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Sediments and water columns in the Los Angeles Outer Harbor, a major port behind a breakwater, contain DDTs and PCBs from a nearby superfund site and contaminants brought in by ships, boats, stormwater, a river and a wastewater outfall. White croaker, a bottom feeder, and queenfish, a water column feeder, are two bioindicators for this marine ecosystem whose conditions are assumed to be robust for this role at all times. The current study tests this benign assumption amidst progressively increasing DDTs/PCBs levels in their tissues. Results, as evident by progressively shrinking gonads, show a less than robust white croaker population particularly. While the males are generally larger than the female fish, the length (standard (SL) or total (TL)) and body mass (BM) of 80 white croakers collected over a period of eight years were found to be similar irrespective of gender (177 mm, 212 mm and 114 g, respectively). Queenfish (67) did not show such similarity over the same period (female: 152 mm SL, 177mm TL, 56 g BM; male: 145 mm SL, 172 mm TL, 50 g BM). The site-specific expressions/values capturing the current conditions of these fish are SL=0.835[TL]-1.68 (r 2 =0.914, n=68) and SL=0.891[TL]-8.88 (r 2 =0.961, n=50) for white croaker and queenfish, respectively. In the allometric growth equation BM=a[SL] b , a and b are 2.83×10-4 and 2.49 (r 2 =0.817) for white croakers, and 6.10×10-5 and 2.73 (r 2 =0.825) for queenfish, respectively. The relative coefficients of condition K n are 0.97±0.07 and 1.01±0.12 for white croakers and queenfish, respectively. Molecular level studies are needed to establish definitively the links between DDTs/PCBs bioaccumulation in fish tissues and the robustness of the fish populations. This article is protected by copyright. All rights reserved.

Outfalls into rivers are the final gate of anthropogenic pollution flowing to receiving waters, which means that outfall surveys are significant to basin environmental protection and ecosystem health management. Unmanned aircraft systems (UAS) with high spatial resolution imagery have become important data for ongoing surveys of outfalls. However, outfalls retrieval from UAS imagery is inefficient to visual interpretation and a challenging task for traditional spectral-based and object-oriented classification methods given the problems of salt-and-pepper noise and scale selection. In this study, an improved geo-deep learning approach based on the faster region convolutional neural network (R-CNN) architecture (GDCNN-outfalls) is proposed for retrieving outfalls into rivers with UAS imagery. In the proposed method, three tactics--anchor size, region of interest (RoI), and hard negative mining--were adopted to optimize the benchmark Faster R-CNN application in outfalls retrieval. Meanwhile, a geo-classifier module with digital surface model (DSM) enhancement and a spatial activation function was integrated with the Faster R-CNN architecture to generate GDCNN-outfalls. The validation experiments indicated that GDCNN-outfalls improved the performance of Faster R-CNN in outfall retrieval by suppressing false positive (FPs) from 33.52% to 26.14% and increasing the F1 score from 0.72 to 0.75. The test results confirm the performance of GDCNN-outfalls with a recall of 79.3% and higher precision (48.4%) than that of Faster R-CNN (2.1%), also show the GDCNN-outfalls is ten times faster than visual interpretation. This study demonstrates that the combination of deep learning and UAS techniques can be a feasible solution to detect outfalls in outfall surveys.

Algeria, like other arid and semi-arid African countries, is confronted by problems related to rapid population growth and water stress (water short-age). This stress fosters raw wastewater reuse in market gardening and hor-ticulture. The advantages of this wastewater consist of their nutrients whose organic materials contribute to soils enrichment with humus, as well as their availability in large quantities. However, raw wastewater reuse entails a po-tential risk of environmental and water resources pollution. The purpose of this work was to evaluate the parasite load of raw wastewater from the city of Biskra’s discharge outfalls (Biskra valley and Z'mor valley), while consider-ing the demographic and socio-economic profile of populations connected to these outfalls. Our results revealed a variety of parasites in the form of hel-minths eggs at the following average concentrations: Ascaris sp. (33.66 eggs/L,), Trichuris sp. (22 eggs/L), Enterobius vermicularis (19.58 eggs/L), Ancy-lostoma sp. (17.41 eggs/L), Nematodirus sp. 17.83 (eggs/L), Hymenolepis nana (21.66 eggs/L), Moniezia expansa (16.5 eggs/L), Taenia sp. (18.5 eggs/L), Fasciola hepatica (0.58 eggs/L) and Strongyloides spp (17.11 eggs/L). The parasitic helminths eggs distribution varies according to the size of urban areas and the socio-economic level of populations connected to each outfall. This study also highlighted the qualitative and quantitative seasonal varia-tions of helminths eggs in wastewater from Biskra’s two outfalls.

