砷污染场地土壤的稳定化技术工程应用研究

Research on engineering application of stabilization technology for arsenic contaminated site soil

基于3种砷污染水平的场地土壤(WSL、WSX及FZ)进行稳定化小试试验,比较FeⅡ/Mg复配型(F2M)、Ca/Fe复配型(CF)及MetaPro©-ani(As)系列修复材料(MPA)对土壤中砷污染的稳定化效果,进一步分析了修复材料用量对稳定化效果的影响,并选择稳定化效果较优的材料进行工程化施工验证(基于FZS土壤样品),WSL、WSX、FZ及FZS土壤样品的砷污染程度依次为FZ>FZS>WSX>WSL。结果表明:对于低/中浓度砷污染土壤样品WSL和WSX,F2M和CF复配型修复材料在较低投加比条件下可达到较好的稳定化效果;对于高浓度砷污染土壤样品FZ,MPA系列修复材料的稳定化效果明显优于前2种复配型修复材料;对于高浓度砷污染土壤实际施工样品FZS,MPA系列修复材料在开放性施工条件下,可达到较理想的稳定化效果,其中,以MPA-Ⅰ型材料修复效果最佳。

Based on the batch stabilization experiments upon arsenic(As)contaminated soil samples with three concentration levels(WSL,WSX,and FZ),As stabilization performance of FeⅡ/Mg compound-typed(F2M),Ca/Fe compound-typed(CF),and MetaPro©-ani(As)typed(MPA)stabilizers were tested,and the effect of stabilizer dosage on stabilization performance were further analyzed.The materials with better stabilization effects were selected for engineering construction verification(based on FZS soil sample).The As leaching concentrations of WSL,WSX,FZ,and FZS soil samples turned to be:FZ>FZS>WSX>WSL.The results showed that:for WSL and WSX soil samples with low/medium concentration,F2M and CF typed stabilizers presented good remediation performance with low dosages;for FZ soil samples with high concentration,MPA series stabilizers showed much better stabilization performance than the former two composite ones;for the actual construction samples of FZS soil samples with high concentration,MPA series stabilizers achieved ideal stabilization effect under the open condition,with the best performance of MPA-Ⅰtyped stabilizer.