Effects of Roadway Contaminants on Titanium Dioxide Photodegradation of Nitrogen Oxides
Effects of Roadway Contaminants on Titanium Dioxide Photodegradation of Nitrogen Oxides
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DOI：
10.3141/2240-04
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发表时间：
2011-01-01
影响因子：
1.7
通讯作者：
Wright, Earle
中科院分区：
文献类型：
--
作者：
Dylla, Heather;Hassan, Marwa M.;Wright, Earle
汽车尾气排放的氮氧化物(NOx)与负面健康影响有关，是臭氧产生的前驱物质。自清洁空气净化混凝土路面是一项通过多相光催化降解NOx等污染物的新兴技术。光催化层包括二氧化钛纳米颗粒，可以捕获和降解空气中的有机和无机颗粒，从而在紫外线(阳光)存在的情况下消除空气中的有害气体。此外，它们的超亲水性使它们能够在下雨的情况下自我清洁。虽然这项技术具有支持环境友好型道路基础设施的潜力，但在全面实施之前，需要评估一些设计和操作参数对该技术有效性的影响。这项研究的目的是测量常见道路污染物对光催化道路从大气中去除NOx能力的影响。三种常见的道路污染物-泥土、除冰盐和机油-在两个不同的覆盖水平上进行了测试。实验结果表明，这三种污染物对光催化脱除NOx的效率都有很大的负面影响。污染物覆盖范围的影响在很大程度上取决于土壤类型，其中石油的负面影响最大。流量和空气相对湿度的增加也会导致NOx效率降低。
Nitrogen oxides (NOx) emitted from vehicle exhaust are associated with negative health impacts and are a precursor to ozone production. Self-cleaning, air-purifying concrete pavement is a rapidly emerging technology that can degrade pollutants such as NOx through heterogeneous photocatalysis. Photocatalytic layers include titanium dioxide nanoparticles that can trap and degrade organic and inorganic particles in the air and thus remove harmful gases from the air in the presence of ultraviolet light (sunlight). In addition, their superhydrophilic properties allow them to self-clean in the presence of rain. Although this technology has the potential to support environmentally friendly road infrastructure, the impacts of a number of design and operational parameters on the technology's effectiveness need to he evaluated before full-scale implementation. The objective of this study was to measure the impact of common roadway contaminants on the effectiveness of the ability of photocatalytic roadways to remove NOx from the atmosphere. Three common roadway contaminants were tested-dirt, deicing salt, and motor oil-at two contrasting coverage levels. Results of the experimental program showed that the three contaminant types had a strong negative impact on the photocatalytic NOx removal efficiency. The impact of the coverage of contaminants largely depended on the soilure type, with oil having the largest negative impact. An increase in the flow rate and air relative humidity also resulted in lower NOx efficiencies.