南水北调中线工程京石段干渠底泥吸附铬研究

近些年水质重金属污染事件频发,南水北调中线工程京石段干渠沿程交叉建筑物较多,对突发意外事故可能产生的水质重金属铬迁移转化规律进行了实验室模拟研究.结果表明,在模拟水流振荡过程中,Cr（Ⅲ）、Cr （VI）之间难以相互转化.酸性条件下底泥对Cr（Ⅲ）的吸附去除效果较好,在pH=5时,底泥对Cr（Ⅲ）的吸附效率最高,为97％;且吸附速度很快,10 min吸附率可达97％左右.Cr（Ⅲ）浓度为1～20 mg/L时,底泥对Cr（Ⅲ）的吸附去除率随铬浓度升高而略有下降,但均在94％以上,底泥对Cr（Ⅲ）的最大吸附量为0.952 mg/g.底泥吸附去除Cr （VI）的效率较低,不同pH、振荡时间条件下,底泥对Cr（VI）的最大去除率为12.50％.不同有机物浓度、吸附时间条件下,底泥对Cr（VI）的最大去除率为20.96％.

Study on the adsorption of Cr by sediment in Middle Route Project from Shijiazhuang to Beijing section of South-to-North Water Diversion

There have been many cross constructions along the Shijiazhuang to Beijing section of South-to-North Water Diversion Middle Route Project and water pollutions by heavy metal have been recurred in recent years, hence the migration and transformation rule of Cr is simulated in the laboratory for supplying basic thinking and reference of Cr pollutions in the urgency conditions. The result indicates that Cr（III） ,Cr（VI） are difficult to be transformed to each other. In an acid condition, the adsorption of sediment for Cr（III） is good,when the pH is 5, the removing rate of Cr（III） reaches 97%, and the adsorption rate is very rapid, 10 minutes removal rate can be around 97%. When concentration of Cr（III） is between 1--20 mg/ L, the removal rate on Cr（III） declines with the concentration＇ s rising, and all of the removal rate on Cr（III） can be above 94%, the maximum capacity of sediment for Cr（III ） is 0. 952 mg/g. Sediment＇s adsorpting of Cr （VI） is hard, under different pH, different oscillation time, the maximum rate of adsorpting Cr（VI） is 12.50 %. Under different organic concentration,adsorption time condition, the maximum rate of adsorpting Cr（g） is 20. 96%.