In Pakistan, marine pollution is a major problem that is caused by the waste from industrial, municipal,agronomy, and oil leak sources. The pollutant loads along with the coastline areas near Karachi is received fromterrestrial contaminants including discharges from Karachi Harbour located on the estuary of the Lyari river. Karachigenerates 472 Million Gallon per Day (MGD) of wastewater out of which only 55 MGD is treated and the rest isdischarged in the sea. The prevailing sewage treatment plants are functioning at reduced capacity due to the insufficienttransmission capacity of interceptors. Water sampling was carried out from the Lyari River and five different selectedcoastal point around Karachi harbour for physicochemical parameters and selected heavy metals. Results show that theKarachi Harbour area is noticeably polluted, whereas; the coastal environment in the vicinity of Karachi is also underthe stress of pollution. High COD and BOD5 values were noticed at the Lyari river samples and the sampling locationsclose to the Lyari river outfall area. The Pb, Cd, Ni, and Hg heavy metals that pollute marine water are found. Thissituation is due to the discharge of mixed effluents of industrial and domestic wastes as well as dredging, cargohandling, dumping of ship waste and other coastal activities. The highest value of pollution observed at KarachiHarbour which is near Lyari river mouth, where the domestic and industrial effluents with organic and inorganic wasteshave a greater influence on the water quality and the marine environment. At present, there is no effective controllingmechanism for industries to treat their waste, nor has any investigation to assess increasing marine pollution beencarried out. As a result, there is an adverse impact on fish habitat and mangroves, corrosion of cargo ships, navalvessels and the residents living in the coastal area. Therefore, the government agencies and industrial sectors shouldwork together to avert marine pollution and attain total environmental sustainability.

This research examines the physical and chemical properties of the potential contamination of condenser cooling water (heat water) at the 2x7 MW West Sumbawa Steam Power Plant. Method’s this research is direct observation in the field. The determination of the sample point was done by purposive sampling. The results showed that the hot water had met the predetermined quality standards, namely a pH of 8.21, a temperature of 38.50C and a content of free chlorine (Cl2) of 0.03 mg / L. There was an increase in sea water temperature in a radius of 17 meters east and west by 80C from 280C to 360C. Direct discharge of hot water has the potential to pollute the marine prawn environment around the 2x7 MW West Sumbawa PLTU. From the results of the study, it was found that the temperature of the hot water had met the specified quality standard, which was 40oC, but direct disposal caused the sea water temperature to rise, exceeding the set sea water temperature quality standard of 320C and the temperature increase should not be more than 20C from the temperature. at first. The status of sea water quality due to the entry of hot water is determined using a pollution index. From the calculation results obtained PIj of 1.125 at the sample point Outfall 2, meaning that the sea water conditions at a radius of 17 meters are lightly polluted. As a form of control and prevention of pollution due to the entry of high temperature hot water, continuous monitoring is necessary and it is necessary to create a mixing pool between sea water and hot water before the heat is discharged into the sea.

