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Baitarani River, Odisha, faces serious deterioration due to massive human intervention. It is particularly susceptible to degradation because it receives industrial and waste water emissions from surrounding organizations and municipal bodies. The current condition of the river is deplorable, leaving behind only minimal economic and ecological values. In this Baitarani Watershed, Odisha, this study emphasizes on analysing the seasonal variation (post-monsoon) of the water quality rating of the river in terms of the Water Quality Index (WQI). Study assessed the hydro-chemical variables, collected from thirteen sampling sites, during 2021–2024; and the whole river was investigated for 15 physicochemical parameters. Again, environ-metrics techniques, such as principal component analysis (PCA), and hierarchical (H) cluster analysis (CA), were used to assess the hydro-chemical variables. In all sites, the indicator Turbidity did not meet the drinking water quality limits (< 5NTU). During the post-monsoon season, the obtained WA-WQI value scored as 21.7 to 191, signifying excellent to unsuitable water quality. In this context, the WAWQI (Weighed Arithmetic Water Quality Index) values show that almost 61.54 % sampling sites have poor to unsuitable quality of water. On the contrary, the computed CCMEWQI (Canadian Council of Ministers of Environment Water Quality Index) value of the present research, varied between 23 and 97. These values indicate that water quality ranges from excellent to very poor water quality. Spanning a spectrum, the values of Integrated Weight (I)-WQI oscillated between 14 and 97. About 23.08 % remained within the excellent-good category, suggesting low pollution. These values also indicate 76.92 % of samples renders poor water and thus, significant contamination of the research zone by elements like turbidity, EC, and TDS indicates that the water quality in these areas is below drinkable limits and requires purification before use. The method, CA grouped four zones into three clusters, i.e., relatively low-polluted, medium-polluted, and high polluted. During post-monsoon season, most of the water quality characteristics were lower owing to dilution by monsoon rainfall, while pollutants were relatively higher in at some places, which might be due to reduced river flow and concentrated pollutants. The PCA resulted into 4 components namely PC-1 (51.31 %), PC-2 (16.044 %), PC-3 (11.799 %) and PC-4 (9.04 %) and indicated that particularly PC-1 contributes parameters such as turbidity, EC, TDS, Na+, K+, Ca2+, and Mg2+, were mostly influenced by mineralization, ions dissolution, and rock weathering. Ultimately, this innovative study from both indexing techniques, concludes that out of the 13 sampling sites, around 61.54 % (WA), 76.92 % (IWQI) and 53.85 % (CCME) is observed to be the most polluted site. CA and PCA identified that natural phenomena, along with agricultural, municipal, and industrial discharges, are the major polluting sources in the river basin. Reducing sewage outflow, blocking direct stormwater discharge, and avoiding continuous solid garbage disposal by neighbouring populations are ways to improve river water quality. This study provides baseline information that would serve as an effective plan for the management of the river basin.

There is a need for a comprehensive comparative analysis of spatiotemporal variations in surface water quality, particularly in regions facing multiple pollution sources. While previous research has explored the use of individual water quality indices (WQIs), there is limited understanding of how different WQIs perform in assessing water quality dynamics in complex environmental settings. The objective of this study is to evaluate the effectiveness of three WQIs (Canadian Council of Ministers of the Environment (CCME), National Sanitation Foundation (NSF) and System for Evaluation of the Quality of rivers (SEQ-Eau) and a national water quality regulation in assessing water quality dynamics. The pilot study area is the Acısu Creek in Antalya City of Turkey, where agricultural practices and discharge of treated wastewater effluents impair the water quality. A year-long intensive monitoring study was conducted includig on-site measurements, analysis of numerous physicochemical and bacteriological parameters. The CCME and SEQ-Eau indices classified water quality as excellent/good at the upstream, gradually deteriorating to very poor downstream, showing a strong correlation. However, the NSF index displayed less accuracy in evaluating water quality for certain monitoring stations/sessions due to eclipsing and rigidity problems. The regulatory approach, which categorized water quality as either moderate or good for different sampling sessions/stations, was also found less accurate. The novelty of this study lies in its holistic approach to identify methodological considerations that influence the performance of WQIs. Incorporating statistical analysis, artificial intelligence or multi-criteria decision-making methods into WQIs is recommended for enhanced surface water quality assessment and management strategies. [ABSTRACT FROM AUTHOR]

