Search

In this research work, a novel design of an electro-Fenton reactor for the treatment of polluted water was investigated. In addition to the reactor with iron electrodes, a ceramic filter was also used. An electrical circuit was designed to change the cathodes and anodes every 24 s via an electrical relay between the electrodes. The untreated water was sucked into the reactor with an air pump and entered the electrocoagulation chamber after filtration with a ceramic filter. Then, it flows to the polyethylene filter to separate the coagulated particles from the fresh water. To produce 12 L of clean water, the system consumed 100 W of energy. Analysis of a river sample showed a reduction in nephelometric turbidity units (NTUs), total suspended solids (TSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD). Turbidity reduction studies have shown that the system can improve water transparency by 95%, thereby improving water quality to acceptable levels. Further, this system reduced TSS by more than 86%. In addition, BOD was reduced by more than 84% and COD by more than 88%, as shown by the change in the ratio of BOD to COD from 0.44 to 0.625, indicating improved water quality. According to the results, the treatment system can clean polluted waters, particularly during floods and when industries discharge their effluents into rivers. [ABSTRACT FROM AUTHOR]

Lake Mead located in the Arizona–Nevada region of the Mohave Dessert is a unique and complex water system whose flow follows that of a warm monomictic lake. Although monomictic lakes experience thermal stratification for almost the entire year with a period of complete mixing, the lake on occasion deviates from this phenomenon, undergoing incomplete turnovers categorized with light stratifications every other year. The prolonged drought and growing anthropogenic activities have the potential to considerably impact the quality of the lake. Lake Mead and by extension the Boulder Basin receive cooler flow from the Colorado River and flow with varying temperatures from the Las Vegas Wash (LVW), which impacts its stratification and complete turnovers. This study analyzes four key water quality parameters (WQPs), namely, total dissolved solids (TDS), total suspended solids (TSS), temperature, and dissolved oxygen (DO), using statistical and spatial analyses to understand their variations in light of the lake stratifications and turnovers to further maintain its overall quality and sustainability. The study also evaluates the impacts of hydrological variables including in and out flows, storage, evaporation, and water surface elevation on the WQPs. The results produced from the analysis show significant levels of TDS, TSS, and temperature from the LVW and Las Vegas Bay regions compared with the Boulder Basin. LVW is the main channel for conveying effluents from several wastewater treatment facilities into the lake. We observed an increase in the levels of TDS, TSS, and temperature water quality in the epilimnion compared with the other layers of the lake. The metalimnion and the hypolimnion layer, however, showed reduced DO due to depletion by algal blooms. We observed statistically significant differences in the WQPs throughout various months, but not in the case for season and year, an indication of relatively consistent variability throughout each season and year. We also observed a no clear trend of influence of outflows and inflows on TDS, temperature, and DO. TSS concentrations in the lake, however, remained constant, irrespective of the inflows and outflows, possibly due to the settling of the sediments and the reservoir capacity. [ABSTRACT FROM AUTHOR]

Municipal and industrial wastewater discharge is a longstanding environmental problem that pollutes water bodies, affecting both the landscape and human health. In the department of Sucre, Colombia, nearby urban sewage is discharged into the Arroyo Grande de la Sabana, and only Sincelejo city has a treatment system in place. Therefore, it is critical to identify effective treatment methods for removing contaminants from water. The objective of this study was to evaluate the efficiency of a constructed wetland (CW) with horizontal subsurface flow (HSSF) planted with Thalia geniculata for treating wastewater from the Arroyo Grande de la Sabana in Sucre, Colombia. The study investigated the effectiveness of a constructed wetland planted with Thalia geniculata for treating wastewater from the Arroyo Grande de la Sabana in Sucre, Colombia. Two different hydraulic retention times (HRTs) of 3 and 5 days were tested, and the plant population density was analyzed to determine the better adaptation of plants to the constructed wetlands. The results showed that on the fifth day of treatment, nitrate concentrations decreased by 33.22%, nitrite by 93.04%, and phosphate by 95.66%. Additionally, the biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) values decreased by 97.27% and 80.27%, respectively. On the third day of retention, turbidity, and total suspended solids (TSS) in the water decreased by 90.13% and 83.08%, respectively. The study concluded that the 5-day HRT was most effective in removing contaminants such as nitrites, nitrates, and phosphates, while the 3-day HRT was more efficient for TSS, turbidity, total coliforms (TCs), and fecal coliforms (FCs). [ABSTRACT FROM AUTHOR]

The wet oxidation of pharmaceutical sludge for the treatment and production of value-added materials was investigated. The experiments were carried out in a stainless-steel autoclave reactor with chemical synthetic pharmaceutical sludge. The highest removal rate of total suspended solids (90.1%) and volatile suspended solids (98.4%) was achieved at 260 °C for 60 min with an initial oxygen pressure of 0.8 MPa. Simultaneously, the total chemical oxygen demand removal rate (78.7%) and the soluble chemical oxygen demand removal rate (81.6%) were obtained. The volatile fatty acid concentration—including acetic acid, propanoic acid, isobutyric acid and isovaleric acid—increased to 4819 mg/L with pH 12.56, which indicated the possibility of improving the quality of wet oxidized sludge solution as a potential carbon source by adding reagents. Scanning electron microscopy images showed that the sludge became a loose porous structure after wet oxidation, which is beneficial for dewatering performance. Energy dispersive spectroscopy images illustrate that carbon elements in sludge migrate from solid to liquid phases during the wet oxidation process. These results provide meaningful data for the design of further works and demonstrate that wet oxidation is a promising method for the treatment of pharmaceutical sludge, and the produced volatile fatty acids, including acetic acid and propanoic acid, are potential carbon sources for the biological treatment of wastewater. [ABSTRACT FROM AUTHOR]

Substantial growth of poultry industry had raised concerns about its environmental impact, particularly in relation to groundwater depletion and pollution. One potential solution to mitigate these issues is the implementation of a wastewater recycling system (WRS) which is not widely adopted in poultry industry due to a limited information on its technical and economic feasibility. Therefore, this study aimed to investigate the application of WRS in a commercial poultry hatchery in Indonesia and how it can be adopted widely to drive sustainability in poultry production. The technical aspect of the WRS was examined by evaluating its performance in removing pollutants and capability of reducing groundwater intensity ratio (GIR). Furthermore, the economic feasibility was explored through a cost benefit analysis (CBA), using net present value (NPV) as sole indicator expressed in United States dollar (USD). The results showed that multistage wastewater treatment applied in WRS consist of physical, biological & chemical process, and the removal percentage of biological oxygen demant (BOD), chemical oxygen demand (COD), total suspended solids (TSS), fat oil and grease (FOG) pollutants ranged from 47.5 - 95.1%, 48.4 - 91.3%, 24.9 - 95.3% and 68.0 - 89.3%, respectively. Furthermore, all the recycled water managed meet Indonesia quality standards. The application of WRS reduce groundwater withdrawal through the reduction of GIR by 30.18%. This decreased the reliance on groundwater sources without affecting productivity. The cost benefit analysis conducted on the WRS has uncovered numerous economic benefits such as cost saving in water bills and avoidance of pollution-related expenses with estimated positive NPV at USD 30,742.54 which exhibits economic feasibility. The study concluded that WRS remains a viable option for widespread implementation in the poultry industry, addressing water crisis and promoting sustainable production. [ABSTRACT FROM AUTHOR]

