Insights into the photodegradation of decamethylammonium bromide (DDAB) under UV/H2O2 system: Photodegradation kinetic modeling, degradation mechanism and toxicity evaluation

Decamethonium bromide (DDAB), as a class of quaternary ammonium-based disinfectants (QACs), was widely used during the COVID-19 outbreak. The abuse of DDAB is harmful to the health of aquatic organisms. The UV/H2O2 process is popularly utilized for the removal of trace contaminants from aqueous environments. Thus, in this paper, DDAB was selected as the model of QACs, and the degradation kinetics were simulated by Kintecus software. It was indicated that the effect of the degradation efficiency of DDAB was dominated by [·OH]ss. The degradation efficiency of DDAB was greater than 95 % when [·OH]ss was higher than 1.04×10−12 M. The high dosages of H2O2 (>100 μM) and the less concentration of pollutants (