Calculation Of Water Quality Index Research Articles

Water quality assessment in the ecologically stressed lower and estuarine stretches of river Ganga using multivariate statistical tool.

Water quality of the Ganga River system is changing day by day due to multifold increase in population, especially near the banks of river Ganga, and associated exponential amplification of anthropogenic activities also played a remarkable role in it. The ecologically important lower and estuarine stretch of river Ganga comprising 7 different sampling stations, i.e., Jangipur, Berhampore, Balagarh, Tribeni, Godakhali, Diamond Harbour and Fraserganj, were selected for the study as the stretch is enriched with the vast number of floral and faunal diversity. The study was conducted for a period of 5years, i.e., from 2016 to 2020. In the study, various analytical tools and techniques were used for the assessment of riverine water quality, i.e., for calculation of water quality index(WQI); The National Sanitation Foundation Water Quality Index (NSF-WQI) and the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) were used for the assessment.Along with WQI various statistical univariate as well as multivariate analytical tools like principal component analysis, correlation, ANOVA, and cluster analysis were also used to achieve the desired outputs. In the study, it has been observed that NSF-WQI varied from 61 to 2552, in which the higher value of NSF-WQI denoted the unsuitability of the water quality concerning the drinking water standards and vice versa. The CCME-WQI represented a similar trend as that of NSF-WQI, as it varied from 18 to 92 in which the lower value denoted degradation in the drinking water quality and vice versa. The study revealed that the Diamond Harbour-Fraserganj stretch is having an undesired level of water quality which were analyzed based on the drinking water guideline values of the Bureau of Indian Standards and that of NSF-WQI and CCME-WQI.

Chemical Quality and Hydrogeological Settings of the El-Farafra Oasis (Western Desert of Egypt) Groundwater Resources in Relation to Human Uses

In the Egyptian deserts, new land reclamation projects have been recently established to meet the increasing-population growth rate and food demand. These projects mainly depend on the different groundwater aquifers. El-Farafra Oasis is one of the “1.5-million-feddan reclamation project” areas recently established in the Western Desert of Egypt where the only available water source is the world’s largest fossil freshwater reservoir “the Nubian Sandstone Aquifer System (NSAS)”. Groundwater-dependent springs, and their artificial counterpart “drilled wells”, are reliable water systems throughout the world. In the present study, hydrochemical parameters were collected in 2015 from 16 different springs and wells of the El-Farafra Oasis, and analyzed using the different water quality indices. The calculated water quality index (WQI), its correlations with the water quality parameters Gibbs, Piper, US Salinity-Lab Staff and Wilcox diagrams, and Principal Component Analysis (PCA) were used to evaluate the groundwater suitability for human drinking and irrigation purposes. WQI values revealed good-to-excellent groundwater quality for human drinking. In addition, the spring and well water samples investigated showed good indices for irrigation activities. Gibbs and Piper’s diagrams were presented, with most samples falling into the rock-dominance category, and belonging to hydrogeochemical facies determining the following water types: Mg(HCO3)2 type water (37.5% of the samples), no dominant ions (mixed water-type category; Ca/MgCl2) (50% of the samples), and, finally, NaCl water type (the remaining 12.5%). The groundwater chemistry in the study area is mainly controlled by rock-water interactions, particularly the dissolution of carbonate rocks and silicate weathering. The elevated nutrient concentrations, in particular nitrates, are most likely due to agricultural activities, indicating substantial anthropogenic activities in the area studied.

Assessment of underground water quality in Okobo local government area of Akwa Ibom State, Nigeria

