添加不等量聚合氯化铝铁对固定土壤砷的影响

摘要

为探索固定土壤砷的有效途径,选取按GB 15618-1995三级标准10倍砷含量人工配制的污染土壤进行添加不等量的聚合氯化铝铁试验.结果表明,添加聚合氯化铝铁对碳酸盐结合态的砷含量影响很小,但可以明显降低可交换态的砷含量.添加聚合氯化铝铁的质量分数在2%时,砷污染土样浸出液离子色谱图中的AsO43-阴离子峰已经消失且砷的稳定效率能达到80%以上.添加质量分数为3%的聚合氯化铝铁,残渣态的砷含量比例从49.37%提高到88.15%.当添加聚合氯化铝铁质量分数在1%时,就能使土壤中砷的浸出浓度低于GB 5058.3-2007的限值5 mg/L.%In order to explore effective ways of fixing arsenic in soil,by selecting three standard GB 15618-1995 arsenic levels of 10 times of the manual configuration contaminated soil to add varying amounts of polyaluminium ferric chloride to test.The results showed that the addition of polyaluminium ferric chloride have little effect for content of carbonate-bound arsenic,but can significantly reduce arsenic levels of exchangeable.Adding mass fraction of 2% PAFC,the peak of AsO43-anionic of arsenic contamination soil leaching solution in ion chromatogram has disappeared and stabilization efficiency can reach more than 80%.Adding mass fraction of 3% PAFC,the highest arsenic levels of residue increased from 49.37% to 88.15%.Adding mass fraction of 1% PAFC or more,the leaching concentration of arsenic in soil below GB 5058.3-2007 limit 5 mg/L.