%A Tianyi Chen, Wancong Gu, Gen Li, Qiuying Wang, Peng Liang, Xiaoyuan Zhang, Xia Huang %T Significant enhancement in catalytic ozonation efficacy: From granular to super-fine powdered activated carbon %0 Journal Article %D 2018 %J Front. Environ. Sci. Eng. %J Frontiers of Environmental Science & Engineering %@ 2095-2201 %R 10.1007/s11783-018-1022-2 %P 6- %V 12 %N 1 %U {https://journal.hep.com.cn/fese/EN/10.1007/s11783-018-1022-2 %8 2018-02-15 %X

SPAC significantly enhanced the efficacy of catalytic ozonation.

Large external surface reduced the diffusion resistance.

Surface reaction was dominant for SPAC-based catalytic ozonation.

Simple ball milling brought favorable material characteristics for catalysis.

In this study, super-fine powdered activated carbon (SPAC) has been proposed and investigated as a novel catalyst for the catalytic ozonation of oxalate for the first time. SPAC was prepared from commercial granular activated carbon (GAC) by ball milling. SPAC exhibited high external surface area with a far greater member of meso- and macropores (563% increase in volume). The catalytic performances of activated carbons (ACs) of 8 sizes were compared and the rate constant for pseudo first-order total organic carbon removal increased from 0.012 min-1 to 0.568 min-1 (47-fold increase) with the decrease in size of AC from 20 to 40 mesh (863 mm) to SPAC (~1.0 mm). Furthermore, the diffusion resistance of SPAC decreased 17-fold compared with GAC. The ratio of oxalate degradation by surface reaction increased by 57%. The rate of transformation of ozone to radicals by SPAC was 330 times that of GAC. The results suggest that a series of changes stimulated by ball milling, including a larger ratio of external surface area, less diffusion resistance, significant surface reaction and potential oxidized surface all contributed to enhancing catalytic ozonation performance. This study demonstrated that SPAC is a simple and effective catalyst for enhancing catalytic ozonation efficacy.