The ground water quality of Okobo Local Government Area was investigated. Sixteen boreholes (BHs) water samples were collected from four zones (Okopedi, Ekeya, Ukwong and Okiuso) in Okobo. Standard analytical procedures were used to analyze the physicochemical, bacteriological and heavy metal parameters in the water samples and the results compared to Nigerian standard for drinking water quality (NSDWQ). some physicochemical parameters investigated were within the acceptable limits set by NSDWQ except pH (5.99 ± 0.37), DO (0.31 ± 0.06) mg/L, BOD5 (6.26 ± 0.4) mg/L and Nitrate (62.53 ± 5.96) mg/L. Bacteriological parameter like fecal coliform (128.69 ± 31.40) MPN/100 mL and total coliform (287.63 ± 40.31) MPN/100 mL were also above the limits set by NSDWQ implying organic pollution due to fecal contamination. Heavy metals were also within the acceptable limit except Lead (0.1 ± 0.1) mg/L, Chromium (0.4 ± 0.2) mg/L, and Manganese (0.16 ± 0.2) mg/L which were slightly above acceptable limits in all the zones. Water quality index calculation results grouped the BHs into; BH7 (26–50) very good; BH1, BH3, BH4, BH8, BH11, BH14, and BH16 (51–75) poor; BH2, BH5, BH6, BH9, BH12, BH13 and BH15 (76–100) very poor and BH 10(> 100) unsuitable for drinking. Pearson coefficient correlation, principal component analysis (PCA) and cluster analysis (CA) were used to establish interrelationship among the parameters, common sources of the pollutants and grouping of the BHs affected by these pollutants. PCA extracted six principal components (PCs) from the investigated parameters in the BHs, with sources of pollution either natural mineral or anthropogenic source. CA grouped all the sixteen BHs investigated into three clusters with various levels of contamination from pollutant sources. Consequently, the polluted BHs require treatment using high test hypochlorite (HTH) as the pollutant common to all the BHs is mostly bacterial pollutant; moreover, BHs should be sited 15 m away from septic tank or latrine to reduce contamination from coliform.

Groundwater Quality Assessment of Ikorodu Local Government Area of Lagos State in Nigeria

An assessment of the quality of groundwater in Ikorodu Local Government Area (LGA) was carried out in September 2020 (Late wet season). A total number of 29 samples were collected from different selected locations of the study area. The samples were collected from private and government bore holes. The pH, Total dissolved solids (TDS), Salinity, Turbidity, Hardness, Biochemical oxygen demand (BOD), Chemical oxygen demand (COD), Phosphate, Nitrate, Sulphate, and Total bacterial count (TBC) were determined according to American Public Health Association (APHA) standard techniques. The results showed that the mean pH, TDS, Salinity, Turbidity, Hardness, BOD, COD, Phosphate, Nitrate, Sulphate, and TBC in the water samples were 7.0 ±0.59, 176.0 ±132.2mg/L, 0.14 ±0.11g/kg, 0.32 ±0.05 NTU, 59.58 ±34.89mg/L, 11.59 ±3.41mg/L, 14.90 ±4.18mg/L, 0.97 ±0.46mg/L, 2.62 ±1.27mg/L, 9.44 ±5.94mg/L, and 4.92 ±2.94 x 102 cfu/mL, respectively. The calculated Water quality index (WQI) of the different sampling points showed the least WQI was 50.3 and the highest WQI was 66.9. Overall, the WQI indicated “Poor” quality of groundwater in the Ikorodu Local Government Area of Lagos State.

MODELING WATER QUALITY INDEX USING GEOGRAPHIC INFORMATION SYSTEMS AND WEIGHTED ARITHMETIC INDEX IN KIRKUK, IRAQ

In this study, various water quality parameters have been selected and examined. Weighted Arithmetic Index (WAI) method used to calculate Water Quality Index (WQI). Besides, a statistical model for WQI prediction was proposed to test the correlation between WQI, Acidity (pH), Turbidity (T), Total Dissolved-Solids (TDS), Total Suspended-Solids (TSS), and Electricalconductivity (Ec). The study was conducted in Kirkuk, north of Iraq. The results of laboratory tests showed that the quality of drinking water that is processed from Kirkuk water project K1 is within the Iraqi specifications, except in one characteristic (Turbidity). The calculated WQI ranged between 67.37-109.92. Water Quality (WQ) was within good and poor water. For the predicted model, an accuracy value was calculated by the regression process. The obtained regression coefficient value R2 was equal to 0.99. The results demonstrated that the features obtained by regression analysis are able to predicate the WQI with very high accuracy.

