Department of Geology, University of Kerala, Kariavattom Campus, Thiruvananthapuram, Kerala, 695581, India.
Department of Geology, University of Kerala, Kariavattom Campus, Thiruvananthapuram, Kerala, 695581, India.
Chemosphere. 2023 Oct;338:139498. doi: 10.1016/j.chemosphere.2023.139498. Epub 2023 Jul 12.
This study investigates the hydrogeochemistry of groundwater samples collected from the Shiriya River Basin (SRB), a tropical watershed located in Kasaragod, Kerala, southern India, with a special focus on trace elements. Fifty-four groundwater samples were collected from deep aquifers, which constitute weathered and fractured granitoids and mafic rocks, and the groundwater is tapped by bore wells from a fractured zone at a depth range of 60-100 m. Concentrations of Sr, Li, Ba, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Ag, Au, Te, Pb, Re, and PGEs in groundwater were determined by using Q-ICPMS. Out of the 25 analysed trace elements in groundwater, only Sr (489.6 μg/L), Ba (226 μg/L), Li (11.76 μg/L) Mn (396.8 μg/L), Ni (68 μg/L) and Fe (2438.5 μg/L) show anomalous values. The PGEs and the majority of trace elements show values within the permissible limit. Raman spectral studies reveal the presence of celsian in aquifer rocks and are the source of Ba in groundwater. Further, XRF data of the rocks show a high enrichment of Fe and Mn in mafic dyke, basalt, and syenite, and Ba and Sr in granite, pegmatite, and granitic gneiss. Therefore, this study proved that the source of these elements is geogenic, i.e., they are released from the crystalline aquifer through rock-water interaction under alkaline conditions. The results of this study show that the groundwater of the basin has enough metals such as Na, K, Mg, Ca, Mn, Fe, Co, Cu, and Zn, which are good for health. Nevertheless, a few metals (Fe, Mn, Ba, Sr, Li, Ni) that may exert toxic effects on humans are also present in the groundwater of the SRB. As groundwater is found to be a dependable source of drinking water in such watersheds, a comprehensive study on the hydrogeochemistry of all watersheds in tropical regions is recommended.
本研究调查了来自印度南部喀拉拉邦卡萨拉戈德的热带流域西里雅河流域（SRB）的地下水样本的水文地球化学特性，特别关注微量元素。从深含水层中采集了 54 个地下水样本，这些含水层由风化和断裂的花岗岩和基性岩组成，地下水是从断裂带的一个深度范围为 60-100 m 的钻孔中抽取的。通过使用 Q-ICPMS 测定了地下水样品中 Sr、Li、Ba、Al、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Cd、Ag、Au、Te、Pb、Re 和 PGE 的浓度。在地下水分析的 25 种痕量元素中，只有 Sr（489.6μg/L）、Ba（226μg/L）、Li（11.76μg/L）、Mn（396.8μg/L）、Ni（68μg/L）和 Fe（2438.5μg/L）表现出异常值。PGE 和大多数痕量元素的值均在允许范围内。对含水层岩石的拉曼光谱研究表明存在钙钛矿，是地下水中 Ba 的来源。此外，岩石的 XRF 数据显示，基性岩脉、玄武岩和正长岩中 Fe 和 Mn 以及花岗岩、伟晶岩和花岗质片麻岩中 Ba 和 Sr 高度富集。因此，本研究证明这些元素的来源是地球成因的，即在碱性条件下通过岩石-水相互作用从结晶含水层中释放出来的。本研究结果表明，该流域的地下水含有足够的 Na、K、Mg、Ca、Mn、Fe、Co、Cu 和 Zn 等金属，对健康有益。然而，该流域地下水中也存在一些可能对人体产生毒性影响的金属（Fe、Mn、Ba、Sr、Li、Ni）。由于在这些流域中发现地下水是可靠的饮用水源，因此建议对所有热带地区流域的水文地球化学进行综合研究。
