期刊名称：Journal of Environmental Science and Technology
印刷版ISSN：1994-7887
电子版ISSN：2077-2181
出版年度：2018
卷号：11
期号：1
页码：1-9
DOI：10.3923/jest.2018.1.9
出版社：Asian Network for Scientific Information
摘要：Background and Objective: Even today, a strong need exists for the quick and easy removal and recovery of heavy metals from industrial wastewater at low cost. In this study, recovery of heavy metals from artificial wastewater containing Cr, Cu, Cd, Pb and Mo (each concentration, 10 mg L1) by precipitation and foam separation using lime and milk casein was investigated. In addition, the performance of foam separation was tested using mining tailing water collected from a mining plant. Materials and Methods: Lime was used as an alkaline agent for heavy-metal precipitation. Milk casein functioned as both a collector and a frother for foam separation. After the precipitation process, casein was added to the precipitated wastewater and foam separation was carried out. The removal efficiencies of heavy metals were determined by inductively plasma spectrometry. Results: Under the optimum alkaline condition at pH 9, where the pH was adjusted by lime addition and a casein dosage of 15 mg L1, 96% of Cr, Cu, Cd and Pb were removed from the wastewater and recovered in the foam, however, Mo remained in the water. When the pH of the treated water was re-adjusted at 5.3 and the water was reprocessed by foam separation, 76% of Mo was removed from the treated water. To demonstrate the effectiveness of the proposed precipitation and foam separation method under actual conditions, it was applied to mining tailing water collected from an ore-mining facility in Mongolia. The removal efficiencies of heavy metals such as Mn, Fe and Cu included in the mining tailing water were greater than 85%. Furthermore, more than 90% of the suspended solids were also removed from the tailing water. Conclusion: The casein enabled the collection and recovery of the precipitation components of heavy metals within a total processing time of 10 min. Precipitation and foam separation using lime and casein is an effective and adaptable method for treating industrial effluents that contain heavy metals.
