Department of Environmental Engineering, Civil & Environment Engineering School, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China.
J Hazard Mater. 2011 Feb 28;186(2-3):1808-15. doi: 10.1016/j.jhazmat.2010.12.065. Epub 2010 Dec 22.
The simultaneous application of microwave (MW) power and UV light leads to improved results in photochemical processes. This study investigates the oxidative decomposition of atrazine in water using an innovative MW and UV photochemical reactor, which activates a chemical reaction with MW and UV radiation using an immersed source without the need for a MW oven. We investigated the influence of reaction parameters such as initial H(2)O(2) concentrations, reaction temperatures and applied MW power and identified the optimal conditions for the oxidative decomposition of atrazine. Atrazine was completely degraded by MW/UV/H(2)O(2) in a very short time (i.e. t(1/2) = 1.1 min for 20.8 mg/L in optimal conditions). From the kinetic study, the disappearance rate of atrazine can be expressed as dX/dt = k(PH)M(b-X)(1-X), where b ≡ H(2)O(2)/M+k(OH)[·OH]/k(PH)M, and X is the atrazine conversion, which correlates well with the experimental data. The kinetic analysis also showed that an indirect reaction of atrazine with an OH radical is dominant at low concentrations of H(2)O(2) and a direct reaction of atrazine with H(2)O(2) is dominant when the concentration of H(2)O(2) is more than 200 mg/L.
微波（MW）和紫外光（UV）的同时应用可改善光化学过程的效果。本研究采用创新的 MW 和 UV 光化学反应器，利用浸入式光源在无需 MW 炉的情况下通过 MW 和 UV 辐射激活化学反应，调查了水中莠去津的氧化分解情况。我们研究了初始 H2O2 浓度、反应温度和施加的 MW 功率等反应参数的影响，并确定了莠去津氧化分解的最佳条件。在非常短的时间内（即在最佳条件下，20.8mg/L 的 MW/UV/H2O2 反应中，t1/2 = 1.1 分钟），莠去津完全通过 MW/UV/H2O2 降解。从动力学研究来看，莠去津的消失速率可以表示为 dX/dt = k(PH)M(b-X)(1-X)，其中 b ≡ H2O2/M+k(OH)[·OH]/k(PH)M，X 是莠去津的转化率，与实验数据吻合较好。动力学分析还表明，在低浓度 H2O2 时，莠去津与 OH 自由基的间接反应占主导地位，而当 H2O2 浓度超过 200mg/L 时，莠去津与 H2O2 的直接反应占主导地位。
