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The burgeoning industrialization and urbanization along the Indian coastline have led to an increased prevalence of port infrastructure and effluent discharge, raising concerns about their potential impact on the delicate macrobenthic communities in coastal ecosystems. This comprehensive review aims to evaluate and synthesize existing literature on the ecological repercussions of port activities and effluent discharge on macrobenthic organisms in Indian coastal regions. The study encompasses a thorough analysis of relevant research articles, government reports, and scientific databases, focusing on diverse ecosystems such as estuaries, mangroves, and open coastlines. The review discusses the various stressors associated with port operations, including dredging, habitat alteration, and chemical contamination from effluent discharge. Furthermore, it explores the response mechanisms of macrobenthic communities, encompassing changes in species composition, abundance, and diversity. Special attention is given to the potential long‐term impacts on ecosystem functioning and services. The synthesis of available data enables the identification of knowledge gaps and the formulation of recommendations for future research and management strategies. Understanding the cumulative effects of port activities on macrobenthic communities is crucial for developing sustainable practices and policies to mitigate adverse impacts while fostering the resilience of coastal ecosystems in the face of anthropogenic pressures. This review contributes to the growing body of knowledge on the ecological consequences of human activities in Indian coastal areas, providing valuable insights for researchers, policymakers, and environmental managers alike. [ABSTRACT FROM AUTHOR]

Abstract This study highlights the importance of managing fishpond effluent to minimize its impact on aquatic environments. Fish effluents are a major concern worldwide in aquatic environments. It also provides information on the impacts of effluents on the water quality index of streams when released into aquatic environments. Streams and fishponds were sampled bimonthly for two annual cycles, covering different sampling stations both upstream and downstream of the fishpond effluents at 50-m intervals. Water quality parameters associated with in situ conditions were determined in the field. In the laboratory, other physicochemical parameters were determined via proper standard protocols. The results of the study revealed that water quality parameters such as turbidity, total suspended solids, total solids, conductivity, total dissolved solids, dissolved oxygen, biological oxygen demand and organic matter recorded in water samples collected from 50 m upstream at the point of effluent discharge were significantly (p

This study highlights the importance of managing fishpond effluent to minimize its impact on aquatic environments. Fish effluents are a major concern worldwide in aquatic environments. It also provides information on the impacts of effluents on the water quality index of streams when released into aquatic environments. Streams and fishponds were sampled bimonthly for two annual cycles, covering different sampling stations both upstream and downstream of the fishpond effluents at 50-m intervals. Water quality parameters associated with in situ conditions were determined in the field. In the laboratory, other physicochemical parameters were determined via proper standard protocols. The results of the study revealed that water quality parameters such as turbidity, total suspended solids, total solids, conductivity, total dissolved solids, dissolved oxygen, biological oxygen demand and organic matter recorded in water samples collected from 50 m upstream at the point of effluent discharge were significantly (p < 0.05) different from those recorded at other sampling stations. The WQI value of the discharge point was higher than the WQI recorded in both the upstream and downstream sections of the stream. The findings of this study showed that the point of discharge of fishpond effluents is particularly concerning for the receiving stream compared with other sampling points. This localized area has experienced marked deterioration in water quality, posing significant threats to the health and biodiversity of aquatic ecosystems. The effluent's impact, though slight when dispersed in the receiving waterbody, underscores the necessity for adequate management practices to mitigate its adverse effects. Effective strategies, including regular monitoring, effluent treatment, and sustainable pond management, are imperative to ensure the long-term health and resilience of the aquatic environment. [ABSTRACT FROM AUTHOR]

This study assessed the quality status of the Eruvbi River in Benin City, Nigeria using the National Sanitation Foundation Water Quality Index (NSFWQI). The physicochemical and microbiological parameters analysed were pH, temperature, turbidity, total dissolved solids (TDS), phosphate, nitrate, biochemical oxygen demand (BOD), dissolved oxygen (DO), and total coliforms. All parameters were analysed using standard methods. For each parameter, the temporal and spatial range were pH (5.3 - 6.2), temperature (22.0 - 28.0 oC), turbidity (5.0 - 128.0 NTU), TDS (20.0 - 128.0 mg/L), phosphate (0.1 - 1.0 mg/L), nitrate (0.2 - 0.8 mg/L), BOD (3.4 - 6.2 mg/L), DO (5.0 - 11.2 mg/L), while the mean for total coliform count ranged from (416.9 - 295120.5 CFU/100 mL). The results were compared against national and international standards with the temperature, TDS, and nitrate values within set limits, while the non-conforming parameters were majorly total coliform, phosphate, turbidity, and pH. The overall NSFWQI results indicated moderate water quality, with WQI values ranging from 54.04 to 61.95 at all sampling locations. The middle stream had the lowest NSFWQI value caused by effluent discharge from a carbonated drink industry. The moderate water quality means that additional treatment is required before the water can be considered safe for drinking and domestic purposes. The NSFWQI protocol makes it easier to explain the water quality to the general public and decision-makers, and it can be a valuable tool for water management. [ABSTRACT FROM AUTHOR]

