光催化降解有机污染物的机理初探

Preliminary Study on Mechanism of Organic Pollutants Degradation by Photocatalytic System

采用自制的光催装置研究了三氯乙醛和甲基橙有机物降解机理．证实了在有机物光催化降解过程中活性物种Ｈ２Ｏ２和ＯＨ的存在．实验结果表明，有机污染物去除效率的关键决定于体系产生活性中间体的量．在本实验条件下，可用体系产生Ｈ２Ｏ２的量来衡量光催化效率的大小．体系产生的Ｈ２Ｏ２水平高，相应有机污染物去除效率愈高，而且仅当体系产生的Ｈ２Ｏ２大于１．０ｍｇＬ－１时，有机物去除效率才会达到８５％以上．

Two types of organic pollutants,chloral hydrate and methyl orange as the objects of the catalytic degradation were investigated by PCS.The existence of H 2O 2 and ·OH was verified.The results showed that removal efficiency depended mainlyon the quantity of the active intermediates for PCS. Photocatalytic degradation efficiency was evaluated by the H 2O 2 yield in our PCS. Not only did pollutants remove highly when H 2O 2 yield increased in PCS,but also removal efficiency of more than 85% was achieved when the H 2O 2 concentration was more than 1 0 mg·L -1 .