Fenton预处理对城市污泥重金属形态及生物淋滤溶出影响

针对生物淋滤处理城市污泥重金属Cr、As和Pd的溶出效率较低的问题，采用芬顿(Fenton)氧化法对城市污泥进行预处理，考察Fenton氧化对污泥中重金属Cr、As和Pd赋存形态转化及后继生物淋滤过程溶出率的影响。实验结果表明，经pH=4.00、Fe2+=1.00 g·L-1、H2O2=9 g·L-1的条件下Fenton预处理后，重金属Cr、As和Pb的存在形态均由稳定性较强的可氧化态和残渣态向不稳定的弱酸提取态和可还原态转化，其不稳定态比重分别由15%、30%、9%提高到了24%、41%、11%；生物淋滤实验结果显示，由于重金属形态变化，重金属Cr、As和Pb溶出率分别由52.71%、11.15%、33.19%提升至60.76%、24.32%、45.96%。Fenton预处理联合生物淋滤法提高了对重金属Cr、As和Pb的去除效果，有助于实现污泥的无害化处理处置。

Influence of Fenton pretreatment on heavy metal speciation and bioleaching efficiency in municipal sludge

In order to improve the low dissolution efficiency of heavy metals (Cr, As and Pd) in municipal sludge by bioleaching, Fenton oxidation was used to pretreat the municipal sludge. The effects of Fenton oxidation on the species transformation of heavy metals Cr, As and Pd in the sludge and their dissolution efficiencies in subsequent bioleaching were investigated. The results showed that after the Fenton pretreatment under the conditions of pH=4.00, Fe2+=1.00 g·L-1 and H2O2=9 g·L-1, both the stable oxidized and residual species of heavy metals Cr, As and Pb partly transformed into the unstable acid extractable and reducible ones. And the ratios of unstable Cr, As and Pb species increased from 15%, 30% and 9% to 24%, 41% and 11%, respectively. The results of bioleaching experiments showed that the variations of heavy metal species led to the increase in the dissolution rates of Cr, As and Pb from 52.71%, 11.15% and 33.19% to 60.76%, 24.32% and 45.96%, respectively. Fenton pretreatment combined with bioleaching can improve the removal efficiency of Cr, As and Pb, and contribute to achieving the harmless treatment and disposal of sewage sludge.