Simultaneous remediation of hexavalent chromium and organic pollutants in wastewater using period 4 transition metal oxide-based photocatalysts: a review

The contamination by hexavalent chromium and organic pollutants is a serious health issue. Moreover, hexavalent chromium can react with organic pollutants to form a complex which is difficult to treat, and thus remains in the natural environment for long times. Simultaneous photocatalysis can remove both organic pollutants and hexavalent chromium. Here we review the use of period 4 metal oxide-based photocatalysts for the removal of organic pollutants and hexavalent chromium. Titanium dioxide exhibited the highest performance, up to 100%, in removing both hexavalent chromium and organic pollutants from water.