Copyright of Agroindustrial Science is the property of Agroindustrial Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Urban waterlogging occurs when precipitation events cause urban runoff to exceed the capacity of stormwater systems, causing water accumulation on the land surface. Valparaiso City is one of the main metropolitan centers in Chile. Rapid urban growth forced the city to invest substantial resources to upgrade its stormwater system. The most recent is the Argentina stormwater canal. However, soon after the stormwater canal was operational, solids (sandy clay, fine sand) washed-off from upland watersheds accumulated in the lower elevation sectors of the canal, close to the conduit outfall to Valparaiso Bay. This has degraded the water conveying capacity of the canal and increased waterlogging hazards if extreme storms and high tide events combine. This research explores management scenarios for reducing the hazard of waterlogging in the canal. Hydrological and in-stream hydrodynamic modeling is used to propose watershed management scenarios aimed to reduce flows and suspended solids wash-off. The impact of those scenarios for reducing waterlogging hazard is assessed. [ABSTRACT FROM AUTHOR]

Coastal eutrophication is a global environmental concern, primarily driven by nutrient contamination from human and natural sources entering the sea via river mouths. The Bang Pakong River, situated on the eastern coast of Thailand's Upper Gulf, exemplifies this issue. Its watershed, largely dedicated to agriculture, has witnessed rapid urban and industrial growth, contributing to water eutrophication in the Upper Gulf. To address this, a study conducted in 2016 and 2017 analyzed the exchange of dissolved nutrients and total suspended solids at the Bang Pakong River mouth across different seasons. During the rainy season, the concentration of nutrients and suspended solids was high. Hypoxia in near-bottom water occurred. The net flux of these materials depended on seasonal variations in runoff, with higher amounts (71.2×106 m³·d-1) being washed into the sea during high runoff periods. In contrast, during the dry season in February, material accumulated in the river due to seawater intrusion, with net water flux (11.6×106 m³·d-1) reversing. Significantly, the study found a strong correlation between the net flux of studied materials and average monthly rainfall in the Bang Pakong Basin. This correlation can be valuable in predicting substance transport from the river to the Upper Gulf, aiding in the assessment of nutrient enrichment in the region. Addressing eutrophication is critical for preserving the ecological balance of coastal ecosystems and ensuring the sustainability of these vital environments. [ABSTRACT FROM AUTHOR]

This study examined the effects of multiple run-of-river hydroelectric power plants (RoRHEPPs) on water quality, discharge, and total suspended solids (TSS) in Kabaca Stream, Türkiye. At ten sampling points, portable devices were used to measure pH, water temperature, dissolved oxygen (DO), electrical conductivity (EC), salinity, total dissolved substances (TDS), and nitrate-nitrogen (NO3-N) values. Monthly discharge and TSS quantities were estimated on-site and in the lab. To study the effects of RoR-HEPPs on selected water quality indicators, sample locations were split into three categories: before regulators, in between HEPPs, and after HEPPs. The sequentially constructed RoR-HEPPs negatively affected the mean values for most water quality parameters in Kabaca Stream, as the mean amounts of EC, salinity, TDS, and TSS measured as 65.9 µS/cm, 0.047 ppt, 0.064 mg/l, and 4.60 mg/l at the before sections increased to 98.7 µS/cm, 0.072 ppt, 0.099 mg/l, and 17.34 mg/l at the after sections. The installation of water transmission lines and roads for the RoR-HEPPs destroyed steep mountainous forest slopes, releasing massive amounts of sediments and other contaminants into the stream bed. Since the RoR-HEPPs taken in up to 90% of the stream water, the mean discharge rate dropped from 3.27 m³/s at the after sections to 0.90 m³/s at the between sections. [ABSTRACT FROM AUTHOR]

Despite increasing wildfires, few studies have investigated seasonal water quality responses to wildfire characteristics (e.g., burn severity) across a large number of lakes. We monitored 30 total lakes (15 burned, 15 control) monthly following the Greenwood Fire in Minnesota, USA, a lake‐rich region with historically prevalent wildfire. We found increases in median concentrations of total nitrogen (68%), total phosphorus (70%), dissolved organic carbon (127%), total suspended solids (71%), and reduced water clarity (48%) and pH (0.45) in burned lakes. Post‐wildfire responses in drainage lakes were often persistent or cumulative throughout the open‐water season, compared to isolated lakes. Total phosphorus (TP) increased linearly with watershed high‐severity burns, and shoreline high‐severity burns explained more variation in TP than lake morphometry and watershed variables. Post‐wildfire chlorophyll‐a responses were nonsignificant and inconsistent, possibly due to light limitation. Our results suggest that increasing wildfires have significant potential to affect water quality of inland lakes. Plain Language Summary: Despite increasing wildfire activity, there has been limited research on wildfire effects on lakes. We monitored lake water quality throughout summer 2022 following the 2021 Greenwood Fire in Minnesota, USA, a lake‐rich region where wildfire was historically common. We found that lakes with burned watersheds were more nutrient‐ and carbon‐rich and more acidic and murky. Responses often increased throughout the summer, particularly for lakes with tributaries from burned areas. However, murkier water may have prevented increased nutrients from increasing algae abundance. Water quality responses were greater following burns near lake shorelines and of greater severity, reflecting damage to vegetation and soil. Our results suggest that increasing wildfire under climate change may degrade lake water quality. Key Points: We observed post‐wildfire increases in nutrients, dissolved organic carbon, sediments, and acidity and reduced water clarity in lakesWater quality responses were often persistent or cumulative throughout the summer, especially for lakes with tributaries from burned areasHigh‐severity and shoreline burns resulted in a nearly two‐fold increase in total phosphorus concentration compared to control lakes [ABSTRACT FROM AUTHOR]

This study aimed to improve the performance of a wastewater treatment plant (WWTP) simulated with Benchmark Model No. 2 (BSM2). To achieve this objective, three control strategies were implemented and tested. The first control strategy aimed to maintain the concentration of nitrate and nitrite nitrogen (SNO) by controlling the external carbon flowrate (strategy A1), and the second control strategy aimed to maintain the ammonia and ammonium nitrogen (SNH) at a desired level with the use of a cascade controller (strategy A2). The third strategy was applied to control the total suspended solids (TSS) (strategy A3). Combinations of these strategies were considered (B1, B2, and B3 strategies), as well as the use of all three together (strategy C1). The control strategies presented in this paper were compared to the default control strategy of BSM2 to validate and identify the one that provided the best performance. The results revealed that the B1 strategy was the most environmentally friendly, while C1 obtained the highest overall performance. Several Monte Carlo simulations were performed for the validated control strategies, to identify the optimal setpoint values. For the C1 strategy, a second method of optimization regarding polynomial interpolation was considered. The applied optimization methods provided the optimal reference values for the PI (proportional integral) controllers. [ABSTRACT FROM AUTHOR]

