饮用水处理残渣对淹水土壤中砷的稳定化过程影响研究

The Effect of Drinking Water Treatment Residue on the Stabilization Processes of Arsenic in Flooded Soils

饮用水处理残渣(DWTR)对土壤砷具有一定的稳定化效果。论文利用土盒培养实验,采用结合形态连续提取技术,探讨了DWTR对土壤砷稳定化过程的影响。结果表明,培养200天后,相比于对照组,添加2%和5%DWTR的土壤中,有效态砷含量分别降低了46.2%和67.8%。此外,在整个培养期内,对照组中砷的稳定化过程可分为4个阶段,而添加DWTR的土壤中砷的稳定化过程被分为2个阶段。研究表明,饮用水处理残渣能有效地降低土壤砷的生物可给性,且能显著缩短土壤砷的稳定化过程。此项研究将为今后修复砷污染土壤提供参考。

Drinking water treatment residue(DWTR)has a certain stabilizing effect on soil arsenic.In this study,the effect of DWTR on soil arsenic stabilization was investigated by soil box culture and morphological continuous extraction.The results showed that after 200 days,compared with the control group,adding 2%and 5%DWTR reduced the available arsenic by 46.2%and 67.8%,respectively.Among them,5%DWTR had the best effect on reducing the arsenic bioaccessibility in the soil.With the passage of time,the DWTR intensified the decrease of easily mobile fractions and the increase of less mobile fractions.In addition,during the whole incubation period(200 d),the stabilization process of arsenic in the control group was divided into four stages,while the stabilization process of arsenic in the soil with DWTR was divided into two stages.This study had shown that drinking water treatment residue can effectively reduce the bioaccessibility of arsenic,stabilize arsenic in soil,and it can shorten the stabilization process of soil arsenic.This study would provide the reference for restoration of arsenic-contaminated soil.