光催化降解对氟苯氧乙酸的规律研究

摘要

以Pt／TiO2为光催化剂，研究了废水中对氟苯氧乙酸的光催化降解反应。考察了反应时间、溶液初始pH值以及污染物初始浓度对光催化反应的影响。实验表明，反应3h内，氟离子平均检出速率为2.64×10-5mol／（L· h）；在反应4～7h内，氟离子平均检出速率为5.38×10-5mol／（ L· h）。反应液的紫外光谱图显示对氟苯氧乙酸浓度不断下降。在溶液初始pH值为3.44～4.95时，光催化生成氟离子的速率最大，在碱性范围内，氟离子的生成速率为零。当C0（对氟苯氧乙酸）＜1.00×10-3 mol· L-1时，光催化降解反应速率随着对氟苯氧乙酸初始浓度的增大而急剧增大；当C0（对氟苯氧乙酸）＞8.00×10-3 mol· L -1时，光催化降解速率与污染物初始浓度无关。%In the presence of Pt/TiO2 ,the photocatalytic degradation of p-Fluorophenoxyacetic acid in sewage had been studied.Effects of reaction time , initial pH and initial concentration of pollutant on photocatalytic degradation were investigated.The experimen showed that average photocatalytic generation fluorine ion rate was 2.64 ×10 -5 mol/( L· h) within 3h.Average photocatalytic generation fluorine ion rate was 5.38 ×10 -5 mol/( L· h) within 4~7 h.Ultraviolet specture of reaction solution showed that the concentration of p-Fluorophenoxyacetic acid continuously decreased.In initial pH value of solution was 3.44~4.95 ,the rate of photocatalytic fluorine ion generation was maxi-mum,in alkaline range,the rate of photocatalytic fluorine ion generation was zero.Within C0(p-Fluorophenoxyacetic acid) 8.00 ×10 -3 mol· L-1 ,photocatalytic degradation generation fluorine ion rate was almost constant.