The present study illustrates the rapid pollution of Euphrates River, inwards Al-Najaf Al-Ashraf governance (Al-Kufa River) in Iraq, which is one of the most important rivers in the region. The river faces formidable pressure due to encroachments, discharge of untreated domestic and industrial waste, drainage water from cultivated orchards, and dumping of solid waste. This study was conducted to assess the temporary and locative organic pollution in the region. Water Quality Index (WQI) of the Al-Kufa river was determined according to the Canadian Council of Ministers of Environment (CCME) method by calculating seven parameters (water temperature, DO, COD, EC, TDS, turbidity, and pH) in two sampling stations. Surface water samples were collected in a period of four months (September to December) in 2023. WQI level, correlation analysis between parameters, and Iraqi and CCME drinking water specification standards were employed to classify the surface water status. The results show that the ecological condition can be classified as marginal with WQI= 49 and poor with WQI= 42 in stations 1 and 2, respectively. [ABSTRACT FROM AUTHOR]

A hydro-geochemical study for water-quality assessment was conducted in the Tuticorin region of Tamil Nadu in southern India during the pre- and post-monsoon seasons of 2022 and the water samples are examined to comply with BIS and WHO guidelines. In the present study, the values of TDS (75%), Mg (37.5%), and TH (25%) have exceeded the permissible limits namely 500, 100, and 600 mg/L, respectively. The WQI proposed by CCME is used to analyze water suitability. The Pearson correlation and principal component analysis are used to study the relationship between various physicochemical parameters and principal components of water quality, respectively. Piper & Gibbs diagrams are plotted to identify the water types and the main water type predicted by the piper plot is Ca-Mg-Cl-SO4 which makes up 74.3% of the the samples studied. WQI suggests that 22.5% and 50.0% specimens have excellent water quality during pre and post-monsoon seasons, respectively. [ABSTRACT FROM AUTHOR]

The water quality index (WQI) was studied monthly, from November 2018 to October 2019, at three stations (Al-Saddah, Al-Burgah, & Al-Marsa) in the Basrah Governorate's East Hammar Marsh. This study measured various environmental factors, including water temperature, pH, dissolved oxygen, biological oxygen demand, light penetration, salinity, total dissolved salts, total hardness, nitrates, nitrites, phosphate, sulfate, calcium, and magnesium. After the end of the salty tide in 2018, the first station showed poor seasonal evidence 43.7 (low WQI score) in the winter, fair 67.6 and 64.9 (third category) in the spring and summer respectively, and marginal 55.9 (fourth category) in the summer and fall. The second and third stations had poor WQI score in the Winter and marginal in the rest of the seasons. The results indicate that the water quality is polluted and deviates from its optimal state. The WQI values varied significantly across all sites. The lack of freshwater drainage and ongoing marine water impacts are the reasons for the deterioration of water quality. Treatment is recommended to address this issue.

The Mundeswari River is the western distributary of the Damodar River system in eastern India. The water of this river is ext ensively used for domestic purposes and agricultural irrigation. This study aimed to evaluate the spatial and temporal water qu ality variation of the Mundeswari River and assess the water quality status of this river using the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI). Water quality was monitored monthly at four selected sampling stations (M1, M2, M3, and M4) during 2020-2022, considering twelve selected water quality indicators. The obtained water quality data were analysed using different statistical techniques. Water quality at different monitoring stations was appraised through the use of CCME-WQI. The results revealed that the overall water quality of most of the monitoring stations based on CCME-WQI values was "marginal." The highest WQI value (82.01) was observed at M1, and the lowest WQI (41.24) was recorded at M3. One -way ANOVA indicated a statistically significant difference in WQI values between sampling sites (P <0.05). The water quality of th e M3 sampling station was found to be in degraded condition throughout the study period. Cluster analysis from the perspective of WQI values revealed two distinct clusters of the sampling stations. Substantial seasonal variation in water quality was al so observed. This river had putrid water quality during the pre-monsoon period, and relatively better water quality was evident aft er the monsoon. This study revealed that the water of the Mundeswari River is utterly unsafe for human consumption and it requires significant treatments before it can be safely used for domestic purposes like cooking, washing etc. [ABSTRACT FROM AUTHOR]

