Kinetics and impact factors of sulfamethoxazole (SMX) degradation in drinking water by UV/TiO2

Photocatalytic degradation of sulfamethoxazole (SMX) in nano titanium (Degussa P-25) suspended system was studied. Effects of TiO2 dosage, initial mass concentration, pH value, CO32- and tertiary butanol on photocatalytic degradation of SMX were respectively investigated. The results indicated that SMX could be effectively removed by UV/TiO2 following pseudo first order kinetics. SMX degradation rate constant was 0.1438 min-1 with half-life period t1/2 of 4.82 min with TiO2 dosage at 500 mg/L and initial SMX concentration at 5 mg/L in neutral pH. Maximum degradation was reached when TiO2 dosage was 500 mg/L under pH 7. SMX degradation was slightly inhibited under low concentration of CO32- while on the other hand the reaction get promoted when CO32- concentration continuous increased. Tertiary butanol was observed greatly inhibited the reaction as well. The electrical energy per order (EEo) values for photocatalytic degradation of SMX were also calculated to estimate the operational cost of the process.