固化/稳定化重金属污染土力学及浸出特性试验研究

为解决传统固化剂在固化/稳定化法处理重金属复合污染土和重度污染土方面存在的不足，研发了一种新型固化剂。以人工制备的Pb、Cd、Cu复合重金属污染土壤为研究对象，开展了室内无侧限抗压强度试验、毒性浸出试验。在此基础上分析了固化体力学特性、浸出特性等随养护龄期、污染土粒径、重金属污染水平的变化规律。以某金矿区三处重金属污染土壤为治理对象，开展了相关测试，验证了新型固化剂对于重金属污染土的固化效果。研究表明：新型固化剂对于复合重金属污染土和重度污染土的效果较好；固化体无侧限抗压强度随养护龄期的增加而增大，随重金属污染水平、污染土粒径的增加而降低，固化体强度达17.35-33.45 MPa，均能满足固废填埋标准及建筑材料强度要求；重金属浸出浓度随养护龄期的增加而降低，随着污染土粒径和污染水平的增加而增加，浸出浓度均远低于（<0.1%）浸出安全标准限值，固化率>99.99%。所研发的高效重金属污染土固化剂，可用于重金属污染场地的固化修复及资源化利用。

Experimental Study on Mechanical Properties and Leaching Characteristics of Solidification/Stabilization Heavy Metal Contaminated Soil

In order to solve the shortcomings of the traditional solidification binder in the treatment of heavy metal composite contaminated soil and heavily contaminated soil by solidification/stabilization, a new solidification binder was developed. The artificially prepared Pb, Cd, Cu composite heavy metal contaminated soil was studied. The laboratory unconfined compressive strength test and toxicity leaching test were carried out. On this basis, the changes of mechanical properties and leaching characteristics of solidified bodies with curing age, contaminated soil particle size and heavy metal pollution level were analyzed. Based on the treatment of three heavy metal contaminated soils in a gold mining area, relevant tests were carried out to verify the solidification effect of the new solidification binder on heavy metal contaminated soil. The results show that the new solidification binder has better effect on the composite heavy metal contaminated soil and the heavily contaminated soil; the unconfined compressive strength of the solidified body increases with the increase of the curing age, and the heavy metal contaminate level and the particle size of the contaminated soil increase. The strength of the solidified body is 17.35-33.45 MPa, which can meet the requirements of solid waste landfill standards and building materials strength; the concentration of heavy metal leaching decreases with the increase of curing age, and increases with the increase of particle size and pollution level of contaminated soil. The leaching concentrations were below (<0.1%) leaching safety standard limits and the solidify rate was >99.99%. The high-efficiency heavy metal contaminated soil binder developed can be used for solidification and resource utilization of heavy metal contaminated sites.