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Transport of contaminants in the presence of colloids is a three-phase problem in the groundwater porous media and colloids can also enhance the transport of contaminants by reducing the retardation factor. In this study, the numerical solution of the equilibrium model is obtained using a fully implicit Crank-Nicolson finite-difference method and validated with ten experimental results. Sensitivity and spatial moment analysis have been performed to investigate the mobility and spreading behavior of contaminants in the presence of colloids. Results suggest that enhancement of contaminant transport in the presence of colloids depends on the colloid concentration and the physical and chemical interaction of contaminants with the stationary solid matrix and suspended colloids. As the colloidal concentration increases, the mobility of contaminants augments, resulting in the early arrival of contaminants at the column outlet. The affinity of contaminants toward the stationary solid matrix of porous media can lead to the reduced transport of contaminants even under the presence of a significant amount of colloid concentration. In contrast, enhanced transport of contaminants is observed if the affinity of contaminants is more toward the suspended colloids. [ABSTRACT FROM AUTHOR]

Oysters have the potential to be a part of more sustainable farming systems, such as multitrophic systems integrated into biofloc systems, due to their filtration activity, which enables them to act as organic consumers. However, the stress experienced by animals in a system with a high organic load can compromise their productive performance. The objective of this study was to evaluate the biological responses of Crassostrea gasar oysters when exposed to different concentrations of total suspended solids in biofloc systems. The oysters were exposed to four different concentrations of solids for 28 days. Hall effect sensors were installed on the outside of the shells to detect the movement of the oyster valves. Also, biochemical and histological analyses were conducted to assess the biological responses of the oysters to exposure to varying levels of solids. A difference in valve opening detected by the Hall sensors was observed from the second week of culture, indicating a relationship between shell closure and higher concentrations of suspended solids present in the system. In terms of biochemical analysis, a significant increase in lipid damage was observed in treatments with medium and high levels of total suspended solids compared with the control group. Conversely, no changes were observed in the gill structure of the oysters caused by the concentrations of suspended solids in the system when compared with the control. According to the analyses of gill activity and biochemistry, it is suggested that C. gasar should be cultured with total suspended solids at less than 200 mg/L. Oysters cultivated in a biofloc system keep their shells closed when subjected to high concentrations of total suspended solids; concentrations of total suspended solids below 200 mg/L do not induce oxidative stress, changes in behavior or histological alterations in C. gasar oysters cultivated in a biofloc system. [ABSTRACT FROM AUTHOR]

Blockage of leachate drainage facilities is a common engineering problem in landfill operation. The key factors that cause blockage of drainage facilities in landfill leachate are the deposition of suspended solids (SS) with colloids and the precipitation of inorganic salts. To determine the combined sedimentation law of SS, colloids and inorganic salts, a combined sedimentation test of suspended solids, colloids and inorganic salts was conducted. To further clarify the resulting clogging characteristics of the water-conducting sand layers, a sand column blocking test were conducted, and mineral composition and grain characteristics of sediments were determined. The experimental results shown that the colloids (silver iodide) and inorganic salts (calcium chloride or aluminum sulfate) increased the sedimentation rate of SS by 8 to18 times. Among them, the effect of AgI colloid was the most significant, followed by effect of calcium chloride, while effect of aluminum sulfate was the weakest. Compared with sand column clogging caused by SS, this combined migration shortened the sand column clogging time by more than half and reduced hydraulic conductivity by nearly two to three orders of magnitude. This study contributes to the accurate assessment of the service performance of landfill leachate drainage systems. [ABSTRACT FROM AUTHOR]

Over the past half century, the demand for sand and gravel has led to extensive quarrying activities, creating many pit lakes (PLs) which now dot floodplains and urbanized regions globally. Despite the potential importance of these environments, systematic data on their location, morphology and water quality remain limited. In this study, we present an extensive assessment of the physical and optical properties in a large sample of PLs located in the Po River basin (Italy) from 1990 to 2021, utilizing a combined approach of remote sensing (Landsat constellation and Sentinel-2) and traditional limnological techniques. Specifically, we focused on the concentration of Suspended Particulate Matter (SPM) and the dominant wavelength (λdom, i.e., water colour). This study aims to contribute to the analysis of PLs at a basin scale as an opportunity for environmental rehabilitation and river floodplain management. ACOLITE v.2022, a neural network particularly suitable for the analysis of turbid waters and small inland water bodies, was used to atmospherically correct satellite images and to obtain SPM concentration maps and the λdom. The results show a very strong correlation between SPM concentrations obtained in situ and those obtained from satellite images, both for data derived from Landsat (R2 = 0.85) and Sentinel-2 images (R2 = 0.82). A strong correlation also emerged from the comparison of spectral signatures obtained in situ via WISP-3 and those derived from ACOLITE, especially in the visible spectrum (443–705 nm, SA = 10.8°). In general, it appeared that PLs with the highest mean SPM concentrations and the highest mean λdom are located along the main Po River, and more generally near rivers. The results also show that active PLs exhibit a poor water quality status, especially those of small sizes (<5 ha) and directly connected to a river. Seasonal comparison shows the same trend for both SPM concentration and λdom: higher values in winter gradually decreasing until spring–summer, then increasing again. Finally, it emerged that the end of quarrying activity led to a reduction in SPM concentration from a minimum of 43% to a maximum of 72%. In this context, the combined use of Landsat and Sentinel-2 imagery allowed for the evaluation of the temporal evolution of the physical and optical properties of the PLs in a vast area such as the Po River basin (74,000 km2). In particular, the Sentinel-2 images consistently proved to be a reliable resource for capturing episodic and recurring quarrying events and portraying the ever-changing dynamics of these ecosystems. [ABSTRACT FROM AUTHOR]

