Heat/PMS Degradation of Atrazine: Theory and Kinetic Studies

The degradation effect of heat/peroxymonosulfate (PMS) on atrazine (ATZ) is studied. The results show that the heat/PMS degradation for ATZ is 96.28% at the moment that the phosphate buffer (PB) pH, temperature, PMS dosage, ATZ concentration, and reaction time are 7, 50 °C, 400 μmol/L, 2.5 μmol/L, and 60 min. A more alkaline PB is more likely to promote the breakdown of ATZ through heat/PMS, while the PB alone has a more acidic effect on the PMS than the partially alkaline solution.HO•andSO4−•coexisted within the heat/PMS scheme, and ATZ quantity degraded byHO•andSO4−•in PB with pH = 7, pH = 1.7~1.HCO3−makes it difficult for heat/PMS to degrade ATZ according to inorganic anion studies, whileCl−andNO3−accelerate the degradation and the acceleration effect ofNO3−is more obvious. The kinetics of ATZ degradation via heat/PMS is quasi-first-order. Ethanol (ETA) with the identical concentration inhibited ATZ degradation slightly more thanHCO3−, and both of them reduced the degradation rates of heat/PMS to 7.06% and 11.56%. The addition ofCl−andNO3−increased the maximum rate of ATZ degradation by heat/PMS by 62.94% and 189.31%.Keywords:heat activation;PMS;atrazine;degradation mechanism;kinetics