Assessmening water quality index for Chau Pha Lake in Viet Nam

Chau Pha Lake is one of the large reservoirs providing water for domestic, irrigation and production of people in Phu My town, Ba Ria Vung Tau province. This study was conducted to analyze the parameters of pH, temperature, DO, BOD5, COD, N-NH4+, P-PO43-, TSS, turbidity, total Coliform on 16 samples in 2020 and the water quality index calculation WQI. The analysis results show that the water quality of Chau Pha lake in the rainy season is quite good, all parameters reach the limit value A2 according to QCVN 08:2015/BTNMT; however, in the dry season, the values of parameters DO, BOD5, P-PO43-, TSS exceed the limit value A2 but not significantly; WQI values fluctuate at a fairly high level from 71 to 92, which is correlated with turbidity, COD, and BOD5 parameters. Thus, the average WQI of the lake reaches 85.4 points, corresponding to level 2 (green) - water used for domestic water supply purposes but needs appropriate treatment measures.

Assessment of Groundwater Quality Using Water Quality Index from Selected Springs in Manga Subcounty, Nyamira County, Kenya

We present the results of groundwater quality assessment that was done during the rainy season in November 2018 in the Manga region of Nyamira County, Kenya. Water samples were collected from three springs, Kiangoso, Kerongo, and Tetema, for the assessment. Water quality index was calculated based on pH, turbidity, nitrate, phosphate, calcium, magnesium, chloride, sulphates, fluoride, iron, total phosphorous, total hardness, total alkalinity, total dissolved solids, and total coliform. These fifteen parameters were analyzed and characterized according to standard methods and with reference to the World Health Organization and Kenya Bureau of Standards for physiochemical and bacteriological parameters which were then used in the calculation of water quality index. The water quality index was 21.32 for Kiangoso, 29.66 for Kerongo, and 25.64 for Tetema. The water quality index was found to be of excellent quality status at Kiangoso, while of good quality status at Kerongo and Tetema. The water quality index of Manga groundwater represented by the three springs therefore is less than 30 and can be used for drinking, irrigation, and industrial purpose. The present results are crucial for future management of groundwater in the Manga region.

Water quality and probabilistic non-carcinogenic health risk of groundwater: a half decadal scenario change in Vadodara.

Groundwater is essential to secure the safety of water supply in Vadodara, Gujarat. In this study, groundwater samples were collected from various part of the city which separated in 12 wards. The present study contains analyses of 720 groundwater samples gathered from various tube and open wells and analyzed for fluoride and other physicochemical parameters during 2014 and 2019. The results indicated that fluoride and TDS were high and the overall water quality was poor in the study area. Gastrointestinal and other health-related issues increased due to higher TDS in east, north and northeast regions. Likewise, hierarchical cluster analysis also indicated that TDS and chloride-rich water. Fluoride concentration was observed in the range of 0.66-1.61mg/l (2014) and 0.86-1.77mg/l (2019) which indicates that 62% samples are unfit for drinking purpose, which could cause dental and skeletal fluorosis. The water quality index (WQI) indicated lack of excellent water in the studied area in the last half-decade. As per WQI calculation suggest that 82.12% (2014) and 69.00% (2019) of groundwater samples represent poor, very poor and unsuitable categories, whereas remaining 17.85% (2014) and 31.00% (2019) of the samples represent good category for drinking purposes in entire Vadodara, Gujarat. Marginal improvement in the groundwater quality is reported due to good rainfall in 2019. Health risks associated with high fluoride drinking water were assessed for various age groups of inhabitants such as children, infants and adults. The non-carcinogenic hazard quotient estimated by oral intake was 1.38-3.36 (2014) and 1.79-3.70 (2019) for infants; 0.69-1.68 (2014) and 0.90-1.85 (2019) for children, whereas 0.07-0.18 (2014) and 0.10-0.20 (2019) for adults. Therefore, infant and children are relatively at higher health risk due to the intake of fluoride-rich drinking water than adult in the studied region. Both indices were indicated contaminated water or closer to contamination which induced non-carcinogenic health risk on citizens. Thus, the comprehensive results of present study can be used as a baseline data and valuable tool for government authorities for long-term monitoring, health monitoring and sustainable development of Vadodara, Gujarat.

