Li Haifei, Ye Maoyou, Zheng Li, Xu Yanbin, Sun Shuiyu, Du Qingping, Zhong Yujian, Ye Shengjun, Zhang Dongsheng
School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China E-mail:
Department of Environmental Engineering, Guangdong Polytechnic of Environmental Protection Engineering, Foshan 528216, China and Key Laboratory of Heavy Metals Pollution Prevention and Vocational Education of Guangdong Environmental Protection of Mining and Metallurgy Industry, Foshan 528216, China.
Water Sci Technol. 2018 May;2017(2):390-403. doi: 10.2166/wst.2018.167.
This study explores the potential for synchronous extraction of Cu, Cr, Ni and Zn during sewage sludge bioleaching processes, using three types of bacterial cultures: a pure culture of Acidithiobacillus ferrooxidans (A. ferrooxidans); a pure culture of Acidithiobacillus thiooxidans (A. thiooxidans); and a mixed culture of A. ferrooxidans and A. thiooxidans. Variable operating parameters included initial pH, solids concentration, sulfur concentration and ferrous iron concentration, with optimization via Box-Behnken design of response surface methodology. Results indicate that the mixed culture of A. ferrooxidans and A. thiooxidans, was the most effective at bioleaching heavy metals from sewage sludge. The optimal operating conditions were as follows: an initial pH of 2.0, with concentrations of 3% solids, 6.14 g L sulfur and 4.55 g L ferrous iron. Maximum extraction efficiencies obtained after 14 days of bioleaching under optimal conditions, were 98.54% Cu, 57.99% Cr, 60.06% Ni and 95.60% Zn. Bioleaching kinetics were effectively simulated using a shrinking core model to explain the leaching reaction, with modelling results suggesting that the rate was determined by the diffusion step.
本研究探讨了在污泥生物沥滤过程中同步提取铜、铬、镍和锌的潜力，使用了三种细菌培养物：氧化亚铁硫杆菌（A. ferrooxidans）的纯培养物；氧化硫硫杆菌（A. thiooxidans）的纯培养物；以及氧化亚铁硫杆菌和氧化硫硫杆菌的混合培养物。可变操作参数包括初始pH值、固体浓度、硫浓度和亚铁离子浓度，并通过响应面法的Box-Behnken设计进行优化。结果表明，氧化亚铁硫杆菌和氧化硫硫杆菌的混合培养物在从污泥中生物沥滤重金属方面最有效。最佳操作条件如下：初始pH值为2.0，固体浓度为3%，硫浓度为6.14 g/L，亚铁离子浓度为4.55 g/L。在最佳条件下进行14天生物沥滤后获得的最大提取效率分别为：铜98.54%、铬57.99%、镍60.06%和锌95.60%。使用收缩核模型有效地模拟了生物沥滤动力学以解释浸出反应，建模结果表明速率由扩散步骤决定。