Bodies of water are usually being polluted by wastes from domestic and industrial sources thereby making them unfit for use. Hence, this study aimed at assessing the water quality from Asa River, Ilorin, Nigeria in terms of bacteriological and physicochemical parameters. The bacteriological parameters assessed were heterotrophic bacterial count, total coliform, faecal coliform, identification of the isolates, antibiotic resistance patterns, and plasmid profile of the isolates. Whereas, the assessed physicochemical parameters were pH, total chloride, suspended solid, and total hardness. The heterotrophic bacterial count, total coliform, and faecal coliform counts ranged from 7.6 x 103 to 3.2 x 106 cfu/ml, 9 to 24000 MPN/ 100ml and 0 to 6.0 x 10³ cfu/ml respectively. Bacteriological analysis showed that the water contained arrays of bacteria heavily contaminated with pathogens. The genera of bacteria isolated were Escherichia, Pseudomonas, Brevundimonas, Enterococcus, Burkholderia, Enterobacter, Proteus, Pasteurella and Aeromonas. The pH, total hardness, total chloride, and suspended solids of the water ranged from 6.2 to 7.9, 128 to 291 mg/l, 6.21 to 17.04 mg/l and 170 to 310 mg/l respectively. All the Gramnegative bacteria were resistant to cefuroxime, cefixime, augmentin, and ceftazidime. Whereas all the Gram-positive bacteria were resistant to cefuroxime, cloxacillin, augmentin, and vancomycin. The bacteria also showed multiple antibiotic resistance. The resistance of Pasteurella multocida to nitrofurantoin was plasmid mediated. After plasmid curing, Brevundimonas diminuta was susceptible to ciprofloxacin and intermediately susceptible to gentamicin, while Pseudomonas fluorescens was susceptible to ofloxacin and ceftazidime and intermediately susceptible to ciprofloxacin. It was concluded that the water from Asa River at the different sampling points was unsafe in term of bacteriological as well as some physicochemical qualities. It is recommended that this water should not be used in its present state without treatment. Discharge of industrial, agricultural and domestic wastes should be stopped; and open defecation at the bank of this river should be discouraged. [ABSTRACT FROM AUTHOR]

A transition from inefficient aerobic wastewater treatment methods to sustainable approaches is needed. Anaerobic bioreactors are a viable solution as they consume less energy, reduce biosolid production, and provide a source of renewable methane‐rich biogas. A barrier to widespread implementation of anaerobic technologies is the lack of design guidance, especially in colder climates. This study bridges this knowledge gap by deriving design principles from three long‐running pilot‐scale anaerobic baffled reactors (ABRs) operating under psychrophilic conditions. The ABRs removed an average of 56% and 80% chemical oxygen demand (COD) and suspended solids, respectively, with a methane yield of 0.21 L CH4/g CODrem. Methane production may be improved with increased influent sCOD concentrations and decreased sulfate concentrations. Results suggest that ABRs can treat a range of wastewater strengths accompanied by useable methane production. Despite sharing location, temperature, and HRT, the ABRs displayed distinct performances, highlighting the significance of influent wastewater characteristics. Practitioner Points: ABRs achieved 56% and 80% removal efficiencies for COD and suspended solids.Average biogas was 63% methane, and methane yield was 0.21 L CH4/g CODrem.Volumetric methane production was positively correlated with the influent sCOD/sulfate ratio and negatively correlated with influent sulfate loading. [ABSTRACT FROM AUTHOR]

BACKGROUND: Dissolved oxygen (DO) and aeration on/off time are the determining parameters for simultaneous carbon and nitrogen removal in biological treatment processes. The most effective way to decide the optimum operational conditions, e.g. aeration on/off time or DO concentration during the aeration period, is to determine specific nitrification/denitrification rates. For this purpose, the effects of DO (6 and 3 mg L−1) and aeration on/off time (from 2/2 to 90/360 min) on the specific ammonium oxidation and denitritation/denitrification rates in a membrane bioreactor (MBR) treating real textile wastewater were deeply investigated. RESULTS: The highest specific ammonium oxidation, denitritation and denitrification rates were obtained as 5.4, 3.8, and 5.3 mg N g−1 volatile suspended solids h−1, respectively, at an aeration on/off time of 90/360 min, which corresponded to the increase in specific ammonium oxidation rates by 1.8 and 2.1 times compared to continuous aeration conditions where DO was 6 and 3 mg L−1, respectively. CONCLUSION: Higher specific ammonium oxidation and denitrification rates can be achieved with the intermittent aeration compared to continuous aeration. Hence existing treatment plants can be retrofitted for higher performance with reduced energy requirements. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Wastewater can be segregated as greywater and blackwater separately. The greywater generated in malls, restaurants, and university buildings is generally dilute, while it will later become concentrated when it is merged into the main sewage collection line. It would be more economical and environmentally friendly if the greywater is treated locally using a modular wastewater treatment facility that produces treated water amenable for other uses such as irrigation or horticulture. The objective of this article is to study the economic feasibility and design a decentralized plant that produces fresh water from greywater generated at the Abu Dhabi university campus located in the United Arab Emirates. The proposed unit will consist of a compact design of filtration, chemical treatment and disinfection processes that would generate treated wastewater that can be used for horticulture in and around the local campus or can be stored and supplied for irrigation purposes. Several parameters such as total suspended solids, biological oxygen demand, and chemical oxygen demand are measured and monitored throughout the entire process and are regulated by appropriate operations performed for each unit. This study shows that decentralization of greywater treatment is not only economical but also essential for the management of fresh water, which in turn assures environmental sustainability. By using coagulation, flocculation and chlorination with a 30 mg/L alum dosage, 0.6 mg/L of polyacrylamide and 0.12 mg/L of sodium hypochlorite, respectively, greywater is treated to meet the water specification for reusing it for horticulture. Further, a modular plant with an investment of USD 8 M is proved to process 90,000 tons of greywater with a 34% discounted rate of return. [ABSTRACT FROM AUTHOR]

In this paper, greywater samples are collected from the kitchens of different types of buildings (residential and commercial) located in different districts within the city of Jeddah, Saudi Arabia. The collected samples are analyzed and compared with the potable water from the same region. The parameters investigated are pH, conductivity, total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), total hardness, temporary hardness, permanent hardness, alkalinity, chloride, and biochemical oxygen demand (BOD). It was found that the amount of total suspended solids is very high in the greywater samples. It shows the presence of both temporary and permanent hardness. Their alkalinity values are greater than hardness. It may be due to the number, lifestyle, age of the occupants, presence of children, and social and cultural behavior of residents. The concentration of BOD level is very low, which shows that the greywater samples have lower concentrations of organic compounds. Design details of the greywater treatment plant are suggested based on the results of the analysis. This includes a screening chamber, grit chamber, settling tank, and filtration unit. The treated greywater is recommended for reuse for gardening, landscaping, and toilet flushing purposes. [ABSTRACT FROM AUTHOR]

