电石渣/偏高岭土固化铜污染土淋滤特性试验

Leaching characteristic of solidification/ stabilization for Cu2+ contaminated soils with carbide slag and metakaolin

摘要:

针对不同配比的电石渣/偏高岭土固化铜污染土,进行毒性浸出试验(TCLP淋滤试验),分析固化剂掺量对淋滤特性的影响规律,优选确定了电石渣和偏高岭土固化铜污染土的最佳配比,对类似实际工程具有借鉴意义。结果表明,电石渣掺量增加会使浸出液pH增加而Cu₂₊浓度下降,但当电石渣掺量超过9%以后滤出液的Cu₂₊浓度则无明显改变；偏高岭土掺量增加会使滤出液pH略微下降,而Cu₂₊浓度先下降后上升。基于试验结果,优选电石渣掺量为10%、偏高岭土掺量为5%时,地聚合物对2%铜污染土的固化/稳定化效果最好。

Abstract:

The geopolymer, consists of carbide slag (CS) and metakaolin (MK), was used to solidify and stabilize the Cu₂₊ contaminated soils. A series of toxic characteristic leaching procedure (TCLP) tests were conducted on the solidified soils and then the optimal contents of CS and MK were selected for this geopolymer. The results obtained from laboratory experiments show that the pH of leaching solution increases and the Cu₂₊ concentration decreases with the increases in CS content, while the Cu₂₊concentration does not continue to reduce when the CS content is more than 9%. As MK content increases, the pH of leaching solution decreases slightly, but the Cu₂₊concentration firstly decreases and then increases. Based on the results, the optimal contents of CS and MK were selected for this geopolymer to be 10% and 5%, respectively.