[粉煤灰浓度对黑曲霉生长及重金属生物浸出效率的影响]

[Influence of fly ash concentrations on the growth of Aspergillus niger and the bioleaching efficiency of heavy metals].

作者信息

Yang Jie, Wang Qun-Hui, Wang Qi, Xue Jun, Tian Shu-Lei

机构信息

Department of Environmental Science and Technology, Harbin Institute of Technology, Harbin 150090, China.

出版信息

Huan Jing Ke Xue. 2008 Mar;29(3):825-30.

PMID:18649552

Abstract

The bioleaching of municipal solid waste incinerator (MSWI) fly ash for metals extraction by Aspergillus niger was investigated. The influence of fly ash concentrations on the biomass concentration, the pH of suspension, the kinds of bio-produced organic acids and the metals extraction yield during the bioleaching process were studied and the leaching toxicities of fly ash before and after bioleaching were compared. The results showed that the decrease of pH was due to generated organic acids by Aspergillus niger during bioleaching, which resulted in the metals extraction from the fly ash. The alkaline and the heavy metals toxicities of fly ash inhibited the Aspergillus niger growth, which was shown as the "lag phase". When fly ash concentration was 20 g/L, the maximum biomass was 28.61 g/L (after bioleaching 192 h), and the minimum pH was 3.85 (after finished bioleaching). The bioleaching efficiency was the highest (i.e., 93.06% for Cd, around 70% for Mn, Pb and Zn, 22%, 33% and 47% for Fe, Cr and Cu, respectively). The TCLP results of the fly ash after bioleaching indicated that the leaching toxicities of the treated fly ash were far lower than the regulated levels of China.

摘要

研究了黑曲霉对城市生活垃圾焚烧（MSWI）飞灰进行生物浸出以提取金属的过程。研究了飞灰浓度对生物浸出过程中生物量浓度、悬浮液pH值、生物产生的有机酸种类以及金属提取率的影响，并比较了生物浸出前后飞灰的浸出毒性。结果表明，pH值的降低是由于黑曲霉在生物浸出过程中产生了有机酸，从而导致从飞灰中提取金属。飞灰的碱性和重金属毒性抑制了黑曲霉的生长，表现为“延迟期”。当飞灰浓度为20 g/L时，最大生物量为28.61 g/L（生物浸出192 h后），最低pH值为3.85（生物浸出结束后）。生物浸出效率最高（即Cd为93.06%，Mn、Pb和Zn约为70%，Fe、Cr和Cu分别为22%、33%和47%）。生物浸出后飞灰的TCLP结果表明，处理后飞灰的浸出毒性远低于中国规定的水平。