摘要
利用小试试验研究了太阳光和硫(S)掺杂TiO2体系对水中双酚A(BPA)的降解效能及影响因素.结果表明,太阳光/S掺杂TiO2体系对纯水中BPA的去除效能较太阳光/TiO2体系显著提高,30 min时的去除率分别为79%和49%,且两体系对BPA的降解过程均很好地符合拟一级反应动力学模型;H2O2的投加量对两体系氧化BPA的性能均有显著的影响,但其最佳投加量不同(两体系的最佳H2O2浓度分别为20 mg/L和15 mg/L,太阳光/S掺杂TiO2比太阳光/TiO2体系高5 mg/L);较低的pH值有利于两体系中BPA的降解,pH为5.5时的反应速率常数比pH为8.5时高50%左右;腐殖酸会不同程度的降低两体系对BPA的降解速率,其影响均可以用二次方程来表示.此外,腐殖酸对太阳光/S掺杂TiO2体系的弱化作用要明显强于对太阳光/TiO2体系的,原因在于腐殖酸不仅会与BPA分子竞争.OH,而且会吸收部分可激发TiO2产生.OH的可见光.
Removal efficiency and influencing factors of bispbenol A by the combined process of solar irradiation and S-doped TiO2 were studied in detail, in which S-doped TiO2 photo-catalyst with high activity was prepared by acid catalyzed hydrolysis method using thiourea as sulfur source. Results showed that bisphenol A could be more effectively oxidized by the solar/S-doped TiO2 process than by solar/TiO2 process, whose removal effect were 79% and 49% after 30 min＇s irradiationl respectively. Pseudo-first-order model could be used to simulate the oxidation process in which the degradation rate coefficients were independent of the initial concentration of bisphenol A. Degradation rate could be gready affected by the concentration of H2O2 , and the optimum concentration for the system of solar/S-doped TiO2 was found to be 20 mg/L, which was 5 mg/L higher than that of solar/TiO2 system. Lower water pH favored the degradation of bisphenol A, whose degradation rate coefficients at pH 5.5 were about 50 % higher than that at pH 8.5. Humic acids decreased both the degradation rate of the two processes, and the influence could be fitted by second-order equation. In addition, solar/S-doped TiO2 process was more easily affected, for the humic acids could not only compete with molecular bisphenol-A for radicals but also adsorb part of visible sunlight which can excite radical with TiO2.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第6期1653-1657,共5页
Environmental Science
基金
国家科技支撑计划项目(2006BAJ08B06
2007BAC26B03)
关键词
太阳光催化氧化
双酚A
硫掺杂TiO2
solar catalyzed oxidation
bisphonel A
S-doped titanium dioxide