This study assessed the quality status of the Eruvbi River in Benin City, Nigeria using the National Sanitation Foundation Water Quality Index (NSFWQI). The physicochemical and microbiological parameters analysed were pH, temperature, turbidity, total dissolved solids (TDS), phosphate, nitrate, biochemical oxygen demand (BOD), dissolved oxygen (DO), and total coliforms. All parameters were analysed using standard methods. For each parameter, the temporal and spatial range were pH (5.3 - 6.2), temperature (22.0 - 28.0 oC), turbidity (5.0 – 128.0 NTU), TDS (20.0 – 128.0 mg/L), phosphate (0.1 – 1.0 mg/L), nitrate (0.2 - 0.8 mg/L), BOD (3.4 - 6.2 mg/L), DO (5.0 - 11.2 mg/L), while the mean for total coliform count ranged from (416.9 - 295120.5 CFU/100 mL). The results were compared against national and international standards with the temperature, TDS, and nitrate values within set limits, while the non-conforming parameters were majorly total coliform, phosphate, turbidity, and pH. The overall NSFWQI results indicated moderate water quality, with WQI values ranging from 54.04 to 61.95 at all sampling locations. The middle stream had the lowest NSFWQI value caused by effluent discharge from a carbonated drink industry. The moderate water quality means that additional treatment is required before the water can be considered safe for drinking and domestic purposes. The NSFWQI protocol makes it easier to explain the water quality to the general public and decision-makers, and it can be a valuable tool for water management.

Urban wastewater treatment plants (WWTPs) are major contributors of microplastics (MPs) in the environment, despite achieving relatively high removal percentages. This study conducted a comprehensive assessment of the abundance and characteristics of MPs in wastewater and sludge at various treatment stages at Gebze WWTP located in the Marmara Sea, for the first time. The influent exhibited an average MPs concentration of 70.1 ± 28.6 MPs/L. After undergoing the fine screen and grit chamber units, the MPs concentration significantly reduced to 19.7 ± 3.6 MPs/L, indicating an impressive removal rate of 71.8%. Upon completion of the secondary treatment, the effluent contained 7.1 ± 1.7 MPs/L, resulting in an overall MP removal of 89.9–91.0%. The findings indicated that fibers constituted the predominant particle shape, followed by fragments. Fibers were effectively removed through primary treatment (71.8%), while fragments were efficiently removed during secondary treatment (81.1%). The analysis of sludge samples from the aeration basin and sludge thickening tank revealed higher concentrations, with 14.3 and 25 folds increase compared to the influent, respectively indicating the accumulation of MPs in sludge. Despite the treatment process, it is noteworthy that the effluent still exhibited a significant abundance of fibers. Micro-Raman analysis identified polyethylene and polypropylene as the main polymer types present. Although the WWTP demonstrated a high overall removal rate, an estimated 1022.4 × 106 ± 244.8 × 106 MPs/d were still being discharged with the effluent into the Marmara Sea. Recognizing the potential impact of MPs on marine organisms, measures, such as introduction of tertiary treatment processes, were taken to mitigate this issue. [ABSTRACT FROM AUTHOR]

Historically, Southern California's four largest publicly owned treatment works (POTWs) were major sources of contaminants in the Southern California Bight (SCB), home to over 22 million residents and diverse marine life. This study conducted a fifty-year review (1971–2020) to assess these facilities' performance in protecting human and aquatic life. We analyzed effluent discharge flow, total annual mass emissions into SCB, and the rate of change of mass emissions in five ten-year timeframes. Results show a significant decrease in contaminant concentrations (43% to 99%) from 1971 to 2020, with most reaching historically low levels. Despite a growing population, effluent volume decreased by 23%, reflecting successful local water conservation and recycling efforts. Some constituents experienced temporary increases that later decreased. Overall, the decline in mass emissions for all constituents over fifty years highlights the POTWs' efforts to treat effluent and reduce their impact on the SCB's ecosystem. [ABSTRACT FROM AUTHOR]

