Treatment Methods for Cadmium Removal from Wastewater

Wastewater produced from industrial and municipal processes has been reported for heavy metal contamination. Amongst them, cadmium (Cd) concentration has been reported (up to 0.02 mg/L) in Pakistan, (up to 0.03 mg/L) in China and (up to 0.07 mg/L) in India, which is quite higher than the standard limits of WHO (0.003 mg/L). It has serious implications for human health, getting into the tissues via direct ingestion, dermal contact, inhalation, and adsorption. Several methods have been explored for the extermination of Cd from the environment. Conventional methods (such as adsorption, chemical precipitation, membrane filtration, electrodialysis, photocatalysis) of metal removal are constrained by the processing problems, expenses, and the generation of toxic sludge, therefore more research is now focused on the use of advanced treatment methods (such as fluidized bed reactor, advanced oxidation process, nanotechnology, hybrid system method, chelation, solvent extraction, foam fractionation, cryogens, graphene, carbon nanotubes, activated carbon, zeolites, microbial fuel cells, and phytoremediation) for the removal of Cd metal ions from the wastewater. These advanced processes may be cost-effective, viable, more efficient and less time taking than the existing techniques and have intense opportunity.