粉煤灰钝化污泥炭中重金属有效性评估

Effectiveness evaluation on the heavy metals in sludge charcoal passivated by fly ash

以粉煤灰和市政污泥水热碳化产生的污泥炭为研究对象,采用欧洲共同体标准物质局提出的重金属提取方法(BCR法)顺序提取其重金属并测定重金属形态分布;使用环境风险评价指数(Hakanson指数)法评估污泥炭中重金属的潜在环境风险。结果表明,升高水热碳化温度能使污泥炭中的重金属向较稳定的残余态转化,添加20%粉煤灰钝化后,可在较低的水热碳化温度条件下显著降低污泥炭中重金属的潜在环境风险水平,合适的水热碳化温度为240℃。

Using the sludge charcoal produced by hydrothermal carbonization of fly ash and municipal sludgeas the research object,the Commission of the European Communities Bureau of Reference（BCR）sequential extraction method was used to extract the heavy metals and determine the speciation of heavy metals.The potential environmental risk of sludge and sludge charcoalwas analyzed by Hakanson potential ecological index.The results indicate that the increase of the carbonization temperature,can promote the transformation of heavy metals in sludge carbon into more stability in residual form.The potential environmental risk of heavy metals in sludge carbon can be significantly reduced at lower carbonization temperature by adding 20%fly ash.Thesuitable carbonization temperature is 240 ℃.