粉煤灰对钝化污泥重金属有效性影响

Heavy metals and trace elements of sewage sludge stabilized by coal fly ash

通过添加不同比例的粉煤灰对城市生活污泥进行钝化,系统的研究了粉煤灰对钝化污泥中金属元素Cd、Pb、Cu、Zn、Ni、Cr、Mn、Fe含量及其有效化的影响。结果表明:粉煤灰对污泥中有效态Cd、Pb、Ni、Cr、Mn、Fe具有钝化作用,其中对Cd和Fe的钝化效果最明显;但对Cu却有促进其向有效态转化的作用;总体上看钝化污泥人工土壤中重金属含量符合国家农用标准,而其中有效态Cd、Pb、Ni、C r的含量均远远低于对植物体造成毒害的临界水平。

The effect of fly ash （FA） on the contents and availability of heavy metals Cd, Pb, Ni, Cr and trace elements Cu, Zn, Fe, Mn in sewage sludge （SS） stabilized by FA were studied. The results show that FA could stabilize the available Cd, Pb, Ni, Cr, Mn and Fe in SS and the passivation capacity for Cd and Fe is significantly stronger than for other elements; Adding FA to SS increases the contents of available Cu; The content of heavy metals of artificial soil composed of FA, SS and mine tailing is low and accords with the control standards for pollutants in sludges for agricultural use （GB4284-84）, especially the contents of available Cd, Pb, Ni, Cr are significantly lower than poison level for plants.