Bisulfite triggers fast oxidation of organic pollutants by colloidal MnO.

Colloidal MnO is the most reactive phase of Mn(IV) while HSO is a common reductant in water treatment. This study shows that the presence of HSO resulted in significant increase in the decomposition rate of organic contaminants by colloidal MnO. The degradation rate of contaminants in the MnO/HSO process dropped with elevating pH and a proper MnO/HSO- molar ratio was critical for efficient decomposition of contaminants.

Reinvestigating the role of reactive species in the oxidation of organic co-contaminants during Cr(VI) reactions with sulfite.

Experimental work was undertaken in this study to re-investigate the mechanisms and active species responsible for oxidation of co-contaminants in the Cr(VI)/HSO reaction system. Batch experiments showed that the degradation rates of 4-chlorophenol (4-CP) correlated well with the rates of Cr(VI) reduction by sulfite in the same solutions, and that O was necessary for the oxidation of 4-CP. Multiple lines of evidences indicate that Cr(VI)/HSO reaction is a SO-based oxidation process.