This study investigated the water recovery of real textile wastewater by Coagulation/Flocculation (CF) integrated with Direct Contact Membrane Distillation (DCMD). The proof-of-concept tests were studied with synthetic solutions of reactive and disperse black dyes at different concentrations, and real textile wastewater from the discharge machine and the equalization tank. Results showed that CF-DCMD exhibited higher permeate fluxes (up to 40%) than single DCMD and maximum color rejection rates (100%). Moreover, CF-DCMD enabled water reclamation from cotton and polyester dyeing wastewater which was not possible by MD (Membrane Distillation). The integrated system showed excellent chemical oxygen demand removal capacity, total suspended solids, turbidity, conductivity reduction, and removed any signs of toxicity from the tested wastewater. The coagulation/flocculation process prior to the MD reduced the fouling factor for all wastewater, highlighting the equalization tank where a reduction of around 72% was observed, achieving the goal of reducing fouling and increasing the efficiency of the MD. Membrane characterization indicated that CF-DCMD confirmed less fouling of membranes than single DCMD. Thus, this study allows to understand the potential and robustness of the CF-DCMD process in the treatment of textile wastewater and that it is possible to develop alternative technologies to treat complex wastewater effectively. [ABSTRACT FROM AUTHOR]

Two variants (preliminary stage and main stage) of the experiment aiming to verify the possibility of using waste materials and composites for septic tank effluent (STE) treatment were investigated. The hydraulic load of filters during main stage was about two times lower than during preliminary stage. The aim of this study was to examine the mechanical and biological treatment efficiencies of four waste materials: polyethylene Raschel mesh (PERM), wood-polymer composite (WPC), cut plastic straws (CPS) and polyethylene (PE). Considering that the used STE was hardly biodegradable, the removal efficiencies of the used materials were relatively high. During main stage for PERM the removal efficiencies of chemical oxygen demand (COD), ammonium nitrogen (NNH4), total phosphorus (Ptot) and total suspended solids (TSS) were 84.6%, 92.8%, 24.5% and 83.6%, respectively. For CPS, efficiencies for COD, NNH4, Ptot and TSS were 58.8%, 40.2%, 43.1% and 84.7%, respectively. For WPC, efficiencies for COD, NNH4, Ptot and TSS were 60.2%, 51.8%, 44.1% and 85.2%, respectively. For PE, efficiencies for COD, NNH4, Ptot and TSS were 46.9%, 30.0%, 43.7% and 85.3%, respectively. The technology used in this study was relatively simple. For maximum effectiveness in wastewater reuse (e.g., for irrigation), mechanical pre-treatment should be performed. [ABSTRACT FROM AUTHOR]

Amazon streams present great biodiversity and offer several ecosystem services, but these systems are threatened by multiple land uses. The changes created by land use are expected to drive the composition of species, ultimately changing the trophic relationships of several biological groups, including zooplankton. We investigated if land use changes the composition of zooplankton functional guilds in Amazon streams and which are the local (physical-chemical) variables driving the zooplankton functional guilds in the land-use gradient. Zooplankton and physical-chemical variables were sampled in 17 water bodies in the municipality of Barcarena, Pará, Brazil in 2018 and 2019, five sampling sites were in the Pará River and 12 in streams. Forest cover (a proxy for land use) was determined through digital image processing and converted in percentage. Zooplankton species were classified into five functional guilds (filter, raptorial, scraper, suctor, and predator feeders). We recorded 98 zooplankton taxa and filters were the most abundant functional guild. The composition of zooplankton functional guilds did not change in the land use gradient. However, the distribution of zooplankton functional guilds in Amazon streams was determined by local environmental variables related to the feeding strategies. Scraper-feeders (cladocerans) were positively related to greater canopy cover, suctor-feeders and predator-feeders (both rotifers) were related to greater total phosphorus, whereas filter-feeders (rotifers, cladocerans, and copepods) and raptorial (copepods) were related to total suspended solids. This study brings new information about zooplankton in Amazon streams that are under-studied. The functional approach clarifies the patterns observed and reflects the trophic relationships in which the zooplankton community is involved in streams under a degree of land use, i.e., scraper-cladocerans can represent more preserved streams under greater canopy cover, whereas the other functional guilds were related to variables that can represent more altered streams. [ABSTRACT FROM AUTHOR]

Ceramic membranes are considered more effective for wastewater treatment applications than polymeric membranes because of their excellent resistance to thermal and chemical environments and possess high durability. To avoid the high cost of commercial ceramic membranes, recently, a significant improvement has been accomplished in developing them using low-cost alternative materials and their application in wastewater treatment. This study investigated the performance of an innovative ceramic microfiltration (MF) membrane fabricated with inexpensive Fuller's earth clay in treating the natural raw rubber (ribbed smoked sheet)-processing wastewater. The flat sheet low-cost membrane used in this study was prepared by uniaxial dry pressing route, followed by sintering at 850 °C, and it possessed 39% porosity with 0.176 µm pore size. The wastewater was treated in dead-end filtration mode at different pressures varying from 0.35 to 2 bar and observed the percentage removal of COD, turbidity, and total suspended solids (TSS). Untreated wastewater had a turbidity of 150 NTU, 1200 mg/L TSS, and 10,800 mg/L COD. At a low operating pressure of 0.35 bar, 94% removal of turbidity and total suspended solids was obtained. Also, significant COD removal of 70.4% from wastewater was obtained using the prepared low-cost MF membrane. Finally, the fouling phenomenon during the wastewater treatment was analyzed and it was concluded that it followed the cake filtration model. For future work, cross-flow filtration of wastewater using fabricated Fuller's earth clay ceramic membrane is recommended as it could pave the way forward towards commercialization and wide-scale industrial applications. [ABSTRACT FROM AUTHOR]

The influence of 3, 10 and 50 washing cycles on the properties of cotton fabric and cotton-polyester blend in plain weave, was investigated in this study. In addition to the analysis of tensile properties in weft and warp directions and thickness, the number of particles produced in the dry state was also measured after 3, 10 and 50 washes. After washing, the entire effluent was analysed by determining the total suspended solids (TSS), the total solids (TS), the pH value and the conductivity. To determine the similarity of the observed wash cycles and properties of all processed samples, hierarchical cluster analysis (HCA) was performed. The fabric changes indicated by total wear in the warp direction after 50 washing cycles compared to unwashed ones amounting to 41.2% for cotton and 30.9% for cotton-polyester blend, may be attributed to the synergy of washing factors and raw material composition. Cotton fabric produced significantly more particles than cotton-polyester fabric in the dry state after the examined washing cycles in all size categories. A smaller number of released particles are in the larger size category >25 μm. The obtained TSS values confirm the degree of loading of the effluent with particulate matter from the analysed fabrics, since the detergent consists of water-soluble components. The HCA dendrograms confirmed that the release of particles during the first washing cycles is mainly determined by the structural properties of fabrics, while in the subsequent cycles the synergistic effect of chemical, mechanical and thermal effects in the interaction with the material prevailed. [ABSTRACT FROM AUTHOR]

