Municipal Sewage Effluent Research Articles

Metal partitioning in sediments and risk assessment of a ramsar site-Cochin estuary, South West India

Geochemical partitioning of sediment bound metals in Cochin estuary were determined by sequential extraction to unravel the processes controlling their distribution, mobility and contamination status. Most of the metals recorded higher content at residual and exchangeable fractions. Abundance of Cd, Zn and Mn in bioavailable form (promoted by surface adsorption on fine grained sediments) was sourced to industrial operations, municipal sewage and agriculture effluents. Pyrite formation effectively controls the fraction distribution of redox sensitive elements- Mn and Fe. Scavenging by Fe-Mn oxide was dominant process regulating the accretion of metals -Zn, Ni, Cr, Co, Cd, Mn whereas organic matter complexation facilitate the accumulation of the metals-Mn, Co, Cu and Zn. Contamination due to Zn and Cd was substantiated by enrichment factor (range for Zn: 4.42–57.22; range for Cd: 0.02–0.37), contamination factor (range for Zn: 0.51–22.19; range for Cd: 3.30–60.67 and geoaccumulation index (range for Zn: 0.10–4.45; range for Cd: 0.66–12.18). Elevated PLI (Range: 0.19–1.58) indicated metal inputs from anthropogenic activities. Potential ecological risk values >40 implied that Cd, Zn and Pb can induce risk to the ecosystem.

Physiochemical Characteristics Analysis of Garrah River Water at Shahjahanpur, Ganga River Basin, Uttar Pradesh, India

This study focuses on the physiochemical analysis of the Garrah River in Shahjahanpur, within the Ganga River Basin, Uttar Pradesh, India. The research evaluates the impact of various pollutants, including industrial and municipal sewage, on the river's water quality. Water samples were collected from three locations along the river, representing different pollution levels. The analysis included parameters such as pH, dissolved oxygen (DO), total suspended solids (TSS), color, odor, electrical conductivity, temperature, chemical oxygen demand (COD), salinity, and the concentrations of various elements. The findings showed variations in water quality parameters, with DO, TSS, COD, and heavy metals indicating significant pollution, particularly downstream. Color and odor also suggested pollution from nearby industries. The study revealed that some parameters exceeded WHO standards for drinking water, raising concerns about health risks from exposure to contaminants like chromium. Urgent actions are required to treat municipal sewage and industrial effluents before discharging into the Garrah River. This research highlights the need for ongoing monitoring and sustainable management of water resources in the Ganga River Basin to protect the ecosystem and local communities. It underscores the importance of improving water quality in the region.

Modelling of Pollutant Transport in Yamuna River from the Najafgarh Drain, NCT Delhi Using Matlab Software

When the river Yamuna leaves the National Capital Territory of Delhi, its situation further deteriorates. Despite accounting for only 1% of the river’s overall catchment area, this region is responsible for more than half of the pollutants discovered in the Yamuna. The river Yamuna, on the other hand, is Delhi’s only natural resource for maintaining all forms of life. The Yamuna River is currently experiencing a significant level of pollution problem, and in order to control pollution in the Yamuna River, continual analysis is essential. The Yamuna River is contaminated by the discharge of untreated municipal sewage and industrial effluent through seven major drains: Najafgarh, Yamunapur, Sen Nursing Home, Barathpula, Maharani Bagh, Kalkaji, and Tuglakabad. In terms of people and chemicals, continuous sampling takes time and money. The primary objective of this study is to analyse the wastewater samples collected by sub-drains and STP’s to predict the pollutant transportation in river Yamuna from Najafgarh Drain. The study focusses on the only pollutant, i.e., Biochemical Oxygen Demand from the starting point to after the confluence of Najafgarh Drain into river Yamuna. The prediction is to be done by using MATLAB software. This study would help to identify the main sources of sub-drains which are polluting Najafgarh Drain and eventually the river Yamuna. This shows how MATLAB may be used to calculate the pollution load caused by organic waste in the Yamuna River as it flows through Delhi, India’s National Capital Territory. The model numerically solves a series of differential equations to simulate the dissolved oxygen and biochemical oxygen demand parameters in two dimensions. MATLAB is an interactive programming language that may be used to develop algorithms, graphics, and user interfaces in other computer languages. MATLAB helps estimate future water quality using present data, which saves time, labour, and other costs associated with the continuous study. There are various software programmes available in the market for predicting river water quality, however, MATLAB GUI provides an accessible and convenient user interface (Graphical User Interface).

