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This paper studies the adsorption of diethyl phthalate (DEP,an environmental hormone) on the surface of nanoscale TiO_2, effects of pH value of solutions, initial concentrations of DEP and additive surfactant on photocatalytic degradation and dynamics of DEP. Under ultra violet illumination, the interaction between DEP and surfactants including DBS (sodium dodecylbenzenesulfon-ate), CTAB (cetyltrimethylammonium bromide), and OP-10 (nonylphenol polyoxyethylene ether) was exploited from the perspective of degradation speed calculated by the data of high pressure liquid chromatography (HPLC) and UV-Vis spectra, respectively. Photocatalytic degradation of DEP followed pseudo first-order reaction kinetics. DEP as substrate degraded fast when its initial concentration was 130 mg/L. TiO_2 had certain adsorption ability of DEP. TiO_2 could adsorb the most DEP at the approximately neutral pH of 6.91. Degradation of DEP was not affected obviously by additives OP-10 and DBS. Degradation rate of DEP was not enhanced greatly in the presence of surfactants, but degradation of DBS was sped up. Degradation rate of DEP was depressed in the presence of additive CTAB. The more CTAB was added, the less DEP was degraded. Degradation rate of CTAB became slow with the increase of initial CTAB concentration. The possible adsorption models among TiO_2, DEP and surfactants were given. 相似文献
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Photocatalytic reduction of 6-chloro-3-nitrotoluene-4-sulfonic acid （CNSA） was studied in UV-irradiated TiO2 suspensions in the presence of methanol and surfactants. A mixture of CNSA, TiO2, water, additives and surfac- tants was put into a quartz glass reactor with a jacket, which was irradiated with a high pressure Hg lamp in the purg- ing of nitrogen gas. With methanol, the conversion of CNSA increased from 7.7% to 34.6%. Three surfactants signifi- cantly promoted the photocatalytic reduction conversion in reduced order of sodium dodecylbenzenesulfonate （DBS）, cetyltrimethylammonium bromide （CTAB） and sodium dodecylsulfate （SDS）. In suspensions involving DBS and CTAB respectively, CNSA conversion increased in consistence with the adsorption ratio with methanol, but varied inversely with the adsorption ratio without methanol. But no obvious influence on the adsorption ratio was observed with or without methanol added when the SDS concentration was critical micelle concentration （cmc）. The photocata- lytic reduction of CNSA was enhanced in UV-irradiated TiO2 suspensions in the presence of methanol and surfactants. Methanol inhibited the recombination of photogenerated holes and electrons efficiently. Surfactants around 1 cmc led to the highest reduction conversion. 相似文献
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张天永 《钦州师专钦州教院学报》2007,22(6):26-28
以数学建模课程建设和数学建模竞赛为例，讨论了财经类高校数学建模课程建设的现状以及存在的问题，并提出了加强财经类高校数学建模课程建设的途径． 相似文献
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以数学建模课程建设和数学建模竞赛为例,讨论了财经类高校数学建模课程建设的现状以及存在的问题,并提出了加强财经类高校数学建模课程建设的途径. 相似文献
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