Lake Powell is a large water storage reservoir in the arid southwestern United States. Here, we present a 58‐yr limnology dataset that captures water quality parameters from reservoir filling to present day (temperature, salinity, major ions, total suspended solids), as well as a 38‐yr record of Secchi depth, and a ~ 30‐yr record of nutrients, phytoplankton, and zooplankton assemblages. The dataset includes 5208 unique site visits spanning 258 unique sites of which 9 have been consistently visited. It also spans the establishment of an invasive bivalve (Dreissena bugensis, i.e. Quagga mussel) which was first detected in 2012. Given the general lack of long‐term data from lakes or reservoirs in arid regions, this dataset represents a unique contribution to regional, continental, and global‐scale limnology studies. As the hot drought in the desert southwest continues, we expect this dataset will inform water management decision‐making for this largest reservoir in the Upper Colorado River Basin. [ABSTRACT FROM AUTHOR]

Hydraulic geometry characteristics can influence stream ecosystem and biogeochemical processes at different spatial scales. Globally, studies are emerging on the relationship between channel geometry and water quality. However, these studies are few and far between most humid tropical basins. In this study, we assessed the relationship between hydraulic geometry and some water quality parameters [temperature, salinity, pH, electrical conductivity (EC), total dissolved solids (TDS) and total suspended solids (TSS)] across stream orders of a tropical headwater basin in southwestern Nigeria. Bankfull width, depth, velocity and discharge were measured at twenty-six (26) reaches across first-, second- and third-stream orders within the basin. Water samples were collected from these reaches and were analyzed. Bankfull width, velocity and discharge showed significant variation across stream orders, while the water quality parameters vary slightly in response to fluvial and geogenic interactions. We obtained r = − 0.417, p < 0.05 for TDS and discharge, r = − 0.399, p < 0.05 for depth and TDS, r = − 0.39, p < 0.05 for width and EC, and r = − 0.42, p < 0.05 for width and pH. The headwater basin is underdeveloped and it is still undergoing fluvial adjustment. We recommend the need for future studies to investigate the intrinsic interaction between channel geometry and stream water contamination for natural and disturbed headwater basins. [ABSTRACT FROM AUTHOR]

Anthropogenic eutrophication is a global environmental problem threatening the ecological functions of many inland freshwaters and diminishing their abilities to meet their designated uses. Water authorities worldwide are being pressed to improve their abilities to monitor, predict, and manage the incidence of harmful algal blooms (HABs). While most water quality management decisions are still based on conventional monitoring programs that lack the needed spatio-temporal resolution for effective lake/reservoir management, recent advances in remote sensing are providing new opportunities towards better understanding water quality variability in these important freshwater systems. This study assessed the potential of using the Sentinel 2 Multispectral Instrument to predict and assess the spatio-temporal variability in the water quality of the Qaraoun Reservoir, a poorly monitored Mediterranean hypereutrophic monomictic reservoir that is subject to extensive periods of HABs. The work first evaluated the ability to transfer and recalibrate previously developed reservoir-specific Landsat 7 and 8 water quality models when used with Sentinel 2 data. The results showed poor transferability between Landsat and Sentinel 2, with most models experiencing a significant drop in their predictive skill even after recalibration. Sentinel 2 models were then developed for the reservoir based on 153 water quality samples collected over 2 years. The models explored different functional forms, including multiple linear regressions (MLR), multivariate adaptive regression splines (MARS), random forests (RF), and support vector regressions (SVR). The results showed that the RF models outperformed their MLR, MARS, and SVR counterparts with regard to predicting chlorophyll-a, total suspended solids, Secchi disk depth, and phycocyanin. The coefficient of determination (R2) for the RF models varied between 85% for TSS up to 95% for SDD. Moreover, the study explored the potential of quantifying cyanotoxin concentrations indirectly from the Sentinel 2 MSI imagery by benefiting from the strong relationship between cyanotoxin levels and chlorophyll-a concentrations. [ABSTRACT FROM AUTHOR]

Detention ponds are effective structures for stormwater management in the urban drainage system of sponge cities. The pond size is taken as the decision variable, while the cost, total suspended solids (TSS), and catchment peak outflow (CPO) serve as the objectives for optimizing the detention pond volume. First, we randomly generated 10,000 pond areas and input them into the stormwater management model to simulate the time series of outflow and suspended solids concentration, thereby generating samples by combining the set of pond area, corresponding cost, TSS, and CPO. Then, two backpropagation neural network models (i.e., BPNN-TSS and BPNN-CPO) were trained, tested, and evaluated for predicting TSS and CPO, respectively. We employed them as surrogates and used the non-dominated sorting genetic algorithm-II to solve the optimization problem. The results showed: (1) The BPNN models accurately predicted TSS and CPO (determination coefficient 0.988~0.996, Nash–Sutcliffe efficiency 0.988~0.997), and efficiently substituted stormwater management model simulations for optimization purposes (residuals −18.49~28.10 kg and −0.45~0.29 m3/s). (2) For the Pareto solutions, the detention pond reduced TSS by 0~8.33% and CPO by 0~72.44% and delayed their peaks by 4~52 min; the reduction in TSS and CPO tends to grow as pond size increases, and CPO reduction exhibits a minor marginal effect. (3) The surrogate-based approach saves 90.03% runtime while preserving the quality of the Pareto solutions, verifying reliability. [ABSTRACT FROM AUTHOR]

Water pollution occurs due to the discharge of domestic waste mixed with residential, industrial, commercial, and agricultural wastewater. Conventional water treatment methods using aerobic/anaerobic methods can cause problems with the production of high green gases and result in the greenhouse effect. Microbial-based domestic sewage treatment technology using polyvinyl alcohol biofilm supporting media was introduced as an alternative measure to overcome this problem. The objective of the study was to determine the performance of polyvinyl alcohol beads in polishing domestic wastewater. In this study, the bacterium Bacillus velezensis isolate JB7 was used together with PVA as a raw material to treat domestic sewage wastewater more efficiently and stably. The results of the study show the effectiveness of domestic wastewater treatment in several factors such as pH value, chemical oxygen demand, phosphorus, nitrate, nitrite, ammonia, and total suspended solids. As conclusion, domestic wastewater treatment methods using polyvinyl alcohol beads are seen to be effective, reducing the use of sewage waste plant construction sites and able to avoid the use of non-recyclable materials such as plastics and synthetics. [ABSTRACT FROM AUTHOR]

