Engineering and Technology Journal 41 (03) (2023) 529-542 Engineering and Technology Journal Journal homepage: https://etj.uotechnology.edu.iq 529 http://doi.org/10.30684/etj.2023.138354.1385 Received 14 February 2023; Accepted 20 March 2023; Available online 25 March 2023 2412-0758/University of Technology-Iraq, Baghdad, Iraq This is an open access article under the CC BY 4.0 license http://creativecommons.org/licenses/by/4.0 The Photo-Oxidation of CO from Ambient Air Using Catalytic Asphaltic Pavement Seba S. Mohammed a , Zainab Y. Shnian b , Mohammad F. Abid c , Asawer Alwasiti* a , Kadhim Noori Abed c , Mohammed I. Mohammed d , Zainab Hameed c , Sajda S. Faris e , Peter Philib f a Institute of Northern Technical University, Department of Chemical and Oil Industries, Mosul, Iraq. b Chemical Engineering Dept., University of Technology-Iraq, Alsina’a street, 10066 Baghdad, Iraq. c Al-Turath University College, Department of Oil & Gas Refining Engineering, Baghdad, Iraq; . d Al-Hikma University College, Department of Medical Instrumentation Techniques Engineering, Baghdad. e Mechanical Engineering Dept., University of Technology-Iraq, Alsina’a street, 10066 Baghdad, Iraq. f Mechanical Engineering and Energy Processes, Southern Illinois University, USA. *Corresponding author Email: asawer.a.alwasiti@uotechnology.edu.iq HIGHLIGHTS ABSTRACT • The effectiveness of the oxidation of carbon dioxide gas emitted by an internal combustion engine was studied. • The CO conversion positively depends on Cu loading, light intensity, and relative humidity. • The best photo-oxidation efficiency of 56.4% was achieved after three hours of operation. Road transportation in urban areas may be considered a major source of environmental pollution. The purpose of this study is to determine the effectiveness of the oxidation of carbon dioxide gas emitted by an internal combustion engine. This is achieved using an asphaltic pavement coated with Cu/TiO 2 nanoparticles by spraying and irradiating with white light under ambient conditions to reduce the air pollution problem (carbon monoxide) caused by vehicles. Using electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy, we determined the physicochemical and morphological characteristics of the photocatalyst. Following the characterization study, the photo-catalytic activity of the asphalt materials was determined. Experimental results showed that CO conversion positively depends on different conditions, including Cu loading, light intensity, and relative humidity. However, the gas flow rate showed a different trend. The optimal operating parameters were determined as follows: Cu loading (3.6% by weight), a flow rate of gas (1 L/min), relative humidity (30%), and light intensity (35 W/m 2 ) to ensure the best photo-oxidation efficiency of 56.4% after three hours of operation. A mathematical correlation related to CO 2 removal as a function of different operating conditions was found with a correlation factor of 0.975 and a variance equal to 0.964. Moreover, a kinetic pathway for photo-oxidation of CO at various oxygen concentrations was presented. ARTICLE INFO Handling editor: Qusay F. Alsalhy Keywords: Carbon monoxide; Air quality; Copper doped Titanium oxide; asphaltic pavement; photooxidation. 1. Introduction Today, the emission of carbon monoxide discharged into the atmosphere due to fuel combustion is one of the most significant emissions concerns in the world. In general, the transport sector has a negative effect on air quality. It can considerably raise the risk of respiratory illness [1]. Consequently, it is advisable to keep these contaminants to a minimum. The advanced oxidation process of carbon monoxide by photoreaction, which depends on semiconductor materials, can be another method of removing carbon monoxide. The advantage of this technique is that it can be successful in ambient conditions and can be simultaneously used for different gaseous pollutants such as volatile organic compounds, which is very convenient at the same time [2]. The share of energy-consuming sectors in pollutant emissions in 2009 is listed in Table 1 [3].