城市污泥好氧发酵前后重金属形态及有效性变化

Changes in Speciation and Bio-availability of Heavy Metals before and after Municipal Sludge Aerobic Fermentation

以徐州国祯水务运营公司脱水污泥为研究对象,添加外源菌剂(食苯芽孢杆菌和恶臭假单胞菌)进行好氧发酵。采用BCR法提取污泥中重金属的各形态,原子吸收和原子荧光法测定各形态含量。结果表明:好氧发酵能降低污泥中Cr、As、Pb的生物有效性;发酵后Cu、Zn、Cd、Ni的生物有效性升高,但加入外源菌剂发酵后,它们的有效性低于对照组;发酵前后Hg的可交换态含量未被测出。

The dewatered sludge from Xuzhou Guozhen Water Operating Company was collected. Aerobic fermentation experiment was conducted by adding exogenous microbial agents into sludge. The species distribution of heavy metals was obtained by modified BCR sequential extraction procedure. The contents in different speciations of Cu,Zn,Cd,Cr,Ni,As,Pb and Hg were measured through atomic absorption and atomic fluorescence. The results indicated that bio-availability of Cr,As and Pb was reduced after aerobic fermentation,the biological effectiveness of Cu,Zn,Cd and Ni was generally increased,but bio-availability was lower than the control group,the exchangeable Hg was not detected.