Singh Gurudatta, Chaudhary Supriya, Giri Balendu Shekher, Mishra Virendra Kumar
Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, 221005, India.
School of Engineering, University of Petroleum and Energy Studies (UPES), Dehradun, 248007, India.
Environ Sci Pollut Res Int. 2025 Feb;32(7):4199-4218. doi: 10.1007/s11356-025-35912-8. Epub 2025 Jan 26.
Surface water chemistry of the River Ganga at Varanasi was analyzed at 10 locations over 3 years (2019-2021) across pre-monsoon, monsoon, and post-monsoon seasons. The study aimed to assess water parameters using principal component analysis (PCA), calculate the water quality index (WQI), determine processes governing water chemistry, evaluate irrigation suitability, and estimate non-carcinogenic health risks. The physical parameters measured included pH (8.12 ± 0.37, 8.17 ± 0.30, 7.80 ± 0.30), electrical conductivity (EC) (857.58 ± 163.17, 667.17 ± 162.15, 754.46 ± 179.32 µS/cm), total dissolved solid (TDS) (428.98 ± 81.74, 334.99 ± 80.75, 376.14 ± 88.91 mg/L), and total coliform (6201.96 ± 6914.17, 4363.76 ± 3379.98, 6176.53 ± 7080.62 MPN/100 mL) for pre-monsoon, monsoon, and post-monsoon seasons, respectively. WQI, based on 9 major parameters via PCA reduction, indicated poor water quality (53-74) across sites and seasons, except for S1, which was rated as good during the monsoon. The major ion concentrations in the samples followed the trend: (bicarbonate) HCO⁻ (360.20 mg/L) > (chloride) Cl⁻ (59.80 mg/L) > (sodium) Na⁺ (53.10 mg/L) > (calcium) Ca⁺ (44.61 mg/L) > (sulphate) SO₄⁻ (43.81 mg/L) > (magnesium) Mg⁺ (24.50 mg/L) > (potassium) K⁺ (5.20 mg/L) > (phosphate) PO₄⁻ (2.41 mg/L) > (fluoride) F⁻ (0.52 mg/L), indicating alkaline water. The Piper diagram is dominated by Ca-Mg-HCO and mixed SO-Cl hydrochemical facies, while the Gibbs plot suggested rock-water interaction as the key driver of ion chemistry. Irrigation indices [sodium percentage (Na%); sodium absorption ratio (SAR); Kelly index (Ki); permeability index (PI); magnesium hazard (MH)] indicated suitability for irrigation. Non-carcinogenic risk assessment showed children were more sensitive to fluoride and chloride ingestion, while teenagers were more affected through dermal exposure.
在2019 - 2021年的3年时间里，在季风前、季风期和季风后季节，对瓦拉纳西恒河的地表水化学性质在10个地点进行了分析。该研究旨在使用主成分分析（PCA）评估水质参数，计算水质指数（WQI），确定控制水化学性质的过程，评估灌溉适宜性，并估计非致癌健康风险。测量的物理参数包括，季风前、季风期和季风后季节的pH值（分别为8.12±0.37、8.17±0.30、7.80±0.30）、电导率（EC）（分别为857.58±163.17、667.17±162.15、754.46±179.32 μS/cm）、总溶解固体（TDS）（分别为428.98±81.74、334.99±80.75、376.14±88.91 mg/L）和总大肠菌群（分别为6201.96±6914.17、4363.76±3379.98、6176.53±7080.62 MPN/100 mL）。基于通过PCA约简得到的9个主要参数的WQI表明，除了S1在季风期被评为良好外，各地点和各季节的水质均较差（53 - 74）。样品中的主要离子浓度遵循以下趋势：（碳酸氢根）HCO⁻（360.20 mg/L）＞（氯离子）Cl⁻（59.80 mg/L）＞（钠离子）Na⁺（53.10 mg/L）＞（钙离子）Ca⁺（44.61 mg/L）＞（硫酸根）SO₄⁻（43.81 mg/L）＞（镁离子）Mg⁺（24.50 mg/L）＞（钾离子）K⁺（5.20 mg/L）＞（磷酸根）PO₄⁻（2.41 mg/L）＞（氟离子）F⁻（0.52 mg/L），表明水呈碱性。派珀图以Ca - Mg - HCO和混合的SO - Cl水化学相为主，而吉布斯图表明岩石 - 水相互作用是离子化学的关键驱动因素。灌溉指标[钠百分比（Na%）；钠吸附比（SAR）；凯利指数（Ki）；渗透率指数（PI）；镁危害（MH）]表明适宜灌溉。非致癌风险评估表明，儿童对氟化物和氯化物摄入更敏感，而青少年通过皮肤接触受影响更大。