Factor Fixing (FF) is a common method for reducing the number of model parameters to lower computational cost. FF typically starts with distinguishing the insensitive parameters from the sensitive and pursues uncertainty quantification (UQ) on the resulting reduced‐order model, fixing each insensitive parameter at a fixed value. There is a need, however, to expand such a common approach to consider the effects of decision choices in the FF‐UQ procedure on metrics of interest. Therefore, to guide the use of FF and increase confidence in the resulting dimension‐reduced model, we propose a new adaptive framework consisting of four principles: (a) re‐parameterize the model first to reduce obvious non‐identifiable parameter combinations, (b) focus on decision relevance especially with respect to errors in quantities of interest (QoI), (c) conduct adaptive evaluation and robustness assessment of errors in the QoI across FF choices as sample size increases, and (d) reconsider whether fixing is warranted. The framework is demonstrated on a spatially‐distributed water quality model. The error in estimates of QoI caused by FF can be estimated using a Polynomial Chaos Expansion (PCE) surrogate model. Built with 70 model runs, the surrogate is computationally inexpensive to evaluate and can provide global sensitivity indices for free. For the selected catchment, just two factors may provide an acceptably accurate estimate of model uncertainty in the average annual load of Total Suspended Solids (TSS), suggesting that reducing the uncertainty in these two parameters is a priority for future work before undertaking further formal uncertainty quantification. Key Points: A novel four‐principle framework is proposed for assessing decision choices in practical factor fixingAdaptive evaluation of errors due to factor fixing uses model emulation to reduce computational loadFactor‐fixing error evaluation suggests reducing uncertainty of the two most sensitive parameters for lowering estimation uncertainty of total suspended solid loads [ABSTRACT FROM AUTHOR]

This study investigated treatment performance of an advanced adsorptive media in treating wastewater from an ethanol production plant for reuse in agriculture. The advanced adsorptive media consisting of zeolite, bentonite, laterite soil and coffee ground were put into 4 laboratory-scale reactors (each with 4 L in size). Treated effluent from an ethanol production plant was fed to these laboratory-scale reactors at hydraulic loading rates (HLRs) of 0.2, 0.8, 1.4 and 2.0 m3/(m2.d). The results showed the treatment efficiencies to decrease with increasing HLRs and the removal efficiencies of total suspended solids (TSS), total dissolved solids (TDS), color and chemical oxygen demand (COD) were 39–69%, 6–16%, 14–48% and 18–46%, respectively. The high treatment performance was observed at the HLR of 0.2 m3/(m2.d), suggesting adsorption and the main mechanism responsible for wastewater treatment. To investigate the effects of flow patterns on treatment performance of the advanced adsorptive media, 5 pilot-scale reactors (each with 24 L in size) were operated at HLRs of 0.8–2.0 m3/m2.d, and the patterns of influent feeding were down-flow, up-flow and in-series flow. Additionally, a commercial media (the commercial name is "Popper" or bentonite soil mixed with the mineral stone) was also put into a pilot-scale reactor and used as the control for data comparison. It was found that the series and down-flow patterns could achieve treatment efficiencies more than the up-flow pattern and the control reactor. [ABSTRACT FROM AUTHOR]

A polyextremophilic fungal strain, A. flavus QMS-8, previously isolated from the hypersaline soil taken from the rhizospheric region of the neem tree, Azadirachta indica (Meliaceae), was recognized as the proficient strain for decolorization of Acid Orange 52, a toxic dye employed in textile operations. A. flavus QMS-8 immobilized on Luffa cylindrica (Cucurbitaceae) attained 80.6% and consecutively complete dye degradation within a hydraulic retention time of 12–24 h in a stirred tank reactor even at salinities of 1–5% and environmental temperatures ranging in between 34 and 39 °C under optimized settings. The SEM micrographs revealed the attachment of fungal hyphae on L. cylindrica, while enzyme profiling demonstrated the participation of laccase (0.17 IU mL−1), manganese peroxidase (0.16 IU mL−1), and lignin peroxidase (0.06 IU mL−1) in the degradation of Acid Orange 52. The decolorized samples were assessed through a UV-Vis spectrophotometer and HPLC which did not provide any information about the formation of aromatic amines or any other metabolite. The values of biological oxygen demand, chemical oxygen demand, total dissolved solids, and total suspended solids were reduced from 2836, 3000, 3415, and 360 mg L−1 to 615, 1179, 916, and 145 mg L−1, respectively, and aligned closely with the established criteria set forth by the NEQ. Phytotoxicity and cytotoxicity assays of effluent treated in STR demonstrated a significant reduction in the toxic impact of dye on plants and microbial cells, suggesting that the luffa immobilized A. flavus QMS-8 employed in this study holds promise for mitigating the potentially harmful effects associated with Acid Orange 52. These results offer valuable insights into the efficacy and potential environmental benefits of the bioremediation approach for textile effluent investigated in this research. [ABSTRACT FROM AUTHOR]

Mineral wool has been used as a filter medium that reaches approximately 95% removal efficiency of total suspended solids (TSS) on a laboratory scale. However, there is no research available has been applied on a larger scale. Hence, this study investigated the ability of mineral wool to remove TSS in two separate segments of the Cikapayang River at different seasons. This analysis utilizes a mineral wool type I, with a dimension of 180×30×120 cm placed in segment 2, and a mineral wool type II with a dimension of 325×30×100 cm placed in segment 9. Samples were taken using the grab sampling method to analyze the TSS concentration before and after being filtered by mineral wool. This investigation concluded that mineral wool could reduce the TSS concentration by up to 65%, and the removal capacity increased by about 6.82% during the dry season. The concentration of TSS in the dry season positively correlates with the increase in the removal capacity of the media. Mineral wool of type I in segment 2 had a better removal ability (31.43%) than type II in segment 9 (14.71%). This research shows that mineral wool can be used as a support material in sanitation sites in large cities experiencing quality degradation in their water bodies.

In this study considering total suspended solids (TSS) parameter monitored in a stream watershed, the predictability of upstream values from downstream data was investigated using regression analysis, which were applied to linear, power, exponential, and quadratic functions, and artificial neural networks (ANNs) method. The data were obtained within the scope of sampling studies carried out 40 times between June 2019 and March 2020 at eight monitoring stations selected in the Sera Stream Watershed (Trabzon). The monitoring stations were divided into two groups as upstream, the first four, and downstream, the last four, stations. Half of downstream data (two stations) was used for training, a quarter (one station) for validation, and the rest (one station) for testing. Two models with different combinations of independent variables were established. In the first model (M1), only the TSS values, and in the other model (M2), the month and week information of the sampling dates were digitized and used as independent variables, in addition to the TSS values. Root mean square error, mean absolute error, and Nash-Sutcliffe (NS) efficiency coefficient statistics were used to evaluate the model and method performances. Compared to other functions, the power one had the best estimation results in the regression analysis. On the other hand, the ANNs method gave better results than the regression analysis. In both methods, M2 performed better overall. In the ANNs method, the NS efficiency coefficients obtained from M1 and M2 were calculated as 0.980 and 0.997, respectively, for the training, and 0.978 and 0.978, respectively, for the testing data sets. Considering the efficiency values, it has been understood that the use of date information as an independent variable will positively affect the model performance in the stream TSS modeling studies. Within the scope of this study, it has been concluded that upstream TSS values can be successfully estimated from downstream TSS data in stream watersheds.

