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The aim of this study was to evaluate a natural coagulant, Moringa oleifera seeds (MOC), to reduce the color concentration in treated tequila vinasses (TVs). TV-A was the effluent of horizontal subsurface flow wetlands (HSSFW); TV-B was the effluent of vertical up-flow wetlands (VUFW); and TV-C was the effluent of vertical down-flow constructed wetlands (VDFW). Raw TVs were also evaluated with MOC. Jar tests were performed to find the optimal dose and pH value for apparent color (AC) removal. With the optimal dose and pH for each type of TV, tests were performed in triplicate to evaluate the removal of apparent color (AC), true color (TC), turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and electrical conductivity (EC). For TV-A and TV-B, the optimal values were 1 g/L of MOC and pH 8, and the removals were 52%, 43%, 50% and 72% of AC, turbidity, TC, and TSS, respectively. For TV-C, the optimal values were 2.5 g/L and pH 5, with removals of 66%, 73%, and 98% for AC, TC, and TSS, respectively. For TV-D, the MOC had no coagulant effect in any of the experimental conditions evaluated, probably due to the high concentration of turbidity and TSS in the raw vinasses, which prevented the interaction between MOC and melanoidins. Deeper studies are required to understand and evaluate those factors that influence MOC efficiency so that the coagulation–flocculation process can be optimized. [ABSTRACT FROM AUTHOR]

Advancements in smart sensing and control technologies enable urban drainage engineers to retrofit stormwater storage facilities with real-time control devices for mitigating stormwater in-site overflow, downstream flooding, and overloaded total suspended solids (TSS) in drainage pipes. While the smart technology can improve the performance of the static drainage systems, coordinatively controlling multiple valve and gate operations poses a significant challenge, especially at a large-scale watershed. Using a benchmark stormwater model located at Ann Arbor, Michigan, USA, we assessed the impact of different real-time control strategies (local individual downstream control and system-level multiple control) on balancing flooding mitigation at downstream outlets and TSS reduction at upstream storage units, such as detention ponds. We examined changes in peak water depth, outflow, and TSS as indicators to assess changes in water quantity and quality. The results indicate that system-level control can reduce peak water depth by up to 7.3%, reduce flood duration by up to 34%, and remove up to 67% of total suspended solids compared with a baseline uncontrolled system, with the outflow from upstream detention ponds being the most important hydraulic indicator for control strategy rule set-up. We find that system-level control does not always outperform the individual downstream controls, particularly in alleviating flooding duration at some downstream outlets. With urban growth and a changing climate, this research provides a foundation for quantifying the benefits of real-time control methods as an adaptive stormwater management solution that addresses both water quantity and quality challenges. [ABSTRACT FROM AUTHOR]

Marine pollution poses significant risks to both human and marine health. This investigation explores the limnological status of the Odisha and West Bengal coasts during the annual cruise program, focusing on the influence of riverine inputs on coastal marine waters. To assess this impact, physicochemical parameters such as pH, salinity, total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), and dissolved nutrients (NO2-N, NO3-N, NH4-N, PO4-P, SiO4-Si, total-N, and total-P) were analyzed from samples collected along 11 transects. Multivariate statistics and principal component analysis (PCA) were applied to the datasets, revealing four key factors that account for over 70.09% of the total variance in water quality parameters, specifically 25.01% for PC1, 21.94% for PC2, 13.13% for PC3, and 9.99% for PC4. The results indicate that the increase in nutrient and suspended solid concentrations in coastal waters primarily arises from weathering and riverine transport from natural sources, with nitrate sources linked to the decomposition of organic materials. Coastal Odisha was found to be rich in phosphorus-based nutrients, particularly from industrial effluents in Paradip and the Mahanadi, while ammonia levels were attributed to municipal waste in Puri. In contrast, the West Bengal coast exhibited higher levels of nitrogenous nutrients alongside elevated pH and DO values. These findings provide a comprehensive understanding of the seasonal dynamics and anthropogenic influences on coastal water quality in Odisha and West Bengal, highlighting the need for targeted conservation and management efforts. [ABSTRACT FROM AUTHOR]

With the aim to establish clean and sustainable sludge treatment, green conditioning using natural flocculants has recently gained a growing interest. In this study, a variety of plant materials, namely Moringa (Moringa oleifera) seeds, Fenugreek (Trigonella foenum-graecum) seeds, Potato (Solanum tuberosum) peels, Aloe (Aloe vera) leaves, Cactus (Opuntia ficus indica) cladodes, and Phragmites (Phragmites australis) stems, were evaluated for their potential bioflocculant activity in conditioning sewage sludge. They were thoroughly characterized to determine their active flocculating compounds. Sludge dewaterability was evaluated by assessing various sludge parameters, including specific resistance to filtration (SRF), dryness of filtration cake (DC), and total suspended solid removal (TSS) from sludge filtrate. The collected results from various physicochemical characterizations of plant materials suggest that the main flocculating agents are carbohydrates in Cactus and Fenugreek and proteins in Moringa, Potato, and Phragmites. Additionally, all tested plant-based flocculants demonstrated effective dewatering performance. Interestingly, compared to the chemical flocculant polyaluminum chloride, Moringa and Cactus showed superior conditioning effects, yielding the lowest SRF values and the highest DC. As a result, the use of these natural flocculants improved sewage sludge filterability, leading to a significant removal of total suspended solids from the filtrate. The conditioning properties of Moringa and Cactus can be attributed to their high protein and sugar content, which facilitates the effective separation of bound water from solids through charge neutralization and bridging mechanisms. Thus, green conditioning using plant-based flocculants, particularly Moringa and Cactus materials, presents a promising and eco-friendly approach to enhance sewage sludge dewatering for safer disposal and valorization. [ABSTRACT FROM AUTHOR]

This study investigates the efficiency of a hybrid coagulation–flocculation process for the treatment of industrial wastewater from the steel industry. The novel method combines a natural coagulant, processed Rosehip Seed Powder (RSP), with a chemical coagulant, aluminum chloride (AlCl3), across varying concentrations and pH levels. The study simulated the pH 8 conditions of iron and steel industrial wastewater and examined the removal of heavy metals, total suspended solids (TSS), chemical oxygen demand (COD), and ammonia–nitrogen (NH3-N). At pH 8, the optimal coagulant dosage was determined to be 0.75:0.75 (g/g) of RSP/AlCl3 powder, resulting in high removal efficiencies across several parameters: 88.29% for COD, 91.85% for color, 99% for TSS, 93.11% for NH3-N, 94.3% for Mn, 98.5% for Fe, 96.7% for Zn, and 99.3% for Ni. The pH optimization demonstrated high removal efficiencies without pH adjudication. The removal of heavy metals at pH 8 demonstrated high efficiencies, with Mn, Fe, Zn, and Al achieving 99.00%, 90.6%, 95.73%, and 92.3%, respectively. These results suggest that no pH adjustment is required when using RSP/AlCl3 for the treatment of iron and steel industry wastewater through the coagulation method. [ABSTRACT FROM AUTHOR]

The Water Quality Index (WQI) is a tool designed to provide a singular figure representing the overall water quality status of a water body. This study applies Malaysia WQI, National Sanitation Foundation WQI (NSFWQI) and statistical analysis to investigate the impact of diverse pollution sources on the Brunei River's water quality, a critical aquatic ecosystem affected by the rapid escalation of urbanization, industrial activities, and agricultural runoff. Principal component analysis (PCA), expert judgement, and correlation analysis were used to propose parameters for developing Brunei River's WQI. Eight monitoring stations were selected to analyze 16 water quality parameters (pH, water temperature (T), dissolved oxygen (DO), oxidation-reduction potential (ORP), chemical oxygen demand (COD), the five-day biochemical oxygen demand (BOD5), salinity, electrical conductivity (EC), total dissolved solids (TDS), turbidity, total suspended solids (TSS), ammoniacal-nitrogen (NH3-N), fecal coliform (FC), total coliform (TC), phosphate and nitrate (NO3−) in this study. The results showed that NSFWQI classified the Brunei River as moderately polluted, while Malaysia (WQI) status was classified as slightly polluted except for Station Q around the quarry area. Statistical analysis revealed that the primary pollution sources are anthropogenic activities such as quarrying, domestic waste, and agricultural and urban runoff. Other specific areas of concern with low WQI and significant pollution levels are situated at Kampong Ayer Stations (N and J) due to proximal anthropogenic activities. The proposed water quality parameters for developing Brunei River's WQI are pH, DO, EC, FC, NO3−, BOD5, T, TSS, turbidity and phosphate. This study addresses the current pollution status of the Brunei River and sets a precedent for future research emphasizing collaborative data-driven strategies for water quality management. [ABSTRACT FROM AUTHOR]

