The role of ferrate(VI) in the remediation of emerging micropollutants: a review

Abstract: The adverse effects of micropollutant residues in water on the environment and public could take place under a very low range of concentrations; from several μg/L to ng/L. Since there is no efficient unit process to remove these pollutants, efficient technologies are sought to treat them. Ferrate(VI) exhibits high oxidation/reduction potentials and has many advantages because of its dual functions of oxidation and coagulation. Removal of micropollutants by ferrate(VI) was pH dependant and this was in coordinate with the chemical/physical properties of the pollutants and ferrate(VI) speciation. Promising performance of ferrate(VI) in the treatment of real wastewater was observed. It is important to determine whether the ferrate(VI)-treated water contains any toxic or mutagenic substances as this should relieve public health concerns when a new chemical is employed for water treatment. The toxicity studies on the ferrate(VI)-treated effluent were carried out initially via Ames tests and recently via zebrafish embryos tests conducted at author’s group. These results suggest that ferrate(VI) reagents do not produce mutagenic by-products for study conditions. However, a recent study showed the formation of adsorbable organic haloids as by-products in the ferrate(VI)-treated wastewater effluents. Obviously, more researches are needed to investigate the potential formation of harmful by-products during ferrate(VI) treatment. Other future work is suggested in order to implement ferrate(VI) into full-scale water treatment and other environmental remediation requirements.