Comparative decoloration study of Neutral Red by different oxidative processes

Neutral Red was subjected to two different oxidative processes, namely the photo-oxidative process and the Fenton process. The dye was found to undergo substantial and rapid decoloration by both the methods. Conditions were optimized in both the sets of experiments to achieve the most efficient dye decoloration. Additionally the effects of added anions on dye decoloration were examined and it was found that in both cases, the chloride ions caused a significant decrease in the decoloration rate. The kinetics data in both the cases fitted well to the first-order equation. A comparison of the effects of various anions on the decoloration rate revealed dramatic differences in apparent rate constant of decoloration of the dye especially in the presence of phosphate ions. Additionally the Fenton process was found to be more efficient in decolorizing the dye as compared to the photo-oxidative process.