The development of sponge cities advocates for sustainable urban rainwater management, effectively alleviating urban flood disasters, reducing non-point-source pollution, and promoting the recycling of rainwater resources. Low-Impact Development (LID) serves as a key strategy in this context, providing essential support for urban rainwater control and pollution reduction. To investigate the runoff control effects of LID measures and to reveal the relationship between facility runoff control performance and installation scale, this study focuses on a sponge community in Beijing. A SWMM model was constructed to analyze the rainwater flood control and pollutant load reduction effects of different LID facilities, including bio-retention cells, green roofs, and permeable pavements. Using evaluation indicators such as surface runoff, node overflow, and pollutant control rates, this study examined how facility performance varies with installation scale under different rainfall conditions. The combination scheme of LID equipment optimal configuration is designed by using multiple criteria decision analysis (MCDA) and cost–benefit theory. The results indicate significant differences in performance among the various LID facilities across different rainfall scenarios. Specifically, the optimal installation proportion for runoff and overflow control of permeable pavements were found to be between 30% and 70%. Green roofs demonstrate superior performance in handling extreme rainfall events, while bio-retention cells exhibit significant effectiveness in controlling Total Suspended Solids (TSSs). Through comprehensive performance evaluation, this study identified the optimal combination scale under a 3-year rainfall recurrence interval as 30% permeable pavements, 20% green roof, and 60% bio-retention cells. This combination effectively leverages the strengths of each facility, ensuring system stability and efficiency while also demonstrating optimal management efficiency in cost–benefit analyses. The findings of this research provide valuable insights for future urban water management and infrastructure development. [ABSTRACT FROM AUTHOR]

This document discusses the importance of rivers in supporting biodiversity and ecosystem services. It highlights the need for integrated approaches to river basin management in order to maintain water quality and quantity. The document also addresses the impact of anthropogenic activities on rivers, such as damming and pollution, which have led to habitat destruction and reduced aquatic biodiversity. The text presents several research studies that explore different aspects of river ecosystem services, including fish restocking, wastewater treatment, genetic diversity, antibiotic resistance, harmful algal blooms, and mine drainage remediation. The conclusion emphasizes the importance of interdisciplinary approaches and stakeholder involvement in ecosystem management. [Extracted from the article]

The intricate processes of surface water erosion are vital for ecological systems and river-scale management; yet, understanding them comprehensively remains a challenge. Forested agricultural catchments, especially in the Carpathian region, face significant degradation, potentially leading to inorganic nutrient leaching and total suspended solid (TSS) flux. Continuous rainwater inundation of soils in river valleys exacerbates this issue. Utilizing innovative tools like SWAT+, studies have revealed higher concentrations of inorganic nutrients in main watercourses from flysch catchments, with agricultural use linked to N-NO3− concentrations and pasture use linked to anion P-PO43−. Maintaining detailed records is crucial for researchers comparing data. SWAT+ proves valuable for studying TSS washing out and inorganic nutrient leaching, informing collaborative watershed management policies involving stakeholders from agriculture, conservation, and water management sectors. The insights on nutrient leaching, particularly phosphorus (P) and nitrogen (N), are instrumental for shaping policies targeting nutrient pollution within pasture land use for EU agriculture. These findings can guide policy frameworks focused on sustainable practices, especially for eco-schemes, and encourage collaborative watershed management efforts. [ABSTRACT FROM AUTHOR]

In this study, two by-products resulting from the processing of cherry (stems and pits) were used as natural coagulants to promote the valorization of these wastes and treat olive mill wastewater (OMW). The efficacy of the plant-based coagulants (PBCs) in the coagulation–flocculation–decantation process (CFD) was evaluated through the removal of turbidity, total suspended solids (TSS), total polyphenols (TPh), and dissolved organic carbon (DOC). The CFD process was demonstrated to be effective in turbidity and TSS reduction in OMW. Using cherry stems (CSs), these reductions were 65.2% of turbidity and 58.0% of TSS, while cherry pits (CPs) achieved higher reductions, 78.6% of turbidity and 68.2% of TSS. To improve the effectiveness of OMW treatment, mainly regarding the removal of TPh and DOC, the CFD process was complemented with the adsorption process (using bentonite clay). The adsorption capacity of bentonite was higher in acidic conditions (pH 3.0) and, with a dosage of 3.0 g L−1, reached 17.3 mg of DOC and 13.8 mg of TPh per gram of bentonite. Several adsorption isothermal models were assessed, and the Langmuir (r2 = 0.985), SIPS (r2 = 0.992), and Jovanovic models (r2 = 0.994) provided the best fittings. According to the optimal operational conditions defined throughout the present work, the combination of CFD and adsorption removals were as follows: (1) 98.0 and 91.3% of turbidity, (2) 80.8 and 81.2% of TSS, (3) 98.1 and 97.6% of TPh and (4) 57.9 and 62.2% of DOC, for CSs and CPs, correspondingly. Overall, the results suggest that cherry by-products can be used as low-cost natural coagulants and, when combined with another natural, abundant, and cheap material, such as bentonite clay, can be a sustainable alternative for treating OMW. [ABSTRACT FROM AUTHOR]

Rainwater runoff samples from a range of roofing materials were temporally collected from 19 small-scale roof structures and two commercial buildings through simulated and actual storm events, and the concentrations of polycyclic aromatic hydrocarbons (PAHs), phosphorus flame retardants (PFLs), and pyrethroid insecticides and other water quality parameters were analyzed. In Part I of this research, the concentrations of these contaminants in roof runoff and soils receiving runoff from a range of roofing materials were evaluated. In Part II, recommendations have been developed for a first-flush exclusion to improve the quality of water harvesting for nonpotable uses. Recommendations focus on a first-flush diversion based on mass removals of total suspended solids (TSS) and PAHs linked to conductivity measurements throughout a storm event. Additionally, an upper-confidence limit (UCL) was constructed to determine the minimum diversion required to obtain 50, 75, 90, and 95% mass removal of TSS and PAH contaminants. The majority of TSS were produced during the initial 1.2 mm of runoff. Likewise, the majority of PAHs were removed during the initial 1.2 mm of runoff, except for the asphalt shingle roofs, where high PAHs were observed after 6 mm of runoff. The Texas Water Development Board (TWDB)-recommended first-flush diversion of one gallon for every 100 square feet of rooftop was not always adequate for removing 50% of TSS and PAHs from the roofs. Rainwater runoff conductivity decreased drastically between 1.2 to 2.4 mm of rainwater runoff. Diverting the first flush based on conductivity has the potential to also divert the majority of TSS and PAHs in roof runoff. [ABSTRACT FROM AUTHOR]

Rainfall runoff may be captured and stored for later use, but the quality of this water can be detrimental in some uses without the use of appropriately designed first-flush diverters. The rainfall runoff water quality was measured on nineteen new small-scale and two aged commercial roofs located near high traffic highways. Roof coverings included asphalt shingles, sheet metal, clay tiles, and tar and gravel. Runoff samples were evaluated for polycyclic aromatic hydrocarbons (PAHs), phosphorus flame retardants (PFRs), and pyrethroid insecticides. Eighteen small-scale roofs were subjected to a range of simulated rainfall events, while natural runoff was sampled on the commercial roofs and one small-scale roof. Runoff was analyzed for pH, conductivity, turbidity, total suspended solids, boron, iron, copper, zinc, manganese, sodium adsorption ratio, nitrate-nitrogen, seventeen PAHs, tris(2-chloroethyl) phosphate, tris(1,3-dichloro-2-propyl)phosphate, bifenthrin, cypermethrin, and lambda-cyhalothrin. Samples from four natural storm events were also analyzed for total coliforms and Escherichia coli. In addition, soils below seventeen existing gutter downspouts were sampled to determine long-term pollutant accumulation. Atmospheric deposition was the main contributor of pollutants in the roof runoff. A majority of samples fell within the U.S. EPA guidelines for non-potable urban and agricultural water reuse. Trace levels of PAHs, PFRs, and insecticides were detected, but all detections were three orders of magnitude below the USGS health-based screening level benchmark concentrations. Results indicate that diverting the first flush, based on turbidity, total suspended solids, or conductivity, can improve the overall water quality and reduce the concentrations of PAHs in harvested rainwater. Downspout soil sampling showed potential for the long-term accumulation of PAHs at concentrations exceeding the minimum human-health risk-based screening levels at these high runoff-loading locations. [ABSTRACT FROM AUTHOR]

