光催化路面材料降解汽车尾气性能试验研究

Experimental Study on Automobile Exhaust Gas Degradation Performance of Photocatalytic Pavement Material

为探讨汽车尾气混合输入模式下试验条件变化对光催化路面材料降解性能的影响效应,采用喷涂法工艺制备了试件,分别应用室内和室外的降解汽车尾气试验,测定了光催化路面试件在不同光照、尾气初始浓度、温度、湿度条件下的累计分解率,分析了尾气中NO、碳氢化合物(HC)、CO的降解效率变化规律。结果表明:室内试验中采用波长为245 nm的紫外光灯管能够较好地模拟晴天时的天然光源;当初始浓度不超过汽车怠速状态尾气排放浓度时,光催化路面材料的累计分解率随初始浓度升高而增大;在10～30℃内,温度的升高对降解效率的提高起促进作用,但在30～40℃内温度的影响并不显著;光催化路面材料的降解效率随湿度增加而下降,特别是在相对湿度为40%～80%内湿度的影响很大。

In order to investigate the effect of the test condition change on the degradation performance of the photocatalytic pavement material under the mixed automobile exhaust gas input mode,specimens were prepared by the spraying process.The indoor and outdoor tests of degrading the automobile exhaust gas were applied to measure the accumulated decomposition rates of photocatalytic pavement specimens under different conditions,including illumination,initial automobile exhaust gas concentration,temperature and humidity.The degradation efficiency change rules of NO,HC and CO in automobile exhaust gases were analyzed.The results show that the ultraviolet tube with a wavelength of 245 nm used in the laboratory can simulate the natural light on sunny day.When the initial concentration does not exceed the emission concentration at the automobile idling condition,the accumulated decomposition rate of the photocatalytic pavement material increases with the increase of the initial concentration.In the range from 10℃to 30℃,an increase in the temperature can promote the improvement of the degradation performance.But in the range from 30℃to 40℃,the degradation performance is not significantly affected by the temperature.The degradation efficiency of the photocatalytic pavement material decreases with the increase of the humidity.Especially in the relative humidity range from 40%to 80%,the efficiency has been influenced a lot by the humidity.