The purpose of this work is to evaluate the performance of the anaerobic baffled reactor (ABR) for on-site primary treatment of domestic wastewater in rural areas of Iraq. The performance of the three-chamber ABR has been investigated at four different hydraulic retention times (HRTs) ranging from 6 to 36 h. The results showed that the chemical oxygen demand (COD) removal efficiency is enhanced with increasing HRT, where it was recorded at 75, 71, 63, and 56% removals rate of COD at HRTs of 36, 24, 12, and 6 h, respectively. The mean steady-state removals of total suspended solids are 91, 78, 72, and 67% at HRTs of 36, 24, 12, and 6 h, respectively. Also, it was shown that there was low-nutrients removal within the ABR. Consequently, the effluent ABR wastewater needs to be post-treated before being discharged to the receiving water bodies. In general, it is concluded that the ABR could introduce a solution for on-site primary treatment of domestic wastewater in rural communities in Iraq.

Water plays a key role in the economic growth of an agricultural country. Pakistan is a farming country that uses almost 90% of its water resources for agriculture. Khyber Pakhtunkhwa (KPK) province of Pakistan has extensive surface water resources. In addition to using groundwater resources for irrigation, large parts of its flat plains are irrigated with the Kabul River surface water. Due to large population growth and unregulated small/local scale industries in the region, surface water quality deteriorates with time, which affects people's health when polluted surface water is used for irrigation purposes. This research investigates the surface water quality of Kabul River's different tributaries. It identifies the most critical and vulnerable locations regarding water quality using the weightage-based identification method and distance-based iteration method, respectively. The Bara River exhibited the most critical location, surpassing the threshold values by a considerable margin in at least seven water quality parameters. The maximum seven critical values determined against the Bara River using the weightage-based method, i.e., 17.5, 5.95, 7.35, 27.65, 1.75, 0.35, and 10.45 for total alkalinity, sodium, total hardness, magnesium, total suspended solids, biological oxygen demand (BOD), and turbidity. The Khairabad station, where the Kabul River meets the Indus River, was identified as vulnerable due to elevated levels of total suspended solids, hardness, sulfate, sodium, and magnesium using distance-based methods. The locations, i.e. Adezai, Jindi, Pabbi, and Warsak Dam, appeared critical and vulnerable due to the prevalence of small-scale industries on their bank and high population densities. All the results are finally compared with the interpolated values over the entire region using Kriging interpolation to identify critical and vulnerable areas accurately. The results from the distance and weightage-based methods aligned with the physical reality on the ground further validate the results. The critical and vulnerable locations required immediate attention and preventive measures to address the deteriorating water quality parameters by installing monitoring stations and treatment plants to stop further contamination of the particular parameter. [ABSTRACT FROM AUTHOR]

Coastal marsh survival relies upon to their ability to increase their elevation and offset sea level rise. It is therefore fundamental to realistically model the sediment fluxes between marshes, tidal channels and bays. Traditionally, numerical models have been calibrated and validated using in-situ measurements located in few locations within the domain of interest. These datasets typically provide temporal information but lack spatial variability. This paper explores the potential of coupling numerical models with high resolution remote sensing imagery. Products from three sensors from the recent NASA DeltaX airborne mission are used. UAVSAR provides vertical water level change on the marshland, and was used to adjust the bathymetry and calibrate the water fluxes over the marsh. AirSWOT yields water surface elevation within bays, lakes and channels and was used to calibrate the Chezy bottom friction coefficient. Finally, imagery from AVIRIS-NG provide maps of total suspended solids (TSS) concentration that were used to calibrate sediment parameters of settling velocity and critical shear stress for erosion. Three numerical models were developed at different locations and scales along coastal Louisiana using Delft3D. The coupling enabled a spatial evaluation of model performance not possible using simple point measurements. Some limitations were highlighted in the remote sensing imagery and the numerical models that need to be accounted for when comparing the results. Overall, the study shows that calibration of numerical models and their general quality will greatly benefit from remote sensing. [ABSTRACT FROM AUTHOR]

This study provides a comprehensive review of the efforts utilized in the measurement of water quality parameters (WQPs) with a focus on total dissolved solids (TDS) and total suspended solids (TSS). The current method used in the measurement of TDS and TSS includes conventional field and gravimetric approaches. These methods are limited due to the associated cost and labor, and limited spatial coverages. Remote Sensing (RS) applications have, however, been used over the past few decades as an alternative to overcome these limitations. Although they also present underlying atmospheric interferences in images, radiometric and spectral resolution issues. Studies of these WQPs with RS, therefore, require the knowledge and utilization of the best mechanisms. The use of RS for retrieval of TDS, TSS, and their forms has been explored in many studies using images from airborne sensors onboard unmanned aerial vehicles (UAVs) and satellite sensors such as those onboard the Landsat, Sentinel-2, Aqua, and Terra platforms. The images and their spectral properties serve as inputs for deep learning analysis and statistical, and machine learning models. Methods used to retrieve these WQP measurements are dependent on the optical properties of the inland water bodies. While TSS is an optically active parameter, TDS is optically inactive with a low signal–noise ratio. The detection of TDS in the visible, near-infrared, and infrared bands is due to some process that (usually) co-occurs with changes in the TDS that is affecting a WQP that is optically active. This study revealed significant improvements in incorporating RS and conventional approaches in estimating WQPs. The findings reveal that improved spatiotemporal resolution has the potential to effectively detect changes in the WQPs. For effective monitoring of TDS and TSS using RS, we recommend employing atmospheric correction mechanisms to reduce image atmospheric interference, exploration of the fusion of optical and microwave bands, high-resolution hyperspectral images, utilization of ML and deep learning models, calibration and validation using observed data measured from conventional methods. Further studies could focus on the development of new technology and sensors using UAVs and satellite images to produce real-time in situ monitoring of TDS and TSS. The findings presented in this review aid in consolidating understanding and advancement of TDS and TSS measurements in a single repository thereby offering stakeholders, researchers, decision-makers, and regulatory bodies a go-to information resource to enhance their monitoring efforts and mitigation of water quality impairments. [ABSTRACT FROM AUTHOR]

Bali Province, Indonesia, experiences serious water shortages and groundwater over-abstraction due to rapidly increasing water demand. Therefore, this study aimed to assess the potential for water reclamation and reuse in Bali Province, focusing on the operational performance of two wastewater treatment plants (WWTPs). Although the Suwung WWTP could increase its treatment capacity to produce reclaimed water for irrigation and landscape, there are multiple management issues to be addressed, including fluctuating water demand, limited customer base beyond hotels, concerns about water quality and safety, and cultural perceptions of reclaimed water. In addition, despite the organic loading rates being lower than the design value, the treatment performance of the Suwung WWTP was found to be significantly lower than that of the ITDC WWTP, which achieved high BOD, COD, and TSS removal rates by performing good maintenance of aerators and post-treatment based on dissolved air flotation (DAF). Causal loop analysis indicates that aerator malfunctioning causes multiple problems, such as low dissolved oxygen, poor BOD removal, sludge carryover, and low sludge concentrations. Therefore, regular maintenance of aerators, as well as the development of aerators robust against malfunctioning, are fundamental to producing effluents from stabilization ponds that meet the requirements for irrigation and landscape reuse. [ABSTRACT FROM AUTHOR]