This research aims to evaluate the water quality of the Vicente Pires basin, a tributary of the Paranoá Lake, with the use of polutographs and hydrographs, through flood and dry events of dissolved (DS), suspended (SS) and total solids (TS) and turbidity. The monitoring happened in the VP Stream outfall with water level measurement, to determine the flow, simultaneously collecting water samples for analysis of pollutant concentrations. Five events were analyzed, from 2018 to 2019, with flow from 0.88 m³/s to 72.17 m³/s, DS concentrations from 13 to 4,445 mg/L, SS from 0 to 5,164 mg / L, and TS from 24 to 7,583 mg/L and turbidity from 6.2 to 9,522 NTU. It is clear from the polutographs that the concentration of solids and turbidity in the VP Stream are related to the flow, with flood events being those with the highest concentrations. Therefore, this fact is related to runoff, which generates large flows, washing off the soil surfaces, and carrying what is deposited, such as landfills of major works that occurred in the drainage basin. In addition to diffuse pollution, large flows from surface runoff reach the stream causing erosion on the banks, further aggravating the sediment transport problem. In fact, in order to guarantee the maintenance of the VP Stream, it is necessary to control the sediment input from diffuse pollution, requiring the adoption of compensatory measures in urban drainage since its construction. KEYWORDS: Diffuse Pollution, Monitoring, Runoff. RESUMO: Esta pesquisa tem como objetivo avaliar a qualidade das águas da bacia do Vicente Pires, afluente do Lago Paranoá, com o uso de polutogramas e hidrogramas, por meio de eventos de onda de cheia e de seca dos sólidos dissolvidos (SD), suspensos (SS) e totais (ST) e da turbidez. O monitoramento ocorreu no exutório do Córrego VP com a medição de nível da água, para determinação da vazão, simultaneamente a coleta de amostras de águas para análise das concentrações dos poluentes. Foram analisados 5 eventos, de 2018 a 2019, com vazões de 0,88 m³/s até 72,17 m³/s, concentrações de SD de 13 a 4.445 mg/L, SS de 0 a 5.164mg/L, e ST de 24 a 7.583 mg/L e turbidez de 6,2 a 9.522 NTU. Percebe-se, quanto aos polutogramas, que as concentrações dos sólidos e da turbidez no Córrego VP estão relacionadas com a vazão, sendo os eventos de cheia os de maiores concentrações. Portanto, este fato é relacionado com o escoamento superficial, que geram grandes vazões, lavando as superfícies dos solos, e carreando o que está depositado, como aterros das grandes obras ocorridas na bacia de drenagem. Além da poluição difusa, as grandes vazões advindas do escoamento superficial atingem o córrego causando as erosões nas margens, agravando ainda mais o problema de transporte de sedimentos. De fato, para a garantia da manutenção do Córrego VP é necessário o controle do aporte de sedimentos advindo da poluição difusa, sendo necessário a adoção de medidas compensatórias na drenagem urbana desde a sua construção. PALAVRAS-CHAVE: Poluição difusa, Escoamento superficial, Monitoramento.

The trace concentrations of a number of elements including: Ti, Cr, Mn, Fe, Co, Zn and Ag have been determined in sediments taken from El-Ryah El Twfiky and some of its extensions through El-Kallobia, El-Dakahlia and Damietta provinces, Egypt, where these water streams are considered the main source for drinking, irrigation and industrial waters, to the three mentioned provinces. The concentration value of the trace elements have been determined and associated with the specific surface area, organic carbon, fraction of particles ( < 100 µ m) and with each other. The levels of metal concentration are compared generally with levels found elsewhere in some river sediments. The high values and trends in metal content of the sediments compared with natural levels may be ascribed to the dumping of metallic waste materials nearby the water course, industrial and domestic effluents discharged into the stream from a number of outfalls within the area, in addition to fertilizers washed down from cultivated land.

The use of duckbill valves in submerged outfalls for dense effluents is now prevalent to prevent the intrusion of ambient water into the outfall pipe during periods of low production of the facility. In the present study, an experimental investigation was conducted using the technique of Planar Laser Induced Fluorescence (PLIF) to examine the mixing characteristics of 45° inclined dense jets from a duckbill shape nozzle in co-flowing currents. The measured characteristics included the jet trajectory, concentration decay, centreline peak dilution and cross-sectional concentration distribution. The Froude number ranged from 10 to 25, and the nominal Froude number from 0.2 to 3.0. Two mounting orientations of the duckbill nozzle, namely vertical and horizontal, were also investigated. The experimental results showed that two regimes, namely dense-jet- and co-flow-dominated, can be clearly observed. When the co-flow velocity increases, the centreline peak height and dilution of the inclined dense jet decrease. Comparing to the available results in the literature for inclined circular dense jets, the centreline peak dilution for inclined duckbill dense jets is generally higher. In other words, the installation of the duckbill valve also contributes to the mixing of the dense effluent with surrounding ambient waters, in addition to preventing the ambient intrusion. With respect to the mounting orientation, the horizontal induces a relatively higher dilution but also a larger centreline peak height. Thus, the horizontal orientation would be preferable when the cover water depth is sufficient, while the vertical orientation can be considered in shallow waters for full submergence. Nanyang Technological University The authors would like to thank the Nanyang Environment and Water Research Institute, Nanyang Technological University, as well as the National Natural Science Foundation, China (42006143) for the financial support.

