The mechanism of bioleaching of heavy metals from sewage sludge using Thiobacillus thiooxidans
Though there are many reports on bioleaching of heavy metals from sewage sludge, the mechanism of bioleaching is still unclear. In this report, the bioleaching of Zn, Cu, Pb, Cr and Ni significantly depending on the concentrations of sulphur and sulphuric acid was observed. The leaching kinetics shows that the indirect solubilisation rates of Cu, Pb, Cr and Ni were higher than those in direct bioleaching except Zn. In addition, techniques such as SEM and EDS used to characterize before and after treatment of sewage sludge demonstrate that the sludge has no definite shape, and there was a decrease in Zn, Cu, Pb, Cr and Ni after bioleaching as well as loss of nutrient elements. Furthermore, the leaching solutions determined by ICP-MS suggest that the other metals (Mg, Fe, Mn, As, Se, V) were also bioleached. In this case, the leaching of Zn from the sludge was dominated by direct leaching, while the removal of Cu, Pb and Cr was dominated by indirect leaching. However, the Ni was leached by both direct and indirect bioleaching.
heavy metals Thiobacillus thiooxidans (T.t) bioleaching sludge mechanism
Heqin Liu Yeming Wen Qingping Wang Zuliang Chen
School of Chemistry and Material Sciences, Fujian Normal University, 350007, Fuzhou, China Environment Protection Agency of Nanping, No. 48 Zhongshan road, 353000, Nanping, China
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
145-149
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）