Degradation of water quality is a major challenge in both developed and developing countries since it poses a great risk to ecological health. The Cauvery river is one of the most important rivers of southern India, where the effect of seasonal variation on the quality of river water and its adjoining groundwater on the lower part of the basin has not yet been studied. Hence, the present study was carried out to evaluate the river water and adjacent groundwater for drinking and irrigational purposes, and also to identify the sources affecting the water quality. About 118 river water and 131 groundwater samples were collected over 4 months from May 2018 to August 2019. The water samples were analyzed for electrical conductivity (EC), pH, major and minor ions, and trace elements. The major, minor, and trace elements were then compared with the Bureau of Indian Standards and World Health Organization for drinking water quality assessment. The drinking water quality was assessed, indicating that both river water and groundwater were unsuitable in the coastal regions, especially during dry seasons. Irrigation water quality was also assessed, which indicates that most of the river water and groundwater samples were unsuitable near the coastal region. The quality of river water and groundwater in the lower Cauvery Basin was found to be better during wet periods compared to the dry season. It was observed that the rock–water interactions was the major factor controlling the water quality for groundwater and surface water, followed by anthropogenic activities such as disposal of domestic sewage and effluents into the river, as runoff from irrigated lands. The study emphasizes the development of a finer observational network for water quality, along with stringent monitoring of the disposal of contaminants in the rivers and groundwater.

The Water Quality Index (WQI) is an important parameter in describing the water resources' suitability for human uses and is one of the most effective methods of describing water quality and indicative of assessing water quality and suitability for human utilization and the health of ecosystems. WQI of the Canadian Council of Ministers of the Environment (CCME) was used in the study to describe the Shatt al-Arab water quality in Basrah Southern Iraq, and its suitability for drinking use. The data for analyzing river water samples were adopted from five stations along the river every month during the years from 2014 to 2018 by the Iraqi Ministry of Environment, as it included the measurement of acidity function PH, Dissolved Oxygen DO, phosphorous PO4, nitrate NO3, Calcium Ca, potassium K, magnesium Mg, sodium Na, Total Hardness TH, sulfates SO4, chlorides Cl, Electrical Conductivity EC, Total Soluble Salts TDS, and Alkalinity ALK. The distributions of water quality index values along the river were mapped by GIS techniques. Study results were referring to illustrate the poor level of the water quality status of Shatt al-Arab in all study periods at all monitoring stations. The reason for this is due to the deterioration of fresh water quality drained from the Tigris and Euphrates, and the provision of salt wedges from the Arabian Gulf. However, with the continuous discharge of sewage water, industrial and oil effluents and sewage discharged from urban areas, the water quality of Shatt al-Arab was declined during the study period. [ABSTRACT FROM AUTHOR]

The present study aimed to employ different modified indices (Canadian Council of Ministers of the Environment (CCME) water quality index (WQI) and comprehensive pollution index (CPI)) to determine the water quality status of the Swakoppoort and Von Bach dams based on physicochemical and biological parameters. The data generated shows that the CCME WQI effectively determined nutrient, salinity, and particulate matter pollution in the two dams. Variables that exceeded the limits of the South African, Canadian, Australian, and New Zealand guideline levels were Cl, NTU, TP, OP, TN, NH3, EC, Cu2+, pH, and chl a in the CCME WQIs. The CCME WQIs showed poor water quality conditions in both dams for 17 years. CPI also showed that the dams were polluted mostly by the selected variables, except for F, SO4, and Mn. The occurrence of Cl concentration above the Target Water Quality Range (TWQR) for aquatic ecosystems (5 μg/l) throughout the study period in both dams could be related to point source sewage pollution. It was evident from this study that the two applied indices showed similar results and, therefore, should be considered for water quality assessment in reservoirs found in the desert climate conditions. [ABSTRACT FROM AUTHOR]

