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环境科学学报 2005
Degradation mechanism of organic dye in water by 172nm vacuum-UV radiation
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Abstract:
The degradation mechanism of organic dye claret in water was investigated by 172nm vacuum-UV (VUV) radiation emitted from the planar Xe-excimer lamp. The solution was served as one of the electrodes of the lamp. The dye solution was respectively saturated with pure oxygen and nitrogen, and KCl was added as hydroxyl radical scavenger. It was found that direct photolysis played a main role in the degradation process of claret dye. The degradation by direct photolysis was observed the pseudo-first-order kinetics in the whole degradation process while the degradation by HO·,HO2· and O2·- radicals deviated from first-order kinetics after 10min. The quantum yield of claret dye by direct photolysis was 6.8×10-3 mol·eistein-1. After the degradation efficiency had got to 80%, the rate of COD removal began to increase significantly. Some organic by-products were identified by GC/MS spectrometry as a result of photolysis and oxidation production of claret dye.