Impact of Namami Gange Programme on Kanpur City Sanitation

The river Ganga, particularly in the city of Kanpur, is facing severe pollution and degradation due to rapid urbanization, industrialization, and inadequate sanitation practices. The city's population growth and industrial activities have put tremendous pressure on the river, leading to the contamination of its water and degradation of its ecosystem. The pollution is primarily caused by the discharge of untreated municipal sewage and industrial effluents into the river. The lack of proper sanitation infrastructure and practices has further exacerbated the problem. The existing water bodies and natural habitats in Kanpur have been adversely affected, posing significant challenges to the sustainability of the city's environment and public health. The pollution levels in the Ganga River, especially in Kanpur, have reached alarming levels, leading to a decline in water quality and biodiversity. To address these issues and restore the purity and ecological balance of the Ganga River, the Indian government has launched the Namami Gange Programme. The program aims to effectively abate pollution, conserve, and rejuvenate the river through various initiatives, including the implementation of sewage treatment plants (STPs), ghat development, surface cleaning, afforestation, sanitation, and public awareness campaigns. This study focuses on assessing the impact of the sanitation schemes implemented under the Namami Gange mission in Kanpur city. It aims to evaluate the effectiveness of the projects in improving sanitation practices, reducing pollution levels, and contributing to the rejuvenation of the Ganga River. The assessment will provide insights into the progress made, identify challenges faced, and suggest potential measures to further enhance the impact of the sanitation initiatives in Kanpur.

Effectiveness of the tropical plants Rhynchospora corymbosa and Coix lacryma-jobi in vertical flow constructed wetlands for municipal primary sewage effluent treatment

The performance of two tropical plants, Rhynchospora corymbosa L. (RC) and Coix lacryma-jobi, L (CL) in treatment of primary sewage effluent in lab-scale vertical-flow constructed wetlands (VFCW) along with no plant control wetland was investigated. A batch-flow VFCWs were operated under batch fill and drain hydraulic loading system with hydraulic retention times (HRT) of 0.5, 1, and 2 days and fill rate of 8 L/day. Removal of solids, organics, nutrients, and pathogens were monitored. The volumetric contaminant removal rates were best described by 1st order kinetics except for ammonia and phosphate, which was best described by Stover-Kincannon kinetics. Influent TSS, PO4 3−, COD, BOD5, and total coliform concentration were low but high in NH4 + concentration. CL was better in nutrient removal as HRT increases compared to RC. RC was more efficient at TSS, turbidity, and organics removal. Pathogen removal was independent of plant type but HRT. Solids and organic removal were lower in CL planted CWs due to preferential flow paths created by their bulky root. CL planted CWs removed more nutrients followed by RC planted CWs and then no-plant control CWs. The results of these tests demonstrate that both CL and RC are suitable for the treatment of municipal wastewater in VFCW system.

Water quality assessment and pollution source apportionment using multivariate statistical techniques: a case study of the Laixi River Basin, China.

Identifying potential sources of pollution in tributaries and determining their contribution rates are critical to the treatment of water pollution in main streams. In this paper, we conducted a multivariate statistical analysis on the water quality data of 12 parameters for 3years (2018-2020) at six sampling sites in the Laixi River to qualitatively identify potential pollution sources and quantitatively calculate the contribution rates to reveal the tributaries' pollution status. Spatio-temporal cluster analysis (CA) divided 12months into two parts, corresponding to the lightly polluted season (LPS) and highly polluted season (HPS), and six sampling sites were divided into two regions, corresponding to the lightly polluted region (LPR) and highly polluted region (HPR). Principal component analysis (PCA) was used to determine the potential sources of contamination, identifying four and three potential factors in the LPS and HPS, respectively. The absolute principal component score-multiple linear regression (APCS-MLR) receptor model quantitatively analyzed the contribution rates of identified pollution sources, and the importance of the different pollution sources in LPS can be ranked as domestic sewage and industrial wastewater and breeding pollution (33.80%) > soil weathering (29.02%) > agricultural activities (20.95%) > natural influence (13.03%). HPS can be classified as agricultural cultivation (41.23%), domestic sewage and industrial wastewater and animal waste (33.19%), and natural variations (21.43%). Four potential sources were identified in LPR ranked as rural domestic sewage (31.01%) > agricultural pollution (26.82%) > industrial effluents and free-range livestock and poultry pollution (25.13%) > natural influence (14.82%). Three identified latent pollution sources in HPR were municipal sewage and industrial effluents (37.96%) > agricultural nonpoint sources and livestock and poultry wastewater (33.55%) > natural sources (25.23%). Using multivariate statistical tools to identify and quantify potential pollution sources, managers may be able to enhance water quality in tributary watersheds and develop future management plans.