Brilliant green, also known as ethanaminium, is a triarylmethane dye derivative that has been employed as a coloring agent in the textile industry. A sizable volume of vivid green dye was made in a lab while the physio-chemical properties were investigated. This study looked at how to extract the brilliant green dye from the aqueous reagent using the coagulation-flocculation method to provide the desired features. Used as a flocculant and coagulant, respectively, polyaluminum chloride (PAC). Sodium bisulfate (NaHSO4) solution and hydrochloric acid (HCl) employed to alter the pH during the treatment process. Different pH values and coagulant and flocculant dosages used in a series of jar tests. The supernatant aqueous effluent determined by numerous experimental studies termed turbidity, chemical oxygen demand (COD), colour, and suspended solids (SS) after every experimental analysis and after the practical investigation. The effectiveness of the treatment ranged from a turbidity reduction of 40%-98% to the elimination of 15%-99.2% of COD and a range of 20%-97.3% of suspended particles. In order to optimize removal efficiency, the optimal parameters for the entire quadratic model found using the analysis of variance (ANOVA). By using SEM, XRD, and FTIR analyses, the surface morphology of the sludge characterized. The treatment of brilliant green dye in aqueous solution identified as the successful solution by this coagulation-flocculation procedure using jar test equipment. [ABSTRACT FROM AUTHOR]

The object of this study is the processes of formation and changes of dispersed particles in fresh, make-up, cooling, and return water in open recirculating cooling systems (RCS) with an assessment of the influence of suspended substances in discharge waters on the aquatic ecosystem. The study was carried out on the example of the Rivne Nuclear Power Plant (RNPP) and the Styr River. Dispersed particles (DPs) pose technological obstacles in the RCS of power plants, and their content in discharge waters determines the ecological quality of water bodies. This paper describes the results of studying the formation and changes of DP in raw, make-up, cooling, and return waters of RNPP RCS with an assessment of the impact of suspended substances in discharge waters on the aquatic ecosystem of the Styr River. It was found that the formed dispersed particles after water treatment by liming contain DP consisting of calcium carbonate and have a size of 10–30 μm. As a result of agglomeration of DP in RCS, they aggregate to 120–150 μm, and due to low sedimentation resistance (sedimentation time 0.97 h), they settle in RCS. As a result of the deposition of DP in RCS, their significant decrease in return water (min–max=7.31–16.12 mg/dm³) is observed, despite the increase in their content in make-up water after water treatment (min–max=10.22–49.46 mg/dm³). According to the ecological classification, according to the content of suspended substances, the water of the Styr River in the zone of influence of RNPP discharges belongs to the II class, category 2, which characterizes the quality of the water as “very good” in terms of its state, and “clean” in terms of its degree of purity. It was concluded that the content of suspended solids does not exceed the established maximum permissible concentration (25 mg/dm³), the increase in the concentration of suspended solids does not exceed the established ecological standard of 0.25 mg/dm³ and does not have a negative impact on surface water. The results of the research could be used for other power plants equipped with an open RCS. [ABSTRACT FROM AUTHOR]

Red mud is an environmental burden during the alumina production process. To mitigate the hazards associated with red mud storage, this study investigated the utilization of alkaline red mud as a treatment agent for acidic mine drainage (AMD) with high concentrations of Fe(II) and Mn(II). This study explored the influence of reaction times, addition amounts of red mud, and pH values on the removal efficiency of Fe (II) and Mn(II) from high-concentration AMD. Various parameters such as suspended solids levels, effluent pH, and zeta potentials were measured to meet discharge standards. The adsorption mechanism of red mud was examined using SEM, XRD, EDX, XPS, and 3D-EEM analysis. Optimal conditions were determined as a reaction time of 2 h, pH value of 5.01 and the addition of 100 g/L red mud, achieving effective removal of Fe(II) (reduced from 1000 to 0.224 mg/L) and Mn (II) (reduced from 20 to 1.03 mg/L). The treated AMD meets discharge standards with reduced suspended matter content of 37.4 mg/L. These findings provided valuable insights for the utilization of red mud waste in engineering applications. [ABSTRACT FROM AUTHOR]

Satellite image channels have been widely used by researchers from various countries to map and analyze variables that have a lot of influence on ecosystem changes including the total suspended solid levels scattered on the coast. The use of 1 channel in satellite images provides many results with various good correlations, but in this study, we want to try to use a 2-channel approach to get more optimal results from total suspended solid mapping. The area of interest for research is the Tuban coastline which has a fairly flat and not hilly coastal morphology so that sea currents that carry solids have characteristics in their growth over time. The method used to construct the algorithm of these 2 channels is the use of reflectance values of visible light wavelengths in blue, green and red channels. The results obtained from the calculation of the 2-channel algorithm show a fairly good suitability and correlation, especially in the comparison of the blue channel with the red channel with an R2 value of 0.76 so that it can be used as a reference to monitor total suspended solids as well as a comparison for the calculation of 1 channel. The conclusion obtained is that the channels from satellite images have their own characteristics in providing reflectance values for objects on earth so that with the right combination of channels will be able to obtain accurate results in mapping total suspended solids. [ABSTRACT FROM AUTHOR]

APHA Standard methods 2130B and 2540D have proven valid and reliable methods to determine turbidity and total suspended solids (TSS). However, both methods have drawbacks and limitations. Carcinogenicity of formazin, inconsistency in preparation, and interference are the primary concerns in turbidity measurement. Equipment complexity, working steps, and measurement time are primary concerns in TSS measurement. The edge detection technique (EDT) is an alternative to overcome the drawbacks and limitations. This research aims to conduct the performance test of the proposed method using pro-analytical grade kaolin (Sigma-Aldrich K7375), which has non-toxic properties compared to the formazin standard. Natural water samples from three different sampling locations became another subject in the EDT-based measurement method performance test. Steps included are elemental characterization with SEM-EDS-JEOLJSM6510LA and particle size analysis with zeta sizer Horiba SZ-100. Turbidity measurement with Eutech TN100 and the TSS measurement with the gravimetric approach. Counted particle (CP) measurement through the EDT compared with the standard measurement. It showed that kaolin characteristics are closer to the natural suspension indicated by the more identical elemental compositions than the formazin elemental characteristics. Another result showed a correlation between kaolin concentration (KC), turbidity level, TSS concentration, and the counted particle is > 0.9. The proposed approach showed promising results indicated by the % Relative Standard Deviation < 20% for KC 0.5-20 mg/L and < 40% for KC 40-100 mg/L, in the linear range of 0.5-100 mg/L. Using a sample cell with a flat surface may improve the performance of the proposed approach. It is thus possible to reduce the reflection of light, which is a noise source in the measurement result. [ABSTRACT FROM AUTHOR]

Physical clogging of porous media plays an important role in controlling their hydraulic conductivity. This study investigates how uniformly graded medium-to-coarse sand in a reservoir’s bed performs in response to the inflow of turbid water with fine suspended sediments. Different particle sizes, heads, and concentrations were simulated to cover a range of hydrologic conditions. A 1D sand column was used with three bed material sizes and three suspended particle sizes. Seven particle size ratios were tested under a constant head. Four heads and three suspended sediment concentrations are also evaluated. It was concluded that the decline in the relative hydraulic conductivity of the bed material is directly proportional to the ratio of sediments-to-bed particle sizes. Increasing the concentration of suspended sediments accelerated the rate of clogging, while bigger heads increased the depth of clogging. The study highlights how physical clogging affects the water balance in surface reservoirs and threatens the safety of dams.

