锌污染土固化处理实验研究

Experimental Study of Immobilization of Zn Contaminated Soils

摘要:

利用不同固化剂处理人工制备的锌污染土，测定固化体的无侧限抗压强度，以评估固化体回收再利用的可能性；采用美国环保署毒性浸出程序（TCLP）进行毒性浸出实验，以评价固化剂的锌污染土壤的固化效果.结果表明，生石灰对于锌离子污染土的修复具有良好效果.加入生石灰后，固化产物强度得到了很大的提升，同时锌离子的浸出质量浓度也大幅下降，其中利用生石灰掺量（质量分数）最大的C5S5（5%水泥+5%生石灰）固化剂修复的锌污染土得到的锌离子浸出质量浓度最小值仅为3.95 mg·L-1.实验证明高吸附性粘土矿物的加入也可以改善固化剂的固化效果.

Abstract:

Different binders were used to immobilize artificial Zn contaminated soil. The unconfined compressive strength of the solidified product was measured to estimate its possibility of recycling. And the efficiency of stabilization of Zn in soils was evaluated by the US EPA TCLP toxicity test. The experimental results suggest that quicklime was a good binder for immobilization of Zn contaminated soils. When lime was added, the strength of solidified product was greatly improved, and the leaching concentration of zinc ion dropped significantly. Zn contaminated soil could be successfully cured by the binder C5S5 (5%cement + 5%lime), whose incorporation of lime was largert. The addition of high adsorption clay can improve the efficiency of stabilization.