Removal of heavy metals and cyanide from gold mine wastewater

Abstract

This paper reviews the technology and biotechnology to remove heavy metals (such as copper, arsenic, lead and zinc) and cyanide from contaminated wastewater. The paper places special emphasis on gold mine wastewater and the use of low cost materials as sorbent. Various biological as well as physicochemical treatment processes are discussed and compared on the basis of costs, energy requirement, removal efficiency, limitations and advantages. Sorption using natural plant materials, industrial and agricultural waste has been demonstrated to have the potential to replace conventional methods for the removal of heavy metals because of its cost effectiveness, efficiency and the local availability of these materials as biosorbent. The parameters affecting sorption, such as initial ion concentration, pH, sorbent dosage, particle size and temperature, are discussed. The overall treatment cost of metal and cyanide contaminated wastewater depends on the process employed and the local conditions. In general, technical applicability, cost-effectiveness and plant simplicity are the key factors in selecting the most suitable treatment method.

Biotechnological advances in bioremediation of heavy metals contaminated ecosystems: an overview with special reference to phytoremediation

“…However, due to problems such as membrane fouling, high costs, high energy requirement and low removal efficiency, these processes show scant relevance in industries. In general, technical applicability, cost-effectiveness and plant simplicity are the key factors in selecting the most suitable treatment method to remove heavy metals (such as copper, arsenic, lead and zinc) and cyanide from contaminated ecosystem (Acheampong et al 2010). However, the latest technologies like photocatalytic reduction, surfactant-based membranes, liquid membranes and surface complexation are more efficient for heavy metals removal from contaminated ecosystems (Malaviya and Singh 2011;Xu et al 2012).…”

Mechanisms and Efficiency of the Simultaneous Removal of Metals and Cyanides by Using Ferrate(VI): Crucial Roles of Nanocrystalline Iron(III) Oxyhydroxides and Metal Carbonates

“…[2,3] Cyanide poisoning can be fatal; nevertheless, cyanide is still either used or produced in large quantities in metal plating, mining, and in the production of gas and pharmaceuticals. [4] More than a million tons of cyanide are produced annually worldwide, and a number of accidental leaks and spills of cyanide have had disastrous consequences. [5] The World Health Organization has suggested 1.9 mm to be the maximum acceptable level of cyanide in drinking water.…”

Low-Cost Technologies for Mining Wastewater Treatment

“…Depending on the structure and surface functional groups of a sorbent, temperature has an impact on the adsorption capacity within the range of 20-35 o C [45]. It is well known that a temperature change alters the adsorption equilibrium in a specific way determined by the exothermic or endothermic nature of a process [29].…”