固化/稳定化重金属复合污染土壤的工程特性

Engineering characteristics of solidifying/stabilizing heavy metal composite contaminated soil

采用新型固化剂对重金属Pb、Cd、Cu复合污染土进行固化/稳定化处理。基于浸出试验和无侧限抗压强度试验,研究了固化剂掺量、污染程度对固化污染土浸出特性、无侧限抗压强度、应力-应变特性以及变形模量的影响规律。结果表明,通过新型固化剂固化后的污染土浸出浓度显著降低,力学性能较优,无侧限抗压强度最高可达13.38 MPa,最低为3.22 MPa;重金属污染土固化体的抵抗变形能力较好,且随着固化剂掺量的增加,表现为在压荷载作用下,应力-应变曲线峰值左移-上移;随着固化剂掺量的增加,固化体破坏应变逐渐减小,变形模量E50逐渐增大,且不同污染程度的污染土固化体规律类似。新型固化剂可用于重金属复合污染场地的固化处理,固化后的土体可达到道路和基础建材的力学强度标准,具有广阔的资源化应用前景。

The new curing agent is used to solidifying/stabilizing the heavy metal Pb,Cd,and Cu composite contaminated soil.Based on the leaching test and the compressive strength test,the effect of curing agent dosage,the degree of contamination on the leaching characteristics of cured contaminated soil,the strong pressure,stress,stress-strain characteristics,and deformation modulus.The results showed that the contaminated soil leaching concentration after curing after the new curing agent was significantly reduced,and the mechanical properties were excellent.There was a maximum of 13.38 MPa without side-free compressive strength,the lowest 3.22 MPa;the resistance of heavy metal contaminated soil is better than the resistance and with the increase of the curing agent dosage,the peak left shift-upward of the stress-strain curve under the pressure load;with the increase in the curing agent,the curable strain gradually decreases,the modified modulus.The E50 gradually increases,and the pollution soil laminate of different pollution is similar.The new curing agent can be used in the curing treatment of heavy metal composite contaminated sites,and the solidified soil can reach the mechanical strength standard of road and basic building materials,with broad resource application prospects.