Automated biomass recycling management system using modified grey wolf optimization with deep learning model

Biomass residues encompass non-recyclable municipal solid waste, crop wastes, sewage effluents and sludges, domestic and industrial greywater, etc. Numerous wastes to energy conversion technology use biomass to generate various kinds of renewable energy to reduce environmental issues. The recycling rate seems to rise continuously, but reports reveal that humans are creating more waste than before. Machine learning (ML) can be used that offers a structure to take as a structural enhancement of the fact without being programmed. This study proposes an automated biomass recycling management system using modified grey wolf optimization with deep learning (ABRM-MGWODL) model. The presented ABRM-MGWODL technique aims to effectually identify and categorize the waste objects to enable effectual biomass recycling. The ABRM-MGWODL method would follow 2 major processes: waste object detection and waste object classification. For the waste object recognition and detection process, the YOLO-v4 model is exploited in this work. Next, the graph convolution network (GCN) method can be used for classifying recognized waste objects. Finally, hyperparameter tuning of the GCN model is effectually carried out using the MGWO algorithm, thereby enhancing the ABRM-MGWODL method's classification outcome. A widespread set of simulations were performed to ensure the superior waste classification efficacy of the ABRM-MGWODL model. The simulation outcomes demonstrate the improvements of the ABRM-MGWODL method to other DL models with increased accuracy of 99.01%.

A shallow constructed wetland combining porous filter material and Rotala rotundifolia for advanced treatment of municipal sewage at low HRT.

Water scarcity is a worldwide problem. Recycled municipal wastewater is considered a useful alternative to the conventional types of water resources. In this study, a shallow constructed wetland (SCW) with porous filter material and Rotala rotundifolia was used for advanced municipal sewage treatment. The wetland without plant was set as the control (SCW-C). The pollutant removal performance of the system at different hydraulic retention times (HRTs) was investigated. The diversity of the microbial community was analyzed, and the fate of nutrients, mainly N and P, in the system was discussed. Results showed that SCW was efficient in pollutant removal. Effluent concentrations of chemical oxygen demand (COD), total phosphorus (TP), and ammonium nitrogen (NH4+-N) were 15.0-23.6, 0.19-0.28, and 0.83-1.16mg/L, separately, with average removal efficiencies of 61.2%, 46.3%, and 88.1% at HRT 18h, which met the requirements of type [Formula: see text] water set by the environmental quality standards for surface water in China. The richness and evenness of the bacterial community were significantly higher in the plant-rooted SCW. They increased along with the system. The dominant genera in the system were phosphate-solubilizing bacteria, nitrifying bacteria, and denitrifying bacteria. The P in the influent mainly flowed to the substrate and plant. At the same time, most N was removed by nitrification and denitrification. These findings suggested that the SCW could remove pollutants from the municipal sewage effluent and meet the standard requirement at low HRT.

Treatability influence of municipal sewage effluent on surface water quality assessment based on Nemerow pollution index using an artificial neural network

Assessing water quality provides a scientific foundation for the development and management of water resources. The objective of the research is to evaluate the impact treated effluent from North Rustumiyia wastewater treatment plant (WWTP) on the quality of Diyala river. The model of the artificial neural network (ANN) and factor analysis (FA) based on Nemerow pollution index (NPI). To define important water quality parameters for North Al-Rustumiyia for the line(F2), the Nemerow Pollution Index was introduced. The most important parameters of assessment of water variation quality of wastewater were the parameter used in the model: biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspension solids (SS), chloride, cl, hydrogen ion concentration, pH, sulfate, SO4-2, nitrate, NO3- and phosphate, PO4-3. Taking these criteria into account, samples of water from the sampling sites were graded as C, indicating the pollutant of the waste treatment. Then the water quality map using neural network model was based on the results of water quality assessment. The results showed that the model North Al-Rustumiyia for line F2 was more efficient and R2 was 0.965 with the impotence parameter was chloride (CL).

