Chen Shen-Yi, Lin Jih-Gaw
Institute of Environmental Engineering, National Chiao Tung University, 75 Po-Ai Street, Hsinchu 300, Taiwan.
Chemosphere. 2004 Jan;54(3):283-9. doi: 10.1016/j.chemosphere.2003.08.009.
A technologically and economically feasible process called bioleaching was used for the removal of heavy metals from livestock sludge with indigenous sulfur-oxidizing bacteria in this study. The effects of sludge solids concentration on the bioleaching process were examined in a batch bioreactor. Due to the buffering capacity of sludge solids, the rates of pH reduction, ORP rise and metal solubilization were reduced with the increase of the solids concentration. No apparent influence of solids concentration on sulfate produced by sulfur-oxidizing bacteria was observed when the solids concentration was less than 4% (w/v). A Michaelis-Menten type of equation was able to well describe the relationship between solids concentration and rate of metal solubilization. Besides, high efficiencies of metal solubilization were achieved after 16 d of bioleaching. Therefore, the bioleaching process used in this study could be applied to remove heavy metals effectively from the livestock sludge.
本研究采用一种名为生物沥浸的技术上和经济上可行的工艺，利用本地硫氧化细菌从家畜污泥中去除重金属。在间歇式生物反应器中考察了污泥固体浓度对生物沥浸过程的影响。由于污泥固体的缓冲能力，随着固体浓度的增加，pH值降低速率、氧化还原电位升高速率和金属溶解速率均降低。当固体浓度小于4%（w/v）时，未观察到固体浓度对硫氧化细菌产生的硫酸盐有明显影响。米氏方程能够很好地描述固体浓度与金属溶解速率之间的关系。此外，生物沥浸16天后实现了高效的金属溶解。因此，本研究中使用的生物沥浸工艺可有效应用于从家畜污泥中去除重金属。