Abstract Lake Hawassa is one of the major Ethiopian Rift Valley Lakes having an endorheic basin system. The surrounding community makes use of the lake water for the multiple purposes of irrigation, domestic water supply, recreation and fish harvesting. The aim of the present study was to ascertain the water quality of the lake in terms of water quality indices (WQI) and its health over a period of three months covering both dry and wet seasons. Overall, the water quality of Lake was unfit and bad as per the weighted arithmetic method (120.06–228.29) and modified Bascarón water quality index (MBWQI) methods (26.81–33.89), respectively. However, the quality was indicated as marginal, as per the Canadian Council of Ministers of the Environment (CCME) water quality index method (44.2–51.1). On average, the lake was under the hypertrophic stage as per the standard based on the results of Secchi depth and nutrient concentration. The current study showed the lake being unfit for all-purposes as per WAWQI range (> 100). According to the physicochemical and biological parameters, of the lake, it requires mitigation measures to control Eutrophication and pollutants inflow.

The water quality index was used for the evaluation of the quality of water, as well its impacts on the rotifer abundance, in the Tigris River as it passes through Mishahda City, northern Baghdad. Five sites were selected and samples were collected during October 2019 to September 2020. It was noticed that the index values in most sites have exceeded the upper limits of river waters. The values ranged from 40 (Poor) to 45 (Marginal) in all sites. While, the values were from 42 (Poor) to 65 (Fair) during different seasons. As for drinking usages, the results demonstrated poor or undrinkable (31-40) water in all sites. Meanwhile, the values ranged from 39 (Poor) to 56 (Clear) in regard to seasons. The index values recorded for the purpose of Conservation of Aquatic Organisms ranged from 36 (Poor) to 66 (Fair) in the all sites, and 56 (Clear) to 69 (Fair) during different seasons. Twenty five rotifer species were recorded, including 11, 2, 1, 5, 2, 1, 2, and 1 species of Brachionidae, Euchlanidae, Gastropodidae, Lecanidae, Lapadellidae, Notomanatidae, Synchoetidae, and Trichotoidae, respectively. It is concluded that the water of the Tigris on Mishahda City is considered to be highly contaminated and not suitable for human consumption without the necessary treatment. It was also noticed that the population density of the rotifers community was affected by the river water quality. However, despite the presence of environmental pressures, the rotifers continued to reproduce and conserve. [ABSTRACT FROM AUTHOR]

Chahnimeh reservoirs, located in the Sistan and Baluchestan Province in the vicinity of Afghanistan border, are the main sources of drinking water for Zabol, Zahak, and Zahedan cities. Water quality and health risk assessment were evaluated based on water quality index (WQI) method (using analytical hierarchy process method), Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI, heavy metals), and hazard quotient (HQ). Eighty-four water samples were collected and analyzed in September 2017 and April 2018 from four Chahnimeh reservoirs. WQI results revealed that most of the water samples have a good quality (64.75–99.68). The CCME WQI for drinking water is varied from fair to excellent (69–100). Results of health risk assessment indicate that Se (Max HQingestion: 2.38) and As (Max cancer risk: 0.0005 and Max HQingestion: 2.89) and U (Max HQingestion: 0.16) have the highest contributions in chronic risks for both adults and children. Therefore, conducting water quality monitoring for at least 2 years is suggested crucial. [ABSTRACT FROM AUTHOR]

Lake Hawassa is one of the major Ethiopian Rift Valley Lakes having an endorheic basin system. The surrounding community makes use of the lake water for the multiple purposes of irrigation, domestic water supply, recreation and fish harvesting. The aim of the present study was to ascertain the water quality of the lake in terms of water quality indices (WQI) and its health over a period of three months covering both dry and wet seasons. Overall, the water quality of Lake was unfit and bad as per the weighted arithmetic method (120.06–228.29) and modified Bascarón water quality index (MBWQI) methods (26.81–33.89), respectively. However, the quality was indicated as marginal, as per the Canadian Council of Ministers of the Environment (CCME) water quality index method (44.2–51.1). On average, the lake was under the hypertrophic stage as per the standard based on the results of Secchi depth and nutrient concentration. The current study showed the lake being unfit for all-purposes as per WAWQI range (> 100). According to the physicochemical and biological parameters, of the lake, it requires mitigation measures to control Eutrophication and pollutants inflow. [ABSTRACT FROM AUTHOR]

