添加稳定剂对尾矿土中砷形态及转换机制的影响

发布时间：2018-06-11 14:57

本文选题：砷 + 形态　；参考：《环境科学》2016年06期

【摘要】：土壤中As的不同存在形态影响着其毒性、可移动性、生物有效性,且产生不同的环境影响.本研究以粉煤灰、干化污泥、硫酸亚铁、碎花生壳为稳定剂,探讨其对土壤As的稳定化效果以及p H、有机质和阳离子交换量与土壤As形态的关系.结果表明添加稳定剂后,土壤p H及有机质含量上升,残渣态砷含量升高.添加10%粉煤灰、10%干化污泥后,可交换态As、碳酸盐结合态As、铁锰氧化物结合态As、有机结合态As分别下降了34.2%、17.5%、19.9%、53.7%,并转化为残渣态As,其含量增长了1.14%.当同时添加10%粉煤灰、10%干化污泥和1%硫酸亚铁后,土壤中可交换态As、碳酸盐结合态As、铁锰氧化物结合态As、有机结合态As含量的降幅分别为62.3%、55.2%、29.6%、58.2%,残渣态As含量增加8.1%.添加10%粉煤灰、10%干化污泥、1%硫酸亚铁和1%粉碎花生壳后,可交换态As下降最显著,最大降幅为73.3%.施用适量的粉煤灰、干化污泥、硫酸亚铁能使土壤中的可交换态、碳酸盐结合态、铁锰氧化物结合态、有机结合态As的一部分转化为残渣态As,降低其毒性.提高p H,残渣态As含量上升,可交换态As、碳酸盐结合态As、铁锰结合态As、有机结合态As含量下降,As在接近中性的环境中稳定性最好;提高有机质含量,碳酸盐结合态As与残渣态As含量上升,可交换态As、铁锰结合态As、有机结合态As含量下降,有机结合态As含量下降明显;阳离子交换量上升,残渣态As含量上升,可交换态As、碳酸盐结合态As、铁锰结合态As、有机结合态As含量下降.
[Abstract]:Different forms of as in soil affect its toxicity, mobility, bioavailability and environmental effects. In this study, fly ash, dried sludge, ferrous sulfate and peanut shell were used as stabilizers to study the stabilization effect of as in soil and the relationship between pH, organic matter and cation exchange capacity and soil as speciation. The results showed that the content of pH and organic matter increased and the content of residual arsenic increased after the addition of stabilizer. When 10% fly ash and 10% dry sludge were added, exchangeable As, carbonate bound As, iron-manganese oxide bound As, organic bound Asdecreased respectively by 34.2and 17.5and 19.9cm, respectively, and transformed into residual As.The content increased by 1.14. When 10% fly ash 10% dry sludge and 1% ferrous sulfate were added at the same time, the contents of exchangeable as, carbonate bound As, iron-manganese oxide bound Asand organic bound Asin in the soil decreased by 62.3% and 55.2%, respectively, and the residual as content increased by 8.1%. After adding 10% fly ash and 10% dry sludge, 1% ferrous sulfate and 1% crushed peanut shell, the exchangeable as decreased most significantly, and the biggest decrease was 73.3%. By applying proper amount of fly ash, dried sludge and ferrous sulphate, the exchangeable state, carbonate bound state, iron-manganese oxide bound state, organic bound state of as can be transformed into residual Asstate, and its toxicity can be reduced. The content of residual as increased, exchangeable as, carbonate bound As, iron-manganese bound As, organic bound arsenic decreased, and the stability of organic bound as was the best in the neuter environment, and the content of organic matter was increased. The contents of carbonate bound as and residual as increased, exchangeable as, iron and manganese bound As, organic bound as, cationic exchange capacity increased, residual as content increased. The contents of exchangeable as, carbonate bound As, iron and manganese bound Asand organic bound Aswere decreased.
【作者单位】：环境保护部华南环境科学研究所土壤污染控制与修复实验室;深圳市环境科学研究院;
【基金】：广东省教育部产学研结合项目(2012B091000152) 广东省科技计划项目(2013B020700010) 公益性科研院所基本科研院业务费专项(pm-zx021-201410-023)
【分类号】：X751;X53

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