Study on distribution of chromium（Ⅵ）and its migration characters in Shaanxi district in Weihe River | 渭河中下游铬（Ⅵ）的分布及迁移规律

anglais. Study on the distribution of chromium (Ⅵ) and its migration characters in Shaanxi district in Weihe river was conducted. Taking the chromium (Ⅵ) content as determining index, with the method of three point and three line, water samples from 13 hydrological stations near the middle and lower reaches of Weihe river were collected to study the content of chromium (Ⅵ) distribution rule of Weihe river in march 2011; In addition, the influence of pollution sources and absorption effect of sediment in middle and lower reaches of Weihe river for the chrome(Ⅵ) content were researched. City sewage and drainage outlet and representative cross-section of the sediment in Shaanxi section were collected to simulate migration rule of the chromium(Ⅵ) along the riser chrome of the middle and lower reaches of Weihe river by one-dimensional steady state water quality model, and to analyze the function of flow self-purification. The concentration of chromium(Ⅵ) in Shaanxi district from upstream to downstream in Weihe river increased first and then decreased. The concentration of chromium(Ⅵ) reached the maximum 0.113 mg/L in Xian district; The results showed that the distribution of concentration of chromium(Ⅵ) in Weihe river’s three inlets including Guozhen bridge-Xingping Xiwu, Tianjiangrendu-Xinfeng bridge and Shuyuan-Suspension bridge of Tongguan was determined, and it was learned that sediment plays a positive role in reducing the concentration of chromium (Ⅵ). The study shows that the pollution of chromium(Ⅵ) has gone beyond the minimum requirements of the surface water environment quality standards and provided the basis for governance.

chinois. 研究渭河中下游铬（Ⅵ）的分布及迁移转化规律。以铬（Ⅵ）含量为测定指标，采用三点三线法，于2011-03采集渭河中下游陕西段13个水文监测站附近的水样，研究渭河河水中铬（Ⅵ）含量的分布规律；此外，采集了陕西段主要城市排污口污水及代表性断面的底泥，研究污染源及泥沙吸附作用对渭河中下游河水中铬（Ⅵ）含量的影响，并采用一维稳态水质模型模拟了渭河中下游铬（Ⅵ）的沿程迁移规律，对水流自净能力进行了分析。从上游至下游，渭河中下游陕西段河水中铬（Ⅵ）含量呈先增加后减少的趋势，其中西安段代表断面河水中铬（Ⅵ）含量达到最大，为0.113 mg/L；对渭河中下游陕西段各主要城市排污口污水中铬（Ⅵ）含量进行了测定，结果表明，各排污口污水对河水中铬（Ⅵ）含量有明显影响，其污染明显超过了河流的纳污能力；对虢镇桥-兴平西吴、天江人渡-新丰桥、树园-潼关吊桥3个河段水样和底泥中铬（Ⅵ）含量的测定结果表明，泥沙对降低河水中的铬（Ⅵ）有积极的净化作用。渭河中下游陕西段大部分河段铬（Ⅵ）含量已超出《地表水环境质量标准》中对Ⅴ类水质的要求，应加强对铬（Ⅵ）污染的治理。