Kuwait Bay, increasingly susceptible to contamination due to urbanization and effluent discharge, serves as a focal point for environmental research. This study aims to provide a scientifically grounded assessment of sediment contamination within the bay, emphasizing the role of effluents as primary pollutants. Sediments, as repositories for both organic and inorganic pollutants, bear significant implications for marine ecosystems. A systematic sampling approach was employed at forty-six georeferenced sites across the bay, utilizing a grab sampler aboard a research vessel. The sediment samples were rigorously analyzed for inorganic geochemistry, encompassing trace elements, nutrients, and heavy metals. A comparative analysis was conducted between the trace element concentrations obtained in this study and established background levels, as well as the guidelines set forth by the United States Environmental Protection Agency (USEPA). The findings indicate a discernible level of contamination in Kuwait Bay. While the current contamination levels are classified as low, there is a pronounced risk of escalating contamination if the practice of discharging untreated effluents persists. In light of these results, the study underscores the urgent need for effluent decontamination prior to discharge into the bay. This research not only maps the spatial distribution of contaminants in Kuwait Bay but also provides a critical evaluation of potential risks to the marine environment, thereby informing future mitigation strategies. The comprehensive nature of this assessment, integrating geochemical analysis with environmental impact evaluation, marks a significant contribution to the field of marine contamination research. [ABSTRACT FROM AUTHOR]

Due to the difference in density between the discharge effluent and coastal water, partially treated wastewater is often discharged into the marine environment as a buoyant jet via submarine outfalls with multiport diffusers. The dilution characteristics of effluent discharge (dual buoyant jets) in a wavy cross-flow environment were studied in a laboratory. The planar laser-induced fluorescence technique was used to obtain the concentration data of the jets. The effects of different environmental variables on the diffusion and dilution characteristics of the jets were examined through physical experiments, dimensional analysis, and empirical formulations. It was found that the dilution process of the dual jets could be divided into two components: the original jet component and the effluent cloud component. The jet-to-current velocity ratio was the main parameter affecting the concentration levels of the effluent cloud. The merging of the two jets increased the jet concentration in the flow field. When the jets traveled further downstream, the axial dilution increased gradually and then increased significantly along the axis. Under the effects of strong waves, the concentration contours branched into two peaks, and the mean dilution became more significant than under the effects of weak waves. Therefore, the dilution of the effluent discharge was expected to be significant under strong wave effects because the hydrodynamic force increased. A dilution equation was derived to improve our understanding of the dilution process of buoyant jets in a wavy cross-flow environment. This equation was used to determine the influences of the jet-to-current velocity ratio, wave-to-current velocity ratio, and Strouhal number on the minimum jet dilution. It revealed that the wave and buoyancy effects in effluent discharges were significant.

Increasing urbanisation and industrialisation of the Visakhapatnam region have brought domestic sewage and industrial wastewater discharge into the coastal ocean. This study examines the indicator and pathogenic bacteria's quantitative abundance and antibiotic susceptibility. This study collected surface and subsurface water samples from ten different regions (147 stations; 294 samples), including 12 industrial discharge points, surrounding stations and two harbours from the coast of Pydibheemavaram to Tuni. Physicochemical parameters like salinity, temperature, fluorescence, pH, total suspended matter, nutrients, chlorophyll-a and dissolved oxygen showed a difference between regions. We noticed the presence of indicator (Escherichia coli and Enterococcus faecalis) and pathogenic (Aeromonas hydrophila, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella and Shigella, Vibrio cholera and Vibrio parahaemolyticus) bacteria among the samples. Waters from the near harbour and Visakhapatnam steel plant showed lower bacterial load with no direct input from industries to the coastal water. Samples collected during the industrial discharge period had a higher bacterial load, including E. coli. Enteric bacteria were found in higher numbers at most stations. Some isolates were resistant to multiple antibiotics with higher antibiotic resistance and multiple antibiotic resistance indexes compared with the other coastal water habitats in the Bay of Bengal. The occurrence of these bacteria above the standard limits and with multiple antibiotic resistance in the study region may pose a potential threat to the local inhabitants. It can create an alarming situation in the coastal waters in the study region. [ABSTRACT FROM AUTHOR]

Due to climate change, desalination systems have been widely used in recent years as a suitable solution to increase freshwater resources. However, there are some environmental concerns about the disposal of brine water from desalination plants into the sea. In this article, a new probabilistic approach is developed for evaluating the environmental performance of these systems by considering the uncertainties in environmental input data. For this purpose, four levels of desalination plants based on the sizes have been defined. After modeling and performing a deterministic design for each level, the most important variables were identified by employing sensitivity analysis. Afterward, simple formulas for reliability analysis were derived using Bayesian regression to obtain the concentration and dilution of effluents. The sensitivity of these formulas to the input variables was also performed using Sobol analysis. Finally, the Probability of failure (Pf) was calculated for each level using seven reliability methods, including the well-known FORM, SORM, MCS, and four other new methods. Investigations were carried out by considering both the independence and dependence between the variables using the copula function, and the results show the importance of the dependence structure. For example, considering dependence structures based on the Gaussian bivariate copula can decrease the calculated Pf of the four defined levels by nearly 17.5, 21, 27.7, and 39.2%, respectively. The results also show the importance of considering safety factors in actual designs of outfall systems. Implementing safety factors based on an acceptable Pf is a novel approach introduced in this research to control the acceptable hours per year that excess concentration can surpass the environmental criteria. The introduced method can be applied either to design new desalination plants or to evaluate the reliability of existing plants. • A novel approach is developed to evaluate and design water outfalls based on probabilistic environmental criteria. • Variables affecting the performance of desalination outfalls were identified for small to big desalination plants. • Formulas for predicting effluent dilutions were derived using Bayesian regression with a Sobol sensitivity analysis. • Importance of considering variable correlations on the outfall performances is resulted via different reliability methods. • The introduced method is applicable to any new or existing plant and controls the times surpassing environmental criteria. [ABSTRACT FROM AUTHOR]