GIS-based framework for artificial aquifer recharge to secure sustainable strategic water reserves in Qatar arid environment peninsula

This study proposes a large-scale artificial aquifer recharge plan to increase the strategic water reserve to cope with future emergencies. The main aim of the plan is to restore groundwater levels to those of the 1980s through artificial recharge. Desalinated water or highly treated municipal sewage effluent could be artificially recharged into the aquifer to recharge it. Potentiometric surface of aquifers and Geographic Information Systems (GIS) analysis were used to assess change in the groundwater levels between 1980 and 2009. Zones that have experienced considerable decline in groundwater levels from their former “natural” status—when the aquifers were barely exploited, were identified. These zones are considered optimum recharge sites as they could provide ‘natural’ ground storage chosen by nature. Therefore, working with nature (not against it) by re-filling these natural spaces is the optimum approach. The artificial recharge of the main and principal upper aquifer in Qatar (Rus and Um er Radhuma) is targeted and recommended. It is estimated that up to 182.8 Million Cubic Meter (mcm) could be recharged and stored in these proposed zones, to increase the strategic water reserve of the country. This increase would sustain supplies of high quality for up to three months if consumption is maintained at the 2018 level. Moreover, this additional reserve could last for over one year, if emergency measures were put in place—in case of serious water-shortages, and disaster preparedness, for example by reducing the per capita consumption to the global average per capita consumption.

Ecological effects and causal synthesis of oil sands activity impacts on river ecosystems: water synthesis review

Oil sands development in the lower Athabasca River watershed has raised considerable public and scientific concerns regarding perceived effects on environmental health. To address this issue for tributaries and the mainstem of the Athabasca River in the Athabasca Oil Sands Region, the Water Component of the Joint Oil Sands Monitoring (JOSM) plan produced monitoring assessments for seven integrated themes: atmospheric deposition, tributary water quality, river mainstem water quality, groundwater quality and quantity, water quality and quantity modelling, benthic invertebrate condition, and fish health. Our review integrates and synthesizes the large and diverse datasets assembled in the seven JOSM theme assessments to (i) evaluate possible environmental effects based on known sources and candidate proximal causes and (ii) determine the importance of cause-and-effect pathways related to contaminant, sediment, and nutrient inputs. Although JOSM research identified ecological effects that appear to be associated with contaminant exposure, the source of this exposure is confounded by co-location of, and inability to differentiate between, oil sands operations (principally released by atmospheric emission) and inputs from the natural bitumen outcrops (e.g., erosional material transported by surface and groundwater flows). Nutrient enrichment from treated municipal sewage effluent was the dominant ecological effect observed for the mainstem Athabasca River, associated with increased fish size and changes in invertebrate assemblages, likely because this pollution source is discharged directly into the river. If the direct release of treated oil sands process water occurs in the future, then the potential ecological impact of these direct industry releases will need to be evaluated carefully. The ecological causal assessment method proved to be a useful tool for better understanding how stressor sources relate to ecological effects through candidate proximate causes. Factors that confound our ability to assess the ecological effects of oil sands development focus on our inability to adequately differentiate between contaminants supplied from natural and anthropogenic contaminant sources. Our causal synthesis identifies options for changes in future monitoring to better anticipate and detect degradation in the ecosystem health of the lower Athabasca River and its tributaries.

Magnetic hybrid coagulant for rapid and efficient removal of nitrogen compounds from municipal wastewater and its mechanistic investigation

• A novel magnetic hybrid coagulant (MHC) was synthesized. • MHC settling time was 2/3 shorter than traditional magnetic seeding coagulation. • MHC efficiently removed dissolved contaminants such as NO 3 − -N and organic nitrogen. • The NO 3 − -N removal pathways by MHC were clarified by MD simulations. • MHC was regenerated by Donnan dialysis combined with biodegradation. Dissolved contaminants (nitrate nitrogen, etc.) in municipal sewage effluent and polluted water resources need to be further removed, but common advanced water treatment technologies usually have unsatisfactory performance and large process footprints. Magnetic seeding coagulation (MSC) has a rapid settling speed; however, it is less effective for removing dissolved contaminants and cannot recover effective components. Herein, a novel covalently bound magnetic hybrid coagulant (MHC) was synthesized and used to treat secondary biological effluent. MHC settling time was 2/3 shorter than traditional MSC and showed high removal efficiencies for conventional coagulation indicators and dissolved contaminants such as nitrate nitrogen and organic nitrogen. The nitrate nitrogen removal mechanisms included nitrate nitrogen capture through the electrostatic attraction and the collision efficiency enhancement. MHC integral structure can be bioregenerated for multiple cycles. Because of its effectiveness in removing dissolved contaminants rapidly, MHC has potential application in advanced water treatment, especially in land-scarce areas.

