Toxicological aspect of water treated by chlorine-based advanced oxidation processes: A review

Isaac Sánchez-Montes; Géssica O S Santos; Alexsandro J Dos Santos; Carlos H M Fernandes; Robson S Souto; Pamela Chelme-Ayala; Mohamed Gamal El-Din; Marcos R V Lanza

doi:10.1016/j.scitotenv.2023.163047

Toxicological aspect of water treated by chlorine-based advanced oxidation processes: A review

Sci Total Environ. 2023 Jun 20:878:163047. doi: 10.1016/j.scitotenv.2023.163047. Epub 2023 Mar 22.

Authors

Isaac Sánchez-Montes¹, Géssica O S Santos², Alexsandro J Dos Santos², Carlos H M Fernandes², Robson S Souto², Pamela Chelme-Ayala³, Mohamed Gamal El-Din³, Marcos R V Lanza⁴

Affiliations

¹ São Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Carlos, SP, Brazil; Department of Civil and Environmental Engineering, University of Alberta, T6G 1H9 Edmonton, AB, Canada. Electronic address: isaacsanchez@usp.br.
² São Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Carlos, SP, Brazil.
³ Department of Civil and Environmental Engineering, University of Alberta, T6G 1H9 Edmonton, AB, Canada.
⁴ São Carlos Institute of Chemistry, University of São Paulo, 13560-970 São Carlos, SP, Brazil. Electronic address: marcoslanza@usp.br.

PMID: 36958544
DOI: 10.1016/j.scitotenv.2023.163047

Abstract

As well established in the literature, residual toxicity is an important parameter for evaluating the sanitary and environmental safety of water treatment processes, and this parameter becomes even more crucial when chlorine-based processes are applied for water treatment. Eliminating initial toxicity or preventing its increase after water treatment remains a huge challenge mainly due to the formation of highly toxic disinfection by-products (DBPs) that stem from the degradation of organic contaminants or the interaction of the chlorine-based oxidants with different matrix components. In this review, we present a comprehensive discussion regarding the toxicological aspects of water treated using chlorine-based advanced oxidation processes (AOPs) and the recent findings related to the factors influencing toxicity, and provide directions for future research in the area. The review begins by shedding light on the advances made in the application of free chlorine AOPs and the findings from studies conducted using electrochemical technologies based on free chlorine generation. We then delve into the insights and contributions brought to the fore regarding the application of NH₂Cl- and ClO₂-based treatment processes. Finally, we broaden our discussion by evaluating the toxicological assays and predictive models employed in the study of residual toxicity and provide an overview of the findings reported to date on this subject matter, while giving useful insights and directions for future research on the topic.

Keywords: Chloramines; Chlorine dioxide; Electrochlorination; Free chlorine; Toxicity.

Publication types

Review