Assessment of groundwater resource around an abattoir site in Igoba area of Ondo State, southwestern Nigeria has been carried out, within 1.3 km radius from the abattoir site in order to determine the influence of the effluents discharge on quality of groundwater in the area, so as to forestall outbreak of diseases that can endanger human health. Eleven water samples were analyzed for physical, chemical and microbial parameters; and result subjected to spatial and statistical analysis using analysis of variance and Duncan’s multiple range of variance. The obtained parameters mean ± SD are pH (5.5±0.50), turbidity (10±5.9 NTU), temperature (27.75±0.35 °C), conductivity (240±105.99µs/cm), total dissolved solid (158.9±46.8 mg/L), total hardness (92.1±14.2 mg/L), nitrate (7.3±4.3 mg/L), iron (0.24±0.04 mg/L), total alkalinity (14.57±4.87 mg/L), manganese (0.017±0.0079 mg/L), calcium (26.53±8.7 mg/L), magnesium (12.20±8.1 mg/L), chloride (21.86±7.39 mg/L), sodium (14.71±4.85 mg/L), bicarbonate (13.95±4.48 mg/L), nitrite (0.0336±0.0269 mg/L), dissolved oxygen (1.82±0.52 mg/L), chemical oxygen demand (133.1±53.7 mg/L), biological oxygen demand (29.55±10.93 mg/L), total coliform (9.36±6.05 cfu/100ml) and E.coli (0.5090±0.4700 cfu/100ml). The analysis of variance showed that statistically significant difference occurs among the parameters (p

Vertical dense effluent discharges are popular in outfall system designs. Vertical jets provide the opportunity to be efficient for a range of ambient currents, where the jet is pushed away so as not to fall on itself. This study focuses on the worst-case scenario of the dilution and mixing of such jets: vertical dense effluent discharges with no ambient current, in shallow water, where the jet impinges the water surface. This scenario provides conservative design criteria for such outfall systems. The numerical modelling of such jets has not been investigated before and this study provides novel insights into simulations of vertical dense effluent discharges in shallow waters. Turbulent vertical discharges with Froude numbers ranging from 9 to 24 were simulated using OpenFOAM. A Reynolds stress model (RSM) was applied to characterize the geometrical (i.e., maximum discharge rise Zm and lateral spread Rsp) and dilution μmin properties of such jets. Three flow regimes were reproduced numerically, based on the experimental data: deep, intermediate, and impinging flow regimes. [ABSTRACT FROM AUTHOR]

Adulteration is an illegal practice often committed in food and cosmetic industries, yet rarely in environmental regulation compliance. The Chinese Ministry of Ecology and Environment recently issued a law prohibiting any intentional use of 'interfering agents' during wastewater compliance testing. For the first time, such illegal practices are brought to public attention, though they have been barely discussed previously in the scientific literature. The fraudulent method involves the addition into wastewater of a sodium chlorate-based compound, named 'COD remover,' which artificially decreases the chemical oxygen demand (COD) measured during legal testing using the dichromate method. Such practices can decrease COD from 214 mg/L to below 100 mg/L. COD removers are designed to work under testing conditions, and they do not effectively purify wastewater. The use of COD removers has created an underground industry, where users can anonymously purchase those products in 25-kg packages from all major domestic online retailers in China. A notable case was recently publicized after the new legislation, where 131 tons of COD remover had been used in a municipal wastewater treatment plant. Nonetheless, very little is known about other possible cases in China and elsewhere, and whether COD is the sole target of fraudulent practice in wastewater testing. For instance, nitrites could be used as interfering agents in the iodometric method for measuring dissolved oxygen in water and wastewater. There are also reports of chemical adulteration in online monitoring of gas emissions. Since targeted chemical adulteration is based on the knowledge of reactions and mechanisms of testing methods, there is a need to develop more robust and adulteration-proof methods for wastewater testing. [ABSTRACT FROM AUTHOR]

