UV/chlorine advanced oxidation processes for degradation of contaminants in water and wastewater: A comprehensive review

• Published in: Journal of environmental chemical engineering Vol. 10; no. 3; p. 107508
• Main Authors: Khajouei, Golnoosh, Finklea, Harry O., Lin, Lian-Shin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.06.2022; Elsevier
• Subjects: Advanced oxidation process; Oxidation by-products; Reactive radical species; Trace organic chemicals; UV/chlorine oxidation; Reactive radical species; UV/chlorine oxidation; Oxidation by-products; Trace organic chemicals; Advanced oxidation process
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2022.107508

Advanced oxidation processes (AOPs) have recently gained increasing attention as promising alternatives to conventional water and wastewater treatment technologies. As an AOP, there has been a growing interest in UV/chlorine due to its multiple disinfection modes and ability to maintain chlorine residuals in drinking water distribution systems. Compared to the popular UV/H2O2 AOP treatment process, UV/chlorine AOP possesses several advantages including a higher radical production efficiency and a lower power demand. The process has recently been applied for the degradation of a wide range of natural and synthetic organic as well as inorganic compounds including pharmaceutical and personal care products, natural organic matter, herbicides and insecticides, taste and odor, and different types of water and wastewaters. The focus of the present work is to review and evaluate the efficiency of the UV/chlorine process on the oxidation of these pollutants. A critical overview is provided of the fundamentals of UV/chlorine, controlling factors of the process performance, and a comparison with other UV-based AOPs. The formation of disinfection by-products (DBPs), one of the concerns associated with UV/chlorine treatment, is discussed and strategies to tackle this obstacle are provided for future studies and applications. [Display omitted] •UV/chlorine’s principles, reaction mechanisms, and factors affecting the treatment process were reviewed.•UV/chlorine process was compared with other UV-based AOP methods.•Applications of UV/chlorine for oxidation of organic and inorganic pollutants were evaluated.•Degradation pathways and water matrix effects on DBPs in UV/chlorine as well as strategies to prevent DBPs were reviewed.