Dams are regarded as crucial pieces of structure that store water for irrigation and municipal uses. Given their vital role, the dam's water quality assessment is considered to be an important criterion and requires constant monitoring. In this research, we attempted to use two water quality indices (WQIs) methods to assess the water quality of the Keddara Dam, which is located on the Boudouaou River, Algeria, using eleven water quality parameters (temperature, pH, conductivity, turbidity, total suspended solids (TSS), full alkalimetric title (TAC), hydrometric title (TH), nitrite ions (NO2−), nitrate ions (NO3−), ammonium ions (NH4+), and phosphate ions (PO43−)) for data recorded from 29 December 2018 to 3 June 2021. Application of The Canadian Council of Ministers of the Environment (CCME) WQIs and the Weighted Arithmetic Method (WAM) indicated that the Keddara Dam's water quality parameters were within the WHO's permissible level, except for the conductivity and turbidity values. The results of the CCME WQI ranged from acceptable (81.92) to excellent (95.08) quality, whereas the WAM WQI ranged from 9.52 to 17.77, indicating excellent quality. This demonstrates that the Keddara Dam is appropriate for agriculture and municipal use. The water quality indices (WQIs) methods are recommended as valuable tools that allow both the public and decision-makers to comprehend and manage the water quality of any aquatic environment by providing flexibility in choosing variables. [ABSTRACT FROM AUTHOR]

This study evaluates the pollution of the Machángara River basin in Ecuador. For the assessment, water samples were pumped from the river for 1 to 4 h, with a representative water sample of 4 L collected. In the site and laboratory, the physicochemical parameters, carbamazepine (CBZ), and diclofenac (DIC) concentrations were measured using standardized analytical methods. On average, a temperature of 17.02 °C, pH of 7.06, electrical conductivity of 760.96 µS/cm, and turbidity of 83.43 NTU were found. Furthermore, the average solids content was 72.88, 495.47, and 568.35 mg/L for total suspended solids (TSS), total dissolved solids (TDS), and total solids (TS) in that order. The highest chloride concentration (Cl− = 87.97 mg/L) was below the maximum permissible limit (MPL) based on the Ecuadorian regulations for surface and underground water for human consumption and domestic use, which only require conventional treatment. In contrast, levels of nitrate (NO3− = 27.75–288.25 mg/L) and nitrite in five points (NO2− = 2.02–5.42 mg/L) were higher than the MPLs. Moreover, sulfate (SO42− = 34.75–110 mg/L) and phosphate (PO4−P = 4.15–16.58 mg/L) contents caused turbidity and eutrophication in the river water., Additionally, concentrations of copper (Cu2+ = 0.002–0.071 mg/L), zinc (Zn2+ = 0.001–0.011 mg/L) and iron (Fe3+ = 0.000–0.287 mg/L) were within the permissible limits. On the other hand, carbamazepine concentrations in the Machángara River basin were below the limit of detection (LOD) up to a value of 0.121 mg/L. At the same time, diclofenac levels ranged from 9.32 to 48.05 mg/L. The concentration discrepancy for both pharmaceuticals is linked with the trend of drug consumption by Quito's inhabitants. As measured in this investigation, meaningful amounts of CBZ and DIC are released to the Machángara River. Accordingly, the two pharmaceuticals in the river water may be dangerous for aquatic species. [ABSTRACT FROM AUTHOR]

In regions where drought has become a common occurrence for most of the year and where agriculture is the main economic activity, the development of hydro-agricultural systems has made it possible to improve water management. Despite this, the intensification of agriculture combined with climate change leads to a potential decrease in water quality and water management practices are essential to improve agro-environmental sustainability. The aim of this study was to assess the water quality for irrigation and potential ecological status of the reservoir (using support chemical parameters). The results showed biological oxygen demand values above the maximum stipulated for an excellent ecological potential in all sampling periods except April 2018 and December 2020 (with the highest values of 10 mg L−1 O2 in dry periods). Most of the total nitrogen concentrations (TN) surpassed those stipulated for a good ecological potential (0.96 ≤ TN ≤ 2.44 mg L−1 N). In fact, TN and total suspended solids were the main parameters used for water classification. From the perspective of irrigation and according to FAO guidelines regarding infiltration rate, these waters presented light to moderate levels of restrictions. Thus, the results revealed that the decrease in the water quality status and its possible impact on the soil infiltration rate can be related, in part, to the meteorological conditions and to the intensive agricultural practices developed around the drainage basin. Despite that, as the Lage reservoir is part of Brinches–Enxoé hydraulic circuit, the water recirculation is also an important factor that may have affected the results obtained. Furthermore, the experimental design, integrating ecological status, irrigation parameters, and the impact on soil systems; using the same parameters from different perspectives; allowed us to have a global idea of water contamination and its impact on agroecosystems, improving river basin management processes. [ABSTRACT FROM AUTHOR]

Given the critical importance of addressing effluent quality concerns, the present study was dedicated to developing a dynamic simulation model based on the Activated Sludge Model 1 (ASM1) of a wastewater treatment plant located in Maghnia City, Algeria. The model calibration process involved collecting and analyzing 56 samples from the plant over a period of 18 months (from July 2021 to January 2023). Thirteen physicochemical parameters were analyzed to identify the variations in their water quality over time. Stoichiometric and kinetic parameters were adjusted during the plant calibration process. These modifications resulted in a reasonable alignment with the investigated variables, enabling the accurate prediction of the wastewater treatment plants (WWTPs)' steady-state behavior regarding the removal measurements of chemical oxygen demand (COD), total suspended solids (TSS), and ammonium (NH4-N). The model was validated using 14-day measurements spanning a 4-month duration, and the results indicated good agreement between the observed and simulated effluent variable of chemical oxygen demand (COD) with a root mean square error (RMSE) of 23%. These findings highlight the utility of the ASM1 Model in comprehending and managing the intricate dynamics of the activated sludge process in wastewater treatment plants. [ABSTRACT FROM AUTHOR]

Wastewater from plastic manufacturing or processing industries is often highly polluted with microplastics (MPs) and high levels of oxidizable organic matter, which results in a high chemical oxygen demand (COD). When industrial wastewater enters wastewater streams, the high microplastic load is a high burden for municipal wastewater treatment plants (WWTPs), as they are not sufficiently removed. To prevent MP from entering the WWTPs, an upstream prevention method is essential. This paper presents a pilot-scale plant study for the removal of MP and COD from industrial wastewater that was tested on-site at a plastic manufacturer in Germany. Eight test phases were performed over 3 months, with each test phase processing 1 m3 wastewater and four treatments. Per test phase, 12 samples were analyzed for 5 parameters: COD, total suspended solids (TSSs), particle count, pH, and turbidity. The results showed an average decrease in MP by 98.26 ± 2.15% measured by TSSs and 97.92 ± 2.31% measured by particle count. This prevents the emission of 1.1 kg MP/m3 water and an estimated 2.7 t MP/year. The COD was reduced efficiently by 94.3 ± 8.9%. Besides MP and COD, this treatment allows reuse of water and agglomerates, resulting in a reduction in the CO2 footprint. [ABSTRACT FROM AUTHOR]