Assessment of Bahr El-Baqar Drain and its Environmental Impact on Manzala Lake in Egypt

Polluted drains are considered one of the most important dangerous elements for the surrounded aquatic environment. The use of polluted water from drains outfalls in fish farms and agricultural lands has a very dangerous environmental effect on plants, soil, and groundwater. Over a year period starting May 2018, 75 water samples were collected from bahr El-Baqr drain outlet, Manzala wetland and Manzala Lake to examine and classifies it water quality and evaluates its suitability for reuse in safe irrigation. Based on physical, chemical and bacteriological results obtained, the calculated water quality index (WQI) classified Bahr El-Baqr drain as poor drainage water, while gradual improvement recognized at the end of wetland stages specially in subsurface follow basin and Manzala Lake as medium quality that attributed most probably to self-purification and dilution concepts. Out of 200 bacterial isolates, 29.8% and 70.2% were recovered from Bahr El-Baqar drain and all wetland station sites, respectively. Identified bacterial strains were verified using 16S-rDNA and all nucleotide sequence data were submitted to the NCBI GenBank database, USA and gained their accession numbers. The bioinformatics analysis supported the analytical data and the correlation coefficient matrix between physicochemical and bacteriological pairs recorded several positive and negative significant relationships. The study recommended continuous treating domestic wastewater and directing it to locations distant from direct disposal in Lake Water and pointed out its possible reuse in cultivating cereal, industrial and fodder crops of economic importance to mitigate health problems outbreaks or any aquatic ecosystem disorders.

Impact of Sewage Water Plant Seepage on Water Quality of Abu Simbel khor’s in Abu Simbel City

The aim of the present study is to examine the water quality of Abu Simbel khor’s, Nasser Lake during the period of flooding and receding water to explores the potential pollution hazards coming from these Khors to the whole Lake through several physico-chemical and bacteriological analyses. Results obtained from calculated water quality index (WQI) showed that the drop in Lake Nasser water's levels led to a decline in the water quality of the Lake and Abu Simbel Khor, from the order of good (period of flooding) to medium (period of receding water). This impact may in turn influence the whole Lake due to water rebounce from the Abu Simbel Khor, to the main channel. Total dissolved solids (TDS), biological oxygen demand (BOD), turbidity and recognizable depletion in dissolved oxygen (DO) were observed in sewage station and affected on Lake Nasser water area adjacent seepage water area. Pollution from total and fecal coliforms as well as fecal streptococci didn't exceed permissible limits except for sewage station basin that discharge agricultural and sewage wastes are the key factors in this environmental problem, particularly in period of receding water. Therefore, it is further concluded that the Abu Simbel Khor, could be considered as potential pollution sources during low water levels of the lake.

Water quality index prediction with hybridized ELM and Gaussian process regression

The Department of Environment (DOE) of Malaysia evaluates river water quality based on the water quality index (WQI), which is a single number function that considers six parameters for its determination, namely the ammonia nitrogen (AN), biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), pH, and suspended solids (SS). The conventional WQI calculation is tedious and requires all parameter values in computing the final WQI. In this study, the extreme learning machine (ELM) and the radial basis function kernel Gaussian process regression (GPR), were enhanced with bootstrap aggregating (bagging) and adaptive boosting (AdaBoost) for the WQI prediction at the Klang River, Malaysia. The global performance indicator (GPI) was used to evaluate the models’ performance. By preparing different input combinations for the WQI prediction, the parameter importance was found in following order: DO > COD > SS > AN > BOD > pH, and all models demonstrated lower prediction accuracy with a lesser number of parameter inputs. The GPR revealed a consistent trend with higher WQI prediction accuracy than ELM. The Adaboost-ELM works better than the bagged-ELM for all input combinations, while the bagging algorithm improved the GPR prediction under certain scenarios. The bagged-GPR reported the highest GPI of 1.86 for WQI prediction using all six parameter inputs.

