摘要
以300W中压汞灯为光源,分别研究了水体系中正癸烷(n-C10H22)和正癸烯(n-C10H20)在TiO2光催化氧化作用下的降解.结果表明,它们的降解反应均符合一级动力学方程,在17.2nm TiO2下,n-C10H22反应速率常数(k)值为5.8010-3min-1,半衰期(t1/2)为120min;n-C10H20的k值为9.9010-3min-1,t1/2为70min.400℃热处理的TiO2对n-C10H22、n-C10H20光解的降解率分别为31%﹑50%,高于其他热处理温度.利用自旋俘获-电子顺磁共振(ST-EPR)方法,在光照的TiO2磷酸盐缓冲水溶液(pH=7.4)中检测到羟自由基加合物(DMPO-OH).产物分析表明,水体中n-C10H22光催化降解生成的中间产物为1-癸醇、2-戊酮、2-庚酮和2-癸酮;n-C10H20的中间产物为辛醛、壬醛、癸醛和2-癸酮.
The degradation of n-decane (n-C10H22) and n-decene(n-C10H20) in water system was studied respectively under TiO2 photocatalytic oxidation with 300W medium pressure mercury lamp as light source. The results showed that their degradation reaction coincided with first-order kinetic equation. Under the condition of 17.2nm TiO2, the reaction rate constant (k) of n-C10H22 was 5.8010-3min-1 with half time (t1/2) 120min; and k of n-C10H20 was 9.9010-3min-1 with t1/2 70min. The photocatalytic degradation rates of n-C10H22 and n-C10H20 by 400℃ heat-treating TiO2 were 31% and 50% respectively, higher relatively than other heat-treating temperatures. Using selfspin trapping-electron paramagnetic resonance (ST-EPR) technique, the hydrocarbon free-radical compounds (DMPO-OH) in irradiated TiO2 phosphate buffer aqueous solution (pH=7.4) was detected. The product analysis showed that the medium products formed in water from n-C10H22 photocatalytic degradation were 1-decanol, 2-pentanone, 2-heptanone and 2-decanone; and those from n-C10H20 were caprylic aldehyde, nonyl aldehyde, decyl aldehyde and 2-decanone respectively.
出处
《中国环境科学》
EI
CAS
CSSCI
CSCD
北大核心
2003年第2期122-126,共5页
China Environmental Science
基金
江苏省社会发展基金资助项目(BS2002039)
