However, their biodiversity and ecological requirements in intermittent Mediterranean karst habitats are still poorly understood. Here, we provide data on Trichoptera assemblage metrics (taxa richness, diversity and abundance), assemblage structure (trophic structure and stream zonation preference), and their relationship with environmental variables in the lotic phase of four intermittent rivers in the Dinaric karst region of the Mediterranean in the Western Balkans. Due to the extreme hydrological conditions in the studied habitats, Trichoptera showed a low taxa richness (10 taxa). The highest diversity was recorded in rivers with greater habitat heterogeneity. In addition, rivers with higher conductivity and water temperature, and lower water velocity had more diverse assemblages. The trophic structure and stream zonation preferences of Trichoptera were significantly different among the intermittent rivers studied, with the influence of anthropogenic activities evident in certain rivers. However, the variability of Trichopteran assemblages along the course of each intermittent river, was generally low, which could be attributed to the uniform microhabitat composition and physico-chemical water parameters in the studied rivers. The results of this study could provide a valuable background for further research and the development of conservation measures for both Trichoptera and intermittent karst habitats in the Mediterranean.
Unlabelled:
Laccase production from an isolated white rot fungus identified as Leiotrametes flavida MTCC 12927 was optimised in flasks, scaled up in 5 and 10 L working volume fermenters and purified to homogeneity. Purified laccase was tested for its decolourisation potential on 3 dyes: Basic Red 46 (azo class), Acid Blue 9 (triarylmethane class) and Reactive Blue 21 (phthalocyanine class). TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl), a less expensive water-soluble hydroxy derivative of mediator TEMPO (2,2,6,6-tetramethylpiperidin-1-yl) oxidanyl), was tested as a mediator which had not been reported before to our knowledge along with well-known mediators hydroxybenzotriazole (HBT) and syringaldehyde (SYD). Laccase in the presence of HBT could decolourise all the 3 dyes. Basic Red 46 and Acid Blue 9 were completely decolourised in 4 and 8 h, respectively. Reactive Blue 21 showed a decolourisation of 70.3% compared to 50.3% with TEMPOL and 20% with the enzyme alone. Laccase + TEMPOL combination was significantly better than HBT in decolourising azo dye Basic Red 46 completely within 30 min compared to 4 h for HBT. Furthermore, laccase TEMPOL and HBT combinations were also tested in azo dye-containing tannery effluent. TEMPOL showed a higher decolourisation rate of 36% compared to 22% for the latter. Chemical oxygen demand (COD) analysis of treated effluent samples showed a COD reduction of 23.2% for laccase + TEMPOL treatment and 19.2% for laccase + HBT compared to 7.8% with laccase alone. TEMPOL showed potential as a low-cost, water-soluble mediator for azo dye decolourisation.
Supplementary information:
The online version contains supplementary material available at 10.1007/s13205-025-04259-9.
O surgimento de bactérias patogênicas com resistência a vários antimicrobianos tem gerado elevada preocupação no meio científico e à Organização Mundial da Saúde, pois essas bactérias, quando ocasionam infecções à saúde humana, geram doenças de difícil tratamento, podendo aumentar o número de morbidades e, até mesmo, promover o aumento no caso de óbitos, principalmente em casos de septicemia hospitalares. Dentre os fatores que contrinuem para o aumento da resistência antimicrobiana, conforme o relatório do Programa Ambiental das Nações Unidas, destacam-se: o índice de pobreza, a falta de saneamento básico, o aumento de poluentes emergentes. Neste contexto, a resistência antimicrobiana (AMR) é um tema de elevada relevância mundial, pois se não for combatida cientifica e eficazmente, poderá ocasionar uma crise global na saúde humana denominada de pan-resistência. Em estudos feitos nas águas do rio Lageado do Pardo que margeia o município de Frederico Westphalen-RS/Brasil, foram identificadas bactérias do gênero Pseudomonas com resistência múltipla aos antibióticos das classes: β-Lactâmicos, Macrolídeos e Quinolonas. A avaliação foi realizada através de antibiogramas em placa de Petri em meio Mueller-Hinton (Bauer et al., 1966) e analisado conforme National Committee for Clinical and Laboratory Standards (CLSI, 2020/Br-Cast, 2023).
A novel photoheterotrophic dual-species biofilm was evaluated for wastewater (WW) treatment and microbial growth under variable cell loads. For that, Chlorella vulgaris was tested under axenic conditions and in combination with three bacteria, Rhodococcus fascians, Acinetobacter calcoaceticus, and Leucobacter sp., assessing the influence of each bacterial strain in biomass productivity, growth rate, thickness, roughness, and production extracellular polymeric substances (EPS) of each co-culture. The cultivation of C. vulgaris with bacteria improved biomass productivity and growth rate for almost all cases (except when using the lowest concentration of Leucobacter sp.) particularly the biofilms containing R. fascians, with biomass productivity of 7.46 ± 1.1 g/L.d when the initial optical density (OD) proportions were 0.1:0.025 for microalga and bacterium, respectively, and a growth rate of 0.97 ± 0.2 d¯1 in 72 h for the initial OD 0.05:0.05. Moreover, the presence of bacteria affected the dual-species biofilm thickness and EPS production, especially those with R. fascians. Nutrient removal by the dual-species biofilms was comparable to the axenic C. vulgaris biofilms, except with Leucobacter sp., while the single-species bacterium cultivation led to nutrient accumulation. This study identified symbiotic behaviours between C. vulgaris and the selected bacteria in WW polishing, where microbial load and proportion influenced the growth dynamics and WW treatment efficiency.
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