Evaluates the physicochemical characteristics and change in the concentration of arsenic species in groundwater, release from 2nd aquifer of coal mining area, its drain outlet and different sites of reservoir: Application of multivariate techniques

Abstract

For energy production activity the ground water of 2nd aquifer (AQ2) of block 2 of Thar coal field is drained out in a reservoir/Gorano dam. In present study the physico-chemical and toxic elemental levels in ground water samples of 2nd aquifer (AQ2) of Thar coalfield at the depth of 100–120 m was carried out. The further sampling of water was carried out from drain outlet (DW) and four sampling sites of reservoir (S1, S2, S3 and S4). The sediment samples of water reservoir were collected from four sites and analyzed for toxic elements. The large data set of water quality of AQ2, DW and four samples sites at different spots of reservoir, carried out during 2019 for 17 parameters in triplicate of each composite samples were further analyzed by multivariate statistical techniques involving cluster (CA) and principal component analysis (PCA). The all water samples were analyzed for physicochemical parameters including cations and anions. The resulted data of cations (sodium, potassium, calcium, magnesium, cadmium, lead, total arsenic and iron), anions (chloride, fluoride, nitrate, sulphate and bicarbonate) and physicochemical parameters were descript in terms of basic statistical parameters, PCA and CA. The chemical correlations among different parameters were observed by PCA, which were employed to categorize the water samples by CA. The positive correlation of fluoride (F−) and total arsenic with sodium and bicarbonate indicated that the GW (AQ2), DW and water samples of reservoir with high conductivity and salinity stabilized the toxic elements in the water samples of different origin. Results showed that all collected water samples have high values of sodium absorption ratio. The water quality assessment indicated that the high levels of physicochemical parameters and toxic elements in ground and reservoir water have concern in and make it unsuitable for drinking and domestic purposes.