Pathogens and chemical contaminants in stormwater are major environmental and public health concerns. Characterizing the variability in composition and bioremediation functions of the microbial community from different sources of stormwater will help with efforts to properly manage water after it rains. To improve understanding of the variability and composition of the microbial community in run-off from different sources, we sampled stormwater over time from an outfall and receiving stream, along with run-off from different locations (rooftop, roadway) to identify microbial components associated with these urban waters. Community composition was variable in space and time for water samples from the same source. Even with this variability, we found taxonomic and functional groups differentially distributed in water samples collected during wet or dry weather or collected from different sources. The differentially distributed taxonomic and functional groups represent the unique characteristics of the source, such as when communities are exposed to iron in pipe material from the outfall or hydrocarbons flushed from various surfaces during rain events. Additionally, fecal indicator sequences from Clostridiales and Bacteroidales taxa made up a larger fraction of the microbial community from water collected under dry conditions. Our work characterizes the variability in microbial community composition and functions from a variety of urban water sources, with specific attention to communities from sources where water might be collected or treated with green infrastructure systems (e.g. rain gardens or biofilters). This will aid our understanding of the impact of human activities in urban environments on the surrounding water system.

The extent of nutrient enrichment over the urbanized shoreline of western Lake Ontario bordering the Cities of Toronto and Mississauga was investigated in 2018. Concentrations of total phosphorus were higher and more wide-ranging compared with nearshore reference areas in eastern Lake Ontario. Area-weighted chlorophyll a was higher over the shoreline from the mouth of the Credit River to Humber Bay west of Toronto Harbour compared with that to the east from the Toronto Beaches to the Rouge River, a pattern also seen broadly in concentrations of phosphorus fractions and nitrates. Concentrations of phosphate measured by mass spectrometry, and using an internal standard to minimize sampling losses, were higher in Toronto Inner Harbour, near wastewater outfalls, river mouths, and to varying extent over the mixing areas of these discharges. Chlorophyll a suggested broadly oligotrophic to oligo-mesotrophic conditions despite areas with nutrient fractions suggestive of more productive conditions. Toronto Inner Harbour was mesotrophic, with wide-ranging levels of phosphorus fractions strongly influenced by the variable loading from the Don River into the harbour. Phosphorus fractions in the harbour quays which also receive CSOs discharges were elevated at times. Blooms or scums of planktonic algae were not observed. Elevated concentrations of phosphate were found at shallow depths suitable for growth of the green algae Cladophora. As these urban areas continue to grow, the potential for additional nutrient loading to exacerbate growth of algae should be watched given the present conditions that indicate variable but pervasive nutrient enrichment.

Urban centers line western Lake Ontario where urban rivers, wastewater treatment plants and stormwater load nutrients, major ions and suspended solids to the nearshore. In 2018, nearshore water quality and associated physical conditions bordering the cities of Toronto and Mississauga were assessed as a benchmark for future effects of urban growth and municipal infrastructure projects to improve water quality. Conductivity and UV-fluorescence were used as water quality surrogates and mapped over blocks of shoreline stratified by distance offshore. Patterns in UV-fluorescence aligned with loading points, and generally higher levels near the shoreline, were correlated with concentrations of nutrients, major ions and suspended solids. Water quality was more land-impacted over the shoreline from the Credit River to Humber Bay contrasting with the more lake-like conditions from Toronto Eastern Beaches to the Rouge River. Within Toronto Harbour, cross-harbour gradients in water quality varied with weather-related changes in river and storm water loading. Mixing areas at wastewater treatment plant outfalls and tributary mouths, frequently shaped by alongshore lake circulation, resulted in a mosaic of water quality over the shoreline. Area-wide elevation of chloride and conductivity, and poorer water quality in late spring, was linked to heightened river discharge. Thermal stratification affected how discharges were distributed in the water column, but measurements at the lake surface reflected the strongest overall land-effects on water quality. The patterns of temporal-spatial variability identified within geographically-defined areas of shoreline can be used as past footprints in future monitoring to detect change.