The Tyndall effect describes light scattering by suspended solid particulates with sizes smaller than or comparable to the wavelength of light. This work describes the design and construction of an instructional kit for observing the Tyndall effect. The kit consists of a 3D printed holder that can be combined with low-cost and readily available materials to enable student laboratory experiments. [ABSTRACT FROM AUTHOR]

The advancements in space technology have facilitated water quality (WQ) monitoring of lake conditions at a spatial resolution of 10 m by freely accessible Sentinel-2 images. The main aim of this article was to elucidate the necessity of spatiotemporal WQ monitoring of the shrinking Lake Burdur in Türkiye by examining the relation between field and satellite data with a state-of-the-art machine learningbased regression algorithm. This study focuses on detection of algal blooms and WQ parameters, which are chlorophyll-a (Chl-a) and suspended solids (SS). Furthermore, this study leverages the advantage of geographic position of Lake Burdur, located at the overlap of two Sentinel-2 frames, which enables the acquisition of satellite images at a temporal resolution of 2-3 days. The findings enrich the understanding of the lake's dynamic structure by rapidly monitoring the occurrence of algal blooms. High accuracies were achieved for Chl-a (R-squared: 0.93) and SS (R-squared: 0.94) detection. [ABSTRACT FROM AUTHOR]

Evidence demonstrates that as the production capacity of a kimberlite mine increases, there is a corresponding increase in the volumetric concentration of suspended solids in the mine water extracted from its watercollecting workings. The Udachny mine, known for its high productivity in comparison to other domestic kimberlite mines, experiences a higher concentration of suspended solids in the mine waters, leading to significant sludge settling within the primary drainage facility’s water-collecting workings. This determinal effect adversely affects the operational efficiency of pumping equipment and the reliability of LHDs. To address these issues, an enhanced version of the conventional main drainage facility scheme, specifically designed for kimberlite mine utilizing the block caving method, is proposed. This modified scheme aims to provide improved clarification of the mine water in the water-collecting workings and facilitate more efficient dewatering of the settled slurry sludges. Furthermore, a methodology has been developed to determine the time required for slurry sludge removal, the sedimentation characteristics of the solid phase, and the rheological properties of the liquid phase of the mine water.

Removal of suspended solids from raw water is an essential process in water treatment plants. Conventional sedimentation tanks in water treatment plants occupy a large area and become expensive in urban areas. The use of plate settlers or tube settlers in sedimentation tanks to increase the efficiency and hence reduce the footprint of sedimentation tanks is an economical solution in water treatment. This study investigated the effectiveness of plate and tube settlers compared to conventional settlers in a water treatment plant. A three-dimensional Computational Fluid Dynamics (CFD) model was set up using ANSYS-CFX 17.2. Seven cases (a conventional settler, three plate settlers and three tube settlers) were analysed to compare the settler performances. The maximum removal efficiencies of all solid classes were approximately equal in plate and tube settlers with the same plate spacing and tube depth: around 100%, 67%, 28% and 9% for the solid classes with particle diameters of 41, 17, 9.5 and 5.0 µm, respectively. The settling efficiency remained unchanged with the increase of the plate settling area beyond 60% of the conventional settler area under the given tank and flow conditions. The tube cross-section shape does not affect the particle removal efficiency of a tube settler. HIGHLIGHTS Plate settlers and tube settlers are increasingly used to reduce the water treatment plant footprint with the increasing land prices in urban areas.; The present study compares the efficiency of these settlers in the removal of suspended solids of different size classes by three-dimensional computational modelling using ANSYS CFX.; The model developed here can be used to upgrade existing conventional settling tanks paying due attention to the removal efficiency of different solid classes.;

Sequencing batch biofilter granular reactor (SBBGR) is a promising wastewater treatment technology owing to its low sludge yield and good toxicity tolerance. However, little attention has been paid to the formation process and mechanism of aerobic granular sludge in SBBGR. This study systematically investigated the formation process and mechanism of aerobic granular sludge in an SBBGR to provide a theoretical basis for optimizing the culture of aerobic granular sludge. Aerobic granular sludge with good performance was successfully cultivated after 40 days of incubation using synthetic wastewater as feed: the mixed liquid suspended solids and mixed liquor volatile suspended solids increased from 3.85 and 1.85 g/L to 31.38 and 24.74 g/L respectively, and the COD, TN, and TP removal efficiencies were 91.21%, 84.99%, and 58.14%, respectively. The experimental results showed that Amoebacteria and Bacteroides played an important role in the formation of aerobic granular sludge, filamentous bacteria acted as a three-dimensional skeleton surrounded by filling bacilli and rod-shaped bacteria, and proteins played a dominant role in promoting granulation during the culture process. [ABSTRACT FROM AUTHOR]

Diverse plant life has been affected by the tropical environment, which includes high humidity and lots of rainfall. This research aimed to discover local plants to be used as biocoagulants in the treatment of coffee effluent. Three species of native plants were chosen: Trichantera gigantea (ketum ayam), Manihot esculenta (cassava plant) and Piper sarmentosum (kaduk). Coffee effluent was chosen because it has high total suspended solids (TSS), contributing to increasing turbidity that exceeds the allowable regulation limits. The coagulation-flocculation method was applied to remove these suspended solids and turbidity in the effluent using a jar test. These potential biocoagulants were extracted using distilled water before being screened and characterized to measure their amount of protein and polysaccharide contents using the Bradford and acid extraction approaches. The protein content for M. esculenta showed the greatest value (87.9 mg/g), while T. gigantea revealed the highest amount of polysaccharide extracted (37.0 mg/g). The optimum operating parameters were set at 300 rpm and 5 min for rapid mixing and then 180 rpm and 30 min for respective slow mixing with 30 min settling time. The findings show that P. sarmentosum was the best biocoagulant with the highest removal of TSS and turbidity at 51.0% and 66.9%, respectively. The mass ratio used in P. sarmentosum was lower when compared to other biocoagulants, which is 45.9 mg biocoagulant/g TSS, with the protein and polysaccharides contained in this biocoagulant were 11.6 mg/g and 34.0 mg/g, respectively. • Plant leaves as biocoagulant/flocculant agent in treating coffee industry effluent • Distilled water was used to extract proteins and polysaccharides from plant leaves • P. sarmentosum leaves contained highest protein with 11.6 ± 0.19 mg/g • Turbidity and total suspended solids were removed up to 66.9% and 51.0%, respectively • P. sarmentosum shows a great performance at a ratio of 45.9 mg biocoagulant/g TSS [ABSTRACT FROM AUTHOR]