Assessment of effects of a Cemetery leachate on Groundwater Quality using an Integrated Approach

The dependency of residents in the vicinity of cemeteries on groundwater from hand-dug wells as an alternative source of water supply for their domestic use without cognisance of the quality of such water has been a concern. So, this research assesses the effects of a cemetery on groundwater quality using an integrated approach in Edunabon, South-western Nigeria. Thirty groundwater samples from available hand-dug wells were collected and analysed for various physicochemical parameters. GIS cloud data collection server and Mobile Data Collector (MDC) were used to obtain these hand-dug wells' locations and spatial distributions. The determination in variation in physicochemical concentration parameters was obtained using the curve fitting technique of ARCVIEW GIS software and digital map. Physicochemical results were used to calculate Water Quality Index (WQI) of each sample. Two Schlumberger Vertical Electrical Soundings (VES) of 130.0m long were conducted at 10.0m intervals to the wall and the next VES, on each side of the cemetery. Current spacing (AB/2) and apparent resistivity (ρa) data were plotted on a double logarithm paper, curved matched and iterated using IPI2Win software for qualitative and quantitative interpretation. WQI results ranged from (107.37–173.64), (76.60–93.37), (54.94–71.53), (31.29–48.01), and (10.84–25.31) for fourteen, seven, three, four and two hand-dug wells respectively, an indication that the water from these wells was unfit for drinking, very poor, poor, good, and excellent respectively. VES results revealed that first, second and third layers were mainly clayey topsoil (46.7–96.8Ωm), lateritic soil (169.0–551.3Ωm), and weathered layer (3.21–27.4Ωm), which favourably enhances the migration of leachate from the cemetery to the surrounding soils and groundwater. The lowest resistivity values recorded in the second and third layers indicated leachate presence at these hand-dug wells. The integration of GIS and electrical resistivity methods would be useful tools to assess groundwater quality around cemeteries. Keywords: Groundwater quality, Mobile Data Collection, unfit for drinking, Vertical Electrical Sounding, Water Quality index

Assessment of groundwater quality of two selected villages of Nawada district of Bihar using water quality index

Unplanned discarding of industrial effluent, sewage, domestic and industrial solid waste, unwise use of insecticides, herbicides, pesticides, and fertilizer in agriculture are the major causes of groundwater quality reduction. In the present paper groundwater quality of the two selected village of Rajauli subdivision of Nawada district of Bihar was assessed using water quality index (WQI). The samples were figured out for the parameters such as temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), alkalinity, dissolved oxygen (DO), total hardness (TH), chloride, calcium (Ca), magnesium (Mg), biochemical oxygen demand (BOD), and fluoride. All the parameters were found below the standard limits of Bureau of Indian Standard (BIS, 2012) except total hardness (328.1mg/l to 346.6mg/l), calcium (105.3mg/l to 122.6mg/l), magnesium (46.1mg/l to 55.7mg/l) and fluoride (4.8 to 4.9mg/l). Fluoride was observed more than 3 times than the standard permissible limit (1.5mg/l). Water quality index (WQI) was also applied on the obtained data to make it easy to understand. Based on WQI (including the fluoride), all the four sites fall in unfit for drinking category (250.79, 258.78, 281.78, 247.30) and in poor to very poor category (80.23, 88.19, 88.59, 64.60) excluding the fluoride from WQI calculation. Both the values of WQI shows that fluoride alone is not responsible for the degraded quality of water but other high concentration of salts is also responsible.

Hydrochemical evaluation of groundwater quality and human health risk assessment of nitrate in the largest peninsula of China based on high-density sampling: A case study of Weifang

Groundwater is an important source of water, and the assessment of its hydrochemical characteristics, quality, and health risks is of great practical significance to ensure safe water use for residents and stable socioeconomic development. This study used high-density groundwater sampling data (1398 water samples) for Weifang to assess the groundwater quality and the health risks associated with drinking nitrate (NO3−)-contaminated groundwater. The results indicated that the major chemical components of groundwater varied widely and had high coefficients of variation. The NO3− concentration in groundwater ranged from 0.1 to 984 mg/L; it exceeded the Chinese standard groundwater quality threshold (88.57 mg/L) in 587 samples (41.99% of all samples). A Piper diagram indicated that the groundwater in Weifang is mainly of the SO4·Cl–Ca·Mg type and the HCO3·Ca·Mg type, and that groundwater with high NO3− concentrations (>300 mg/L) is mainly of the SO4·Cl–Ca·Mg type. Hydrochemical analysis indicates that the groundwater chemistry in Weifang is mainly influenced by the weathering of silicate and carbonate rocks, cation exchange, and human activities. In addition, the NO3− concentration in groundwater considerably influences its quality. The NO3− concentration in the groundwater in Weifang is higher than that in many other regions of China, and is primarily attributed to agricultural activities. The calculated water quality index (WQI) shows that the groundwater in Weifang is mainly medium -quality water, but extremely poor -quality water is distributed extensively in some parts of the study region. The spatial distribution of the hazard quotient (HQ) is consistent with the spatial variation in groundwater NO3− concentrations. Overall, the health risks associated with NO3− in drinking water were greatest for infants, followed in decreasing order by children, teenagers, and adults.