Seawater desalination has been considered an important solution for the water scarcity in coastal areas. Brazil has an 8,000 km long coastline where population and tourism have grown tremendously in the last years. Fortaleza is the fifth-largest city in Brazil with nearly 2.6 million inhabitants, representing an important economic, recreational and touristic area in the Northeast. In addition, it is the city with the greatest gross domestic product (GDP) in the region, and ninth in the country. In the past 7 y, the dams that supply water to the Metropolitan Region of Fortaleza have undergone droughts. This led the government to start a large-scale seawater desalination project that shall produce desalinated water at about 1.0 m3/s, for which plant location, water intake and brine disposal studies were performed. The most common environmental impact associated with desalination plants is the high concentration brine discharge. Aiming to evaluate the possible impact of such discharges, environmental modeling has become an important tool for projects, environmental management and studies, due to the complexity of these environments. With this tool, it is possible to integrate a large number of variables and processes to obtain a dynamic vision of those systems and evaluate present and future conditions. This work presents outcomes from brine discharge modeling in the water quality of the coast of Fortaleza, in particular, increased salinity, using Visual Plumes to evaluate near-field dilution and SisBaHiA (Environmental Hydrodynamic Base System) software to generate a hydrodynamic model and evaluate far-field dilution. Hydrodynamic models, forced by wind and tide, were coupled with a wave propagation model and then used in a Lagrangian transport model, which was fed by the outcomes of the near-field model. From the results generated, it was identified that the installation of the proposed desalination plant in Fortaleza does not compromise water quality and is consistent with the results reported in the literature, regarding the reduced impact caused by the disposal of this type of concentrate.

Marine sewage outfalls are the cheapest method of disposal for municipalities with restricted funds, despite their negative effects on marine ecosystems. This study was conducted on the marine sewage outfalls of the Turkish cities Rize (Black Sea) and Yalova (Sea of Marmara). Heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were investigated in the sediments for determine pollution degree. Two of Yalova stations were classified as having high contamination levels (1034.436 and 1476.483 ng/g, respectively) and all the other stations suffered moderate pollution in terms of ?16PAHs. ?DTTs in sediments above probable effect levels (PELs), were observed both stations Yalova and Rize. The highest metal concentrations in the sediments from the eight stations ranged from 4.97 to 29.65 mg/kg for Ni; 7.57–44.14 mg/kg for Cr; 9.84–42.76 mg/kg for Cu; and 48.08–103.77 mg/kg for Zn. In sum, examination of pollutant sources provides clear evidence of an anthropogenic effect on the discharge environments. © 2020 The Author(s) Recep Tayyip Erdogan Üniversitesi: FDK-2018-866 The present research was part of a project supported by the Recep Tayyip Erdogan University, Research Project Fund (Project Number FDK-2018-866).

In this study, an integrated approach for runoff estimation using the storm water management model (SWMM) was applied to undertake a stormwater and sewerage modelling in urban setting. The main objectives of the research and this manuscript include overload detection of sewer systems during extreme rainfall events with SWMM and to model and predict the relationship between precipitation parameters and overflooding of sewer collection system that includes emergency ponds to relieve flow from pump stations. The study takes into account monitored concurrent extreme rainfall event data and peak wet weather flows observed at outfall of collection system entering a wastewater treatment plant draining the urban centre. In the study SWMM was modified and adapted for the Tati and Ntshe confluence rivers draining the urban centre of Francistown in Northern Botswana. Landuse, soil, geological, drainage and sewerage network and imperviousness data sets were acquired and developed in GIS database. The runoff coefficient is found to range between 0.12 and 0.24 in the studied catchments. The calibrated model was able to predict the observed outputs with reasonable accuracy for calibration datasets of two peak flood events of 2016-Jan 12 and 2017-Feb 16 and verification flood events of 2016-Feb 05 and 2017-Feb 26. For six watersheds that drain the study area considered with a seventh entire collection system catchment area, we have evaluated the model performance using different criteria. We have found that correlation coefficients range from 0.539 to 0.813 and NSE ranges from 40.9% to 89.0%, and RSR ranges from 0.330 to 0.812 for the calibration datasets. Whereas, for the verification dataset, the correlation coefficients range from 0.539 to 0.813 and NSE values range from 40.9% to 89.0%, and RSR values range from 0.330 to 0.812. Using the criteria adopted, the SWMM-simulated runoff values are in acceptable agreement with the observed hydrographs.

