二氧化钛纳米管光催化降解水中百草枯

二氧化钛纳米管被用于光催化氧化水体中的百草枯,对光催化反应条件、常见Fe3+离子的干扰情况和百草枯光催化降解动力学规律进行了研究。结果表明,浓度为25 mg/L的百草枯溶液,在二氧化钛纳米管(TNT)1.0 g/L,H2O20.5 mL/50 mL,pH=5.0的最优光催化氧化条件下,经过30 min反应可以被100%从水体中去除,表现出非常高的光催化降解效率;动力学方程拟合表明,百草枯光催化氧化反应符合拟一级动力学规律,动力学方程为ln(C0/C)=1.0267t-0.1282,反应速率常数K为1.0267 h-1;双氧水存在时常见的Fe3+能够进一步提高百草枯光催化降解率;该光催化反应体系对低浓度百草枯废水有很好的处理效果,预示着光催化氧化技术适合地表或地下水体中百草枯的去除。

Photocatalytic degradation of paraquat in water with titanate nanotubes

Photocatalytic degradation of paraquat (1,1-dimethyl-4,4-bipyridylium dichloride) in water with titanate nanotube (TNT) was investigated. The photocatalytic reaction conditions, the interference of Fe³⁺ and the kinetics of photocatalytic degradation of paraquat were discussed. The results show that paraquat (25 mg/L) was completely removed from water after 30 min of UV irradiation under the optimal photocatalytic conditions: 1.0 g/L of TNT, 5.0 of pH and 0.5 mL/50 mL of H₂O₂; photocatalytic oxidation of paraquat follow with quasi one level dynamics law; Fe³⁺ can improve the photocatalytic degradation rate of paraquat when hydrogen peroxide exist in water. The technique of photocatalytic is suitable to treat low concentration of paraquat in the surface or underground water.