Recent advances on simultaneous removal of hexavalent chromium and tetracycline: A short review

Abstract

Contamination of water sources with various organic and inorganic non-biodegradable pollutants is becoming a growing concern due to industrialization, urbanization, and the inefficiency of traditional wastewater treatment processes. Simultaneous removal of dual pollutants via photocatalytic redox reaction has been tremendously explored in the last five years due to the effective decontamination of pollutants compared to a single pollutants system. In a photocatalysis mechanism, the holes in the valence band can remarkably promote the oxidation of a pollutant. At the same time, photoexcited electrons are also consumed for the reduction reaction. The synergist between the reduction and oxidation inhibits the recombination of electron-hole pairs extending their lifetime. Here we review the use of metal oxide-based photocatalysts for the simultaneous removal of tetracycline and hexavalent chromium. Several strategies for the enhancement of this treatment method which are the pH of mixed pollutants and the addition of additives are discussed This review offers a recent perspective on the development of photocatalysis systems for industrial applications.