QSAR Model for Predicting the Degradation of Sulfonamide Antibiotics by the PMS/cu(II) System

Cu(II) can promote the activation of peroxymonosulfate (PMS), thereby enhancing the degradation of sulfonamide antibiotics (SAs). However, SAs are widely varied, and conducting experimental measurements for each type is not only time-consuming and labor-intensive but also makes it difficult to evaluate their degradation behavior under different water quality conditions systematically. In this study, 18 SAs were evaluated as target contaminants. Compared with the PMS system, the introduction of trace Cu(II) significantly increased SAs degradation rates, achieving 1.34–4.99 times the degradation rate of the PMS system alone. A QSAR model was subsequently employed to correlate reaction rate constants with molecular descriptors. And it identified four key molecular descriptors (LogS, f+per, α, and q(N−)) that determine the Cu (II) induced promotion efficiency. These results provide a theoretical foundation and predictive tool for evaluating the degradation efficacy of the PMS/Cu(II) system toward SAs.