The results of comprehensive studies of anthropogenic impacts caused by deep water discharge into coastal waters near the city of Sevastopol using an experimental model of a ground-space monitoring system are presented. The nature of anthropogenic pollution of the investigated basin associated with an emergency rupture of the collector of the discharge device with a design capacity of 43 800 thousand m3/year (from 2014 to 2018) and the situation after the elimination of the accident in 2019 were assessed based on an analysis of space data. The features of optical anomalies associated with the discharge of wastewater into the marine environment in the region of the collector rupture are revealed, which are manifested in the changes in the normalized indices of sea-surface color recorded from space multispectral images of various resolutions, ranging from 1.25 to 1.45, while the background values are ~1. After the recovery of the collector rupture in 2019, the values of these indices were close to 1. The length of the zone where intense pollution appeared is ~3.0 km and its width is ~0.8 km; the center of the zone is at the place of the collector rupture. Based on remote sensing data, a positive effect has been demonstrated associated with the repair, which is recommended based on the results of space monitoring.

Palladium (Pd) is widely used in automotive catalytic converters to reduce toxic gas emissions. The input of Pd in the rainfall-runoff is an important contributing factor to the accumulation of Pd in receiving water bodies. In this study, the Meishe River in Haikou, Hainan Province, China, was used as the research area, and palladium (Pd) was selected as the target pollutant. This study explored the response of Pd in the receiving water body to rainfall-runoff and to analyze the influencing factors. The results showed that the dissolved Pd concentration in the receiving water body had a corresponding relationship with that in rainfall-runoff. The response of suspended Pd in the receiving water body to rainfall-runoff was closely related to the location of the drainage outlet. Compared with that of suspended Pd, the response of dissolved Pd in the receiving water body to that in the rainfall-runoff was more obvious. Seven meters downstream from the outfall was the most sensitive response distance of dissolved Pd in receiving water bodies to rainfall-runoff, and the response time was approximately 0–10 min. The suspended Pd at 3 m downstream from the outfall also had a certain response to the rainfall-runoff, and the response time was approximately 15–25 min. The response time of the suspended Pd in the receiving water body depended largely on the first flush ability of the runoff. There was a moderately positive correlation between the dissolved Pd and Cl− in the receiving water body (r = 0.687; p

The aim of this study was to screen and quantify 23 pharmaceutical compounds (including illicit drugs), at two sampling points near the diffusers of the Guaruja submarine outfall, State of Sao Paulo, Brazil. Samples were collected in triplicate during the high (January 2018) and low (April 2018) seasons at two different water column depths (surface and bottom). A total of 10 compounds were detected using liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). Caffeine (42.3–141.0 ng/L), diclofenac (3.6–85.7 ng/L), valsartan (4.7–14.3 ng/L), benzoylecgonine (0.3–1.7 ng/L), and cocaine (0.3–0.6 ng/L) were frequently detected (75% occurrence). Orphenadrine (0.6–3.0 ng/L) and atenolol (0.1–0.3 ng/L), and acetaminophen (1.2–1.4 ng/L) and losartan (0.7–3.4 ng/L), were detected in 50% and 25% of the samples, respectively. Only one sample (12.5%) detected the presence of carbamazepine (< 0.001–0.1 ng/L). Unexpectedly a lower frequency of occurrence and concentration of these compounds occurred during the summer season, suggesting that other factors, such as the oceanographic and hydrodynamic regimes of the study area, besides the population rise, should be taken into account. Caffeine presented concentrations above the surface water safety limits (0.01 μg/L). For almost all compounds, the observed concentrations indicate nonenvironmental risk for the aquatic biota, except for caffeine, diclofenac, and acetaminophen that showed low to moderate ecological risk for the three trophic levels tested.

River pollution is one of the major concerns for sustaining a healthy and liveable environment as rivers are prime source of water for the majority of livelihoods. Self-purification of river is mistaken as treatment of wastewater and results into heavy discharge of waste water either into the tributaries or directly into the river by human beings. Continuous deterioration of river water by means of sewage changes the perception of river into open sewer drain popularly known as nallahs. The present study deals with the strategies required for a stretch of 4 km of one such nallah i.e. river Kahn to prevent the pollution and make the water flowing in the river of acceptable quality. The study indicates the current status of river Kahn which receives domestic waste water directly through various outfalls of residential colonies by measurement of water quality parameters. Feasibility for an in situ treatment based on constructed wetland has been analysed and proposed as one of the remedial measure that can be considered as initial step towards restoring river Kahn.