Ecological causal assessment of benthic condition in the oil sands region, Athabasca River, Canada

Contaminant loads to rivers of the Canadian oil sands region are linked to industrial and natural sources. To date, biomonitoring studies have been unable to unequivocally assess potential environmental impacts associated with this development. As part of the Joint Alberta-Canada Oil Sands Monitoring initiative, we aimed to assess cumulative effects of anthropogenic activities and exposure to natural bitumen geology on benthic macroinvertebrate assemblages in the lower Athabasca River. We examined associations among macroinvertebrates and environmental correlates, such as nutrients, ions, metals, polycyclic aromatic compounds, and total suspended solids. The study design included sites within and outside the mineable bitumen deposits, within and outside of the active mining and extraction area, and above and below municipal sewage effluents. We predicted observing a negative association between ecological condition of the river and exposure to natural bitumen and oil sands activity. However, contaminant concentrations in water and sediment were far below known toxicity thresholds, and benthic macroinvertebrate assemblages in sites exposed to oil sands mining activities appeared more affected by nutrient enrichment from the MSE than contaminants from mining or natural bitumen. Although sites within the area of intense oil sands activity showed signs of mild environmental stress, assemblage pattern was more strongly associated with MSE nutrient enrichment than to diffuse contamination from either natural bitumen or oil sands mining. Enrichment likely increases food resources available to consumers, thereby potentially masking toxic responses of consumers to contaminants. Current regulations prohibit the direct release of oil sands contaminants to waterways, with diffuse atmospheric deposition of aerial emissions and fugitive dust the main contaminant pathways to freshwaters. As the storage capacity of tailings ponds is reached, this nutrient-contaminant pattern could change if the river receives the proposed direct release of treated oil sands process water. Focused investigation-of-cause studies are required to better assess the consequences of cumulative interactions and ecological effects of nutrients and contaminant exposure in this system.

MONITORING WATER INTAKES OF EL-GEDIA AND EDFINA DRINKING WATER PLANTS AS A RESULT OF ROSETTA BRANCH POLLUTION CASE STUDY EDKU-ROSETTA

River Nile is the most important and principal source of fresh water for Egyptians. Rosetta branch supplies fresh water for the governorates of Western Delta (Giza, Qaliubia, Menofia, Kafr El-Sheikh, Beheira and Alexandria). Rosetta branch receives organic, in-organic pollution and heavy metals through the discharge of municipal sewage and industrial effluents in Elrahawy drain water which is pumped to Rosetta branch. The aim of this work is to investigate pollution loads in Rosetta branch in the path (212-230km); a CaseStudy (Edku-Rosetta) with special reference to chemical parameters. Water samples were collected monthly during the period from June 2015 to May 2016. Samples from water intakes from Edfina and El-Gedia water drinking plant were collected. Results showed that COD and ammonia recorded 22.0-38.0 ppm and 2.5-4.0 ppm respectively. Also, total nitrogen varied from 5.1-7.1 ppm. The results were out of the permissible levels according to the Egyptian Ministry of Health and the International Standards. It can be concluded that Rosetta branch suffers from pollution loads that should be investigated periodically and controlled.

Comparison of metalworking fluids biodegradation efficiency by autochthonous and environmental communities

The aim of this study was to evaluate the biodegradation potential of microbiota isolated from different environmental niches towards different types of metalworking fluids (MWF). The first experimental stage was focused on the assessment of biochemical oxygen demand reduction efficiency of autochthonous and environmental microbial communities. Based on the obtained results, the following order describing the biodegradation potential of communities from the studied niches was established: petroleum contaminated soil > waste repository ≥ waste MWF tanks > pesticide-treated field > activated sludge > municipal sewage effluents. For comparative purposes, the most efficient community originating from petroleum contaminated soil (PCS1) was selected for further studies along with the most efficient community originating from a waste MWF tank (WMT1). The studied communities achieved 100% biodegradation efficiency of decanedioic and dodecanedioic acids as well as glycerine and polyethoxylated dodecanol. However, the PCS1 community was more versatile and displayed significantly higher biodegradation efficiency of mineral oil (80% compared to 50% in case of WMT1). Similarly, experiments using pristine and spent MWF solutions confirmed that the PCS1 community outperformed the WMT1 community during the biodegradation of MWF containing oil as the main component (COD reduction of 80, 60 and 30% in case of semi-synthetic MWF, soluble oil and spent MWF, respectively). Results of community dynamics assessment using quantitative real-time PCR after the biodegradation of different types of MWF confirmed that the PCS1 community was characterized by high genetic stability and allowed to indicate the potential ‘key players’.

