ABSTRACT
9This chapter reviews the relevant parts of technology and biotechnology to remove heavy metals (such as copper, arsenic, lead and zinc) from contaminated wastewater. The chaper places special emphasis on gold mine wastewater and the use of low cost materials as sorbent. Various biological as well as physicochemical treatment processes were discussed and compared on the basis of costs, energy requirement, removal efficiency, limitations and advantages. Sorption using natural plant materials, industrial and agricultural wastes has been demonstrated to poses a good potential to replace conventional methods for the removal of heavy metals because of its cost effectiveness, efficiency and local availability of these materials as biosorbent. The parameters affecting sorption such as initial ion concentration, pH, sorbent dosage, particle size and temperature were discussed. The overall treatment cost of metal 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.
