Sunlight enhanced the formation of tribromomethane from benzotriazole degradation during the sunlight/free chlorine treatment in the presence of bromide

In this study, benzotriazole was selected as a model compound to investigate the degradation rate and the subsequent formation of disinfection byproducts via sunlight/FC with Br‒ process. The rate constants for the degradation of benzotriazole under pseudo first order conditions in sunlight/FC with Br‒ and sunlight/FC are 2.3±0.07 × 10-1 min-1 and 6.0±0.7 × 10-2 min-1, respectively. The enhanced degradation of benzotriazole can be ascribed to the generation of HO•, bromine species, and reactive halogen species (RHS) during sunlight/FC with Br‒. Despite the fact that sunlight/FC with Br‒ process enhanced benzotriazole degradation, the reaction results in increasing tribromomethane (TBM) formation. A high concentration (37.8 μg/L) of TBM was detected in the sunlight/FC with Br‒, which was due to the reaction of RHS. The degradation of benzotriazole was notably influenced by the pH value (pH 4 - 11), the concentration of bromide (0 - 2 mM), and free chlorine (1 - 6 mg/L). Furthermore, the concentration of TBM increased when the free chlorine concentrations increased, implying the formation potential of harmful TBM in chlorinated seawater swimming pools.PMID:38621488 | DOI:10.1016/j.chemosphere.2024.142039

Source: Chemosphere - April 15, 2024 Category: Chemistry Authors: Ming-Chi Hsieh Wan-Ning Lee Yi-Hsuan Chu Hank Hui-Hsiang Lin Angela Yu-Chen Lin Source Type: research