This paper presents the numerical results for inclined dense effluent discharges into a shallow receiving water body. Two jet discharge angles relative to the horizontal (30° and 45°) were investigated based on the experimental results from Jiang et al. (J Hydraul Eng 140:241–253, 2014). Five Reynolds-averaged Navier–Stokes (RANS) turbulence models were examined in this study: realizable k-ε and k-ω SST models (known as two-equation turbulence models), v2f (four equations to model anisotropic behavior) and LRR and SSG turbulence models (known as Reynolds stress models—six equations to model anisotropic behavior). Three mixing regimes introduced in Jiang et al. (J Hydraul Eng 140:241–253, 2014) were reproduced numerically for both discharge angles applying various turbulence models: full submergence, plume contact and centerline impingement regimes (i.e., FSR, PCR and CIR). Key geometrical and dilution properties of these jets at surface contact (Xs, Ss) and jet centerline return point (Xr, Sr) were compared to those available from experiments. Normalization parameter that was selected for jets in shallow waters is H/D (water depth above discharge point over nozzle diameter). It was found that surface attachment increases the return point length from the nozzle and that surface dilution decreases from FSR toward CIR. Among turbulence models tested herein, Reynolds stress models (LRR and SSG) predicted the effluent discharge kinematic and dilution properties better compared to two- and four-equations models. This is mainly attributed to the anisotropic nature of the effluent discharge problem studied herein and that these models are better capable to account for anisotropies. [ABSTRACT FROM AUTHOR]

Ngo River in Gboko, Benue State, Nigeria which serves as a source of water for domestic and agricultural purposes for the agrarian community receives effluent from Dangote Cement factory. Physicochemical analysis of the effluent outfall and water samples collected along 15 km of the river stretch were carried out in dry and wet seasons respectively. The results obtained were compared to FEPA, WHO and NESREA Standards. For effluent outfall, Temperature, TDS, pH, EC, BOD, COD, sulphate and chloride, total hardness, calcium and magnesium, were found to be within the FEPA standards, while TSS, turbidity, and nitrate, were above the standards. Along 15 km study reach, mean temperature range of 32.4oC to 29.0oC, a TSS of 224 mg/l to 218 mg/l, a turbidity of 45 NTU to 42 NTU, and DO of 1.6 mg/l to 1.2 mg/l were obtain during the dry season, while mean temperature range of 36.8oC to 36.6oC, a TSS of 255 mg/l to 252 mg/l, turbidity of 176 NTU to 168 NTU, and DO 2.8 mg/l to 2. 6 mg/l were obtained during the wet seasons. These results were above WHO and NESREA temperature (25oC drinking water), TSS (30 mg/l domestic and 100 mg/l agriculture) water use, 5 NTU turbidity, and 5mg/l to 7.5mg/l DO standards. The effluent is relatively treated and effects such as aquatic depletion in the environment, decreased soil pore size and decreased permeability in the use of the water for irrigation, and water related diseases are not ruled out. [ABSTRACT FROM AUTHOR]

• Effluent discharge amplifies the hyporheic exchange fluxes in the discharge area. • Higher microbiota diversity and complexity was observed in the discharge area. • Lower abundance of keystone taxa led to reduced community stability in EF area. • Keystone taxa largely determine the metabolic functions and community stability. • Controlling efficiency of keystone taxa on metabolic functions reduced in EF area. We lack a clear understanding of how anthropogenic pressures, exemplified by effluent discharge from wastewater treatment plants, destabilize microbial communities in the hyporheic zone (HZ) of receiving rivers. In this study, the spatiotemporal characteristics of hydrological parameters, and the physicochemical properties of surface and subsurface water in a representative effluent-dominated river were monitored. Sequencing of 16S rRNA amplicons and metagenomes revealed the microbial community structure in the HZ of both effluent discharge area and downstream region. The keystone taxa (taxa vital in determining the composition of each microbial cluster) and the keystone functions they controlled were subsequently identified. Effluent discharge amplified the depth of the oxic/suboxic zone and the hyporheic exchange fluxes in the effluent discharge area, which was 50-120% and 40-300% higher than in the downstream region, respectively. Microbial community structure pattern analysis demonstrated an enhancement in the rate of dispersal, an increase in microbial diversity, and an improved community network complexity in the effluent discharge area. By contrast, the number of keystone taxa in the effluent discharge area was 50-70% lower than that of the downstream region, resulting in reduced community network stability and functionality. The keystone taxa controlling metabolic functions in the networks categorized to effluent discharge area were comprised of more genera related to nitrogen and sulfur cycling, e.g., Dechloromonas, Desulfobacter, Flavobacterium, Nitrosomonas , etc., highlighting a research need in monitoring species associated with nutrient element cycling in the HZ of receiving waterbodies. The results showed that the keystone taxa could contribute positively to network stability, which was negatively correlated to hyporheic exchange fluxes and redox gradients. This study provides valuable insights that will improve our understanding of how river ecosystems respond to changes in anthropogenic pressures. [Display omitted] [ABSTRACT FROM AUTHOR]

