Sulfamethoxazole removal enhancement from water in high-silica ZSM-5/ozonation synchronous system with low ozone consumption

An ozonation process combined with hydrophobic adsorbent high silica ZSM-5 (HSZSM-5) was designed to enhance sulfamethoxazole (SMX) removal and reduce the ozone consumption. The promoted effect of HSZSM-5 on SMX removal was investigated in terms of SMX removal and TOC removal efficiency as well as the ozone consumption. The impacts of pH and CO32-/HCO3- were also analyzed. The presence of HSZSM-5 helped to increase the SMX degradation and TOC removal efficiency and their kinetics rate constants. HSZSM-5 adsorption behaviors for SMX and its degradation intermediates were responsible for the findings. Direct ozone oxidation was the main mechanism of SMX removal as HZSM-5 could not contribute to producing H2O2 and (OH)-O-center dot. Much higher CO32-/HCO3- concentration (>= 10 mM) and pH value (> 7) were in favor of SMX degradation. HSZSM-5 had a positive contribution to SMX removal. The mass ratio of ozone consumption to the removed SMX reduced to 0.63 g O-3/g SMX. This system of introducing high silica zeolite in the ozonation/adsorption process is an environmentally and economically sound technology to removal micropollutants.