The Cicatih River in the Cikembar sub-watershed, located in Sukabumi Regency, flows along the upstream of the Cikembar sub-watershed and Palabuhan Ratu Bay. For decades, the river has served as a vital water resource, catering to various needs such as domestic use, agriculture, livestock, fisheries, industry, mining, tourism, and hydroelectric power. Recently, the Sukabumi Regency Government made the pollution of coastal and river areas one of the priority issues on sustainable development initiatives for the Sukabumi Regency. This highlights the importance of managing the Cicatih River, one of the main rivers in the regency. This research aims to analyze the potential pollution loads in the Cikembar sub-watershed to the Cicatih River by assessing its water quality status and potential pollution loads from four main sectors: domestic, agricultural, livestock, and industrial. The water quality was calculated based on the Pollution Index method. The potential pollution load from different sources was analyzed using various emission factor calculations. For each pollutant source, the following parameters were analyzed: total suspended solids (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), Total-N (nitrogen), and Total-P (phosphorus). Results showed that the condition of the Cicatih River is slightly polluted. The parameter exceeding its maximum threshold is BOD. The largest contributor to the potential pollution load of BOD is the domestic sector (53%), while the agricultural sector is the least (2%). In the domestic sector, Bojongkembar Village is the largest contributor to the potential pollution load. The results of this analysis can be used to develop strategies for managing the overall Cikembar sub-watershed. [ABSTRACT FROM AUTHOR]

River pollution resulting from unregulated and improper water sewage management is a global issue of concern. The discharge of inadequately treated sewage into rivers and the sudden release of excessive quantities during heavy rainfall can result in significant fish mortality. This phenomenon has been observed repeatedly in the case of the Sąpólna River, NW Poland. Consequently, a decision was made to monitor the water quality at two key locations: the drainage channel that feeds into the river and downstream of the channel. Seventeen water quality indicators were measured, including temperature, pH, conductivity, total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), total organic carbon (TOC), alkalinity, total hardness, total reactive phosphorus (TRP), total phosphorus (TP), nitrite-nitrogen (NO2−-N), nitrate-nitrogen (NO3−-N), total ammonia nitrogen (NH4-N), total organic nitrogen (TON), and total nitrogen (TN). It was determined that, at the location farthest from the drainage channel, water quality still falls short of meeting the specified standards. The primary factors leading to the degradation of water quality at this point were TSS, TRP, NO2−-N, and TN. It was concluded that the primary localized source of water pollution in the studied section of the Sąpólna River is the discharge from sewage treatment plants in Nowogard. Consequently, actions should be taken to address sewage quality and reduce discharge quantities. [ABSTRACT FROM AUTHOR]

Water transparency is widely used in environmental monitoring programs and in assessing water quality in aquatic environments. The purpose of this study was to determine which of two water transparency-measuring tools, a Secchi disk or a water turbidity meter, is better to assess environments in shallow eutrophic waters. Measurements of the Secchi disk depth (Dsd) and water turbidity (Turb) were carried out simultaneously at eight stations of the hypereutrophic Sestroretsky Razliv reservoir in 2015–2018. In May, October, and December, Dsd varied around 0.6 m but was significantly lower in August during algal blooms. Turbidity ranged from 10 to 20 nephelometric turbidity units (NTU) in different seasons but increased to almost 70 NTU in August. Principal component analysis revealed that Dsd was inversely proportional to Turb, total suspended solids, and chlorophyll concentrations. The data showed that at turbidities below 20 NTU, the Secchi disk clearly distinguishes differences in water transparency, but when Turb exceeds 40 NTU, measuring transparency using the Secchi disk no longer allows for water differentiation. In this case, it is preferable to use water turbidity measurements, which remain an effective indicator even in highly turbid waters. This should be taken into account when assessing the environment in eutrophic waters. [ABSTRACT FROM AUTHOR]

The transition from the linear economy paradigm to the circular economy in industrial wastewater treatment systems is on the global agenda. The search for new simple, eco-innovative, and low-cost processes for treating industrial wastewater, which can also be used by small and medium-sized industries, has been a constant challenge especially when environmental sustainability is considered. So, a new integrated industrial wastewater treatment system has been developed that includes the immediate one-step lime precipitation process (IOSLM) and atmospheric carbonation (AC), followed by constructed wetlands (CWs) or adsorption. The current review provides an overview of industrial wastewater treatment strategies for high- and low-biodegradable wastewater. A background on functionality, applicability, advantages and disadvantages, operating variables, removal mechanisms, main challenges, and recent advances are carried out for each process that makes up the IOSLM+AC+CW/adsorption integrated system. The prospects of the IOSLM+AC+CW/adsorption integrated system are also discussed. Not neglecting the improvements that still need to be made in the integrated treatment system as well as its application to various types of industrial wastewater, this review highlights that this treatment system is promising in industrial wastewater treatment and consequent by-product recovery. The IOSLM+AC integrated system showed that it can remove high amounts of organic matter, total suspended solids, oils and fats, phosphorus, and ammonium nitrogen from industrial effluents. On the other hand, constructed wetlands/adsorption can be alternatives for refining effluents still containing organic matter and nitrogen that were not possible to remove in the previous steps. [ABSTRACT FROM AUTHOR]

Remote sensing plays a crucial role in modeling surface water quality parameters (WQPs), which aids spatial and temporal variation assessment. However, existing models are often developed independently, leading to uncertainty regarding their applicability. This study focused on two primary objectives. First, it aimed to evaluate different models for chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), and total suspended solids (TSS) in a surface water body, the J. A. Alzate dam, in the Mexican highland region (R2 ≥ 0.78 and RMSE ≤ 16.1 mg/L). The models were estimated using multivariate regressions, with a focus on identifying dilution and dragging effects in inter-annual flow rate estimations, including runoff from precipitation and municipal discharges. Second, the study sought to analyze the potential scope of application for these models in other water bodies by comparing mean WQP values. Several models exhibited similarities, with minimal differences in mean values (ranging from −9.5 to 0.57 mg/L) for TSS, TN, and TP. These findings suggest that certain water bodies may be compatible enough to warrant the exploration of joint modeling in future research endeavors. By addressing these objectives, this research contributes to a better understanding of the suitability of remote sensing-based models for characterizing surface water quality, both within specific locations and across different water bodies. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the water quality in two streams of the Valles region of Jalisco, Mexico and fully determine if they are being used as tequila vinasse disposal sites. Three sampling campaigns were carried out at eight different points of the two streams that run near tequila factories (TFs). Different physicochemical parameters of water quality were measured: chemical oxygen demand (COD); biochemical oxygen demand (BOD5); total suspended solids (TSSs); total phosphates; fats, oils, and grease (FOG); Kjeldal nitrogen; nitrite; nitrate; pH; conductivity; temperature; dissolved oxygen (DO); and turbidity. Also, the analysis of samples of tequila vinasses (TVs) diluted with tap water were carried out to have a reference for the level of pollution in the streams. Furthermore, due to the fact that COD could be considered the main indicator of pollution with TVs, a linear regression was performed between COD concentrations and the percentage of dilution of TVs (with tap water). A positive correlation was found between these two variables, and based on this analysis, the vinasse content was estimated at each sampling point of the streams. It was found that on average, a volume of 8.5 ± 6.3% and 11.5 ± 4.9% of TVs were present in each sampling point of the Atizcoa and Jarritos Streams, respectively. Additionally, it was found that, in general, the concentration of pollutants increased as the streams passed through the TFs, particularly the Atizcoa Stream. According to the Water National Commission criteria, most of the points would be classified as highly polluted, since they reach concentrations of COD and BOD5 up to 6590 mg/L and 3775 mg/L, respectively, temperature values up to 37 °C, and DO values of 0.5 mg/L. Therefore, it was confirmed that the streams are being used as tequila vinasse disposal sites. Due to the above, there is an urgent need for tequila companies to implement treatment systems for the vinasse generated, since under current conditions, the monitored streams are practically devoid of aquatic life. [ABSTRACT FROM AUTHOR]