Sixty-five water samples were collected in July 2016 in the Mathura district and have experimentally determined the physio-chemical parameters and evaluated by comparing their values with Bureau of Indian Standards (BIS). The aim of the study is to find out the status of water quality in Mathura district. Results show that Total Hardness(TH), Total Dissolved Solids (TDS), Cl− and Mg2+ are found to be very much higher than (>50%) the permissible limit. Majority of the samples have high values NO 3 − and Cl−. The sources of Ca2+, Mg2+, Na+ and K+ are from the weathering process. In general, water chemistry is governed by complicated weathering procedure, ion exchange, impact of horticultural and sewage. CCME WQI values ranged from 1.862 to 82.254 and shows that the quality of water is good to poor. Agriculture indices like Gibbs Plot, Percent sodium (Na%), Residual Sodium Carbonate (RSC), Sodium Adsorption Ratio (SAR), Permeability Index (PI) Potential salinity and Magnesium hazard has values 0.50 to 0.99, 8.37% to 86.66%, −90.59 to 7.71 meql−1, 9.59 to 96.34, 1.82 to 21.82, 4.58 to 112.83 meql−1, and 45.57 to 8221.03 respectively. These values show that the quality of water is poor and moderately suitable for irrigation purpose. It also indicates that an anthropogenic effect on groundwater quality needs water management strategy according to their regional demand for humans. [ABSTRACT FROM AUTHOR]

This study emphasizes hydrogeochemistry and quality degradation of groundwater in the upper Kodaganar basin, located in Dindigul district, South India. The Kodaganar basin has a particular significance and requires great attention because groundwater is the only major source for domestic and irrigation consumption. Twenty wells in the basin are randomly identified for sampling groundwater. The standard sampling procedures and laboratory experiments are followed for analyzing each sample. Index representing the suitability of drinking water is estimated based on the recommendations of Canadian Council of Ministry of Environment. The spatial distribution of the suitability was prepared by inverse distance weighted method. The traces of pollution and sources of pollution analyzed through Piper diagram suggested the role of natural and anthropogenic causes. The Gibbs boomerang diagram for both season illustrated around 85% of anions concentration dominated by rock type and also 80% of cation concentration influenced by surface interactions. This survey concludes that the overall drinking suitability of groundwater is fair in 7 wells and good in 13 wells. Only nine wells are found suitable for irrigation and rest of the wells can be used for irrigation only after minor treatment. [ABSTRACT FROM AUTHOR]

This paper presents the results of investigations to develop an optimized in-house catalyst- coated membrane electrode (CCME) assembling technique which is the fast and most cost-effective method for quick selection of electrode materials and components. Due to the absence of hydrogen, this method is safer than single cell. The hot-pressing conditions of the CCME of a proton exchange membrane fuel cell in this preparation technique were investigated by using a central composite design. The influence of CCME fabrication parameters like hot pressing parameters on performance of hydrogen fuel cells was studied by cathode half cell measurements. Compression pressure, temperature and time duration were key parameters varied from 35 to 105 kgf/cm 2 , 80 to 140 °C and 1 to 5 min, respectively. The CCME was prepared with a Nafion 117 membrane and the gas diffusion layer (GDL) has an active area of 0.785 cm 2 with Pt/MWCNT catalysts of 0.1 mg cm −2 loaded at the cathode side. The design of experiment (DOE) work was performed with the response surface method using the central composite design. The results show that the proposed mathematical model in the response surface methodology (RSM) can be used adequately for prediction and optimization within the factor levels investigated. As it was predicted in present study, The combined optimum hot pressing parameters, gave the highest performance of 22.9 mW cm −2 predicted in this study are 35 kgf/cm 2 , 93 °C and 5 min. [ABSTRACT FROM AUTHOR]

