徐州城市污泥重金属赋存形态及生物有效性研究

摘要

以徐州市3个城市污水处理厂脱水污泥为研究对象，测定了 Zn、Cu、Cr、Ni、As、Hg 6种重金属元素的含量，分析了各金属元素的形态分布。另外，对污泥进行添加外源菌剂（食苯芽孢杆菌和恶臭假单胞菌）的好氧发酵实验。结果表明：徐州市污泥中重金属含量除 Cu 有超标危险外，其他均低于污泥农用标准（GB 4284—1984）。形态分析得出污泥中 Cu、Cr、Ni 的不稳定形态所占比例较高；而 Zn、As、Hg 的稳定形态所占比例高，生物有效性低；污泥经过好氧发酵后，Zn、Cr、Ni 的生物有效性降低，Cu、Hg 的生物有效性变化不大，As 的生物有效性呈升高趋势。%The dewatered sludge from 3 wastewater treatment plants of Xuzhou City was analyzed.The total con-tents of Zn,Cu,Cr,Ni,As,Hg were determined.The speciation distribution of these heavy metals was investiga-ted.In addition,aerobic fermentation experiment was conducted by adding exogenous microbial agents.The results showed that the contents of heavy metals were below the standard of sludge for agricultural use except for Cu.The proportion of unstable morphology was high for Cu,Cr and Ni by morphological analysis,while the stable morphol-ogy proportion was high for Zn、As and Hg.After aerobic fermentation experiment,the exchangeable proportion of Zn、Cr、Ni was decreased,the bioavailability has little change for Cu and Hg,the bioavailability showed an increasing trend for As.