Systematic review of the ecotoxicological profile of carbamazepine byproducts generated by advanced oxidation processes

Carbamazepine (CBZ) is commonly detected in aquatic environments owing to its widespread use and high chemical stability. The advanced oxidation process (AOP) is a treatment technique that efficiently removes CBZ. However, AOP systems generate byproducts, which are considered one of their drawbacks that have been frequently reported. Thus, created the necessity for assessing the progress of CBZ removal by AOP from a toxicological perspective and investigating whether AOP type and the chronological order of the technologies influence the toxicity of CBZ byproducts. In this systematic review, the Quantitative Structure–Activity Relationship (QSAR) was applied to predict the toxicity of CBZ byproducts under different toxicity tests. Some frequently detected CBZ byproducts may be more toxic to aquatic organisms than CBZ itself. Additionally, the ANOVA results revealed no significant association between the type of AOP system and the toxicity of CBZ byproducts. Also, the chronological order of AOP technologies does not play a significant role in the toxicity level of CBZ byproducts. These results imply that the effluents of AOP systems applied for CBZ removal are not safe to release to the environment. To the best of our knowledge, this work is one of the first trials that investigated the toxicity of CBZ byproducts generated from AOP systems based on their types and chronological order. Unlike previous studies focusing mainly on CBZ removal efficiency, this review combines several toxicological endpoints and QSAR analysis of transformation products. It also compares the effects of different AOP technologies and their chronological development on byproduct toxicity.