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River Damodar situated in the South Bengal region of India is the main source of water for the surrounding industries and agricultural places. The objective of the present study is to evaluate the water quality of Damodar River in terms of an index under the influence of several physical and chemical parameters by using Canadian Council of Ministers of Environment Water Quality Index (CCME WQI) method as the river has been subjected to enormous contamination in recent times. Water samples have been procured from eight different locations along the river bank in the pre-monsoon, monsoon, and post-monsoon for the entire period of 2012. Immensely complex data were coined into a single term for the sake of convenience using CCME WQI method. This index consists of three elements: scope, frequency, and amplitude. Besides this, the seasonal variation of different water quality parameters like pH, total dissolved solid, total suspended solid, conductivity, turbidity, dissolved oxygen, chemical oxygen demand, biological oxygen demand, chloride, fluoride, chromium, alkalinity, total hardness, calcium and magnesium hardness, oil, grease, and total Coliform were also assessed during the aforementioned time period. The relationships among the eight sampling stations were emphasized by cluster analysis to characterize and evaluate CCME WQI that produces an index value in the range of 0–100 to reflect the worst and best quality water, respectively. Nevertheless, the CCME WQI values obtained from the respective stations depict fair values on an average except the last sampling station Tetul Bagan Gas Canal where the river water is heavily contaminated and thus require pre-treatment before use. [ABSTRACT FROM PUBLISHER]

This paper presents an important new approach to improving the timeliness of Total Petroleum Hydrocarbon (TPH) analysis in the soil by Gas Chromatography – Flame Ionization Detector (GC-FID) using the CCME Canada-Wide Standard reference method. The Canada-Wide Standard (CWS) method is used for the analysis of petroleum hydrocarbon compounds across Canada. However, inter-laboratory application of this method for the analysis of TPH in the soil has often shown considerable variability in the results. This could be due, in part, to the different gas chromatography (GC) conditions, other steps involved in the method, as well as the soil properties. In addition, there are differences in the interpretation of the GC results, which impacts the determination of the effectiveness of remediation at hydrocarbon-contaminated sites. In this work, multivariate experimental design approach was used to develop and validate the analytical method for a faster quantitative analysis of TPH in (contaminated) soil. A fractional factorial design (fFD) was used to screen six factors to identify the most significant factors impacting the analysis. These factors included: injection volume (μL), injection temperature (°C), oven program (°C/min), detector temperature (°C), carrier gas flow rate (mL/min) and solvent ratio (v/v hexane/dichloromethane). The most important factors (carrier gas flow rate and oven program) were then optimized using a central composite response surface design. Robustness testing and validation of model compares favourably with the experimental results with percentage difference of 2.78% for the analysis time. This research successfully reduced the method's standard analytical time from 20 to 8 min with all the carbon fractions eluting. The method was successfully applied for fast TPH analysis of Bunker C oil contaminated soil. A reduced analytical time would offer many benefits including an improved laboratory reporting times, and overall improved clean up efficiency. The method was successfully applied for the analysis of TPH of Bunker C oil in contaminated soil. [ABSTRACT FROM AUTHOR]

Water quality is one of the major criteria for determining the planning and operation policies of water resources systems. In order to classify the quality of a water resource such as an aquifer, it is necessary that the quality of a large number of water samples be determined, which might be a very time consuming process. The goal of this paper is to classify the water quality using classification algorithms in order to reduce the computational time. The question is whether and to what extent the results of the classification algorithms are different. Another question is what method provides the most accurate results. In this regard, this paper investigates and compares the performance of three supervised methods of classification including support vector machine (SVM), probabilistic neural network (PNN), and k-nearest neighbor (KNN) for water quality classification. Using two performance evaluation statistics including error rate and error value, the efficiency of the algorithms is investigated. Furthermore, a 5-fold cross validation is performed to assess the effect of data value on the performance of the applied algorithms. Results demonstrate that the SVM algorithm presents the best performance with no errors in calibration and validation phases. The KNN algorithm, having the most total number and total value of errors, is the weakest one for classification of water quality data. [ABSTRACT FROM AUTHOR]