Pollution and health risk assessment models were used to study the effects of effluents discharged into the Inyishi River, Ikeduru LGA, Imo State, Nigeria. The study aims at investigating the environmental health effects of wastewater effluent discharge from the aluminum extrusion company on the Inyishi River. Samples were collected from both the aluminum extrusion company and Inyishi River and analyzed for physicochemical and trace metal parameters. Models adopted for assessment include transfer factor (TF), contamination factor (Cf), pollution load index (PLI), ecological risk factor (Er), water quality index (WQI), hazard quotient (HQ), and hazard index (HI). The results of the study revealed that pH and TH were within the Nigerian Standard for Drinking Water Quality (NSDWQ) and World Health Organization (WHO) standards. EC values at 2235 ± 0.001 and 105 ± 0.03 μS/cm for S3 and S4 respectively were higher than the permissible standards, while the values of EC at 24.04 ± 0.03, 5.26 ± 0.005, and 0.05 ± 0.01 μS/cm respectively for S1, S2, and SR are within the WHO standard. Very high concentration of SO42− was recorded at S3, while low concentration was measured at S2. Mean values of heavy metal ions studied were within NSDWQ and WHO standards for safe drinking water except for Al, Zn, Cd, Fe, and Mn, with the mean values of metal concentrations observed in the order Al > Fe > Zn > Mn > Cd > Cr. Positive linear correlation based on heavy metal contamination was observed for samples S1 and S2 with SR. High TF values were observed in decreasing order Mn > Cd > Cr > Fe > Zn. Similarly, very high CF was observed for Cd and Al while the PLI was generally high for all the samples. Low Er values were observed for all metals except for Cd, with the mean value of Er observed in the decreasing order Cd ˃ Mn ˃ Zn ˃ Cr. The river water sample generally revealed high WQI and was thus categorized as poor quality. HQ and HI values were below unity (< 1), but might pose health risk to children in cases of prolonged dermal adsorption. In conclusion, the quality of the Inyishi River has been negatively impacted by the wastewater effluent from the aluminum extrusion company. Proper treatment of the river water is therefore recommended before use for domestic purposes as prolonged usage of the untreated water might likely pose serious environmental health risks. [ABSTRACT FROM AUTHOR]

The temporal variation of the microplastic concentration was studied in the Langueyú stream, which is located in the department of Tandil, in the southeast of the Buenos Aires province in Argentina. This stream receives discharge from the wastewater treatment plants from a medium-sized city. A quantitative analysis of the microplastic concentration was carried out in different samplings, corresponding to different seasons. The study focused on the most contaminated point, located after the discharge of effluents from plants. Higher concentrations of MPs were found in winter (dry season), having approximately 6 times the concentrations found in summer and autumn (wet seasons). However, these differences would not be a direct consequence of the amount precipitation, but rather would be associated with a seasonal variation of human activities, mainly with respect to the type of clothing used in the cold season. The microfibers correspond to around 60–90% of microplastics found. The discharge from the plants causes changes in the parameters of the stream water, such as high electrical conductivity values, and also provide metallic contaminants such as Ca, Zn, and in smaller amounts Pb, Fe, Ni and Cu, which were found adhered to the microplastics and remain in the stream water in high quantities 3 km after the study point. The microplastic concentration presents a linear empirical correlation with the conductivity, and it was found that conductivity measurements would serve as an indicator of the microplastic concentration in the system under study. [Display omitted] • The highest microplastic concentrations were measured in winter (dry season). • There is no direct consequence of precipitation with microplastic concentration. • Discharges from the plants cause changes in the stream water (conductivity and pH). • Conductivity would serve as an indicator of the microplastic concentration. • Metallic contaminants were found adhered to the microplastics. [ABSTRACT FROM AUTHOR]

Sewage treatment plants (STPs) are one of the sources of pathogens discharged into surface water. An investigation was carried out over the duration of 12 months in Henan Province, China, to evaluate the health influence of municipal wastewater effluent discharge on water quality of the receiving water. A discharge-based quantitative microbial risk assessment (QMRA) was employed, taking into account the vegetables consumption habits of the Chinese, population subgroups with different immune statuses and ages, to evaluate the incremental disease burden from agricultural irrigation and swimming exposure scenarios associated with increased concentration of the protozoan Cryptosporidium and/or Giardia in the receiving river. The results shown that all the STP influent samples contained Cryptosporidium and Giardia with average density of 142.31 oocysts/L and 1187.06 cysts/L, respectively. The QMRA results demonstrated that the estimated additional health burdens due to discharged effluent for both parasites were slightly violated the threshold of 10 −6 DALYs per person per year set by WHO. Mitigation measures should be planned and executed by season since more disease burdens were borne during hot season than other seasons. The sensitivity analysis highlighted the great importance of stability of STP treatment process. This study provides useful information to improve the safety of surface water and deduce the disease burden of the protozoa in Henan Province and other region inside and outside China. [ABSTRACT FROM AUTHOR]

