PERSULFATE ACTIVATION BY A NATURAL IRON OXIDE FOR THE REMEDIATION OF DYE CONTAMINATION

Abstract

The objective of this work was to evaluate the removal of crystal violet (CV), a cationic dye, using sodium persulfate (PS) as an oxidant in presence of a natural iron oxide (NIO). Experimental results indicate that approximately 89 % and 98% of CV removal was achieved by PS alone and by (PS/NIO) system respectively after 1 hour of reaction. Persulfate oxidation activated with soluble Fe (II) enhanced the kinetic oxidation of CV. The increase in removal is due to the adsorption of CV onto NIO surface and to the increased formation of either SO4•- or •OH radicals. The effect of pH on the degradation of CV by PS/NIO was studied. Persulfate degradation increases with a reduction in pH causing increased rate of degradation of organic contaminants. An additional factor in the NIO/PS/UV process may be the photolysis of PS which produce two sulfate radicals (SO4•-). Results of this study suggest that NIO can be used as iron source to activate persulfate oxidation.