粒径与前驱体对活性炭催化臭氧氧化的影响

利用煤质、木质、椰壳3种前驱体活性炭制得6种粒级共18种活性炭样品,作为催化剂进行催化臭氧降解草酸的效果研究.结果表明,减小活性炭粒径对催化臭氧氧化效率提升效果显著,160~300目活性炭催化臭氧氧化降解草酸速率常数是10~20目颗粒活性炭的9.2~19.0倍.煤质160~300目活性炭催化臭氧氧化降解效果最佳.活性炭粒径的倒数与催化臭氧氧化伪一级动力学速率常数呈线性关系.对官能团的滴定表明,活性炭表面的羟基数量与催化臭氧氧化一级动力学速率常数存在较为明显的指数关系.

The influence of particle size and precursor material on activated carbon catalytic ozonation

Using woody, coconut, or coaly activated carbons, 18 catalyst samples with 6 different particle sizes were prepared in order to study their catalytic ozonation characteristics on the degradation of oxalic acid. The results showed that a decrease in activated carbon particle size could significantly improve the catalytic efficiency. The rate constant for the degradation of oxalic acid of 160~300 mesh activated carbon was 9.2 to 19 times that obtained for 10~20 mesh activated carbon. The performance of 160~300 mesh coaly activated carbon in catalytic ozonizing oxalic acid was the best, among all 18 catalyst samples. The reciprocal of the activated carbon particle size was linearly and positively correlated with the rate constant of the pseudo-first-order kinetic constant for the catalytic ozonation process. The results of Boehm titrations showed that the amount of hydroxyl groups on the surface of the activated carbons was exponentially correlated with the rate constant for the catalytic ozonation kinetic.