Removal Of Acid Red 92 By Homogeneous And Heteregenous Fenton And Fenton Like Processes

Abstract

The decolorization and degradation of Acid Red 92 (AR92) by Fenton and Fenton-like processes have been investigated. Some parameters, like concentrations of Fe²⁺ and Fe⁰(ZVI-Zero Valent Iron),  concentrations of H₂O₂ and AR92, pH were evaluated aiming to find the optimal conditions to promote the efficient degradation of the dyes. This investigation reveals that both methods can remove the COD (Chemical Oxygen Demand) and color of AR92. The results indicated that complete the color and COD removal were obtained in less than 20 min under optimum conditions. Furthermore, results showed that dye degradation was dependent upon pH, H₂O₂, Fe²⁺, ZVI and initial dye concentrations. The removal efficiencies for color and COD in the Fenton and Fenton- like processes were increased by increasing the Fe²⁺ and ZVI concentrations.

The optimum pH for both Fenton and Fenton-like processes in this study are about pH 3.0. Increasing the dose of Fe²⁺ and ZVI enhances the color and COD removal. The optimum levels of H₂O₂ required for the processes are also examined. High levels of H₂O₂ appear to reduce dye decolorization and degradation for Fenton process. In Fenton-like process, increase in the amount of H₂O₂ increased color and COD removal. The decolorization kinetics of AR92, has also been investigated in the different dye concentrations. Kinetic data were studied using pseudo-first and pseudo-second order kinetic models for decolorization. It has been found that experimental kinetic data are represented well by pseudo-first kinetic model. The experimental results showed that the homogenous Fenton process and heteregenous Fenton-like process were an effective process for the degradation of AR92 in optimum conditions.