Department of Geology, Andhra University, Visakhapatnam 530 003, Andhra Pradesh, India.
Department of Geology, Andhra University, Visakhapatnam 530 003, Andhra Pradesh, India.
J Contam Hydrol. 2022 Jun;248:103990. doi: 10.1016/j.jconhyd.2022.103990. Epub 2022 Apr 4.
This study aimed to evaluate the degree of groundwater pollution and to assess the contribution of specific ionic sources to groundwater, thereby helping to identify the changes in groundwater chemistry and also in groundwater quality from a rural part of Telangana, India, using the comprehensive understanding of geochemical ratios (GR), pollution index of groundwater (PIG), unmix model (UM), and land use/land cover. Groundwater samples collected (22) from the study area were analysed for pH, EC, TDS, Ca, Mg, Na, K, HCO, Cl, SO, NO, and F The hydrogeochemical diagram showed the dominant groundwater type of Ca- Mg- HCO due to the water-soil-rock interactions. GR, chloro-alkaline indices, and saturation indices revealed the groundwater chemistry that explains the mineral weathering and dissolution, ion exchange, and evaporation processes as the chief geogenic origin, and also the contamination of surface water due to the influence of household wastewater, septic tank leaks, irrigation-return-flows, chemical composts, etc. as the secondary anthropogenic sources on the aquifer system. Changes in groundwater quality from the recharge area to the discharge area and the correlation coefficient of chemical variables further supported the sources of geogenic and anthropogenic origins. According to PIG's calculations, the present study area was classified as the insignificant pollution zone (5.89%), which shows all chemical variables within their drinking water quality limits, and the low pollution zone (43.34%), medium pollution zone (27.48%), high pollution zone (17.34%), and very high pollution zone (5.95%), which exhibit the TDS, Mg, Na, K, HCO, Cl, NO, SO, and Fcontents above the drinking water quality standards. This indicates the gradual increase in the intensity of pollution activity. UM also classified the contribution of specific ions (>50%) into three sources: Source I (K) measures the poor sewage conditions and potash fertilizers; Source II (SO, Mg, NO, Na, and Ca) specifies the poor sewage conditions, irrigation-return-flows, and chemical fertilizers (gypsum and nitrate); and Source III (F and HCO) represents the dissolution of fluoride minerals as a major contributor to groundwater chemistry. Furthermore, the land use/land cover observations had also supported the assessment of groundwater pollution levels and the contribution of specific ionic sources made by PIG and UM. As a result, the present study clearly indicated that groundwater quality of a geogenic origin is primarily overcome the impact of anthropogenic sources. Therefore, the present study suggested strategic measures to control groundwater pollution and improve groundwater quality.
本研究旨在评估地下水污染程度，并评估特定离子源对地下水的贡献，从而帮助识别印度特伦甘纳邦农村地区地下水化学和水质的变化，方法是综合运用地球化学比（GR）、地下水污染指数（PIG）、非混合模型（UM）和土地利用/土地覆被。从研究区采集的（22）个地下水样本进行了 pH、EC、TDS、Ca、Mg、Na、K、HCO、Cl、SO、NO 和 F 分析。水-土-岩相互作用导致地下水类型主要为 Ca-Mg-HCO。GR、氯碱性指数和饱和度指数揭示了地下水化学，解释了矿物风化和溶解、离子交换和蒸发过程是主要的地球成因起源，以及地表水由于家庭废水、化粪池泄漏、灌溉回流、化学堆肥等的影响对含水层系统的二次人为来源造成的污染。从补给区到排泄区的地下水水质变化以及化学变量的相关系数进一步支持了地球成因和人为成因的来源。根据 PIG 的计算，本研究区被归类为无显著污染区（5.89%），表明所有化学变量均在饮用水质量限值内，低污染区（43.34%）、中污染区（27.48%）、高污染区（17.34%）和极高污染区（5.95%），表明 TDS、Mg、Na、K、HCO、Cl、NO、SO 和 F 含量超过饮用水质量标准。这表明污染活动的强度逐渐增加。UM 还将特定离子（>50%）的贡献分为三个来源：来源 I（K）表示污水条件差和钾肥；来源 II（SO、Mg、NO、Na 和 Ca）表示污水条件差、灌溉回流和化学肥料（石膏和硝酸盐）；来源 III（F 和 HCO）代表氟化物矿物的溶解，是地下水化学的主要贡献者。此外，土地利用/土地覆被观测结果也支持了 PIG 和 UM 对地下水污染水平和特定离子源贡献的评估。因此，本研究清楚地表明，地下水的地球成因起源主要克服了人为来源的影响。因此，本研究提出了控制地下水污染和改善地下水质量的战略措施。
