UV/TiO2去除水中磺胺甲 唑的动力学及影响因素分析

采用UV/TiO2工艺去除磺胺甲 唑(SMX),研究了SMX在纳米TiO2(Degussa P-25)悬浆体系中的光催化去除效果,考察了TiO2投加量、SMX初始质量浓度、pH值、CO32-和叔丁醇等因素对SMX去除效果的影响.结果表明,UV/TiO2工艺可以有效地去除水中的SMX,其反应过程符合拟一级反应动力学模型.当TiO2投加量为500mg/L,SMX初始质量浓度为5mg/L,反应液pH值为7时,SMX的去除率达到98.76%,反应速率常数k为0.1438min-1,半衰期t1/2为4.82min.相同条件下,反应速率在TiO2投加量为500mg/L 时最大,pH7时最大,并随SMX初始质量浓度增加而降低.少量CO32-投加不利于SMX的去除,但大量CO32-投加明显促进反应速率.叔丁醇对SMX光催化去除存在显著的抑制效果.同时引入和计算了每一对数减小级电能输入(EEo)指标以评价该工艺的电能利用效率.

Kinetics and impact factors of sulfamethoxazole (SMX) degradation in drinking water by UV/TiO2

Photocatalytic degradation of sulfamethoxazole (SMX) in nano titanium(Degussa P-25) suspended system was studied. Effects of TiO2 dosage, initial mass concentration, pH value, CO32- and tertiary butanol on photocatalytic degradation of SMX were respectively investigated. The results indicated that SMX could be effectively removed by UV/TiO2 following pseudo first order kinetics. SMX degradation rate constant was 0.1438min-1with half-life period t1/2 of 4.82min with TiO2 dosage at 500mg/L and initial SMX concentration at 5mg/L in neutral pH. Maximum degradation was reached when TiO2 dosage was 500mg/L under pH 7. SMX degradation was slightly inhibited under low concentration of CO32- while on the other hand the reaction get promoted when CO32- concentration continuous increased. Tertiary butanol was observed greatly inhibited the reaction as well. The electrical energy per order (EEo) values for photocatalytic degradation of SMX were also calculated to estimate the operational cost of the process.