固化重金属Pb污染土无侧限抗压强度增长规律的研究

Study on Increasing Rules of Unconfined Compressive Strength of Solidified Soil Polluted by Heavy Metal Pb

通过重金属Pb污染土固化处理室内试验,采用固化稳定技术对不同浓度的硝酸铅人工污染土进行固化,探讨了重金属浓度、固化剂种类、不同CSH/AFt比和龄期对固化重金属污染土无侧限抗压强度的影响规律,并由重金属淋滤试验结果评价其环保性能。研究结果表明:随着龄期的增长,固化污染土的无侧限抗压强度增长;重金属浓度对不同固化剂配比的影响规律不一样;CSH/AFt的生成量对固化重金属污染土的无侧限抗压强度影响估计存在一个临界比值"1";采用试验中的任一固化剂,重金属Pb淋出浓度都能满足RCRA规定要求。

Depending on the laboratory test of consolidation treatment for soil polluted by heavy metal Pb , as well as the solidification and stabilization of soil artificially polluted by lead nitrate in different concentration, the paper discussed how the heavy metal concentration, kind of solidifying agent, CSH/AFt ratio and curing age influence the unconfined compressive strength by solidified soil polluted by heavy metal, and then evaluated the environmental performance thereof by heavy metal leaching test. The study results show that, as the curing age increases, the unconfined compressive strength increases; the heavy metal concentration has different increasing rules of the proportion of solidifying agent; the effect of CSH/AFt formation amount on the unconfined compressive strength thereof is estimated that there is a critical ratio ＂ 1 ＂ ; with any one of the solidifying agent used in the test, the leaching concentration of Pb may meet the requirement of RCRA.