Vegetable tannery wastewater, highly laden with recalcitrant organics, is not easily treatable through biological processes. This study focuses on the use of response surface methodology in optimizing a coagulation-flocculation process for pretreatment of vegetable tannery wastewater. This study also assessed the possibility of replacing chemical coagulants such as aluminum sulphate with green alternatives such as cassava starch and orange peel powder. The effects of coagulant dosage and pH on three key wastewater quality parameters (chemical oxygen demand (COD) and total suspended solids (TSS)'s removal efficiencies as well as sludge volume index (SVI)) were also assessed. Quadratic models developed for all the three responses were adequate. The optimal conditions were attained at a pH of 3.17 and a dosage of 2.76 g/L for cassava starch coagulant, pH of 3.74 and a dosage of 5.16 g/L for orange peel powder coagulant, and pH of 6.09 and a dosage of 11.60 g/L for aluminum sulphate. The COD and TSS removal efficiencies as well as SVI achieved under these optimal conditions were 37.25%, 73.95%, and 14.80 mL/g, respectively, for cassava starch coagulant; 17.97%, 66.08%, and 19.87 mL/g, respectively, for orange peel powder coagulant; and 38.51%, 76.06%, and 29.57 mL/g, respectively, for aluminum sulphate. The outperformance of cassava starch over orange peel powder and its comparable results with aluminum sulphate makes the former a more environment-friendly alternative to aluminum sulphate for treatment of tannery wastewater. [ABSTRACT FROM AUTHOR]

The selectivity of catalytic materials suitable for oxygen reduction potential of bio‐electrochemical systems is very affluent. Therefore, exploring magnetite and static magnetic field as alternative option to promote microbial electron transfer comes in handy. In this study, the application of magnetite‐nanoparticles and a static magnetic field on a microbial fuel cell (MFC) in anaerobic digestion was investigated. The experimental set‐up included four 1 L biochemical methane potential tests: a) MFC, b) MFC with magnetite‐nanoparticles (MFCM), c) MFC with magnetite‐nanoparticles and magnet (MFCMM), and d) control. The highest biogas production obtained was 545.2 mL/g VSfed in the MFCMM digester, which was substantially greater than the 117.7 mL/g VSfed of the control. This was accompanied by high contaminant removals for chemical oxygen demand (COD) of 97.3%, total solids (TS) of 97.4%, total suspended solids (TSS) of 88.7%, volatile solids (VS) 96.1%, and color of 70.2%. The electrochemical efficiency analysis revealed greater maximum current density of 12.5 mA/m2 and coulombic efficiency of 94.4% for the MFCMM. Kinetically, the cumulative biogas produced data obtained were well fitted on the modified Gompertz models and the greatest coefficient of determination (R2=0.990) was obtained in the MFCMM. Therefore, the application of magnetite‐nanoparticles and static magnetic field on MFC showed a high potential for bioelectrochemical methane production and contaminant removal for sewage sludge. [ABSTRACT FROM AUTHOR]

The Karasu River (Van, Turkey) is one of the most important sources of intensive reproduction for Tarek (Alburnus tarichi Güldenstädt, 1814) in the Van Lake basin. However, sand pits and sand extraction activities in the Karasu River threaten the spawning areas of A. tarichi. This study aimed to investigate how increased sediment concentration in the Karasu River affects the eggs and larvae of A. tarichi during the reproductive period. The study in the laboratory was designed by measuring total suspended solids and turbidity associated with the river over two years for five different experimental groups (corresponding to 0, 10, 50, 100, and 600 mg L-1, and associated groups: control group, Group 1, Group 2, Group 3, and Group 4, respectively). The percentage of hatched out larvae was statistically different between the groups (p<0.05). The highest percentages of hatched out larvae were found in the control group (73.98±5.89%) and Group 1 (68.05±2.96%). The highest survival rates in larvae were determined in the control group (53.35±5.62%) and Group 1 (44.98±4.41%). These results demonstrate that A. tarichi is sensitive to suspended solid concentrations that are very common in the natural environment. In conclusion, sand pits and sand extraction activities must be stopped completely during the reproductive period of A. tarichi between May and July and strict controls should be put in place during this time. These measures will provide an important contribution to ensuring the continuity of this species. [ABSTRACT FROM AUTHOR]

This work describes the design, construction, and evaluation of a sequential discontinuous reactor with recirculation and aeration through a Herschel-type Venturi tube made of high-density polyethylene, coupled to a centrifugal pump. Four laboratory-scale prototypes were built, each with a volume of 8 L and a characteristic distance for venturi discharge. During the evaluation, temperature, pH, and dissolved oxygen were monitored. Also, the chemical oxygen demand (COD), the biological oxygen demand (BOD5), and the total suspended solids (TSS) in the clarified discharge liquid were determined. The BOD5 reduction efficiency registered values higher than 80%, while the COD reduction efficiency was around 60%. Thus, the action of microorganisms reduced the biodegradability factor, the BOD5, and contributed to the DQO through soluble microbial products. Besides, the increase of solids retention time (SRT) evidenced the increase in biomass settleability, which positively contributed to SBR operation. The results obtained support the implementation of the sequential batch reactor with mixing and aeration by recirculation through a Venturi as a technology for wastewater treatment. [ABSTRACT FROM AUTHOR]

Heavy metal contamination ruins the ecosystem and water quality. The adsorption method for heavy metal remediation is preferred because of its low cost and high efficiency. This work created eco-friendly ground biochar (GB) biomass-based derivatives reinforced polylactic acid (PLA) with titanium dioxide (TiO2). The composites improved palm oil mill effluent (POME) conditions, and H2SO4 activation increased pores by 80%. PLA and TiO2 altered GB characteristics, according to FTIR analysis. A significant adhesion interaction showed that GB, PLA, and TiO2 particles were compatible. Ball milling's shear force increased surface area, according to Brunauer-Emmett-Teller (BET) research. Particle size reduction increased GB porosity. Scanning electron microscopy (SEM) was used to study the porous structure of GB and the synergistic effect of PLA and TiO2 on POME during treatment. The SEM showed several components on the composite surface, demonstrating its efficacy. Atomic absorption spectroscopy (AAS) showed that sample C's composite, which had the most GB, decreased POME heavy metals by 94.4% manganese (Mn), 88.4% cadmium (Cd), and 94.4% zinc (Zn). The resulting POME met the Malaysian Department of Environment's POME discharge limit by reducing chemical oxygen demand (COD), total suspended solids (TSS), turbidity, and pH. [ABSTRACT FROM AUTHOR]

