【摘要】 以42组水化学测试数据为基础,结合野外调查资料,分析研究区Cr(Ⅵ)异常地下水的分布规律和水化学特征,探讨Cr(Ⅵ)富集的影响因素.结果表明Cr(Ⅵ)异常地下水主要位于基岩含水层,水化学类型以HCO3-Na、HCO3-Na·Ca型为主,随地下水埋深的增加,Cr(Ⅵ)浓度、γNa+/γCl-系数逐渐增大,γCa2+/γHCO-3系数逐渐减小;与正常水相比,Cr(Ⅵ)异常地下水的p H、溶解氧、离子强度的平均值分别由7.2、4.3 mg·L-1、0.011 mol·L-1变为7.6、5.5 mg·L-1、0.028 mol·L-1,溶解氧增加有利于Cr(Ⅲ)的氧化,p H升高、离子强度降低可以促进Cr(Ⅵ)的活化,这些是促使含水介质中Cr(Ⅵ)的解吸、迁移和富集的主要水化学因素.更多还原

【Abstract】 Based on 42 water chemistry test data and the field survey data,this paper analyzed the distribution of hexavalent chromium anomaly of groundwater as well as it’ s chemistry characteristic,and investigated the enrichment factors affecting hexavalent chromium. The results show that hexavalent chromium-rich water was mainly located in bedrock groundwater aquifer,and the main water chemistry type was HCO3-Na or HCO3-Na·Ca. The hexavalent chromium concentration as well as γNa+/ γCl-increased with the groundwater depth,but γCa2 +/ γHCO-3showed an opposite trend. The mean value of p H,DO and ionic strength was 7. 2,4. 3 mg·L- 1and 0. 011 mol·L- 1respectively in normal groundwater,changed to 7. 6,5. 45 mg·L- 1and 0. 028 mol·L- 1respectively in hexavalent chromium-rich groundwater. The increased dissolved oxygen was conducive to the oxidation of trivalent chromium in sediment. The elevated p H and decreased ionic strength increases the activity of hexavalent chromium. All these are the main factors affecting the desorption and migration of hexavalent chromium in aquifers.更多还原