Synergism and Radicals Dynamics in the Efficient Degradation of Basic Blue 41 via UV/Chlorine Process: Dependence on Processing Conditions

ABSTRACT The UV/chlorine process, a promising advanced oxidation process, demonstrates remarkable synergism and radical dynamics for the efficient degradation of Basic Blue 41 (BB41). This study investigates the effects of processing conditions, including solution temperature (25°C–45°C), pollutant dose (10–40 mg/L), chlorine concentration (100–1000 μM), and pH range (3–9), on BB41 degradation. The UV photolysis system achieved a consistent removal efficiency of ~40%, whereas chlorination alone showed reduced performance (35.68% at pH 3 and ≤ 13% at pH 5–9). In contrast, the UV/chlorine process achieved near‐complete BB41 removal (96.3%–100%) across all pH levels, driven by synergistic interactions between reactive species. Radical distribution analysis revealed • OH and Cl • as the dominant contributors (64.96%–91.24%) across the pH range, with ClO• significantly enhancing degradation at pH 9 (25.18%). The contribution of Cl 2 •− was minimal (6.06%–9.86%). These findings underscore the critical role of radical dynamics and processing conditions in optimizing BB41 degradation via the UV/chlorine process.