A Review on Sewage Sludge (Biosolids) a Resource for Sustainable Agriculture

Sewage sludge (Biosolids) generation is fastly increasing resulting from the regular increase of population, urban planning and industrial developments worldwide. The sludge needs to be adequately treated and environmentally managed to reduce the negative impacts of its application or disposal. The present review deals with the different applications of sewage sludge for sustainable agriculture. The scattered literature is harnessed to critically review the uses of biosolids to promote sustainable practices focusing on the productive uses of sewage sludge or biosolids. Biosolids or sewage sludge is the byproduct of municipal wastewater, sewage effluent and effluent treatment plants. The treatment plants are generating huge amount of biosolids. The present review focuses on the different applications of biosolids or sewage sludge as in many countries the biosolids or sewage sludge are frequently using for various purposes like for biogas production, land filling, organic fertilizer, soil amendment, and to enhance the crop yield of agricultural crops. Therefore, biosolids or sewage sludge is in the consideration as a resource worldwide. Besides this higher content of different heavy metals and microorganisms are the important constraints for the application of biosolids or sewage sludge in the various fields. Thus, this review emphasizes the different applications and possible limitations for the use of biosolids or sewage sludge as a resource. Efforts have been made on the possible pretreatment of biosolids or sewage sludge to make it more feasible for their applications. Therefore, different properties of biosolids or sewage sludge, their applications along with possible limitations have been discussed in the present review to formulate the biosolids or sewage sludge as a resource for the sustainable development.

The relative risk and its distribution of endocrine disrupting chemicals, pharmaceuticals and personal care products to freshwater organisms in the Bohai Rim, China

In this study, the risks to aquatic organisms posed by 12 commonly detected pharmaceuticals and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs) that are extensively used in Bohai coastal region of China were examined. These were linear alkylbenzene sulfonate (LAS), nonylphenol (NP), diethylhexyl phthalate (DEHP), norfloxacin (NOR), sulfamethoxazole (SMX), erythromycin (ERY), bisphenol A (BPA), ofloxacin (OFL), carbamazepine (CBZ), naproxen (NPX), atenolol (ATL) and metoprolol (MET). Their relative risk was ranked based on the proximity between the medians of the reported effect concentrations and measured river or lake water concentrations. The surfactants (LAS) and endocrine disrupting chemicals NP (a breakdown product of the surfactant nonylphenol polyethoxylate) and DEHP (a plasticizer) were identified as posing the greatest risk from this range of chemicals. LAS had a hundred-fold higher risk than any of the pharmaceuticals. The highest risk ranked pharmaceuticals were all antibiotics. Zinc (Zn) and mercury (Hg) were added to the comparison as representative heavy metals. Zn posed a risk higher than all the organics. The risk posed by Hg was less than the surfactants but greater than the selected pharmaceuticals. Whereas LAS and DEHP could cause harmful effects to all the wildlife groups, NP and BPA posed the greatest risk to fish. Antibiotics showed the highest risk to algae. Spatial and temporal distributions of PPCPs and EDCs were conducted for risk identification, source analysis and seasonal change exploration. Municipal sewage effluent linked to urban areas was considered to be the major source of pharmaceuticals. With regard to seasonal influence the risk posed by LAS to the aquatic organisms was significantly affected by wet and dry seasonal change. The dilution effects were the common feature of LAS and ERY risks. The difference in LAS and ERY risk patterns along the rivers was mainly affected by the elimination process.