The objective of this study was to model the operation of a vertical-flow constructed wetland (VF-CW) for domestic wastewater, using Monte-Carlo simulations and selected probability distributions of various random variables. The analysis was based on collected wastewater quality data, including the values of the pollutant indicators BOD5 (biochemical oxygen demand), CODCr (chemical oxygen demand), and TSS (total suspended solids), in the 2017–2020 period. Anderson–Darling (A–D) statistics were applied to assess the fit of the theoretical distributions to the empirical distributions of the random variables under study. The selection of the best-fitting statistical distributions was determined using the percentage deviation (PBIAS) criterion. Based on the analyses that were performed, the best-fitting statistical distributions for the pollution indicators of the raw wastewater were the generalised extreme value distribution for BOD5, the Gaussian distribution for CODCr, and the log-normal distribution for TSS. For treated effluent, the log-normal distribution was the best fit for BOD5 and CODCr; the semi-normal distribution, for TSS. The new data generated using the Monte-Carlo method allowed the reliability of the VF-CW operation to be assessed by determining the reliability indices, i.e., the average efficiency of the removal of pollutants (η), the technological efficiency index (R), the reliability index (CR), and the risk index of the negative control of the sewage treatment plant operation (Re). The obtained results indicate that only in the case of CODCr, the analysed treatment facility may fail to meet the requirements related to the reduction of organic pollutants to the required level, which is evidenced by the values of the indicators CR = 1.10, R = 0.49, and η = 0.82. In addition, the risk index of the negative operation of the facility (Re) assumes a value of 1, which indicates that during the period of its operation, the VF-CW system will not operate with the required efficiency in relation to this indicator. The novelty of this work is the implementation of the indicated mathematical simulation methods for analysing the reliability of the operation of the domestic wastewater treatment facility. [ABSTRACT FROM AUTHOR]

Landowners and natural resource agencies are seeking to better understand the benefits of best management practices (BMPs) for addressing water quality issues. Using edge-of-field and edge-of-farm runoff analysis, we compared runoff volumes and water quality between small watersheds where BMPs (e.g., prescribed grazing, silvicultural practices) were implemented and control watersheds managed using conventional practices (i.e., continuous grazing, natural forest revegetation). Flow-weighted samples, collected over a 2-year period using automated samplers, were analyzed for nitrate/nitrite nitrogen (NNN), total Kjeldahl nitrogen (TKN), total phosphorus (P), ortho-phosphate phosphorous (OP), total suspended solids (TSS), and Escherichia coli (E. coli). Comparison of silvicultural planting to conventional reforestation practices showed a significant decrease in NNN loads (p < 0.05) but no significant differences in TKN, P, OP, TSS, or E. coli. Continuously grazed sites yielded >24% more runoff than sites that were under prescribed grazing regimes, despite receiving less total rainfall. Likewise, NNN, TSS, and TKN loadings were significantly lower under prescribed grazing management than on conventionally grazed sites (p < 0.05). Data suggests that grazing BMPs can be an effective tool for rapidly improving water quality. However, silvicultural BMPs require more time (i.e., >2 years) to establish and achieve detectable improvements. [ABSTRACT FROM AUTHOR]

To solve the upcoming environmental problems, sponge city concepts as well as new technologies are being developed these days. One of the future challenges is to reduce drinking water demand by using decentralized water recycling systems. This study aimed to investigate the performance of a specially designed pilot wetland roof (PWR) treating domestic greywater (GW) at ground level under outdoor conditions and to evaluate the effects of different hydraulic loading rates (HLRs) for a period of two years. The results showed highly efficient removal of typical greywater pollutants from the system, e.g., five-day biochemical oxygen demand (BOD5) > 96%, chemical oxygen demand (COD) > 93%, total suspended solids (TSS) >94%, anionic surfactants (AS) > 94%, ammonium-nitrogen (NH4-N) > 84%, total nitrogen (TN) > 71%, total phosphorous (TP) > 87%, and E. coli (1.86 ± 1.54 log-removal). The mean concentrations of the targeted parameters at the outflow were in compliance with the requirements for discharge to the environment and met reclaimed water quality standards for agricultural irrigation, except for E. coli. Statistically significant (p < 0.05) results of pollutant mass removal rate across different HLRs indicated the potential effect of HLR on treatment performance, and HLR in a range of 67–80 L m–2 d–1 contributed to a higher removal efficiency without compromising the limit values. A comparatively low HLR of 45 L m–2 d–1 should be applicable if pathogen removal is the most important requirement. Plant species showed good plant vitality and adapted well to the water storage mat. The higher the mean ambient air temperature, the greater runoff reduction (>50%) was observed due to high evapotranspiration. The results showed the system is a promising green technology for GW recycling and can be scaled up for application to urban buildings. [ABSTRACT FROM AUTHOR]

Juwana et al. [[1]] evaluated water quality programs aiming to achieve pollution reduction through uncertainty and sensitivity analysis of the Citarum River, Indonesia. Remote sensing technology with large-scale synchronous observations in the Pearl River Delta in China have also been used to effectively monitor total nitrogen (TN) [[4]]; however, TN is a non-optically active substance, so it is difficult to retrieve TN through analysis methods. When water pollution is a severe issue, forecasting water quality to control water pollution and informing consumers in the event of the detection of poor water quality is crucial. At a low discharge rate, deposited sediment on the pipe bottom changed the hydraulic roughness and magnitude of the dispersion coefficient at low Reynolds numbers (close to the laminar flow), but water quality models often assume turbulent flow. [Extracted from the article]

This research aimed to identify water quality changes in the Cirata Reservoir and the factors affecting them in terms of hydrology and climate. The sampling was carried out in both the rainy and dry seasons at 12 locations in the Cirata Reservoir. The Mann–Whitney U-test (different test) results showed that salinity, total suspended solids (TSS), the potential of hydrogen (pH), nitrate (NO3-N), phosphate (PO4), nitrate and phosphate content in the sediment were significantly different (α < 0.05) between the rainy and dry seasons. The principal component analysis (PCA) results showed that the water quality characteristics in the Cirata Reservoir in the dry season were influenced by environmental conditions in the reservoir, especially by the floating cage aquaculture and climate conditions. The high solar radiation, low rainfall, and floating cage aquaculture increased the pH and amounts of dissolved oxygen (DO), ammonia (NH3-N), PO4, nitrate and phosphate in the sediment while decreasing transparency, salinity, TSS, and NH3-N. During the rainy season, the high runoff from Citarum Watershed controlled the water quality characteristics of the Cirata Reservoir. In this season, transparency, salinity, pH, DO, NH3-N, PO4, nitrate and phosphate in the sediment increased, while TSS tended to be low. In general, the water volume addition decreased the nutrition and salinity concentration in the water body. However, a distinct phenomenon occurred in the Cirata Reservoir. The runoff from agriculture, settlement, livestock, and the Citatah Karst in the Upper Citarum Watershed increased nutrition and salinity in the reservoir. Land use in the Citarum Watershed and floating cage aquaculture had an important role in the reservoir water quality. [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]

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]

Artisanal and small-scale gold mining activities have an impact on natural resources and human health. This study addresses the assessment of surface water quality in the Lom gold basin. A combined approach of water quality index calculation, multivariate statistical analysis and spatial interpolation was used. Sampling was performed at 15 stations during low- and high-water periods in 2021 for classical physicochemical parameters and total mercury measurements. The results show that the physicochemical parameters were below drinking water standards for both periods, except for pH, total suspended solids and total mercury. These waters show a large cation deficit as well as an anion deficit. The water chemistry is controlled by precipitations and silicate dissolutions in rock that convert the water into the Ca-HCO3 and Ca-Mg-HCO3 types. The level of mercury contamination varied from acceptable to high due to high flow rates during high water that cause a dilution effect for the mercury concentration upstream and its accumulation downstream. The water quality varied from excellent to very poor with better quality during the high-water period. The Lom watershed is locally affected by physical and chemical pollution due to the abundance of suspended solids and mercury resulting from the different gold mining activities. [ABSTRACT FROM AUTHOR]

In this research, the modification of different polyester structures (fabrics and knits) by the biopolymer chitosan was studied to evaluate the effects of the polyester structure and treatments on the particulate pollution of wastewater. The pristine polyester and the chitosan-polyester fabric and polyester knit composites were washed cyclically with standard ECE A detergent at 60 °C. The laser diffraction technique was used to characterize the particle size of the washing wastewaters from the 1–5, 6–10 and 1–10 wash cycles. In addition, the total solids (TS), total suspended solids (TSS), total dissolved solids (TDS), turbidity and chemical oxygen demand (COD) were also determined, according to standard procedures. The obtained results show the influence of the polyester fabrics and polyester knit structures and chitosan-polyester composites on the particle size distribution (PSD) in the washing wastewater. Differences in the values of the characteristic parameters, especially the span value and shape factor (k) of the individual curves, are visible, indicating the release of particles during the washing process. The experimental results show that the laser diffraction technique is suitable for characterizing the particle dimensions of the washing wastewater for different pristine polyester structures and chitosan-polyester composites. Modification with chitosan has been shown to provide potential protection against the release of microplastic particles into the environment. [ABSTRACT FROM AUTHOR]