The physico-chemical characteristics of the Marikina River in an urban area of Metro Manila, Philippines was determined to evaluate the current degree of pollution. The study focused on one source at the site with general coordinates of 14°38’07.95” N, 121°05’36.33” E based on the World Geodetic System (WGS), at an average surface water elevation of around 9 m above mean sea level (AMSL). The area was chosen because of its proximity to a main road and the presence of an outfall from a cemented pipe near a major shopping mall. Comparing the results from the sampling source with the DENR effluent standards for surface waters based on (DAO-2016-08, US-EPA), the effluent is considered as too polluted to be discharged to the surface water in terms of Total Dissolved Solids (TDS: 608.9 mg/L) and Phosphates (PO4: 12.46 mg/L). The pH (6.9) and Nitrate (0.17 mg/L) of the effluent conforms to standards. A Stream Visual Assessment Protocol was conducted with a resulting Protocol Score of 5.7, which is relatively low for a moving water body. The failure to conform to set standards using the physico-chemical components is supported by the land-use profile which shows that domestic (85%), industrial/commercial (10%) and agricultural wastes (5%) greatly affect the water quality of the river. It is our recommendation therefore that continuing information and education campaigns for the maintenance of water quality be regularly conducted for the residents along the riverbanks to create awareness of the importance of keeping the water clean through minimum direct waste contributions. Keywords: Physico-Chemical characteristics, Marikina river, water quality

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. Keywords: Cement industry, Effluent discharge, Water quality, Ngo River.

The Main Outfall drain pumping station in Nassiriyah is an important part in operation system of the Main Outfall Drain (MOD) where it reduces the water levels in the U/S area of its and converted through Syphon freely under the Euphrates, its consists of several parts: U/S Basin, Station Building which contains 12 pumps, and Head Basin with Syphon, This station suffers from high levels especially in D/S area due to the current situation which is represented by establishing of dyke with pipes on MOD which located at 24 km from D/S of pumping station and Al-Khamisiyah Canal which located at 2.3 km from the U/S of dyke which feeds(Al Hammar Marsh) during drought season, several scenarios were adopted in order to explore the hydraulic effect of the current situation on the water levels and the performance of the syphon pumping system. The hydraulic effect of current situation causes an increase in D/S levels from 0.75 to 1 m,0.37to0.6m in operating (1,2)pumps, and the highest lack of the performance equal to 9.87%,5.58%,3.62%,2.62 % in operating (1,2,3,4)pumps respectively with designed head and 8.55%,5.40%,3.11%,1.8% with non- designed head.

Zooplankton samples were collected using 505, 160 and 77 µm mesh nets around a power plant during four seasons in 2011. We measured total length of zooplankton and divided zooplankton into seven size classes in order to explore how zooplankton community size-structure might be altered by thermal discharge from power plant. The total length of zooplankton varied from 93.7 to 40 074.7 µm. The spatial distribution of mesozooplankton (200 −2 000 µm) populations were rarely affected by thermal discharge, while macro- (2 000 −10 000 µm) and megalo-zooplankton (>10 000 µm) had an obvious tendency to migrate away from the outfall of power plant. Thus, zooplankton community tended to become smaller and biodiversity reduced close to power plant. Moreover, we compared the zooplankton communities in three different mesh size nets. Species richness, abundance, evenness index and Shannon-Wiener diversity index of the 505 µm mesh size were significantly lower than those recorded from the 160 and 77 µm mesh size. Average zooplankton abundance was highest in the 77 µm mesh net ((27 690.0±1 633.7) ind./m3), followed by 160 µm mesh net ((9 531.1±1 079.5) ind./m3), and lowest in 505 µm mesh net ((494.4±104.7) ind./m3). The ANOSIM and SIMPER tests confirmed that these differences were mainly due to small zooplankton and early developmental stages of zooplankton. It is the first time to use the 77 µm mesh net to sample zooplankton in such an environment. The 77 µm mesh net had the overwhelming abundance of the copepod genus Oithona, as an order of magnitude greater than recorded for 160 µm mesh net and 100% loss through the 505 µm mesh net. These results indicate that the use of a small or even multiple sampling net is necessary to accurately quantify entire zooplankton community around coastal power plant.