In this paper, a dithiocarbamate-type flocculant DTC-TETA was prepared by using triethylenetetramine as the material and combination of DTC-TETA and polyacrylamide was used for the coagulation-flocculation of flowback water from shale gas hydraulic fracturing (FWSG). The coagulation-flocculation process was optimized by using turbidity as index and the recommended process was as follows: DTC-TETA dosage 200 mg/L, anionic polyacrylamide AN905 dosage 1 mg/L, flocculation stirring speed 200 rpm, flocculation stirring time 3 min and settlement time 5 min. The turbidity of FWSG can be reduced to be 13 NTU from the initial turbidity of more than 2000 NTU under the recommended process. The performance of DTC-TETA was much better than that of polyaluminum chloride and the Fe2+ in FWSG also can be removed. The function mechanism of DTC-TETA was investigated through the studies of zeta potential change of suspended solids and structural characteristics of flocs. The results confirmed that the flocs were developed by the network formed by the coordination reaction between DTC-TETA and Fe2+, which can filter out suspended solids. This study signifies that both suspended solids and Fe2+ ion can be removed by using DTC-TETA as flocculant, which is a new choice for the FWSG treatment. [ABSTRACT FROM AUTHOR]

We conducted a study in Lake Abaya and Lake Chamo, the two largest Ethiopian Rift Valley lakes, between 2016 and 2019, to evaluate their limnological features and infer longer-term changes in some water-quality parameters. Data generated through in situ measurements and laboratory analyses of physico-chemical parameters and the plankton communities were compared with results from the literature. Turbidity, salinity, nitrates and soluble reactive phosphorous showed an increasing trend in Lake Abaya, while in Lake Chamo conductivity, salinity, nitrates and soluble reactive phosphorous showed an increasing trend. In both lakes the water transparency and chlorophyll a concentration showed a declining trend. Despite higher available nutrients in Lake Abaya compared with Lake Chamo, higher turbidity with suspended solids contributed to lower chlorophyll-a concentrations and lower zooplankton abundance. The abundances of rotifers and crustaceans were lower in Lake Abaya compared with Lake Chamo. The mean trophic state index using total phosphorus, Secchi depth and chlorophyll-a shows that both lakes are in a eutrophic state. Our findings are consistent with previous studies and indicate that changes in major limnological features are a signal to take intervention measures to prevent further ecological degradation and to sustain the ecological services and livelihoods of fishers who are directly dependent on the lakes. [ABSTRACT FROM AUTHOR]

We investigated the relative influence of local environmental and spatial factors in structuring the community composition of fish at 15 sampling sites along the longitudinal gradient of the Lower Niger River Basin (LNRB) in dry and rainy seasons using distance‐based redundancy analysis and variation partitioning analysis. We collected a total of 3807 fish specimens representing 42 species. Our result indicated that the fish community composition differed between the upper and lower regions of the river. The communities in the upper region is influenced by high‐nutrient concentrations, while downstream sites were characterized by high concentrations of suspended solids. Variation partitioning revealed higher contributions of spatial than environmental predictors on fish community composition, with a higher total predicted variance in dry season. The variations in the community composition between upper and lower region may be attributable to the differences in the nature of anthropogenic activities within the regions, which influenced the local conditions differently. Differences in flow dynamics between upper and lower regions as attributable to black and white floods in the LNRB modify the connectivity between sites. Dispersal among sites may be more limited downstream than in the upper region, particularly in the dry season, because damming in the upper region also interrupts the natural flood regime such that there are low water levels in the lower region, which spatially isolate fish communities at certain sampling sites. The relatively higher total predicted variance during dry season may be attributable to the temporal differences in abiotic conditions between sites, which may have influenced site level community composition and abundance differently. [ABSTRACT FROM AUTHOR]

Treatment of Municipal wastewater by Electrocoagulation (EC) process using punched aluminium and zinc electrodes was studied in a batch EC cell reactor. Response surface methodology (RSM) based on Central Composite Design (CCD) was utilized to optimize the operating parameters for the removal of % Total Suspended Solids (TSS) and % Chemical Oxygen Demand (COD) from Municipal Sewage. Effect of operating parameters such as Electrode Distance (x1), Electrolysis Time (x2) and Voltage (x3) has been optimized for the removal of TSS and COD. The prediction of removal percentage of TSS and COD in various Operational circumstances is done by using Quadratic model. The significance of each operating parameter was computed by Analysis of variance (ANOVA). To achieve the maximum removal of % TSS and % COD, the optimum conditions were Electrode distance(x1)—3 cm, Electrolysis Time (x2)—70.299 minute and Voltage (x3)—6.5V. It was observed that the performance of electrocoagulation process increased up to 61.45% for COD removal, and 73.73% for TSS removal using punched electrode compared to plane electrodes. [ABSTRACT FROM AUTHOR]

In the context of freshwater ecosystems, turbidity and suspended solids play crucial roles, with their levels significantly influenced by anthropogenic activities. This study focuses on assessing and monitoring these parameters in Albufera de Valencia using Sentinel-2 imagery. The primary aim is to establish reliable estimation algorithms that can contribute to effective ecosystem management. This study calibrated and validated algorithms for estimating turbidity and suspended solids. The R783 × R705/R490 model proved to have the best performance for estimating turbidity and total solids in Albufera. However, R783/R490 obtained a higher coefficient of determination for the organic part, while the R705 band was selected for the inorganic part. However, to achieve better estimates of turbidity and inorganic matter, more research is needed in the future. The implications of excessive suspended solids are underscored, including the depletion of dissolved oxygen and reduced primary productivity due to limited light penetration and habitat availability. Collaboration between disciplines such as limnology, optics, and water chemistry is crucial to advance water quality estimation models in lakes and lagoons such as Albufera. By integrating expertise and approaches from these diverse fields, new knowledge can be gained, and the basis for more effective management and conservation strategies can be laid. [ABSTRACT FROM AUTHOR]

