纳污水体中铬的迁移规律及各形态分配系数

Migration Laws and Speciation Distribution Coefficient of Cr in Polluted Water

制革厂高浓度含铬废水的排放对环境造成的影响越来越受到关注. 通过测定某制革厂纳污水体中铬的质量浓度和形态，研究纳污水体中铬的质量浓度变化规律，确定铬在水相和悬浮相中的分配系数（k），并探讨水质参数对分配系数的影响. 结果表明，在制革厂排污口处纳污水体中ρ（CrT）平均值为298.64 μg/L，而距离排污口1 km处，水体中ρ（CrT）平均值为17.81 μg/L，较排污口处下降了94%，在距离排污口1-7 km范围内，水体中ρ（CrT）无明显变化. 在水相和悬浮相中铬的分配系数（k）为0.041-0.059，并且随污染源距离的增大呈下降趋势；k值的变化与水体的ρ（CODMn）和ρ（SS）有关.

Environmental issues caused by the discharge of waste water from tanneries containing high concentrations of chromium have been attracting more and more attention. To study the variation rules of the concentration of chromium, and to determine the distribution coefficient of chromium between the water phase and the suspended matter phase, a series of surface water samples collected from a river which is a main acceptor for tannery waste water were analyzed. Furthermore, the effect of water quality parameters on the distribution coefficient was also discussed. The results showed that the average concentration of chromium was 298.64 ug/L at the sewage outfall of the tannery, while it was 17.81 ug/L at a distance of 1 km away from the outfall, which was about 94% less than that at the outfall. It was also found that there was no significant change in the concentration of chromium within 1-7 km from the outfall. The distribution coefficient of chromium between the water phase and the suspended matter phase declined from 0. 041 to 0. 059 with the increase of the distance from the pollution sources. The change of the distribution coefficient is related to CODMn and suspended solid in water.