生物沥滤去除污泥、土壤和底泥中3种重金属比较研究

Comparative study of removal of heavy metals in sludge,soil and sediment by bioleaching

以硫酸亚铁为底物,对城市污泥、土壤和河流底泥进行生物沥滤实验,探讨了污泥、底泥和土壤在沥滤过程中重金属的去除效果和化学形态转化规律,了解当地土壤在酸化条件下重金属的释放过程,并对三者的研究结果进行比较分析。结果表明,污泥生物沥滤对重金属（Zn、Cu和Pb）的沥滤的沥滤效果较佳（去除率75.45%、63.12%和40.96%）。沥滤过程中,重金属Cu在生物沥滤中期（3～5 d）沥出效果较好,而Zn和Pb则在沥滤后期（5～9 d）。同一重金属在不同沥滤体系中的形态变化过程差异较大,沥滤后的污泥、土壤和底泥中的重金属大部分呈现稳定状态。

In this study, a bioleaching test, with ferrous sulfate as substrate, was carried out on city sewage sludge, and soil and river sediment. We discussed the removal effect and the chemicals from the transformation of heavy metals during the leaching process, and what was learnt about the release of heavy metals in the acidized local soil condition. A comparative analysis was conducted on the research results, which showed that the effect of bioleaching was superior. The respective removal rates of bioleaching of the sewage sludge were 75.45% , 63.12% , and 40. 96% for the heavy metals Zn, Cu, and Pb. Leaching of the heavy metal Cu was more suc- cessful during the middle of the leaching process （3 to 5 d） , whereas that of Zn and Pb was superior later in the process （5 to 9 d）. The same heavy metals exhibited quite different morphological changes in the different leac- hing systems, and it was found that most heavy metals in leached sewage sludge, soil, and river sediment ap- 3eared to be stable.