Indirect bioleaching recovery of valuable metals from electroplating sludge and optimization of various parameters using response surface methodology (RSM). (15th June 2022)

• Record Type: Journal Article
• Authors: Tian, Bingyang; Cui, Yanchao; Qin, Zijian; Wen, Lingkai; Li, Zhihua; Chu, Huichao; Xin, Baoping
• Is Part Of: Journal of environmental management. Volume 312(2022)
• Publication Date: 2022-06-15
• Subjects: Electroplating sludge -- Hazardous solid waste -- Detoxification -- General solid waste -- Valuable/toxic metals -- Extraction of heavy metals -- Bioleaching; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.114927
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Electroplating sludge contains amounts of valuable/toxic metals as a typical hazardous solid waste, but existing technology is hard to simultaneously gain the high recovery of valuable metals and its convert into general solid waste. In this study, indirect bioleaching process was optimized by using RSM for high recovery of four valuable metals (Ni, Cu, Zn and Cr) from electroplating sludge and its shift into general waste. The results showed that the maximum leaching rate respectively was 100% for Ni, 96.5% for Cu, 100% for Zn and 76.1% for Cr at the optimal conditions. In particular, bioleaching saw a much better performance than H2 SO4 leaching in removal of highly toxic Cr (76.1% vs. 30.2%). The extraction efficiency of Cr by H2 SO4 leaching sharply rose to 72.6% in the presence of 9.0 g/L Fe 3+, suggesting that Fe 3+ played an important role in the bioleaching of Cr. Based on bioleaching dynamics analysis, it was speculated that Fe 3+ passes through the solid shell and enter inside the sludge to attack Cr assisting by extracellular polymeric substances (EPS), leading to high extraction and low residue of Cr. Meanwhile, due to high-efficient release and removal of valuable/toxic metals by bioleaching, the bioleached residues successfully degraded into general based on TCLP test and can be reused as construction material safely. Graphical abstract: Image 1 Highlights: Active bioleachate leaching of electroplating sludge. Rapid and efficient extraction of valuable metals by the active bioleachate. The bioleaching process has some advantages over simple chemical leaching. Determining the optimal process parameters by response surface method. Detoxification of electroplating sludge was realized through bioleaching.