Impact of industrial effluents on physico-chemical parameters of water and fatty acid profile of fish, Labeo rohita (Hamilton), collected from the Ramsar sites of Punjab, India.

In this contemporary era, wetlands and the entire aquatic diversity are suffering from major pollution problem. Not only the aggregation of higher population in metropolitan causes the production of plenty of solid, liquid and gaseous wastes, but also the high-technological industries contribute to a mammoth of wastes in the ecosystem. During the process of industrial effluent discharge into the water bodies, the toxic substances available in these wastes can affect the aquatic flora and fauna, resultantly disturbing the entire system and constituting human health hazards indirectly or directly. The objective of this study was to estimate the nutritional value of the liver and intestine of fish which is being discarded as waste during fish processing and pollution status by calculated water quality index (WQI) and comparison of both wetlands during diverse seasons. WQI of Harike Wetland was observed to be 56.68 which indicates that water quality in this wetland is “poor”, while at Nangal Wetland WQI was calculated to be 39.54 and comes under “good” water quality and safe for the entire ecosystem. HPI (heavy metal pollution index) for Harike Wetland was observed 144.9 and for Nangal Wetland was 3.12, indicating heavy load of heavy metal pollution at test sample site. MI (metal index) value was also detected higher at test sample site (4.76) as compared to that at control site (0.22). The mean total n-3 and n-6 polyunsaturated fatty acids (PUFAs) declined in the liver of test fish samples (Harike Wetland) as compared to control fish (Nangal Wetland) samples except in winter season. Similarly, mean total saturated fatty acids (SFAs) were also found to decline significantly (p<0.05) in the liver of test fish sample as compared to control fish sample during autumn and winter seasons. Significant (p<0.05) decline of mean total n-3 PUFAs (except winter) and total n-6 PUFAs (except rainy) in the intestine of test fish sample was observed during all the seasons when compared to control fish samples. However, total SFAs were found to increase in the intestine of test fish samples as compared to control fish samples during all the studied seasons. In the present investigation, fluctuations recorded in the water quality parameters and major groups of FAs in the tissues were due to the geographical location and pollution load in the fish samples taken from Harike Wetland.

Development of an Adaptive Model for the Rate of Steel Corrosion in a Recirculating Water System

The stable quality of circulating water ensures the long-term stable operation of various processes in petrochemical production and achieves energy savings and emission reduction while reducing environmental pollution and yielding economic benefits to petrochemical enterprises. However, traditional circulating water quality evaluation and modeling for corrosion rate prediction suffer from adaptability and accuracy problems. To address these problems, the water quality analysis data of the circulating water in the field were subjected to data preprocessing and water quality index calculation to perform feature engineering, followed by modeling using a machine learning method that integrates the adaptive immune genetic algorithm and random forest (RF) algorithm and can intelligently select the water quality parameters to be used as the input variables for the RF modeling. Finally, the method was validated using an industrial example, and the results indicate that the method is capable of removing interference variables and is suitable for carbon steel corrosion rate prediction based on water quality models. The proposed method provides a basis for water quality management and real-time decision-making by circulating water field personnel.

Spatial and temporal assessment of surface water quality using water quality index. The Saguling Reservoir, Indonesia

Developments in agriculture, industry, and urban life have caused the deterioration of water resources, such as rivers and reservoirs in terms of their quality and quantity. This includes the Saguling Reservoir located in the Citarum Basin, Indonesia. A review of previous studies reveals that the water quality index ( WQI) is efficient for the identification of pollution sources, as well as for the understanding of temporal and spatial variations in reservoir water quality. The NSFWQI (The National Sanitation Foundation water quality index) is one of WQI calculation methods. The NSFWQI is commonly used as an indi-cator of surface water quality. It is based on nitrate, phosphate, turbidity, temperature, faecal coliform, pH, DO, TDS, and BOD. The average NSFWQI has been 48.42 during a dry year, 43.97 during a normal year, and 45.82 during a wet year. The WQI helped to classify water quality in the Saguling Reservoir as “bad”. This study reveals that the strongest and most significant correlation between the parameter concentration and the WQI is the turbidity concentration, for which the coeffi-cient correlation is 0.821 in a dry year, and faecal coli, for which the coefficient correlation is 0.729 in a dry year. Both parameters can be used to calculate the WQI. The research also included a nitrate concentration distribution analysis around the Saguling Reservoir using the Inverse Distance Weighted method.