Evaluation of seasonal variations in river water (raw), treated and distributed water quality is vital for assessing spatial and temporal changes in the quality of water delivered to consumers. In this study, raw water, treated and distributed water collected from 27 sampling points in the dry and rainy seasons were analyzed for 21 physical, chemical and bacteriological parameters from the Barekese dam. The results showed a seasonal trend in the physical, chemical and coliform bacteria with the rainy season having higher values of the measured parameters. Langelier Saturation Index (LSI) and two well documented Water Quality Index models, Canadian Council of Ministers of Environment (CCME) and Tiwari and Mishra (Indian J. Environ. Prot. 5:276-279, ) were used as a complementary tool to assess the overall suitability of the water for industrial and drinking purposes. The LSI indicated that all the samples are under saturated, and thereby, suitable for domestic and industrial purposes. The CCME and TM models showed that the raw water in both seasons was unsuitable for drinking without any form of treatment, while the treated water in both seasons was of 'excellent' quality. The distributed water in both seasons showed a wide variation in the quality rating in the two models. The CCME model rated 52%, 30% and 17% of the distributed water as 'excellent', 'very good' and 'good', respectively, while the TM model rated 74% of the distributed water as 'excellent' and 26% as 'very good' in the dry season. In the rainy season, the CCME rated 43% of the distributed water as 'excellent', 48% as 'very good' and 8% as 'good' while the TM model rated 87% of the distributed water as 'excellent' and 13% as 'good'. The CCME and TM models showed comparable results, even though they were developed for surface water and groundwater, respectively. The calculated efficiency ( E%) of the treatment process using the CCME WQI was found to be 52% and 57%, while the average distributed water quality deterioration ( D%) was 2.79% and 2.70% for the dry and rainy season, respectively. The study also showed great improvement in the water quality after the treatment process, however, maintenance of free chlorine residual was found to be insufficient to control coliform occurrences in the distribution system. Furthermore, the distribution line, especially the service lines, impacted negatively on the water quality resulting in high coliform bacteria. This is partly due to illegal connections, leakages or pipe burst along gutters or drainage systems and low pressure leading to back sucking. The study has also shown a high rise in nutrients load in the raw and distributed water. This phenomenon is likely to cause algae growth in the dam and the distribution networks, thereby increasing the risk of coliform bacteria and production cost. [ABSTRACT FROM AUTHOR]

Abstract: A superfamily of integral membrane proteins is characterized by a conserved tryptophan-rich region (called the WWD domain) in an external loop at the inner membrane surface. The three major members of this family (CcmC, CcmF, and CcsBA) are each involved in cytochrome c biosynthesis, yet the function of the WWD domain is unknown. It has been hypothesized that the WWD domain binds heme to present it to an acceptor protein (apoCcmE for CcmC or apocytochrome c for CcmF and CcsBA) such that the heme vinyl group(s) covalently attaches to the acceptors. Alternative proposals suggest that the WWD domain interacts directly with the acceptor protein (e.g., apoCcmE for CcmC). Here, it is shown that CcmC is only trapped with heme when its cognate acceptor protein CcmE is present. It is demonstrated that CcmE only interacts stably with CcmC when heme is present; thus, specific residues in each protein provide sites of interaction with heme to form this very stable complex. For the first time, evidence that the external WWD domain of CcmC interacts directly with heme is presented. Single and multiple substitutions of completely conserved residues in the WWD domain of CcmC alter the spectral properties of heme in the stable CcmC:heme:CcmE complexes. Moreover, some mutations reduce the binding of heme up to 100%. It is likely that endogenously synthesized heme enters the external WWD domain of CcmC either via a channel within this six-transmembrane-spanning protein or from the membrane. The data suggest that a specific heme channel (i.e., heme binding site within membrane spanning helices) is not present in CcmC, in contrast to the CcsBA protein. We discuss the likelihood that it is not important to protect the heme via trafficking in CcmC whereas it is critical in CcsBA. [ABSTRACT FROM AUTHOR]

The proteins CcmA and CcmB have long been known to be essential for cytochrome c maturation in Escherichia coli. We have purified a complex of these proteins, and found it to have ATP hydrolysis activity. CcmA, which has the features of a soluble ATP hydrolysis subunit, is found in a membrane-bound complex only when CcmB is present in the membrane. Mutation of the Walker A motif in CcmA(K40D) results in loss of the in vitro ATPase activity and in loss of cytochrome c biogenesis in vivo. The same mutation does not prevent covalent attachment of heme to the heme chaperone CcmE, but holo-CcmE is, for some unidentified reason, incompetent for heme transfer to an apocytochrome c or for release into the periplasm as a soluble variant. Addition of exogenous heme to heme-permeable E. coli with a ccmA deletion did not restore cytochrome c production. Our results suggest a role for CcmAB in the handling of heme by CcmE, which is chemically complex and involves an unusual histidine–heme covalent bond. [ABSTRACT FROM AUTHOR]

