Efficiency of the Fenton Process for Removing Reactive Red Dyes from Wastewater: A Systematic Review

Abstract

Background: Reactive red dyes are hazardous pollutants in textile wastewater because of their environmental persistence and toxicity. The Fenton process, which generates highly oxidative hydroxyl radicals, presents a promising solution. This systematic review evaluates the efficiency of the Fenton process in removing reactive red dyes from wastewater. Methods: A systematic search was conducted in the ISI Web of Science, Scopus, PubMed, Embase, and ProQuest databases without time restrictions and limited to English-language publications. After the screening phase, eligible studies meeting the inclusion criteria were identified and qualitatively analyzed. Two indices for assessing and comparing dye removal efficiency by the Fenton and photo-Fenton processes ‒ namely, catalyst consumption efficiency (M) and hydrogen peroxide consumption efficiency (N) ‒ were defined and calculated. Findings: After screening and evaluating 1152 articles, 53 studies were ultimately analyzed. The highest M index of 2.38 was achieved in the Fenton process at pH = 3, with a catalyst concentration of 4.19 mg/l and an optimal reaction time of 10 minutes, resulting in 100 dye removal efficiency. Furthermore, the highest hydrogen peroxide consumption efficiency (N = 3.64) was observed in the photo-Fenton process at an optimal time of 2 minutes, with hydrogen peroxide consumption of 13.61 mg/l. Conclusion: The Fenton process is highly effective for removing reactive red dye within short reaction times. Selecting the appropriate catalyst and optimizing operational conditions are crucial for enhancing efficiency and ensuring process stability. © 2026, Isfahan University of Medical Sciences(IUMS). All rights reserved.