纳米二氧化钛环保涂料在城市道路应用中的试验研究

发布时间：2018-07-24 10:30

【摘要】：城市交通的迅猛发展给人们出行带来了极大便利，但是汽车尾气对城市空气环境造成了严重的污染。如何有效的降解汽车尾气改善空气质量是目前急需解决的问题之一。本论文立足于城市道路基础设施建设与养护，以光催化材料纳米二氧化钛为基础材料，将其与硅丙乳液以一定的质量比配合形成混合涂料，在不影响市政基础附属设施正常服务功能的前提下，将这种光触媒涂料用在汽车尾气浓度比较大的地区，利用纳米二氧化钛的光催化能力，降解有害气体，达到净化环境的目的。 PM2.5是当前国内外公认的评价城市空气质量的最佳指标，同时，汽车尾气是构成PM2.5的主要成分之一。本论文从汽车尾气和PM2.5两个角度，对纳米二氧化钛环保涂料在城市道路基础设施中的应用进行了试验研究。首先，，本文对纳米二氧化钛基路用材料进行了研发。为了避免纳米二氧化钛飞散对大气产生二次污染，研究将纳米二氧化钛与硅丙乳液有机融合在一起，形成涂料状物质，将纳米二氧化钛牢固粘结在道路基础设施表面。同时，为了测试涂料的工程实用性，还对涂抹涂料后的试块进行了基本性能试验和路用试验，符合规范要求；其次，自主研发并设计了一套降解汽车尾气和空气PM2.5室内试验装置。该装置可以最大限度模拟实际道路环境，满足不同工况下的模拟试验；再次，考虑不同影响因素下纳米二氧化钛环保涂料对汽车尾气的催化效能，对光照条件、不同配合比及重复降解效能等因素进行了试验，最后，进行了纳米二氧化钛环保涂料对空气PM2.5的降解效能的试验，考虑了光照条件、涂抹量、距试件表面垂直高度及重复降解效能等因素的影响。试验结果表明：光是纳米二氧化钛环保涂料发生催化效能的主要条件，紫外灯和太阳光下，尾气中HC降解率分别为23.6%、30.6%，NOX降解率为57.9%、60.0%；纳米二氧化钛溶液与硅丙乳液以1:5、2:5、1:2、3:5的质量比进行混合时，尾气中HC降低率为25.0%、29.1%、32.4%、34.1%，NOX降低率为33.4%、36.2%、39.4%、42.1%，得到了涂料最佳质量比为0.5-0.6之间；涂料重复降解试验时，尾气中HC降低率为31.0%、30.7%、30.4%、30.6%，NOX降低率为36.4%、36.0%、36.2%、36.2%。用最佳配合比配置的涂料进行PM2.5降解试验，紫外灯和太阳光下的PM2.5降解率为43.7%、45.6%；涂抹在不同面积试样板（0m2,0.5m2,1.0m2）上的PM2.5降解率为0%、24.4%、30.4%；随着距试件表面垂直高度的变化（0.5m,1.0m,1.5m），PM2.5的降低率为40.0%、33.3%、23.3%；涂料的重复降解试验中，PM2.5降低率为33.6%、31.2、30.4%。
[Abstract]:The rapid development of urban traffic has brought great convenience for people to travel, but the automobile exhaust has caused serious pollution to the urban air environment. How to degrade automobile exhaust effectively to improve air quality is one of the urgent problems to be solved. In this paper, based on the construction and maintenance of urban road infrastructure, the photocatalytic nano-TiO _ 2 was used as the basic material, and the mixed coating was formed by blending it with silicon-acrylic emulsion at a certain mass ratio. Without affecting the normal service function of municipal infrastructure ancillary facilities, this photocatalyst coating is used in areas with high vehicle exhaust concentration to degrade harmful gases by using the photocatalytic capacity of nanometer titanium dioxide. PM2.5 is the best index to evaluate urban air quality at home and abroad, and automobile exhaust gas is one of the main components of PM2.5. In this paper, the application of nano-TiO _ 2 environmental protection coatings in urban road infrastructure was studied from the perspectives of automobile exhaust and PM2.5. Firstly, nano-TiO2 based road materials are researched and developed in this paper. In order to avoid the secondary air pollution caused by nano-TiO _ 2 dispersion, the nano-TiO _ 2 and silicon-acrylic emulsion were combined to form a coating material, and the nano-TiO _ 2 was firmly bonded to the surface of road infrastructure. At the same time, in order to test the engineering practicability of the coating, the basic performance tests and road tests are carried out on the test blocks after coating, which meet the requirements of the specifications. An indoor test device for the degradation of automobile exhaust and air PM2.5 was developed and designed. The device can simulate the actual road environment to the maximum extent and satisfy the simulation test under different working conditions. Thirdly, considering the catalytic efficiency of nano-titanium dioxide environmental protection coating on automobile exhaust gas under different influence factors, The effects of nano-TiO _ 2 environmental protection coatings on the degradation of PM2.5 in air were tested with different mixing ratio and repeated degradation efficiency. The light condition and the amount of smear were taken into account. The influence of the vertical height to the surface of the specimen and the efficiency of repeated degradation. The results show that light is the main condition for catalytic performance of nano-TiO _ 2 environmental protection coatings. Under ultraviolet lamp and sunlight, the degradation rate of HC in tail gas is 23.66% and 30.6% respectively. The degradation rate of NOX in tail gas is 57.9% and 60.0%, respectively. When the nano-titanium dioxide solution was mixed with the silicone acrylic emulsion at the mass ratio of 1: 5 to 2: 1: 3: 5, the reduction rate of HC in the tail gas was 25.0 and 29.1g, 32.41% and 33.4% respectively. The optimum mass ratio of the coating was 0.5-0.6, and the optimum mass ratio of the coating was 0.5-0.6 in the repeated degradation test. The reduction rate of HC in the tail gas was 31.0% and 30.7% and 30.64%, and the reduction rate of NOX was 36.4% and 36.20%, 36.2% and 36.2%, 36.2%, 36.2%, 36.2%, 36.2%, 36.2% and 36.2%, respectively. The PM2.5 degradation rate of UV lamp and solar light was 43.70.The degradation rate of PM2.5 on different area sample board (0m2m2m2m2m21.0m2) was 0: 24.4m210m2. With the change of perpendicular height from the surface of sample (0.5m21.0m-1. 5m), the reduction rate of PM2.5 was 33.323.33.33. the degradation rate of PM2.5 was 43.323.30.The degradation rate of PM2.5 was 43.323.3 with the change of perpendicular height to the surface of the sample. The reduction rate of PM2.5 in the repeated degradation test of coatings was 33.6% 31.2% 30.4%.
【学位授予单位】：北京市市政工程研究院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414;TU997

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