Dissolved oxygen (DO) is the main corrosive substance in the transport process of urban reclaimed water by pipelines, and it can be removed by catalytic reduction. Activated carbon (AC) has been conventionally used as a carrier for catalysts. This paper focuses on the effect of modification conditions of AC on the catalytic performance for DO removal by hydrazine. The catalytic performance of modified AC (MAC) samples by single and combinatory methods has been investigated. The results showed that the combinatory method was better than the single method, and the MAC by combinatory method of high-pressure hydrothermal method followed by metal salt solution impregnation method could remarkably promote the catalytic activity for DO removal. The prepared catalyst GS270-5-Ni-60-3 had the optimal catalytic activity at the conditions of reaction temperature of 30°C, pH 10 and the initial DO concentration of 5.31 mg/L, and the DO removal rate could reach 98.74%. Meanwhile, the samples of AC and MAC were characterized using BET, SEM and FTIR technologies. The experimental results showed that the high-pressure hydrothermal method could significantly improve the pore structure of AC, and the clogging of AC was not obvious by impregnation modification. Furthermore, the surface group of MAC also has a certain influence on the DO removal in reclaimed water.
Keywords: Dissolved oxygen; activated carbon; high-pressure hydrothermal; impregnation; reclaimed water.