固化/稳定化重金属污染底泥渗透特性试验研究

采用固化剂对含Cd、Pb、Zn、Mn重金属底泥进行固化/稳定化处理,在酸性条件下,研究了固化底泥的渗透系数变化规律和重金属渗出规律。试验结果表明:渗透初期,渗透系数及Cd、Zn的渗出量逐渐增大,Mn先小幅减小后增大,入渗15 d后均逐渐减小,Cd和Zn的渗出对Mn有抑制作用,Pb的渗出量为0。添加螯合剂EDTA后,渗透系数及Mn的渗出量逐渐降低,入渗30 d后趋于稳定,Pb、Cd、Zn的渗出量先增大,15 d后逐渐减小,重金属的渗出量均有大幅提高,但远小于国家浸出限值,固化效果显著。

Experiment on permeability feature of contaminated sediment of heavy metal of solidification and stabilization

The paper took hardener to conduct the sediment of stabilization and solidification to contaminated sediment of heavy metal such as Cd, Pb, Zn and Mn in acidic environment,and studied the variation law of curing sediment permeability coefficient and leaking law of heavy metal.The results show that in early penatration, the permeability coefficient and leaching concentrations of Cd and Zn increase gradually,the seepage of Mn first decreases and then increases. After 15 days, all of seepages decrease gradually.The leakings of Cd and Zn have inhibitory effect on the seapage of Mn.The seepage of Pb is zero.When EDTA is added,the permeability coefficient and leaching concentration of Mn decrease gradually and tend to be stable after 30 days.The seepages of Pb, Cd and Zn increase at first and decrease after 15 days.The seepages of heavy metals raise substantially but the highest efflux of toxic heavy is far less than the national leaching limit, and the stabilizated/solidificated effect is remarkable.