Combined sewage overflows (CSOs) are a common consequence of heavy rainfall events and can have significant implications for water quality in receiving waterbodies. With climate change, these events are becoming more frequent and intense, placing greater pressure on aquatic ecosystems. To prevent water pollution, it is essential to utilize numerical tools to investigate, forecast, and establish control measures for CSOs. Typically, these tools involve a dynamic model for flow simulation combined with either a detailed model for pollutants or a simplified event mean concentration (EMC) calculation. However, both approaches have drawbacks: a detailed model requires extensive calibration time, while the EMC does not account for system dynamics. To overcome these issues, a novel system was developed that integrates the dynamic nature of the detailed model with the rapid calibration of the EMC. This model employs two distinct concepts for pollution modeling: one for soluble compounds and one for suspended solids. The resulting model was evaluated at multiple locations with varying hydraulic dynamics, demonstrating its potential utility at any location where a dynamic model of the sewer system is available. [ABSTRACT FROM AUTHOR]

Environmental protection is becoming a primary objective when choosing processes and technologies for treating oily waters resulting from hydrocarbon production. The focus of treating oily waters is to eliminate contaminants from effluents before discharging them into the receiving environment while adhering to discharge standards. Our work aims to analyze the treatment process for oily waters in the API unit of the North Industrial Center (CINA), which involves a physical–chemical treatment using activated silica and Kurifix. The study aims to improve the treatment process used for oily water treatment to ensure water conservation for reuse. To enhance the CINA-HMD oily water treatment process, we created coagulants with different doses (C1–C6) using sodium silicate, activated silicate (sodium silicate + sulfuric acid), distilled water, Kurifix, and an oxygen scavenger while measuring pH, HC (hydrocarbon), and SS (suspended solids) levels. Coagulation and flocculation processes were used to remove suspended solids and hydrocarbons from the water. The results show that the coagulant used reduces suspended matter and hydrocarbon content and increases pH. The best treatment is achieved with a coagulant prepared with distilled water, 5% sodium silicate, and 2% sulfuric acid. The optimal dose of coagulant is 16 ppm. Automatic dosing provides better efficiency than manual dosing. The study recommends continuous verification of chemical preparation and injection, periodic cleaning of settling tanks, and monitoring of oily water entering the station. [ABSTRACT FROM AUTHOR]

The protection of water bodies requires the reduction of pollutant emissions from all major sources. In urbanized areas, these include: wastewater treatment plants (WWTPs) and (depending on the type of sewage system) combined sewer overflows (CSOs) and stormwater drainage outlets. WWTPs are usually monitored and emitted pollutant loads are known, but it is more difficult to assess the pollutant load discharged by CSOs and stormwater drainage systems. The article attempts to use the Stormwater Management Model (SWMM) to assess emissions of suspended solids from a large urban combined catchment. Suspended solids are the main pollutant of stormwater runoff in urban areas, and the dynamics of their emission from catchments is very diverse. The amount of suspended solids discharged by CSOs functioning in the given city was assessed in comparison with emissions from a wastewater treatment plant. The results show that CSOs discharge a pollutant load to the receiver which is comparable to WWTPs, but in a much shorter time and in a violent manner which can lead to the severe deterioration of receiving water quality. The modelling took into account the quality of dry weather sewage, the build-up of suspended solids, wash-off processes in the catchment area, and local precipitation characteristics. Factors affecting the quality of the obtained model and the accuracy of the emission level assessment were analysed. [ABSTRACT FROM AUTHOR]

Purpose: Multimodal effective particle size distributions (EPSDs) develop as flocculation and particle breakage occur dynamically in a fluid shear and such distributions have been previously reported in coastal and estuarine waters to understand flocculation processes. Here, we use time varying multimodal EPSDs and hydraulic parameters (discharge and bed shear stress) to assess freshwater flocculation in a gravel-bed river in southern Alberta, Canada. Methods: Instantaneous discharge, volume concentration (VC), and EPSD of suspended solids were measured during three high discharge events at four study sites in a 10 km reach of the Crowsnest River. The EPSD and VC of suspended solids (< 500 µm) were measured in the centroid of flow with a LISST-200x. Bed shear stress for measured discharge was obtained using a flow model, MOBED. Results: Multimodal EPSDs consisted of primary particles, flocculi, microflocs, and macroflocs. Shear dependent flocculation was consistently observed for all sites and events, due to low and high shear stress flocculation, particle breakage, and mobilization of tributary sub-catchment derived particles. Higher shear stress limited flocculation to smaller floc sizes, while lower bed shear stress conditions created higher volumes of macroflocs. Conclusion: Flocculation and particle breakage processes based on relationships between particle size and hydraulic properties presented herein have implications for advancing fine sediment transport models by a variable cohesion factor as a function of floc size class. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing 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.)

Background: In this study, the effect of static magnetic fields (SMFs) on improving the performance of activated sludge process to enhance the higher rate of microbial growth biomass and improve sludge settling characteristics in real operation conditions of wastewater treatment plants has been investigated. The effect of SMFs (15 mT), hydraulic retention time, SRT, aeration time on mixed liquor suspended solids (MLSS) concentrations, mixed liquor volatile suspended solids (MLVSS) concentrations, α-factor, and pH in the complete-mix activated sludge (CMAS) process during 30 days of the operation, were evaluated. Results: There were not any differences between the concentration of MLSS in the case (2148.8 ± 235.6 mg/L) and control (2260.1 ± 296.0 mg/L) samples, however, the mean concentration of MLVSS in the case (1463.4 ± 419.2 mg/L) was more than the control samples (1244.1 ± 295.5 mg/L). Changes of the concentration of MLVSS over time, follow the first and second-order reaction with and without exposure of SMFs respectively. Moreover, the slope of the line and, the mean of α-factor in the case samples were 6.255 and, − 0.001 higher than the control samples, respectively. Changes in pH in both groups of the reactors were not observed. The size of the sluge flocs (1.28 µm) and, the spectra of amid I' (1440 cm−1) and II' (1650 cm−1) areas related to hydrogenase bond in the case samples were higher than the control samples. Conclusions: SMFs have a potential to being considered as an alternative method to stimulate the microbial growth rate in the aeration reactors and produce bioflocs with the higher density in the second clarifiers. [ABSTRACT FROM AUTHOR]

In the uppermost stream of the Mimikawa River, in northern Miyazaki Prefecture, the contribution to river turbidity of a huge, collapsed slope alternating sandstone and mudstone layers was qualitatively shown in our previous study. In this study, the water level and turbidity were continuously observed, to obtain a quantitative estimation of this contribution. The conversion equation from the water level to the flow rate is required, but field measurements during the flooding term in the mountainous site are difficult. In this study, a high-resolution survey was conducted, and the relationship was determined via a small-scale hydraulic model shaped using a 3D printer from the survey results, to determine the relationship between the water level and the flow rate. The flow rate time series was reproduced with the distributed runoff model that is verified with the flow rate converted from the water level. The flow rate and turbidity load time series were also estimated from the long-term rainfall. The area of the bare soil surface of each small basin was obtained via satellite image analysis, and the soil yield from each surface condition was calculated. Furthermore, the amount of turbidity produced upstream of Kamishiiba Dam was calculated for each small basin. It was estimated that 24% of the turbidity was generated from the small basin covering 5.7% of the total catchment area. This study showed that it is possible to verify the hydrological model by obtaining the water-level–discharge relationship, even in the mountains, where it is difficult to observe the discharge on-site, via small-scale hydraulic model experiments. [ABSTRACT FROM AUTHOR]