Impact on Water Quality of Nandoni Water Reservoir Downstream of Municipal Sewage Plants in Vhembe District, South Africa

The deterioration of water quality in our freshwater sources is on the increase worldwide and, in South Africa, mostly due to the discharge of municipal sewage effluent. Here we report on the use of principal component analysis, coupled with factor and cluster analysis, to study the similarities and differences between upstream and downstream sampling sites that are downstream of municipal sewage plants. The contribution of climatic variables, air temperature, humidity, and rainfall were also evaluated with respect to variations in water quality at the sampling sites. The physicochemical and microbial values were higher than the Department of Water Affairs and Forestry (DWAF) and World Health Organization (WHO) guidelines. The cluster analysis showed the presence of two clusters for each of the Mvudi, Dzindi, and Luvuvhu Rivers and Nandoni reservoir sampling sites. The principal component analysis (PCA) accounted for 40% of the water quality variation and was associated strongly with pH, electrical conductivity, calcium, magnesium, chloride, bromide, nitrate, and total coliform, and negatively with rainfall, which represented Mvudi downstream and was attributed to the Thohoyandou sewage plant. The PCA accounted for 54% of the variation and was associated strongly with electrical conductivity, sulfate; total dissolved solids, fluoride, turbidity, nitrate, manganese, alkalinity, magnesium, and total coliform represented Dzindi downstream, with inflows from the Vuwani sewage plant and agriculture. The PCA accounted for 30% of the variation and was associated strongly with total dissolved solids, electrical conductivity, magnesium, fluoride, nitrate, sulfate, total coliform average air temperature, and total rainfall, and negatively associated with manganese and bromide represented Luvuvhu upstream and was associated with commercial agriculture. The PCA accounted for 21% of the variation and was associated strongly with turbidity, alkalinity, magnesium, chloride, fluoride, nitrate, and strongly negatively associated with rainfall, which represented Luvuvhu downstream, associated with inflows from Vuwani oxidation ponds, Elim and Waterval sewage plants, and agriculture. The PCA accounted for 14% of the variation and was moderately associated with rainfall and weakly associated with chloride and bromide and negatively associated with nitrate, which represented the natural Nandoni reservoir system. The continued discharge of effluent may render the raw water supply unsuitable for human consumption and lead to eutrophication due to nitrate enrichment and proliferation of harmful algal blooms and schistomiasis infections in the long term.

Seasonal variation and enrichment of metals in sediments of Rosetta branch, Nile River, Egypt.

This study investigated heavy metal pollution in sediments of the Rosetta branch of the River Nile of Egypt to quantify the toxic distribution potential of metals into the surrounding environment. Sediment samples were collected at 9 sites during in four seasons. Organic matter and total metal concentrations were determined using loss on ignition and inductively coupled plasma spectrometry, respectively. Principal component analysis has been applied to evaluate the metal sources and the relationships between metals in sediments. Metal concentrations showed the following order: winter > autumn > spring > summer. Mean concentrations of Cu, Zn, Cd, and Pb in sediments were above the average background value of metals in shale. Pb and Cd showed higher enrichment during all seasons at stations N3/N4, Zn at stations N1 to N4, and Cu at stations N6/N8. The variations in heavy metal total concentration and organic matter are due to different input sources, physico-chemical conditions, and adsorption/precipitation/redox conditions in sediments. Mean values of Geo-accumulation index (Igeo) for Fe, Mn, and Cu were below 0 which were classified as unpolluted during spring, summer, and autumn, except Cu increased from unpolluted to moderately polluted during winter. Igeo values for Cd, Pb, and Zn increased from unpolluted-moderately polluted to highly-very highlypolluted during autumn and winter. Pollution Load Index was recorded in highest values during winter, especially at Fuwwah/Basioun and in lowest values during summer at after the Edfina Barrage/before Kafer El-Zayat due to industrial/human activities. Both natural and anthropogenic sources contributed to the metal accumulations in sediments, and industrial, agricultural, and municipal sewage effluents discharged from non-point sources may be the main anthropogenic sources for metals in the Rosetta branch.

Microbial abatement of toluene using Aspergillus niger in upflow bioreactor

Microbial abatement of toluene using Aspergillus niger in coir packed upflow bioreactor was investigated in this study. Toluene degrading microbes were isolated from municipal sewage effluent and identified by 16s rRNA sequencing method. The microbes were cultured in 2% (v/v) toluene input per day, which exhibited 95% removal efficiency with the kinetic correction value (R2) of 0.9024 at the optimum flow rate of about 0.4m3h−1. Various parameters such as effect of flow rate, column height, elimination capacity and EBRT with removal efficiency for 50 day cycle were also optimized. The plug flow model for toluene degradation was properly expressed and the Monod kinetics constant Km and rmax values were determined as 2.25gm−3 and 67.773gm−3h−1 respectively for microbial growth rate.