水体系中正癸烯的光催化降解

Photocatalytic degradation of n-decene in water

以中压汞灯为光源 ,研究了水体系中正癸烯 (n C10 H2 0 )在TiO2 光催化氧化作用下的降解。结果表明 ,降解反应符合一级动力学方程 ;n C10 H2 0 在不同粒径TiO2 下的反应速率常数k为 6 .80— 9.90× 10 -3 min-1(在 30 0W中压汞灯下 ) ,其值随粒径的增加而降低 ;在相同粒径下 ,k值随光强增加而增大。同时测定了在水体中掺杂 1wt% (即过渡金属质量占Ti原子质量的百分数 )的过渡金属离子时 ,n C10 H2 0 的光降解速率常数k为 11.4— 15 .9× 10 -3 min-1,因而其对光降解的影响顺序是 :Ag+ >Fe3 + >Pb2 + >Fe2 + >Zn2 + >Mn2 + 。产物经GC/MS分析表明 ,水体中n C10 H2 0 光催化降解生成辛醛、壬醛、癸醛和 2 癸酮。

The treatment of toxic n-decene(n-C 10H 20) wastewater (800 mg/L) by TiO 2 photocatalytic degradation was preliminarily investigated. The results showed that n-C 10H 20 was degraded to caprylic aldehyde,nonyl aldehyde, decyl aldehyde and 2-decanone, its kinetics was the first-order.Under different particle sizes of TiO 2 , rate constants of n-C 10H 20 were 6.80—9.90×10 -3 min -1(300 W medium mercury lamp), decreased with inceased particle sizes. Furthermore, the TiO 2 photocatalytic degradation ability of the organic compounds can be enhanced by the increasing intensity, adding 1wt% transitional metal ions in water, respectively at the same particle size. In the presence of transitional metal ions, degradation of n-decene had been enhanced ordered as Ag+> Fe 3+> Pb 2+> Fe 2+> Zn 2+> Mn 2+.