The process of wine making is well known to produce large amounts of wastewater with highly variable characteristics. The disposal of untreated winery wastewater is strictly prohibited since it adversely affects the recipient environment. Due to the variability in characteristics of winery wastewater, developing a treatment system which can handle high organic and inorganic loads, especially during the vintage season, is a complex challenge. This study investigated the theory, methodology and implementation of a wastewater treatment technology called shear enhanced flotation separation (SEFS) as a potential primary treatment stage towards the treatment of winery wastewater. Winery effluent was subjected to a coagulation process in a high shear environment, with and without the introduction of air, followed by flocculation. Upon successful optimization of operating parameters, a polymeric-based coagulant AB121 and polyelectrolyte flocculant AB796 yielded the highest reduction in turbidity (95%) with typical values of 630 NTU for the raw wastewater and 25 NTU for the SEFS-treated effluent. A substantial reduction in total suspended solids (97%) was achieved with average raw winery wastewater values of 2275 mg/L compared to the 50 mg/L obtained for the SEFS-treated effluent. Furthermore, a notable reduction (54%) in COD (from 11,250 mg/L to 5220 mg/L) using SEFS technology was achieved. [ABSTRACT FROM AUTHOR]

The present work sheds light on the potentiality of proteins extracted from oak (Quercus robur) leaves to treat both drinking water and industrial oily wastewater. The work was structured in three steps: firstly, oak leaves in powder form were analyzed by FTIR, XRD and SEM, thus showing the presence of proteins acting as bio-coagulants; secondly, an experimental design was conducted. According to the design of experiences based on fractional design (28−4), the highest protein concentration (4.895 mg/g) was obtained for the following operating parameters: no filtration, pH of 12, temperature of 20 °C, stirring speed of 300 rpm, stirring time of 60 min, maceration time of 4 h, centrifugation speed of 400 rpm, centrifugation time of 10 min. Finally, a jar test apparatus was used to study the effects of proteins from oak leaves on the characteristics of both drinking water and industrial oily wastewater. In drinking water, the turbidity was reduced from 15.7 to 4.82 NTU when 0.098 mg/L of oak leaves protein was added, thus satisfying the requirements of the national drinking water standards; whereas, in industrial oily wastewater turbidity, total suspended solids, chemical oxygen demand and organic matter were reduced by 96.87, 89.86, 96.39 and 46.28%, respectively, when 0.538 mg/L of oak leaves protein was added. This study opens new perspectives related to the research and development of organic coagulants applicable to industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

Urbanization, industrialization, and the loss of freshwater resources are leading to an increased awareness of the importance of surface water quality worldwide. Limited ground water resources, prolonged drouths, and flooding are creating pressure on the availability of freshwater sources in the Vietnamese Mekong Delta. However, the surface water quality in this region is measured mainly at the provincial level, without reference to the water quality of adjacent regions. In order to identify and understand the key factors that contribute significantly to the quality of surface water, it is necessary to consider the delta region as a holistic system and to systematically investigate the influence of different land uses on water quality. In this study, surface water quality was evaluated during the dry season, when flow is low and water exchange is limited. For this purpose, the temporal variation in the surface water quality of 12 water quality parameters at 132 monitoring stations was analyzed according to their surrounding type of land use. To further investigate the impact on low-hierarchy canals, a correlation analysis between the river and canal class hierarchy and all investigated water quality parameters was performed. The results show that surface water quality suffers particularly in the case of a low dissolved oxygen (DO) content, with a measured minimum of 0.48 mg/L, and in cases of organic pollution in the form of total suspended solids, biochemical oxygen demand, and chemical oxygen demand, with values up to 146 mg/L, 75.0 mg/L, and 41.0 mg/L, respectively. As the main factors influencing surface water pollution, freshwater aquaculture and industrial activities were identified. This could have a relevant impact on future sustainable land use planning. [ABSTRACT FROM AUTHOR]

Many coagulants such as aluminium sulfate, ferric sulfate, and ferrous sulfate have been investigated in the past, but there is a lack of data on their effectiveness to some specific water quality parameters. This study aimed at investigating the efficiency of the coagulation water treatment process to remove pollutants such as total organic carbon (TOC), total nitrogen (TN), and total suspended solids (TSS) from urban drinking water. The polyaluminium chloride (PAC) coagulant was applied to determine the impact of the treatment process on the structure and diversity of these pollutants in urban drinking water. All water samples were collected from the Yangtze River, Baoshan district, Shanghai, China, over a period of three months which coincided with the late summer and early winter periods. Specific to different coagulant characterizations, a preliminary test was performed with three other coagulants, namely, aluminium sulfate, polyaluminium, silicate sulfate, and ferric sulfate to determine their optimal conditions for floc characterization and removal efficiencies. In summary, the overall performance of the PAC coagulant was better than that of the other three coagulants used in the pre-treatment of the sampled water. The obtained results revealed that under the optimum operating conditions, the doses of the PAC were as follows: 20, 35, 50, 65, and 80 mgL−1, respectively. The water temperature and pH were determined by using a pH meter, the TOC and TN determined by using a TOC analyzer, and the TSS by following the ASTM D2540 method. Furthermore, the response surface methodology by the Box–Behnken optimization analysis was applied to coagulant dosage, temperature, pH, and three corresponding dependent factors (TSS, TOC, and TN) to determine the best optimal conditions for the PAC performance. To determine whether or not the quadratic model adequately explained and predicted the response during the coagulation process, an analysis of variance was performed. Multiple optimal factors were identified for the urban drinking water treatment, including a pH value of 6.9, water temperature of 20.1 °C, and a coagulant dosage of 9.7 mgL−1. [ABSTRACT FROM AUTHOR]

Anthropogenic activities often compromise the water quality of natural water systems, rendering it unfit for domestic and agricultural use. This paper evaluates the effects of anthropogenic activities on the water quality of Ngong River in Nairobi County, Kenya. It aimed to assess the river's physico-chemical parameters, identify major anthropogenic activities that act as pollutant sources and establish the relationship between the anthropogenic activities and water quality along the Ngong River. Twelve water samples were systematically collected in each of the twelve study sites in April and August 2021 and analyzed in the laboratory for various water quality parameters. The accumulation factor (AF) indicated that E. coli, total coliforms, BOD and COD were found to significantly build up downstream of Ngong River. The ANOVA test results showed that all the physicochemical parameters studied (BOD, E. coli, pH, total suspended solids, total coliforms, turbidity, conductivity, nitrates, oil and grease and TDS), except COD, were not significantly different (p ≤ 0.05) for the different sites. Measured heavy metals, such as lead (Pb) levels at different sampled points, were all found to be below the detectable limit (0.001 ppm) for both seasons. Cadmium (Cd) was detectable during the dry season with the highest levels (0.113 ppm) being recorded at Ngong Forest Boundary. The findings of this study revealed that anthropogenic activities, such as raw sewage disposal, industrial activities, solid waste dumping and small-scale agriculture, had adverse effects on Ngong River's water quality. The study recommends a need to closely monitor anthropogenic activities along Ngong River to reduce their probable pollution of the water in the River basin. This will ensure the sustainability of the water resources. [ABSTRACT FROM AUTHOR]

Phosphorus input with excessive use of fertilizers and manure as one of the main sources of nutrient pollution has increased recently in the wastewater as result of intensive farming and industrialized and densely populated areas. The novelty of the current work lies in improving a Vertical Aerated Rock Filter (VARF) using steel slag and limestone media to enhance the efficiency of a rock filter (RF) to eliminate total phosphorus (TP) from domestic wastewater. RF was designed with steel slag and limestone (calcium hydroxide) as a pilot scale called vertical aerated steel slag filter (VASSF) and optimized based on hydraulic loading rates (HLR) (0.16 to 5.44 m3/m3 day) and airflow rates ranging from 3 to 10 L/min. The highest removal for the design of the laboratory scale steel slag filter (LSSSF) was achieved by approximately 58%, while for the laboratory-scale limestone filter (LSLSF), it was 64%. The VASSF achieved a removal percentage at 30% of TP, biological oxygen demand (BOD; 89%), chemical oxygen demand (COD; 75%), total suspended solids (TSS; 73%), and total coliforms (TC; 96%), recorded with 7 L/min of an airflow rate and 1.04 m3/m3.day of hydraulic loading rate (HLR) at potential of hydrogen (pH) 7.3 and 5.09 mg/L of dissolved oxygen (DO). These findings indicated that the steel slag is higher than limestone in TP removal, because of ion exchange between phosphorus hydrolysis and the adsorption process. Moreover, in the pilot study, the removal efficiency needs more investigation to determine the best conditions for TP considering the temperature, which is unstable, and presence of other pollutants, which might negatively affect the removal efficiency under unstable conditions. [ABSTRACT FROM AUTHOR]

