Applicability of TiO₂‐Laden Asphalt Pavements in Reducing the Vehicular Pollution of Chandigarh, India

Abstract

Vehicular emissions play a significant role in urban-environmental pollution. Therefore, in the present investigation, efforts are made to estimate the applicability of Titanium dioxide (TiO 2 )-laden asphalt pavements in degrading the ambient Nitrogen Dioxide (NO 2 ) in Chandigarh, India. In this regard, an artificial environment is created, and experiments are designed to degrade NO 2 and Sulfur dioxide (SO 2 ) using photocatalysis. Further, the process parameters, viz., concentration of TiO 2 emulsion (25 to 125 mL m −2 ), Ultraviolet UV-A irradiance (1 to 5 mW cm −2 ), and proportion of bitumen (4 to 6%), are optimized to achieve the maximum degradation of NO 2 and SO 2 . Results reveal that maximum degradation of NO 2 and SO 2 , that is, 61.91 and 55.39%, respectively, is achieved at 81.67 mL m −2 of TiO 2 emulsion, 5 mW cm −2 of UV-A irradiance, and 5.78% of bitumen. The optimized conditions of photocatalytic application are further used to treat the ambient NO 2 of Chandigarh, India. Analysis of the ambient air data of Chandigarh, India, from 2005 to 2015, depicts significant contribution of vehicular emissions. It is also predicted that by 2031 the ambient concentration of NO 2 , may exceed the permissible limits. However, layering of asphalt payments with TiO 2 could prevent such situation by 2114.