A Review Paper on Heterogeneous Fenton Catalyst: Types of Preparation, Modification Techniques, Factors Affecting the Synthesis, Characterization, and Application in the Wastewater Treatment

This comprehensive review focuses on the different factors, modification in the synthesis method, characterization and application of heterogeneous catalyst in the wastewater treatment based on the Fenton process. The present review highlights the different catalyst preparation methods like wet impregnation method, hydrothermal method, sol-gel method, precipitation method and their application to treat different recalcitrant organic chemicals. Major heterogeneous catalyst synthesis methods were discussed with their excellent workability. The importance of modification through physical and chemical method  was  also reported. Different catalyst, pollutants and optimum parametric conditions available in the literature along with some relevant studies are summarized. The effect of factors like pH, calcination and some other modifiers on the synthesis and their efficiency in the wastewater treatment has been described. The important characterization of synthesized catalysts explaining their working efficiency has also been discussed. In the final section, the application of heterogeneous catalyst synthesized by different methods in the wastewater/effluent treatment has been investigated. The main aim of this review is to find out the influence of process parameters and catalytic method on degradation/decolorization of organic compounds present in industrial or synthetic wastewater. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Benzoic Acid Degradation by Highly Active Heterogeneous Fenton-like Process using Fe³⁺-Al₂O₃ Catalyst

262-268This work examines oxidative degradation of benzoic acid in an aqueous solution using an eco-friendly advanced oxidation (heterogeneous Fenton) process. The degradation of benzoic acid (1,000 mgL−1) with H2O2 was performed using Fe3+ immobilized within an Al2O3 matrix as a heterogeneous Fenton catalyst and the efficiency of the system was compared to that of the homogeneous Fe3+/H2O2 system. The influence of various operational conditions like catalyst dosage, H2O2 concentration, Fe3+ concentration, pH of the solution and initial substrate concentration on % degradation for both the processes has been studied to find out the best operating conditions for these processes. The experimental results show that the optimum conditions for homogeneous Fe3+/H2O2 process are [Fe3+] = 1,250 mgL−1, [H2O2] = 2,000 mgL−1, initial pH = 3 and 87.5 % degradation was obtained within 35 min. In the case of heterogeneous catalyst, degradation improved to 91.7% using 12.5 gL−1 catalyst for the same duration keeping other operating conditions the same. The use of iron immobilized in alumina matrix as heterogeneous Fenton catalyst is an alternative approach for degrading organic contaminants