Redox processes in water remediation technologies

Abstract

For life sustainability water is an essential resource present on the earth. In the current era of economical growth, groundwater is getting polluted due to the various human activities, urbanization and industrialization in addition to geogenic contamination. Water contamination by toxic and hazardous heavy metals, inorganic and organic pollutants, is a widespread environmental problem and removal of these pollutants from contaminated water is a major scientific concern of research and development. Water remediation technology is the process that is used to remove various pollutants from contaminated water. Various remediation techniques such as ultrasonication, bioremediation and nano are used for water remediation. Redox processes are chemical reactions that proceed by transfer of electrons resulting in a change in oxidation state of elements that are either oxidized to a higher oxidation state or reduced to a lower oxidation state. The use of redox processes in water remediation technologies has not been properly reviewed till now even after its versatile applications in water remediation technologies. The chemical speciation, bioavailability, toxicity, mobility and suitability for biodegradation as well as adsorption for water pollutants in environment are directly affected by redox processes that occur in water. Here, we present an overview on (1) general introduction of redox processes, (2) applicability of redox processes in water remediation, (3) catalytic enhancement of redox potentials to explore its wide applicability in environmental chemistry, (4) a brief comparative study of redox processes with some other water remediation technologies and (5) current and future prospective of redox processes in water remediation as well as in environmental remediation. Thus, scope of this review will provide a brief literature review of recent advances in redox processes in water remediation.