Seasonal variability of water quality index in the Hooghly Estuary areas of West Bengal, India

Health of the Hooghly estuary was estimated through Water Quality Index (WQI) developed using ten water quality parameters, viz., specific conductivity, turbidity, pH, total dissolved solids, dissolved oxygen, biochemical oxygen demand, chloride, total alkalinity, total hardness, and nitrate-N measured at three different stations along the salinity gradient. Weighted arithmetic index method was used for calculation of WQI. For classifying water quality in each of the sampling stations, five-point rating scale was used. Wide fluctuations in monthly WQI were observed in this estuarine zone with the highest values during pre-monsoon month of May and the lowest values during monsoon month of October. From WQI values (mostly >100) throughout the year, it was evident that Hooghly-Bhagirathi estuarine system is unsuitable for drinking and propagation of wildlife and freshwater aqua culture as per water quality standards. It was also observed that there is a severe anthropogenic influence on most of the parameters. Major causes of deterioration in water quality were discharge of untreated industrial and municipal wastes, besides high level of other anthropogenic activities. Key words WQI; Hooghly estuary; India

A brief review of water quality indices and their applications

Water Quality Indices (WQIs) refers to a set of water quality parameter data that aggregate to produce a single value to the water quality, reducing the huge amount of data into a simple and easy expression. Also enabling comparisons of water quality status for different locations and at different times, which eventually will help inform of water quality status to management and the public in a simple manner. Before generating and developing an appropriate mathematical model, there should be a process of evaluating, reviewing, and considering the Challenges and limitations of the existing developed models of similar nature. Therefore, this review paper intends to summarize the scientific literature papers from different countries related to the development of the water quality indices and practical applications. In general, five common steps are used in approaches of WQI calculation: (1) selection of parameter, (2) transform the data from a parametric system to a dimensionless system, (3) creation of subindices, and (4) compute the final WQI score by using the aggregation of subindices.

Water quality evaluation and non-cariogenic risk assessment of exposure to nitrate in groundwater resources of Kamyaran, Iran: spatial distribution, Monte-Carlo simulation, and sensitivity analysis.

Water is exceptionally vital for all living beings and socio-economic development. This study aimed to investigate the groundwater suitability for drinking in rural areas of Kamyaran city, Kurdistan province, Iran, by using the water quality index (WQI) and evaluating the non-carcinogenic health risk caused by nitrate from the drinking route. Forty-five groundwater samples were collected (2019) from operated dug-wells, and twelve parameters (TDS, pH, TH, EC, HCO3 -, K+, Na+, Mg2+, Ca2+, Cl-, SO4 2-, and NO3 -) were measured to the calculation of WQI. Hazard Quotient (HQ) and sensitivity analysis (SA) using the Monte-Carlo Simulation technique with 10,000 iterations were employed to determine the non-carcinogenic effects of Nitrate in different exposed groups (Infant, children, teenagers, and adults). The results of WQI showed that 74% of groundwater samples fall within the excellent water quality class, and 26% of rural areas fall in the category of good water type. The nitrate concentration in drinking water ranged from 22.42 ± 11.44mg/L. The HQ mean for infants, children, teenagers, and adults were 0.5606, 0.7288, 0.5606, and 0.438, respectively. Probability estimation showed the HQ values for the 5th, and 95th percentile in infants, children, teenagers, and adult groups were (0.25-1.81), (0.13-1.08), (0.13-0.97), and (0.07-0.51), respectively. The SA showed that the most significant parameter of non-carcinogenic risk in all exposed populations was nitrate concentration. Generally, nitrate concentration in the study area was relatively high, and remarkably in agriculture and fertilizer management required more attention.