An experiment was conducted in a permeability tank constructed at the Laboratory of Department of Land and Water Management. Two soils with different textures collected from Khesana Mori and Nasarpur were used in the experiment. Soils were analyzed for the textural class and hydraulic conductivity. The soil collected from Khesana mori was sandy with hydraulic conductivity of 6.9 m/day, while the soil brought from Nasarpur was clay loam with hydraulic conductivity of 0.0564 m/day. Three impervious layers were imposed at 100, 200, and 300mm depths and four water table depths were maintained from soil surface at 0.0, 30.0, 60.0, 90.0 mm depths above the lateral. The effluent discharge was measured by volumetric method and same was calculated using Hooghoudt’s formula. The results showed that the effluent discharge from laterals was maximum when the water table depth was maintained at soil surface under both sandy and clay loam soils. The effluent discharge decreased with the increase in the depth of impervious layer. Hydraulic head above the lateral influenced the effluent discharge. When the hydraulic head increased the effluent discharge also increased. The study also found that the sandy soil with higher value of hydraulic conductivity collected from Kesana Mori had more effluent discharge compared to that of clay loam soil with lower value of hydraulic conductivity collected from Nasarpur. Therefore the drain spacing must be decided on the basis of water table depth, location of impervious layer, soil texture and hydraulic conductivity.

Liquid Natural Gas (LNG) processing facilities typically are located on ocean shores for easy transport of LNG by marine vessels. These plants use large quantities of water for various process streams. The combined wastewater effluents from the LNG plants are discharged to the coastal and marine environments typically through submarine outfalls. Proper disposal of effluents from an LNG plant is essential to retain local and regional environmental values and to ensure regulatory and permit compliance for industrial effluents. Typical outfall designs involve multi-port diffuser systems where the design forms a part of the overall environmental impact assessment for the plant. The design approach needs to ensure that both near-field plume dispersion and far-field effluent circulation meets the specified mixing zone criteria. This paper describes typical wastewater process streams from an LNG plant and presents a diffuser system design case study (for an undisclosed project location) in a meso-tidal coast to meet the effluent mixing zone criteria. The outfall is located in a coastal and marine ecosystem where the large tidal range and persistent surface wind govern conditions for the diffuser design. Physical environmental attributes and permit compliance criteria are discussed in a generic format. The paper describes the design approach, conceptualization of numerical model schemes for near- and far-field effluent mixing zones, and the selected diffuser design.

With the intensification of human activities, fresh water resources are increasingly being exposed to contamination from effluent disposal to land. Thus, there is a greater need to identify the sources and pathways of water contamination to enable the development of better mitigation strategies. To track discharges of domestic effluent into soil and groundwater, 10 synthetic double-stranded DNA (dsDNA) 3 3 Double-stranded DNA (dsDNA); single-stranded DNA (ssDNA); base-pair (bp); bromide (Br); polymerase chain reaction (PCR); colony-forming units (cfu); relative mass recovery ( RB ); relative transport speed ( RV ); relative dispersion ( RS ); concentration breakthrough curve (BTC). tracers were developed in this study. Laboratory column experiment and field groundwater and soil lysimeter studies were carried out spiking DNA with oxidation-pond domestic effluent. The selected DNA tracers were compared with a non-reactive bromide (Br) tracer with respect to their relative mass recoveries, speeds of travel and dispersions using the method of temporal moments. In intact stony soil and gravel aquifer media, the dsDNA tracers typically showed earlier breakthrough and less dispersion than the Br tracer, and underwent mass reduction. This suggests that the dsDNA tracers were predominantly transported through the network of larger pores or preferential flow paths. Effluent tracking experiments in soil and groundwater demonstrated that the dsDNA tracers were readily detectable in effluent-contaminated soil and groundwater using quantitative polymerase chain reaction. DNA tracer spiked in the effluent at quantities of 36 μg was detected in groundwater 37 m down-gradient at a concentration 3-orders of magnitude above the detection limit. It is anticipated it could be detected at far greater distances. Our findings suggest that synthetic dsDNA tracers are promising for tracking effluent discharges in soils and groundwater but further studies are needed to investigate DNA-effluent interaction and the impact of subsurface environmental conditions on DNA attenuation. With further validation, synthetic dsDNA tracers, especially when multiple DNA tracers are used concurrently, can be an effective new tool to track effluent discharge in soils and groundwater, providing spatial estimation on the presence or absence of contamination sources and pathways. [ABSTRACT FROM AUTHOR]

