Photocatalytic degradation kinetics of common surfactants over TiO2
表面活性剂光催化降解动力学研究

The photocatalytic degradation of sodium dodecylsulfate (SDS), cetyltrimethylammonium bromide (CTAB) and octadecyldimethylbetaine (BS18) was studied using TiO2 and UV radiation. The effects of TiO2 dosage, initial concentrations of the surfactants and initial pH on the photodegradation were investigated. The photodegradation profiles of the surfactants at different initial concentrations were fitted with pseudo-first order kinetics equation. The photodegradation rates followed the order BS18>CTAB>SDS. The optimum catalytic dosages were 1 g L-1, 1 g L-1, 2 g L-1 for SDS, BS18 and CTAB, respectively. The initial concentrations of CTAB and BS18 exhibited a significantly negative effects, whereas the initial concentration of SDS showed a slightly positive effect on the photodegradation rate. Alkaline pH was more efficient for the photodegradation of CTAB and BS18, while weak acidic pH for the photodegradation of SDS.