A coagulation treatment is a separation technology widely used in industries as a pre-treatment step to remove the dissolved organic matter in wastewater. However, the type of coagulant, the optimized dose, and the treatment cost associated with various commercially employed coagulants must be investigated for the treatment of oil and gas produced water. In this study, five widely employed coagulants—ferric chloride, aluminum potassium sulphate, chitosan, sodium sulfide, and magnesium oxide—were tested for the treatment of actual complex oilfield-generated produced water. Water quality parameters such as the total suspended solids (TSS), total dissolved solids (TDS), turbidity, salinity, and pH were assessed for a better understanding of different coagulant activities against the produced water treatment. All the coagulants were efficient for the treatment of produced water. The findings of this study showed that ferric chloride led to the best removal of total solids (74.25%) of all water quality parameters, with treatment costs of USD 4 per m−3 of produced water. The results from this study contribute to the environmentally friendly, broader, and cost-effective application of a coagulation treatment to produced water. [ABSTRACT FROM AUTHOR]

Climate change and human actions will exacerbate eutrophication cases in inland waters. By external or internal inputs, there will be an increase in nutrient concentrations in those systems worldwide. Those nutrients will bring faster trophic changes to inland waters and possible health and recreational advisories. A novel approach using a floating filtration system, a silt curtain, and geotextiles (woven and non-woven) is under investigation. This method has been applied as an in-situ pilot experiment deployed at Lake Caron, a shallow eutrophic lake in Quebec, for two summers. Turbidity, total suspended solids (TSS), total phosphorus (TP), blue-green-algae-phycocyanin (BGA-PC) and chlorophyll-a showed statistically significant average removal efficiencies of 53%, 22%, 49%, 57% and 56%, respectively, in the first year and 17%, 36%, 18%, 34% and 32% in the second. Statistical correlations were found with TSS, turbidity and variables that could represent particles (TP, turbidity, chlorophyll-a). Employing this in situ management method could be a promising remediation for not only shallow lakes (average depth < 2 m) but also for ponds, rivers, coastal regions, bays and other water types, to enable cleaner water for future generations. [ABSTRACT FROM AUTHOR]

Particle aggregation modifies sediment dynamics, which is a determining factor for morphodynamic and ecological processes in deltaic plains. Here, we investigated the link between intra-annual hydrodynamics variability and flocculation in the Grijalva-Usumacinta system. Monthly (2016–2017) and seasonal (2021–2022) river data was processed using analytical methods and the simplified sonar equation. Flocs were reformed and characterized in the laboratory, validating the in situ settling velocities (0.5–3.8 mm/s) and the existence of large low-density macro-flocs (>300 μm). We verified that flocculation prevailed, exhibiting seasonal patterns; (1) the highest aggregation rates matched the increase in total suspended solids at rising-flow (>100 mg/L), (2) periods of high-flow showed stable aggregation rates, and (3) an influence of marine conditions occurred at low-flow. Particulate phosphorous and organic fraction showed seasonal patterns linked to flocculation. Due to damming, the shear rates varied slightly (7–11 L/s) in the Grijalva, leading to high flocculation intensities affecting the diffusivity ratio. In the Usumacinta, aggregation was limited by shear rates that normally exceed 15 1/s. We found seasonal Rouse parameters representative of sediment dynamics. [ABSTRACT FROM AUTHOR]

Excess nutrients and suspended sediment exports from agricultural watersheds are significant sources of global water quality degradation. An improved understanding of surface water and groundwater pollutant loads is needed to advance practices and policies. A study was conducted in an agricultural-forested catchment of the mid-Atlantic region of the United States. Stream water (SW) and shallow groundwater (SGW) samples were collected monthly between January 2020 and December 2021 from eight sub-catchment study sites. Samples were analyzed for nitrate (NO3-N), nitrite (NO2-N), total ammonia (NH3-N), total nitrogen (TN-N), orthophosphate (PO43-P), and total phosphate (TP-P) concentrations using spectrophotometric methods. Total suspended solids concentrations (mg/L) were quantified gravimetrically and volumetrically to estimate mean particle diameter (MZ, µm), particle surface area (CS, m2/mL), sample skewness (Ski), and particle size distributions (sand/silt/clay%). Results showed significant (p < 0.05) differences in nutrient concentrations and suspended sediment characteristics between SW and SGW between study sites. Differences were attributed to source water type and sub-watershed location. Principal components analysis indicated seasonal effects on water quality in summer months and connected land use with TSS, TN-N, and TP-P concentrations. Study results emphasize the importance of SGW water quality metrics for non-point source loading predictions to inform management decisions in agro-forested watersheds. [ABSTRACT FROM AUTHOR]

Changes in water quality were examined during selected rainfall events in a headwater stream severely damaged by a forest fire on 21–23 February 2021. Seven water quality parameters were analyzed: pH, electrical conductivity, biochemical oxygen demand, chemical oxygen demand, total suspended solids (TSS), total nitrogen, and total phosphorous. First-flush effect and event mean concentration analyses were conducted in spring (dry season) and summer (wet season) immediately after the forest fire. In spring, the non-biodegradable organic matter concentrations increased along with pollutants related to ash-enhanced soil water repellency in water affected by first-flush effects. In summer, TSS and nutrient concentrations increased along with pollutants related to fire-induced soil surface disturbances after a series of rainfall events. First-flush analyses indicated that cumulative pollutant loads were greater in the spring than in the summer due to a higher concentration of forest fire ash in the early storm runoff immediately after the forest fire. The event mean concentrations revealed that pollutant loads were associated with both forest fire ash and storm events in the immediate post-fire period. Therefore, this study indicated that water quality along a headwater stream is affected by short-term effects of large and intense forest fires and rainfall seasonality. [ABSTRACT FROM AUTHOR]

The influence of CO2 addition and feeding regime (continuous versus semicontinuous) on the removal of Pseudomonas aeruginosa, Clostridium perfringens, Staphylococcus, Enterococcus faecalis, and Escherichia coli (E. coli) from three shaded high-rate algal ponds (HRAPs) treating raw sewage (RS) was studied. The three HRAPs were operated at an analogous hydraulic retention time (HRT) for 5 days and with shading of 50%. The CO2 addition and feeding regime had no statistically significant influence on the removal of Pseudomonas aeruginosa, Clostridium perfringens, Staphylococcus sp., and Enterococcus faecalis, with 2.39–3.01, 2.07–2.31, 3.02–3.38, and 3.14–3.45 log units, respectively. However, the removal of E. coli decreased significantly with the feeding regime of 0.1 h d−1 and 2.23–3.29 log units. The productivity and the total suspended solids (TSS) removal efficiency were significantly improved with the semicontinuous feeding regime and CO2 addition. The highest productivity was obtained in the semicontinuous feeding regime, 5.93 g m2 d−1, while the TSS removal efficiency was similar between the semicontinuous feeding regime and CO2 addition (31–36%). The control of light intensity led to greater variability in the algal community, and was present in the three reactors, in different proportions, in the form of the microalgae Scenedesmus acutus, Scenedesmus obliquus, and Chlorella sp. [ABSTRACT FROM AUTHOR]

