固化/稳定化垃圾焚烧飞灰中的Pb在干湿交替环境中的溶出风险评估

评估了水泥+螯合剂协同处理垃圾焚烧飞灰中的铅(Pb)在干湿交替环境中的溶出风险。结果表明:在干湿交替环境中,水泥+螯合剂协同处理飞灰的矿物组成可保持稳定,水化程度有所提高。经过30次干湿交替后,由于飞灰颗粒受到更多水化产物的保护,Pb的浸出毒性从0.15 mg/L降低至0.05 mg/L。另外,协同处理与单独的水泥固化相比,对Pb的稳定化效果更好,Pb的浸出毒性更易达到GB 16889—2008《生活垃圾填埋场污染控制标准》;经过同样的12次干湿交替后,协同处理飞灰中Pb的浸出毒性(<0.05 mg/L)远低于单独的螯合稳定飞灰(0.53 mg/L),溶出风险显著降低。因此,水泥+螯合剂协同工艺适用于干湿交替高发地区的垃圾焚烧飞灰中Pb的稳定化处理。

LEACHING ENVIRONMENTAL RISK EVALUATION OF Pb IN SOLIDIFIED/STABILIZED MUNICIPAL SOLID WASTE INCINERATION FLY ASH UNDER WETTING AND DRYING INTERMITTENT

This study evaluated the environmental risk of lead (Pb) under wetting and drying (W-D) intermittent in fly ash from municipal solid waste incineration (MSWI), co-treated with cement and chelator. The results showed that the mineral composition of the co-treated fly ash kept stable and the hydration degree improved under W-D intermittent. Thus, the environmental risk of Pb got reduced due to the protection by more hydration products. In addition, compared with traditional cement-solidification method, co-treatment was more efficient in stabilizing Pb and easily made Pb meet the standard for pollution control of the landfill site of municipal solid waste (GB 16889—2008); compared with chelator-stabilization, the environmental risk of Pb under W-D intermittent was significantly reduced. Therefore, cement and chelator co-treatment was suitable for the stabilization of Pb in MSWI fly ash in areas with high W-D intermittent incidence.