温度对TiO_2-膨润土紫外光降解十二烷基苯磺酸钠的影响

The effect of temperature on degradation of sodium dodecyl benzene sulfonate by TiO_2-bentonite

投加0.5‰的TiO2-膨润土光催化剂于浓度为20 mg/L的十二烷基苯磺酸钠(SDBS)溶液中,在紫外光照射下,在温度分别为10、20、30℃下,反应2 h后的溶液中的SDBS分别降解了86.0%,89.5%和90.5%,反应6 h后降解率分别达98.0%,98.8%和99.3%,可见温度对TiO2-膨润土复合光催化剂降解水溶液中的SDBS的影响不明显。溶液的COD值受温度影响较大,温度越高,COD值降低越多,在10、20、30℃条件下,反应6 h后溶液的COD值分别降低50.6%,58.1%和97.0%。TiO2-膨润土光催化剂降解水溶液中SDBS的反应为一级反应,符合Langmuir-Hinshelwood方程。同样条件下,环境温度由10℃增加到30℃时光催化反应速率常数由0.0105增大到0.0137,增加了30%。

Input 0.5 Ti-bentonite photocatalyst to aqueous solutions which original concentration of sodium dodecyl benzene sulfonate（SDBS） was 20 mg/L.86.0%,89.5% and 90.5% of SDBS were degradated respectively at 10 ℃,20 ℃,30 ℃ under 6 W ultraviolet lamp within 2 h.98.0%,98.8% and 99.3% of SDBS were degradated respectively within 6 h.The effect of temperature on above degradation is not very obvious.The effect of temperature on chemical oxygen demand（COD） of aqueous solutions is obvious.The higher the temperature,the less the value of COD.50.6%,58.1%,97.0% of COD decreased respectively at 10 ℃,20 ℃,30 ℃ within 6 h.The degradation reaction is first-order reaction.Its law of dynamics accords with Langmuir-Hinshelwood equation.Under the same conditions,as the temperature rises from 10 ℃ to 30 ℃,the speed constant of the above degradation reaction changes from 0.0105 to 0.0137（increase by 30%）.