Abstract Ecologo-geochemical conditions of surface water and groundwater are considered in the case of one of the industrially most developed states of India, West Bengal, within the Damodar river basin near Damodar City. The observations were made in the pre-monsoon period of March 2019, a period with the worst conditions of wastewater dilution. To analyze total chemical composition of water samples, a standard set of analytical methods was used; trace elements were analyzed by inductively coupled plasma mass spectrometry. Data obtained indicate both the unsatisfactory water quality and the intense self-purification processes. The waters under study are, in general, characterized as freshwaters (except for the stream receiving wastewater from the chemical plant where the water is “brackish”), HCO 3 –Ca or HCO 3 –Na (except for the water in the stream near the chemical plant, which is Cl–Na, and groundwater, which is Cl–Ca). In most cases, the waters are oversaturated with carbonates, compounds with humic acids, quartz and undersaturated with primary aluminosilicates. The main ollutants are organic compounds according to the values of permanganate demand and chemical oxygen demand, Al, F – , NH 4 + , Fe, and Mn. Phosphates, As, Pb, and some other chemical elements are also present in significant concentrations It is shown that most pollutants settle in bottom sediments of the streams receiving wastewater from industrial enterprises within a few kilometers from the wastewater discharge points. The mechanism of water selfpurification is, possibly, associated with co-precipitation and sorption of a great number of substances on particles of poorly soluble carbonates and hydroxides of Ca, Fe and some other metals at relatively high pH values associated with the consumption of carbon dioxide by microorganisms.

中文翻译：

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低水期达莫达尔河流域（印度）内水体的生态地球化学条件

摘要 以印度工业最发达的邦之一西孟加拉邦为例，在达莫达尔市附近的达莫达尔河流域内，考虑了地表水和地下水的生态地球化学条件。观测是在 2019 年 3 月的季风前时期进行的，这是废水稀释条件最差的时期。为了分析水样的总化学成分，使用了一套标准的分析方法；微量元素采用电感耦合等离子体质谱法进行分析。获得的数据表明，水质不令人满意，而且自我净化过程很激烈。所研究的水域通常被定性为淡水（除了接收来自化工厂的废水的水流是“微咸的”），HCO 3 -Ca 或 HCO 3 -Na（化工厂附近溪流中的水，Cl-Na 和地下水，Cl-Ca 除外）。在大多数情况下，水被碳酸盐、腐植酸化合物、石英过饱和，而原生硅铝酸盐则不饱和。根据高锰酸盐需量值和化学需氧量值，主要污染物为有机化合物、Al、F – 、NH 4 + 、Fe 和Mn。磷酸盐、As、Pb 和一些其他化学元素也以显着浓度存在。研究表明，大多数污染物沉积在接收工业企业废水的河流底部沉积物中，距离废水排放点几公里。水的自净机制可能是