Tailings Microorganisms as an Alternative for Recycling StrategicMetals: A Green Management Approach

Modern life witnesses a new huge stream of waste called electronic waste, containing variousbase, valuable, and toxic metals. The entry of this volume of e-waste into the environment cancause many problems for human health and the environment. Therefore, there is a need to establisha green management system for the effective recycling of metals. As regards, this study aimed toinvestigate the potential of the bacteria isolated from iron ore tailings in the bioleaching of copperand zinc from waste mobile boards. Bioleaching experiments using the isolated consortiums wereinvestigated at ۵, ۱۰, and ۱۵ g/L of mobile boards within ۱۵ days of incubation. Metalconcentrations were detected by the ICP-MS instrument. Two-way ANOVA was used forstatistical analysis. After the bioleaching period, The concentrations of biosolubilized copper andzinc were raised to ۴۰۰۰ mg/L (۳۶%) and ۵۳۰ mg/L (۹.۱۷%) in the solutions respectively. Themaximum leached metal concentration was achieved by iron-oxidizing bacteria at the density of ۱۵g/L. There was a significant difference between the two bacterial groups in terms of bioleaching ofthe total metals (P = ۰.۰۱۱). The results showed that an increase in waste density might lead to adecrease in metal solubilization due to the toxicity of metal in the present study; the toxicity of Znmight be higher. Accordingly, the iron-oxidizing bacteria were found to be a good candidate forthe bioleaching of strategic metals. Also, the bacterial consortium of iron mine tailings could be agood option to recover strategic metals such as copper and zinc through biohydrometallurgicaltechnologies in low densities of e-waste (less than ۱۰ g/l).

کلیدواژه ها:

Electronic Waste ، Bioleaching ، Recovery ، Bacteria ، Green Technology