Ammonium (NH4+) recirculation from the streams generated in the dehydration stage of the sludge generated in the anaerobic digestion of urban wastewater treatment plants (WWTPs), known as centrate or sidestream, produces a reduction in the efficiency of WWTPs. Given this scenario and the formulation that a WWTP should be considered a by-product generating facility (biofactory), solutions for ammonia/ammonium recovery are being promoted. These include a nitrogen source that reduces the need for ammonia production through the Haber–Bosch process. Therefore, the recovery of nutrients from urban cycles is a potential and promising line of research. In the case of nitrogen, this has been aimed at recovering NH4+ to produce high-quality fertilizers through membrane or ion exchange processes. However, these techniques usually require a pretreatment, which could include an ultrafiltration stage, to eliminate suspended solids and organic matter. In this case, the coagulation/flocculation (C/F) process is an economical alternative for this purpose. In this work, the sidestream from Vilanova i la Geltrú WWTP (Barcelona, Spain) was characterized to optimize a C/F process before being treated by other processes for ammonium recovery. The optimization was performed considering a bibliographic and experimental analysis of several operating parameters: coagulant and flocculant agents, mixing velocity, and operation time, among others. Then, the removal efficiency of control parameters such as turbidity, chemical oxygen demand (COD), and total suspended solids (TSS) was calculated. This optimization resulted in the use of 25 mg/L of ferric chloride (FeCl3) combined with 25 mg/L of a flocculant composed of silicon (SiO2 3%), aluminum (Al2SO4 64.5%), and iron salts (Fe2O3 32.5%), into a 1 min rapid mixing process at 200 rpm and a slow mixing for 30 min at 30 rpm, followed by a final 30 min settling process. The numerical and statistical results of the process optimization reached 91.5%, 59.1%, and 95.2% removal efficiency for turbidity, COD, and TSS, respectively. These efficiencies theoretically support the enhanced coagulation/flocculation process as a pretreatment for a higher NH4+ recovery rate, achieving 570.6 mgNH4+/L, and a reduction in the dimensioning or substitution of other membrane processes process due to its high TSS removal value. [ABSTRACT FROM AUTHOR]

Conventional wastewater treatment processes require extensive energy inputs for their operations. Biologically enhanced primary treatment (BEPT) is a promising technology to capture incoming organics that may be utilized to produce biogas and potentially hydrogen with further downstream processing. This study involved a biologically enhanced primary treatment (BEPT) of raw wastewater at bench and pilot-scale using activated sludge (AS) addition and dissolved air flotation (DAF) using raw wastewater at a municipal wastewater facility in Western Australia with average chemical oxygen demand of ~800 mg/L. The results of pilot-scale testing showed an improved removal performance for total chemical oxygen demand (COD-T), soluble chemical oxygen demand (COD-S), and total suspended solids (TSS) compared to conventional primary treatment (PT). Specifically, average COD-T, COD-S and TSS removals for BEPT were 33.3%, 13.5% and 45%, respectively which was 10%, 100% and 6% higher than PT. Moreover, the sludge produced from BEPT had a high solids content of 4.8 g/L, which might not need further thickening prior to anaerobic digestion. It is important to note that no chemicals were used during BEPT testing, which makes the process very cost-effective. [ABSTRACT FROM AUTHOR]

Reductions in industrial pollutant loads and the introduction and modernization of wastewater treatment facilities have improved the quality of inland waters in Europe and elsewhere, but climatic change, changes in runoff and the legacy of mine wastes may increase pressures on many aquatic environments. In the present study, data obtained by monitoring the French–German river are collated to visualize long-term trends in the pollution, river discharges and temperatures of Moselle waters. While air temperatures and accumulated heat sums in the catchment area showed an upward trend, precipitation and discharge levels as well as river temperatures were less affected by the ongoing climatic change. At the same time, the electric conductivity, i.e., the total suspended solids, did not show the anticipated reductions, while oxygen levels and pH values have showed upward trends since the 1990s. Despite the improvements in classical water quality parameters, the flooding of abandoned mines, increased water abstraction for cooling and agriculture and untreated old and emerging pollutants may aggravate environmental problems in the future. Climatic change will probably modify the runoff of pollutant loads by increasing the severity of flash floods and by concentrating water pollutants in drought spells. [ABSTRACT FROM AUTHOR]

Evaluating the functionality of small and decentralized low-impact development (LID) technologies often requires extensive labor, time, and costs for water quality analysis. In order to reduce these in an infiltration trench in South Korea, monitoring data gathered over a period of 8 years were used to determine its long-term performance, establish a stormwater quality estimation model, and develop a comprehensive evaluation tool. Our findings show that the infiltration trench can treat up to 90% of the stormwater runoff from a paved road but would require annual maintenance to minimize the reduction in infiltration capacity. The facility was able to remove an average of 83% of total suspended solids (TSS), 75% of biochemical oxygen demand (BOD), 80% of chemical oxygen demand (COD), 76% of total nitrogen (TN), and 79% of total phosphorus (TP), with the highest removal efficiencies observed after maintenance was conducted. Rainfall depth and air quality parameters (i.e., PM2.5 and PM10) were found to be positively correlated with TSS, COD, TN, and TP. These parameters were then used to develop a model for the estimation of influent stormwater quality, which can help in estimating the effluent water quality based on the average removal efficiencies. Furthermore, a comprehensive evaluation tool considering indicators such as treatment efficiency, cultural benefits, and facility and operating conditions was established through the analytic hierarchy process (AHP). Aside from determining the facility's overall efficiency, this can also serve as a diagnostic tool to identify whether maintenance is needed or not. While atmospheric and hydrological characteristics differ in different regions, and the results may vary if applied in other facilities, this study can serve as a guide to the effective and efficient evaluation of similar stormwater management facilities in South Korea. [ABSTRACT FROM AUTHOR]

Groundwater risks driven by population growth and industrialization in metropolitan cities have become a worldwide problem. Faisalabad is Pakistan's third largest city with a population of more than 2 million and is renowned for its diverse industries. Many factories in the area dump their untreated effluent into nearby drainage systems, having a direct negative effect on the marine ecosystem. This research focuses on the Madhuana drain and Khurrianwala industrial region of Faisalabad to investigate groundwater quality status. Sixty water samples from groundwater bore wells and open wells were obtained, and all these samples were subjected to lab experiments for physical and chemical analysis. Sixteen physiochemical parameters, namely, electrical conductivity (EC), pH, total dissolved solids (TDS), total suspended solids (TSS), turbidity, carbonate, Ca2+, Fe, HCO3−, Cl−, Mg2+, SO24−, As, Cr, Cu, and Mn, were examined. To provide a comprehensive picture of water quality from a human perspective, we calculated the water quality index (WQI) by integrating 16 physiochemical criteria. The results revealed that a larger proportion had poor drinking quality due to direct releases of toxins by industries. It was observed that 87% of the water samples showed an unsuitable status of groundwater for drinking purposes in terms of pH, EC, Fe, Mn, Cu, and Cr. The results of this study could be used to build and construct wastewater treatment plant facilities for the Madhuana drain, reducing pollution loads on the drain and river, as well as contaminant seepage rates into groundwater. The research's resulting maps will help policymakers to manage groundwater supplies more efficiently for sustainable development. [ABSTRACT FROM AUTHOR]

Benthic diatoms are important components of marine shallow-water habitats that may affect primary production, stabilize sediment, and produce extracellular polymeric substances. Benthic diatoms are useful for estimating the trophic status of marine ecosystems. In this study, we investigated the diversity and abundance of benthic diatoms to integrate these data with the physicochemical characteristics of shallow coastal areas in Negeri Sembilan. A total of 39 species of epipelic diatoms were extracted by removing organic matter from sediments that were dominated by pennate diatoms. Results showed that Diploneis crabro, Eunotogramma laevis, Actinoptychus sp., and Cocconeisplacentula were the important species in the area. The abundance varied between 1.85 × 103 and 3.43 × 103 cells/g, and the diversity index fluctuated between 2.13 and 2.58. The abundance had significant positive correlations with seawater surface temperature (SST) but had negative correlations with pH and NH3. The diversity on the other end was positively correlated with SST but negatively correlated with total suspended solids and SiO2. Principal component analysis (PCA) demonstrated that the abundance of D. crabro, E. laevis, and Actinoptychus sp. can be attributed to high levels of NO2−, NH3, and total dissolved solids. PCA also showed positive correlations of C. placentula with NO3−and SiO2 but negative ones with PO43− and pH. The epipelic diatom community showed high diversity with high variations throughout the study area. [ABSTRACT FROM AUTHOR]