长江中游鄂东南铜矿集区铜等重金属元素水环境地球化学特征

Water environmental geochemical characteristics of copper and other heavy elementsin the regions rich in copper deposits in Southeast Hubei Province, along the middle reaches of the Yangtze River

对鄂东南铜矿集区山间谷地各类水体Cu等元素的水环境地球化学研究表明:(1)区域各类水体Cu背景值含量范围为1.71～5.07μg/L,平均3.18μg/L,这表明了研究区各类水体富Cu、Zn元素的化学组成特征;(2)区域地质背景是制约区域水体Cu背景值的主导因素;(3)区域水环境污染有两类:一类为自然污染,是中生代酸性岩体与碳酸盐岩接触带夕卡岩型Cu、Fe等矿体(矿化)的裂隙水及流经二叠纪梁山煤系(P1l)和龙潭煤系(P2l)溪水;另一类属人为污染,它们是选矿厂、化工厂和有色金属冶炼厂等的工业废水;(4)各类水体的Cu等重金属元素含量、元素组合及pH、电导值(G)等理化特征迥异。

The systematic analysis of each type of water body in intermountain basin in the regions rich in copper deposits in Southeast Hubei Province indicatesthat the content of Cu in each type of water body fluctuates between 1.71 μg/L and 5.07 μg/L, with an average value of 3.14 μg/L. This value represents the characteristics of enrichment of Cu and Zn in the background water bodies in the regions rich in copper deposits. Commonly, the content of heavy elements in low level of underground water is too low to harm the environment. The regional geological background is the chief factor affecting the background value of Cu in each type of water body. The content of Cu in water bodies is relatively high in the clasolite regions, and the pH value is acidic to neutral (6.54～7.14), with a slight high electrical conduction, G, of 600～1 860 μS. In the regions,the water bodies are polluted by Cu naturally and artificially. The skarn type Cu Fe ore body (mineralization) in the contact zone between the Mesozoic acidite and carbonate rock and the coal measure strata in Permian Liangshan Formation and Longtan Formation are the natural sources of Cu pollution in the regionalwater bodies; the man made pollution sources in the study regions are dressingworks, chemical plants and non ferrous metal smelteries. There are many conspicuous differences among all the pollution sources in the total content of Cu, the combination of elements, and the physical and chemical characteristics (such as pH and G). In addition, we must pay more attention to the environmental hazard caused by the poisonous heavy elements Cd and Tl in the waste waters discharged by the non ferrous metal smelteries.