UV/oxone降解水中甲氧苄啶的效能及模型评价

The research studied the degradation effects and kinetics of trimethoprim (TMP) by three processes, namely UV, oxone, and UV/oxone. The response surface curve method was used to study the degradation effect and model of UV/oxone on TMP under water body conditions with four factors (HCO_3~-, Cl~-, NO_3~-, and pH) and three levels. Four actual water source water bodies were selected as the water quality background to evaluate the difference between the model predicted values and the actual degradation values. Finally, the degradation efficiencies of the three processes under the condition of the same degradation rate were compared. The results showed that when UV and oxone degraded TMP alone, only 5.5% and 62.0% were degraded respectively, while UV/oxone could reach 93.2%, and the degradation process conformed to the pseudo-first-order reaction kinetics with a kinetic constant of 0.1758 min~(-1). The reaction rate constant of ·SO_4~- with TMP obtained by the relative rate method was 2.07×10~8 L/(mol·s). The regression equation of UV/oxone degrading TMP was obtained by the response surface curve method, with the corresponding p value less than 0.0001, the fitting lack-of-fit term P not significant (0.9726 > 0.05), and the adjusted determination coefficient R~2 = 0.82 > 0.8, indicating that the model had high reliability. After model verification with actual water bodies, it was found that the actual degradation values basically conformed to the model predicted values. Under the condition of a certain degradation rate, UV/oxone took the shortest time and was an efficient, rapid, and feasible degradation process.

研究采用UV、oxone、UV/oxone共3种工艺降解甲氧苄啶(TMP)的效果及动力学。采用响应面曲线法研究含有HCO_3~-、Cl~-、NO_3~-和pH四因素、三水平的水体条件下UV/oxone对TMP的降解效果及模型,并选用4种实际水源水体为水质背景来评价模型预测值与实际降解值的差别,最后比较了3种工艺的同等降解率条件下的降解效能。结果发现UV和oxone单独降解TMP时仅降解了5.5%和62.0%,而UV/oxone可达到93.2%,且降解过程符合拟一级反应动力学,动力学常数为0.1758min~(-1)。采用相对速率法可得到·SO_4~-与TMP的反应速率常数为2.07× 10~8L/(mol.s)。通过响应面曲线法得到UV/oxone降解TMP的回归方程式,对应的p值小于0.0001,拟合缺失项P不显著(0.9726>0.05),校正决定系数R~2=0.82>0.8,说明该模型可信度高,采用实际水体进行模型验证后发现实际降解值基本符合模型预测值。降解率一定的条件下UV/oxone耗时最短,是一种高效、快速、可行的降解工艺。