UV/oxone降解水中甲氧苄啶的效能及模型评价

Degradation effect and model evaluation of trimethoprim by UV/oxone

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HCO3^-、Cl^?、NO3^-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0.1768min^-1。采用相对速率法可得到 SO4^–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R2=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。

The efficiency and dynamics of degradation TMP with UV,oxone and UV/oxone processes were investigated in this study.The efficiency and model of four factors and three levels with response surface curve method were explored to investigate the effect of HCO3^-、Cl^?、NO3^-and pH on degradation TMP.Furthermore,four kinds of real source water were applied to evaluate the difference between the real degradation value and the modal predication value.Finally,the degradation efficiency of three processes were compared.The results showed that only 5.5%and 62%of TMP were degraded by UV and oxone alone.However,the degradation rate of UV/oxone process can reached 93.2%,which fitted the pseudofirst-order reaction equation,and the first-order reaction rate constant(K)was 0.1768min^-1.The secondorder reaction rate constant of SO4^–and TMP was 2.07×10^8L/(mol·s)with relative rate method.The regression equations of UV/oxone degradation TMP with RSM was obtained,the corresponding p value was less than 0.0001,the lack of fit was not significant(0.9726>0.05),R2=0.82>0.8,which indicated that the model was reliable.The actual degradation value and the model prediction value were similar during actual water basic degraded.UV/oxone was a highly efficient,rapid and feasible degradation process under the same degradation rate.