Assessing the Applicability of Photocatalytic-Concrete Blocks in Reducing the Concentration of Ambient NO2 of Chandigarh, India, Using Box–Behnken Response Surface Design Technique: A Holistic Sustainable Development Approach

Neeru Singla,Jasgurpreet Singh Chohan,Alibek Issakhov,Sandeep Singla,Shubham Sharma,Shashi Prakash Dwivedi,Sandeep Singh,Somnath Chattopadhyaya,Ambuj Saxena,Raman Kumar,Nima Khalilpoor,Parteek Singh Thind,Pei-Yi Wang

doi:10.1155/2021/6468749

Abstract

Anthropogenic emissions, such as industrial, vehicular, biomass burning, and coal combustion, play a significant role in degrading the atmospheric conditions of India. Therefore, in the present study, applicability of the photocatalytic-concrete blocks was estimated in improving the ambient environment of Chandigarh, India. The photocatalytic-concrete blocks were prepared by mixing the TiO2 particles with cement. All the experiments, designed in accordance with the Box–Behnken approach, in combination with response surface methodology, were performed in a batch reactor. Further, the process parameters, namely, concentration of TiO2 (1 to 5 g), UV-A irradiance (1 to 5 mW/cm2), and relative humidity (RH) (10 to 70%), were optimized to achieve maximum degradation of NO2. Outcomes of batch experiments depicted that the maximum degradation of NO2, that is, 68.32%, was attained at 3.35 g of TiO2, 5 mW/cm2 of UV-A irradiance, and 64.60% RH. The findings of batch experiment were further theoretically applied to degrade the ambient NO2 concentration of Chandigarh, India. It was estimated that using the photocatalytic concrete for construction of Chandigarh’s pavements may reduce the ambient NO2 concentration of Chandigarh, India, to an average of 5.80 μg/m3. Afterwards, reusability of photocatalytic-concrete blocks was also assessed, and it was made evident that after five cycles, their efficiency was reduced by only 7.15%. Subsequently, it was revealed that hydrogen peroxide-based treatment of photocatalytic-concrete blocks could completely regenerate its treatment efficiency. Therefore, it is expected that the findings of this study may prove beneficial in urban planning, as it may assist scientific auditory in identifying the applicability of TiO2-based photocatalysis in mitigating the impacts of vehicular emissions.

Highlights

It is irrefutable that a comprehensive development of any nation is depicted by the extant of its road network.erefore, in the race of development, all the developing nations are expanding their road network by laying more roads
Studies have reported that owing to the exposure to such pollutants, the residents of urban areas are more susceptible to respiratory diseases as compared to the residents of rural areas of developing nations [6, 7]
It is expected that this study may prove beneficial in the scientific quest for finding the solution for air pollutionrelated problems arising from uncontrolled vehicular emissions in developing nations

Summary

Introduction

It is irrefutable that a comprehensive development of any nation is depicted by the extant of its road network. It is evident that with an efficient road network, the number of fossil fuels’ powered vehicles increases [1] In this way, the emissions attributed to vehicular exhausts increase and degrade the environmental conditions of the nation [2]. Erefore, in recent years, scientific community is working towards exploring the applicability of photocatalysis in reduction of urban-air pollution [18,19,20]. In this regard, several surfaces of the global-urban areas, namely, buildings, roads, and monuments, were reported to be laden with different photocatalysts, and significant reduction in concentration of air pollutants was reported [19]. It is expected that this study may prove beneficial in the scientific quest for finding the solution for air pollutionrelated problems arising from uncontrolled vehicular emissions in developing nations

Materials and Methods

H Humidifier

Results and Discussion