Suspended solids (SS) have become the main cause of water quality deterioration in aquaculture ponds. The application of ozone to aquaculture water bodies can improve the water quality and facilitate the removal of suspended solids. We used different concentrations of ozone to oxidize aquaculture water and then determined the resulting concentration of suspended solids and their particle size distribution, as well as CODMn, UV254, algal density, and nitrogen content. The results showed the following: (i) The decrease in SS was the highest, amounting to 10.47%, after the addition of 2 mg/L of ozone and the completion of the oxidation reaction. Ozone caused the fragmentation of large SS particles and the flocculation of small particles, and these effects became more pronounced as the ozone concentration increased; (ii) After the introduction of ozone, the humus macromolecules naturally present in the water were oxidized, which improved the biochemical degradation of the water pollutants; (iii) Ozone oxidation caused the degradation of algae, resulting in a decrease in phytoplankton biomass and in the eutrophication of the water body; (iv) As the ozone concentration increased, the level of nitrous nitrogen decreased, while the concentrations of nitrate nitrogen and ammonia nitrogen were unchanged. The highest increase in total nitrogen was measured when 0.5 mg/L of ozone was applied. This study provides a theoretical basis for the application of ozone to eliminate eutrophic substances in freshwater ponds. [ABSTRACT FROM AUTHOR]

Tight gas belongs to unconventional gas reservoirs, and to obtain high gas production, it needs to be fractured and reformed. After the construction is completed, a large amount of flowback fluid is produced. In order to reduce the cost of flowback fluid treatment and avoid environmental pollution, a slippery water system with flowback fluid is usually used on the site of hydraulic fracturing. Almost all flowback fluids contain high‐order cations such as calcium ions, magnesium ions, iron ions, and a large amount of suspended solids. Some flowback fluids contain incomplete gel‐breaking micelles and unseparated condensate oil. The performance of the viscosity‐reducing and slippery water system with flowback fluid as the base fluid is poor, usually manifested as low viscosity of the slippery water, low friction reduction rate, and high formation damage. To study the effect of tight gas fracturing flowback fluid on the performance of modified polyacrylamide viscosity‐reducing and slippery water system, this paper found through cryo‐electron microscopy scanning experiments that the flowback fluid made the modified polyacrylamide molecular chain unable to form a complex network structure and showed the phenomenon of reduced strength and aggregation. The effects of mineralization degree, calcium and magnesium ions, divalent and trivalent iron ions, suspended solids, pH value, and oil content on the viscosity, friction reduction performance, and rock damage of the viscosity‐reducing and slippery water system were analyzed experimentally. It was found that the viscosity of the viscosity‐reducing and slippery water system was mainly affected by divalent iron ions, calcium and magnesium ions and other divalent cations; the friction reduction rate was mainly affected by the content of suspended solids and oil content; and the rock damage was mainly affected by the pH value and the content of suspended solids. Based on this, recommended parameters for reusing tight gas fracturing flowback fluid are given to guide the smooth progress of hydraulic fracturing construction on‐site. [ABSTRACT FROM AUTHOR]

Dissolved air flotation (DAF) is an important water treatment process for removing suspended solids. Understanding the characteristic size and spatial distribution of both bubbles and suspended solids, including their hydrodynamics, within flotation tanks is key to optimising flotation performance. In this study, a continuously operating lab scale DAF tank was constructed to simultaneously monitor size distributions and motions of microbubbles (Ø = 67–86 ± 13–19 µm) and spherical polyethylene microplastic particles (Ø = 69.8 ± 5.3 µm) in unbuffered water at circumneutral pH without salt addition and with 0.5 g L−1 sodium chloride (NaCl) added. Microplastic particles were used for the first time in such a setup. Particle tracking showed different flow regimes in the separation zone, with short-circuiting flow paths varying at different flow rates. Within the range of flowrates employed, the bubble bed that formed was not prominent enough to promote stratified flow. The addition of NaCl greatly reduced microplastic particle counts within the separation zone during flotation. This new multi-factorial approach provides critical insights into the variations in DAF performance. • Method for monitoring several factors simultaneously in DAF developed. • Image analysis observes flow patterns, particle and bubble size distribution. • First time microplastics particle removal in a DAF tank design investigated. [ABSTRACT FROM AUTHOR]

The growth of the human population brought about the global intensification of aquacultural production, and aquaculture became the fastest growing animal husbandry sector. Effluent from aquaculture is an anthropogenic environmental burden, containing organic matter, nutrients and suspended solids that affect water quality especially in the water bodies of high biodiversity and conservation value. Water quality assessment often relies on bioindicators, analysing changes in taxonomic diversity of various freshwater organismal groups. Stepping beyond taxon diversity, we used functional and phylogenetic diversities of rotifers to identify factors affecting their community organization in response to an aquaculture effluent gradient in the largest oxbow lake in the Carpathian Basin, Hungary. Sampling was carried out three times per season at five points along a 3.5 km section of the oxbow lake, including the point of effluent inflow. We used eight traits to evaluate functional diversity: body size, trophi type, feeding mode, protection type, body wall type, corona type, habitat preference and tolerance level. Functional and phylogenetic distances among the 24 species identified indicated trait conservatism. Rotiferan diversity increased with increasing distance from the point of influx in spring and summer. Among the factors affecting community organization in spring and summer, we find examples of environmental filtering, while in autumn the role of biotic interaction is more frequent. Under nutrient‐rich conditions in spring and summer, organisms belonging to the same functional group were dominant, whereas under oligotrophic conditions, more diverse but less abundant groups were present. Considering functional and phylogenetic traits allowed us to identify organising forces of rotifer communities in the largest oxbow lake of the Hungarian Lowland. [ABSTRACT FROM AUTHOR]