This study assessed the spatio-temporal dynamics of the phytoplankton community in backwaters of the Ketar River, central Ethiopia, in relation to water quality and macrophyte coverage. Phytoplankton samples and physicochemical information were collected at six sites along the river over 1 year (December 2017 to November 2018). Phytoplankton was collected using a 15-μm mesh net. A total of 56 species belonging to three algal phyla were identified; the most diverse phylum was Bacillariophyta (35 species), followed by Chlorophyta (13 species) and Euglenophyta (eight species). Bacillariophyta had the highest abundance and contributed 80.08% of the total phytoplankton abundance. Site 6 in the downstream portion had the highest abundance and greatest diversity of phytoplankton species. The algal phyla present showed significant differences in species diversity and abundance both spatially and temporally. Redundancy analysis results revealed that the spatial distribution of phytoplankton in the river positively correlated with pH, electrical conductivity, dissolved oxygen and nitrate-nitrogen, while water temperature and total suspended solids correlated negatively. Some indicators of organic pollution suggest that the water quality of the river is progressively declining, meriting close monitoring. [ABSTRACT FROM AUTHOR]

The condition of reducing the negative impact on the environment and especially on natural water sources, caused by industry, justifies that the treatment of industrial water is a process of vital importance within the operating activities of companies, which is why it is proposed as an objective in this research, the use of chitosan as a coagulant and flocculant, to treat industrial water generated in the production processes of paint and glue of a company in the industry, in order to propose an environmentally sustainable industrial water treatment process. The evaluations of indicators related to the treatment of industrial water using chitosan to promote the coagulation and flocculation process allow inferring that the process is successful, and the values obtained for pH, chemical oxygen demand (COD), total dissolved solids (TDS), and total suspended solids (TSS) are suitable for disposal in the internal sewage system. The post-treatment water obtained has pH values between 6.8-7.5, COD reduction of about 85 %, and STD and STS reduction of about 90 %, considerably reducing the negative effects of the various components involved in the company's production processes and making it suitable for disposal into the sewage system. [ABSTRACT FROM AUTHOR]

The rate at which freshwater sources are being contaminated by mining operations in the South-Western part of Ghana is alarming. However, no study has quantified the degree of contamination of the freshwater in such areas, leaving a gap in the literature that requires immediate attention. This study assessed the quality of the surface and groundwater in the Tarkwa Nsuaem Municipality. Even though the physical parameters such as pH and electrical conductivity were indicative of safe freshwater, other parameters such as turbidity, total suspended solids (TSS), dissolved oxygen (DO), and heavy metals in the water sources were high; thus, confirming possible leaching, runoff, and dissolution of the hazardous substances employed in the manganese mining operations. The water quality of 82% of the water sources along the Kawere Stream was low (Classes III and IV). Therefore, the local people are at risk of contracting water-related diseases, and health problems associated with the ingestion of Fe, As, and Mn. The findings in this study are important in establishing the rate at which mining operations are reducing the quality of freshwater in developing countries, and potentially affecting human health. [ABSTRACT FROM AUTHOR]

Introduction: The honey water generated in the wet coffee processing becomes one of the most contaminating byproducts of water sources and soil due to their high organic load, characterized by nutrients such as lipids, enzymes, proteins, sugars, among others. Objective: to evaluate the efficiency of biological processes aimed at reducing COD and BOD in an artisanal system for the treatment of coffee water and its potential use at the end of the process. Materials and methods: an artisanal system for the biological treatment of coffee wastewater was built, consisting of two biofilters inoculated with efficient microorganisms and a green lagoon that includes the use of aquatic plants such as Azolla filiculoides and Pistia stratiotes, the efficiency of the process was measured through the analysis of the variables; pH, total suspended solids, turbidity, BOD and COD, Results: Removal efficiencies of up to 93.4 % for BOD and 94.24 % for COD were achieved, thereby ensuring compliance with the guidelines outlined in Article 9 of Resolution 631 of 2015 concerning the discharge of spent water. Subsequently, the treated spent waters were employed for fertigation, serving as irrigation for oneyear- old King grass plots. A comparison was made with untreated plots. The fertigated plots exhibited a high biomass production (223 %) and maintained the nutritional composition of the grass without impacting soil characteristics. Conclusion: The artisanal treatment system showed high percentages of removal of organic load from the coffee wastewater, enabling its reuse for King grass fertigation with high biomass yields. [ABSTRACT FROM AUTHOR]

The waste and inadequate management of organic waste generates environmental problems in cities; this research proposes the reuse of waste such as pineapple peel to create new eco-friendly materials. In order to determine whether it is feasible or not, it is necessary to perform the physicochemical characterization of the peel, describing in detail the performance of the process, measuring turbidity, color, acidity by titration, boiling point, humidity, total suspended solids, Brix grades, mesh screening, analysis of the degrading fungus from the peel to the weather and PH. The main conclusion is that pineapple peel juice contains favorable properties for making new eco-friendly materials. [ABSTRACT FROM AUTHOR]

Statistical process control techniques are useful tools for monitoring the production process and detecting abnormal process behavior due to special causes. Once the special causes for abnormal process behavior are identified and consequently eliminated, the process can be further improved. The aim of this study is to apply univariate and multivariate statistical process control techniques to enhance the monitoring of a wastewater treatment process and achieve a higher effluent quality. Phase I, Shewhart univariant control charts and Hotelling's T2 multivariate control chart were developed for non-correlated and correlated variables of a wastewater treatment plant, respectively. Five representative water quality parameters: turbidity, total suspended solids (TSS), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and fecal coliform were investigated. The interpretation of the Phase I for both types of control charts initially revealed that the process was out of statistical control conditions for all the investigated variables. T2 decomposition technique revealed that the main contributors for the out-of-control points were turbidity with 67% (average T2 = 28.86) followed by TKN 25% (average T2 = 31.12). The assignable causes for the observed abnormalities were the result of seasonal variations with respect to the temperature in such hot climates. Control charts proved their applicability for the wastewater process as a quick and efficient monitoring strategy despite the complex nature of the wastewater and the contribution of the hot climate in the Arabian Gulf region. [ABSTRACT FROM AUTHOR]

Owing to its multiple removal mechanism, electrocoagulation (EC) is a potential treatment for stabilized leachate. EC process variables such as current density (CD) (25–85 A/m2) and types of electrodes (iron, aluminum, and zinc) were investigated for up to 2 h in a 1.1 L EC unit equipped with 10 parallel electrodes. The beneficial addition of up to 0.14 g/L of cationic polyacrylamide (cPAM) was also investigated. Besides chemical oxygen demand (COD), total suspended solids (TSS), and turbidity, the rarely reported Cu and As removals were also comparatively elucidated. The run at pH 6.7, CD 75 A/m2 for 1.5 h using iron electrodes led to 39%, 43%, and 68% of COD, TSS, and turbidity removals, respectively. At the same time, 59% of Cu and 67% of As were also removed mainly through the flocs adsorption. 0.1 g/L of cPAM significantly increased the removal efficiencies of COD, TSS, and turbidity by 6%, 28%, and 20%, respectively. However, only 12% of TOC managed to be removed due to the limited effect on soluble organics. Due to an effective inter-particle bridging mechanism, cPAM resulted in larger sludge particles (56.8 µm) compared to that of EC alone (25.4 µm). It also supplemented the charge neutralization and improved the adsorption of soluble constituents in the leachate on the tougher and heavier floc particles. Hence, the EC process coupled with cPAM addition was revealed to be an effective treatment option for stabilized leachate. [ABSTRACT FROM AUTHOR]