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Since the introduction of the water footprint concept in 2002, in the context of humankind’s ever-increasing awareness of the valuable global freshwater resources, it has received more and more attention. The application of this relatively new concept has been expected to provide ecological and environmental benefits. For the water-intensive papermaking industry, it seems that water footprint needs to be addressed. The water footprint of cellulosic paper can be divided into three components, including its green water footprint, blue water footprint, and grey water footprint, which may be accounted for by considering the individual contributions of wood or non-wood materials, pulp production processes, effluent discharge to the receiving water bodies, process chemicals and additives, energy consumption, etc. In the literature, the accounting of water footprint during the whole production chain of cellulosic paper is already available, and relevant research findings can provide useful insights into the application of the concept; however, further development of the accounting methodologies is much needed, so that the quantitative and qualitative evaluation of water footprint can be internationally recognized, certified, and standardized. Although there are ongoing or upcoming debates and challenges associated with the concept, its application to papermaking industry may be expected to provide various encouraging possibilities and impacts.

The article discusses the effluent water quality in phosphate mining sites in M'Dhilla, Tunisia highlighting the suitability of water discharged in the mine for irrigation and its impact to the environment.

Municipal wastewater treatment plants (WWTPs) are frequently suspected as significant point sources or conduits of microplastics to the environment. To directly investigate these suspicions, effluent discharges from seven tertiary plants and one secondary plant in Southern California were studied. The study also looked at influent loads, particle size/type, conveyance, and removal at these wastewater treatment facilities. Over 0.189 million liters of effluent at each of the seven tertiary plants were filtered using an assembled stack of sieves with mesh sizes between 400 and 45 μm. Additionally, the surface of 28.4 million liters of final effluent at three tertiary plants was skimmed using a 125 μm filtering assembly. The results suggest that tertiary effluent is not a significant source of microplastics and that these plastic pollutants are effectively removed during the skimming and settling treatment processes. However, at a downstream secondary plant, an average of one micro-particle in every 1.14 thousand liters of final effluent was counted. The majority of microplastics identified in this study had a profile (color, shape, and size) similar to the blue polyethylene particles present in toothpaste formulations. Existing treatment processes were determined to be very effective for removal of microplastic contaminants entering typical municipal WWTPs. [ABSTRACT FROM AUTHOR]

The release into the environment of antimicrobial compounds from both human and agricultural sources is a growing global concern. The Grand River watershed, the largest mixed-use watershed in southern Ontario, receives runoff from intensive animal production as well as municipal wastewater effluents from a rapidly increasing human population. A survey of surface waters and wastewater effluents was conducted across the watershed to assess the occurrence and distribution of several antimicrobials (i.e., trimethoprim, sulfamethoxazole, sulfamethazine, lincomycin, and monensin) and chemical indicators (i.e., ammonia, nitrate, ibuprofen, venlafaxine, atrazine) and to characterize exposure levels. The human antimicrobials trimethoprim and sulfamethoxazole were detected in the urban areas of the main channel at mean concentrations of 8 ± 7 ng/L and 31 ± 24 ng/L, respectively, but at much lower concentrations in the agricultural tributaries. In contrast, the veterinary antimicrobial sulfamethazine was detected at a mean concentration of 11 ± 9 ng/L in the main channel, and at a much higher concentration in the agricultural tributaries. Lincomycin was detected in only two river samples and not in the effluents while monensin was not detected in all samples. The herbicide atrazine was detected at very low concentrations in the surface waters of both the tributaries and the main channel. The concentrations of the antimicrobials and chemical indicators generally increased downstream of the confluences with agricultural tributaries and effluent outfalls. In the wastewater effluents, the concentrations of trimethoprim, sulfamethoxazole, ibuprofen, and venlafaxine decreased with increasing treatment levels (i.e., secondary to tertiary) as indicated by ammonia/nitrate concentrations. There was a strong correlation among trimethoprim, sulfamethoxazole, and venlafaxine in the main channel and in the wastewater effluents. While the environmental concentrations of antimicrobials in the watershed are low relative to toxicity thresholds, their persistence in the environment may be an important consideration in defining strategies for future water management. [ABSTRACT FROM AUTHOR]

Designing and building a treatment facility is complex. To succeed, engineers and operators must break down barriers and collaborate during design, construction, and the initial years of facility operations. An operator typically understands the space, mechanical requirements, and actions required for day-to-day work, and can help the engineering design team account for practical considerations. Many older treatment facilities feel stuck at their current location. They also are often limited in their ability to implement upgrades based on the footprint of the existing facilities. However, based on dialog with the city of Ellsworth, Maine, planners, operators, and engineers were able to think outside the box and develop a plan to design and build a new facility at a new off-site location that was both economical and state-of-the-art. Building a new wastewater treatment facility (WWTF) at a new location has allowed the city to address the lack of adequate sanitary wastewater infrastructure that challenged goals for expansion of the local economy. This and the cost-saving features of the new WWTF demonstrate the value of the city's decision to invest in a new facility and provide sustainable utility service. [ABSTRACT FROM AUTHOR]