Since its development in 2001, the Canadian Council of Ministers of the Environment (CCME) Water Quality Index (WQI) has established itself as a valuable tool for communicating ambient water quality data. Due to the high natural background levels of particular parameters in water bodies throughout the country it is often necessary to use Site-Specific Water Quality Guidelines (SS-WQGs) as opposed to generic national Water Quality Guidelines (WQGs) or provincial Water Quality Objectives (WQOs) in the CCME WQI model to obtain truly representative rankings. SS-WQGs have only been developed for a limited number of ambient water quality sites and this has been a major hurdle to the widespread use and acceptance of the CCME WQI. This paper presents the adaptation and implementation of an existing CCME-approved SS-WQGs derivation method called the background concentration (BC) procedure into a Site-Specific Water Quality Index (SS-WQI) calculator and tool. It discusses the application of the SS-WQI calculator to compute water quality indices for five pristine ambient water quality sites in Newfoundland and Labrador. The effects of using five different BC-based SS-WQGs (mean; median; mean ± one standard deviation; mean ± two standard deviations; 90th and 10th percentile) are examined. The paper also discusses the challenges and benefits of using this methodology and provides recommendations for further testing. [ABSTRACT FROM AUTHOR]

Water quality indices (WQIs) have been developed to assess the suitability of water for a variety of uses. These indices reflect the status of water quality in lakes, streams, rivers, and reservoirs. The concept of WQIs is based on a comparison of the concentration of contaminants with the respective environmental standards. The number, frequency, and magnitude by which the environmental standards for specific variables are not met in a given time period are reflected in WQIs. Further, the water quality trend analysis predicts the behavior of the water quality parameters and overall water quality in the time domain. In this paper, the concept of WQI was applied to three selected watersheds of Atlantic region: the Mersey River, the Point Wolfe River, and the Dunk River sites. To have robust study, two different water quality indices are used: Canadian Water Quality Index (CWQI), and British Columbia Water Quality Index (BWQI). The complete study was conducted in two steps. The first step was to organize and process the data into a format compatible with WQI analysis. After processing the input data, the WQI was calculated. The second step outlined in the paper discusses detailed trend analysis using linear and quadratic models for all the three sites. As per the 25 years trend analysis, overall water quality for agriculture use observed an improving trend at all the three sites studied. Water quality for raw water used for drinking (prior to treatment) and aquatic uses has shown improving trend at Point Wolfe River. It is further observed that pH, SO4, and NO3 concentrations are improving at Dunk River, Mersey River, and Point Wolfe River sites. To ascertain the reliability and significance of the trend analysis, a detailed error analysis and parametric significance tests were also conducted It was observed that for most of the sites and water uses quadratic trend models were a better fit than the linear models. [ABSTRACT FROM AUTHOR]

Cytochromes c are ubiquitous proteins, essential for life in most organisms. Their distinctive characteristic is the covalent attachment of heme to their polypeptide chain. This post-translational modification is performed by a dedicated protein system, which in many Gram-negative bacteria and plant mitochondria is a nine-protein apparatus (CcmA-I) called System I. Despite decades of study, mechanistic understanding of the protein-protein interactions in this highly complex maturation machinery is still lacking. Here, we focused on the interaction of CcmC, the protein that sources the heme cofactor, with CcmE, the pivotal component of System I responsible for the transfer of the heme to the apocytochrome. Using in silico analyses, we identified a putative interaction site between these two proteins (residues Asp 47 , Gln 50 , and Arg 55 on CcmC; Arg 73 , Asp 101 , and Glu 105 on CcmE), and we validated our findings by in vivo experiments in Escherichia coli Moreover, employing NMR spectroscopy, we examined whether a heme-binding site on CcmE contributes to this interaction and found that CcmC and CcmE associate via protein-protein rather than protein-heme contacts. The combination of in vivo site-directed mutagenesis studies and high-resolution structural techniques enabled us to determine at the residue level the mechanism for the formation of one of the key protein complexes for cytochrome c maturation by System I., (© 2018 Shevket et al.)