The effects of anthropogenic pressures in coastal areas are extensively studied in temperate but not in tropical zones, where their impact might be amplified by high water temperatures and upwelling phenomena. Sedimentary features and benthic metabolism were studied during the non upwelling (NUPW) and upwelling (UPW) seasons in Taganga Bay (Colombia). The bay is impacted by a submarine outfall of virtually untreated, organic and nutrient-rich wastewater. Samplings were performed in November 2017 (NUPW) and in January–February 2018 (UPW) at 4 stations located in the proximity and 100, 750 and 1800 m far from the outfall, respectively, at depths between 22 and 28 m. Aerobic respiration, denitrification, dissimilative nitrate reduction to ammonium (DNRA) and nutrient fluxes were measured. The influence of the outfall was detectable 750 and 1800 m away from the point pollution source, where δ13C data suggested that ~ 40 and ~ 20% of organic inputs were terrigenous, respectively. In the proximity of the outfall benthic oxygen demand peaked and the presence of Beggiatoa mats suggested reoxidation of sulphides, that were abundant in pore water. Under sulfidic conditions, DNRA was the major driver of nitrate demand, whereas at stations far from the outfall, denitrification dominated nitrate consumption. Organic matter and nitrate inputs to the bay during the UPW season enhanced the effects of the outfall by increasing aerobic respiration and DNRA. Higher N availability during the UPW season reversed fluxes of molecular nitrogen and turned the sediments of 3 out of 4 sites from net sinks to net N2 sources. Results from this study suggest that the analysis of sediments allows tracing the impact of the outfall and that such impact is enhanced during the upwelling season. In tropical areas, marine outfalls and upwelling may act in synergy and contribute to ecosystem deterioration due to high temperatures, increase of microbial respiration, sulphide toxicity and benthic biodiversity loss.

Energy is considered as a vital sign of any country. The energy resource of any country is governed by their owned resources either through fossiliferous or alternative/renewable energy reserves. Due to depleting reserves of fossil fuel, countries including Pakistan are now focusing and converting themselves on renewable energy sources. Out of the different renewable sources, Hydel Power is among those indigenous sources which are considered as cheap, efficient and environmentally friendly. Pakistan is among those countries, which have the largest irrigation system which portrays a huge hydel potential within it. Government of Pakistan has also identified different potential sites where Hydel Energy can be obtained. However, apart from the recognized potential sites, there are still many streams/canals/ drains that can also be studied for their hydro potential and estimated generation capacity using mini/micro hydropower plant. Different studies have been carried out in calculating the energy potential of canals. In this paper, Hydropower Potential (HPP) of a Drainage System that is Left Bank Outfall Drain (LBOD), at Sindh has been calculated using field-based data parameters such as hydraulic depth, the width of the canal and flow velocity. Other studies were also reviewed for data collection. Based on the calculated HPP, five types of turbines with their benefits have been identified and proposed. This study concludes that different locations of LBOD can be considered for setting up a micro hydropower plant; however, a vertical head through extended penstock or weir needs to be considered for an effective hydropotential.

Total pollutant load control management for total dissolved nitrogen (TDN) is an urgent task required to gain a good water quality status in Jiaozhou Bay (JZB), China. In this paper, the stoichiometry of multiform TDN on land-ocean interactions associated with marine biogeochemical reaction (LOIMBR) was studied by modeling the load-response relationship based on a three-dimensional water quality model of nitrogen in JZB. The results showed that the stoichiometry on LOIMBR of dissolved organic nitrogen (DON), NO3-N and NH4-N was 3:1:1, with one-third of the contribution on the concentration of dissolved inorganic nitrogen (DIN) in JZB for the land-based DON loads to DIN loads. Based on the stoichiometric relationship of nitrogen forms, the total maximum allocated load (TMAL) of equivalent TDN (ETDN) was approximately 5300 t a−1 in JZB, equivalent to the TMAL of 5700, 5800 and 15600 t a−1 for NH4-N, NO3-N and DON, respectively. According to the loads of ETDN, there were four outfalls overloaded in JZB in 2015, which lie in the head of the bay. In the four overloaded outfalls, besides NO3-N, NH4-N was the critical nitrogen control form for Moshui River, while DON for Dagu River and Haibo River. The results of numerical experiments further showed that JZB will achieve good water quality after 7 years by implementation of the ‘different emission reduction’ based on TMAL of ETDN, which is significantly better than ‘equal percent removal’.

Deep-Sea Tailings Placement (DSTP) systems have been used at several mines to discharge diluted mine tailings at great depths. DSTP often provides considerable environmental and engineering benefit...