TiO_2/浮石光催化降解水中邻苯二甲酸二甲酯

Photodegradation of dimethyl phthalate in water using TiO_2/pumice

采用溶胶-凝胶法制备TiO2/浮石催化剂,光催化氧化水中内分泌干扰物邻苯二甲酸二甲酯(DMP)。考察催化剂用量、pH值对降解率的影响;同时分析降解动力学和有机物矿化程度。结果表明,催化剂最佳投放量为40g·L-1,最佳pH为6.5。在最佳条件下,DMP初始质量浓度20.0mg·L-1,5hDMP降解率达90%以上。降解速率符合准一级动力学方程,动力学方程为:Ln(ρ0/ρ)=0.470t-0.050,速率常数=0.470h-1。考察降解过程水样的矿化程度,前4h矿化率没有明显变化,4h后矿化率逐渐加快,7h矿化率达到70%。TiO2/浮石具有成本低、易回收利用、能充分与被降解物接触等优势,用于治理水体中DMP具有一定的实际可行性。

The photocatalytic degradation of dimethyl phthalate （DMP） in water was studied, which catalyzed by TiO2/pumiee pre- pared by sol-gel method. The effects of reaction time, pH, TiO2/pumice dosage on the degradation of DMP were investigated. The degradation kinetics and mineralization of DMP were also discussed. The results showed that the optimized TiO2/pumiee dosage and pH value for the DMP degradation were 40 g.L^-1 and 6.5, respectively. Degradation efficiency of DMP reached 90% under the conditions of initial concentration of DMP of 20.0 mg.L^-1, TiO2 dose of 40 g.L^-1, solution pH of 6.5, and reaction time of 5 h. The degradation rate of DMP could be in good agreement with pseudo first-order kinetics, and the equation was： Ln（ρ0/ρ）=0.470 t- 0.050. The mineralization efficiency changed insignificantly within 4 h, while changed dramatically after 4 h. It reached 70% after 7 h. TiO2/pumice was an effective catalysis which can be used to degrade DMP.