摘要
采用主波长367 nm的紫外-发光二极管(UV-LED)作激发光源,Degussa P25-TiO2薄膜作催化剂,在平板反应器中模拟了低浓度(8.3mg.m-3)典型恶臭气体甲硫醚(DMS)的光催化降解过程;研究了催化剂负载量、光照强度、温度、相对湿度、体积流速对DMS光催化降解过程的影响规律.甲硫醚的去除效率和反应速率随着催化剂负载量的增加(5.0—36.0μg.cm-2)而增大,其最大去除率可达到97.6%.在本实验条件下,室温21.6℃、相对湿度47.5%要比低温12.1℃、低相对湿度10.9%—29.8%更有利于反应的进行;DMS的反应速率随着体积流速的增大呈现先增大后稳定的趋势,当流速小于3.4×10-7m.3s-1时,反应受传质控制,流速大于6.8×10-7m.3s-1时,反应受反应速率控制,流速在3.4×10-7—6.8×10-7m.3s-1之间时为过渡态.
Photocatalytic degradation of low concentration（8.3mg·m^-3） gaseous dimethyl sulfide over Degussa P25-TiO2 films under UV-LED lamps irradiation in a homemade plate-type reactor was investigated.Effects of catalyst loading,light intensity,temperature,gas flow rate and relative humidity on the removal efficiency and reaction rate were discussed in detail.Enhancement of catalyst loading,light intensity and decrease of gas flow rate were effective methods to improve the removal efficiency.DMS removal efficiency increased with the enhancement of catalyst loading from 5.0 to 36.0μg·cm^-2 and the maximum of 97.6% was achieved.Under the present condition,room temperature of 21.6℃ and ambient relative humidity of 47.5% were appropriate to the photocatalytic degradation of DMS than lower temperature of 12.1℃ and lower RH of 10.9%—29.8%.We noted that DMS reaction rate was affected significantly by gas flow rate.It increased sharply at low flow rate（3.4×10^-7m^3·s^-1,mass transfer controlling stage） and changed slightly at the interim period（3.4×10^-7-6.8×10^-7m^3·s^-1,transitional stage） then reached a plateau at high flow rate（6.8×10^-7m^3·s^-1,chemical reaction controlling stage）.
出处
《环境化学》
CAS
CSCD
北大核心
2010年第5期814-818,共5页
Environmental Chemistry
基金
上海市自然科学基金资助项目(No.07ZR14005)
复旦大学"世纪之星"培养计划资助
教育部留学回国人员科研启动基金资助项目
关键词
LED
光催化降解
甲硫醚
LED
dimethyl sulfide
photocatalytic degradation.