During the dewatering process, centrate is produced, which is returned to the beginning of the technological system. The quality of the resulting centrate, and therefore the size of the returned load of pollutants, affects the demand for electricity in the process of biological wastewater treatment. The following study presents the results of centrate quality tests at five wastewater treatment plants located in Poland. The dependence between suspended solids content and ammonia and COD concentrations in the centrate was determined. It was estimated that an increase in the overall suspended solids leads to an increase in COD by about 1.15 kgCOD/kgTSS. No correlation was found between TSS concentration and ammonia. It was calculated that the complete elimination of suspended solids from the sludge would reduce the electricity consumption for all five objects by about 535 MWh/y. [ABSTRACT FROM AUTHOR]

Diverse feedstocks utilized in anaerobic digestion (AD) pose challenges to enzymatic disintegration because of their nature and complex physical structures and thereby limiting biogas generation. To overcome this, the AD process is often combined with pretreatment techniques, which facilitate the breaking of organic feedstock into smaller molecules and eventually result in enhanced biogas production. Among several techniques, ultrasound-assisted pretreatment of AD feedstock remains promising because it is simple to implement, requires no chemicals, and combines physical (or cavitation) and biological phenomena for degrading AD feed. This review is primarily centered on the applications of ultrasound pretreatment for disintegrating various feedstocks and increasing biogas production during AD. Biogas generation is described in relation to the ultrasound-assisted disintegration of dairy industry waste, hybrid food and municipal wastes, olive mill wastewater, rice straw, tannery wastewater, meat processing sludge, hybrid industrial waste municipal sewage sludge, and lignocellulosic biomass. The disintegration schemes of feedstocks under ultrasound are proposed. COD is solubilized, and suspended solids (SS) are reduced upon ultrasonication. The impact of ultrasonic treatment on biogas production might be amplified if paired with alkali. Furthermore, the techno-economic commercial scopes of ultrasound pretreatment-based biogas production are discussed, and recommendations for future studies are suggested. [ABSTRACT FROM AUTHOR]

The methanol-to-olefins (MTO) process is regarded as a crucial approach for ensuring the sustainable growth of China's chemical industry. However, the fine catalyst particles and insoluble organics in the water system poses a serious threat to the stability of the MTO process. A novel horizontal swirl regeneration micro-channel separation (HSRMS) method for purifying the MTO reaction wastewater was developed in this study. On-site experiments were conducted using a device with a capacity of 1 t/h to investigate the separation and regeneration effects under various parameters and to verify the feasibility of this method through a long-term observation. The results showed that this method could effectively remove the fine solids and insoluble organics in the reaction wastewater, and the device operated stably with fluctuations in both the quality and quantity of wastewater for 24 consecutive days. The suspended solids in the effluent was maintained below 5 mg/L, and the average removal efficiency for insoluble organics exceeded 75%. Furthermore, the excellent regeneration performance was achieved, with solid particles and oil in the media reduced to less than 0.2% after regeneration. This method could ensure long-term stable operation of the water system and outperform other commonly used reaction wastewater treatment methods in terms of investment, maintenance cost, freshwater supplementation, and energy consumption. [Display omitted] [ABSTRACT FROM AUTHOR]

Compost leachate was treated with coagulation/flocculation followed by filtration in order to obtain effluent suitable for further purification by reverse osmosis process. The poly aluminium chloride coagulant and the poly acryl amide flocculant were applied for coagulation/flocculation process. Filtration tests were performed to choose the proper fabric for filtration of compost leachate. There were huge differences between compost leachate samples’ properties taken at the plant; therefore, it was difficult to determine the optimum coagulant/flocculant dosage. It was found that, among the fabrics available, only one was appropriate, and was made of polypropylene. With other filter fabrics the pressure during the filtration increased above 6 bar, which means above the highest specified allowed pressure for the device used. The filtration was carried out with several differently pretreated samples of compost leachate. The turbidity was reduced by as much as 89.8 %. The particle-size distribution analyses showed that most colloids and suspended solids were removed after the treatment. The results indicate that combination of coagulation/flocculation followed by filtration is not adequate for proper treatment of compost leachate, and some other technique, such as electrocoagulation, ultrafiltration, and nanofiltration need to be investigated. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office 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.)

The chemical and ecological quality of small rivers or streams is not normally classified, but any urban stormwater discharges will result in their impairment. To assist in understanding the resulting applied environmental stress to benthic communities, the empirical relationships between in-stream suspended solids and metal pollutants, initially identified by principal component analysis, are explored using data from a small urbanised upland catchment. When data are amalgamated from individual storms, a correlation for each metal pollutant with suspended solids is obtained, starting very strongly, and decreasing in the order Fe > Al > Mn > Pb > Cr > Zn > Cu > Ni. Comparison of pollutant/solids correlations for individual storms is, for some metals, excellent, but differing intercepts and/or gradients can be obtained for an individual metal between storms. The practice of assessing their correlation based on event mean concentrations or longer-term averages across several storm events may conceal strong correlations for individual storms, exemplifying the impact of variable catchment characteristics and storm conditions; Cd and Be are poorly correlated with suspended solids and are likely affected by changes in background pollution levels. The analysis of covariance also highlights a significant difference between certain storm events for specific metals, which calls into question the validity of using combined storm-event datasets. The relationships identified here enable the determination of stormwater pollutant loads from suspended solids concentrations for heavy metals and are useful for developing water quality assessments. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute 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.)

The problem of microplastics (MP) is increasingly discussed in the context of surface water pollution. Preliminary studies were carried out for an unusual river basin. The researched catchment is characterized by the presence of areas under legal protection and high pressure related to tourist traffic. Three series of tests of microplastic content in the waters of the Upper Vistula were carried out on the section from the Wisła Czarne (above the dam reservoir) to the town of Ochaby. Six sampling points were selected. The research material (suspended solids) was collected using a plankton net with a diameter of 0.25 m and a mesh size of 250 µm, each time from 1 m³ of river water. During the tests microplastics were found in all the taken samples. The least amount of microplastic was observed at sample points 1 and 2. An increase in the microplastic content in the waters of the Vistula was shown, especially in the cities of Wisła and Skoczów. The increase in microplastic content was also observed downstream of the wastewater treatment plant, although it should be noted that it was not as significant as in the case of rivers flowing through the central part of the Upper Silesian Agglomeration. Also noticeable is the decrease in the microplastic content in the samples collected in Ochaby (sampling point 6). This may be caused by both the dilution of the Vistula waters with streams flowing above this point, as well as the natural processes responsible for the removal of suspended solids from the river (sedimentation, retention of suspended particles on the vegetation growing on the river banks or in natural ponds and fragments of the riverbed with reverse current). The Vistula River may be contaminated with microplastics even from their entire length, regardless of whether they flow through legally protected areas, with residual anthropogenic development of the catchment area and the riverbed, or through tourist resorts. [ABSTRACT FROM AUTHOR]

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]