A classic critique on concrete adsorbing pollutants emitted by automobiles and statistical envision using trend...

Globally, road transportation is responsible for about 1/3 of total air pollution, among which Co₂ , No_X and So_X are major by volume which are directly responsible for ozone layer depletion. As these activities continue to rise, the nature faces the threat of an unprecedented environmental catastrophe. In this survey, the adsorbent and the methods used to adsorb the vehicle emission pollutant directly from the ambient air and enhance the air quality are reviewed. There are extensive number of adsorbents available namely titanium oxide, polyethyleneimine (PEI), activated carbon, and other natural admixtures and methods that adsorb these pollutants such as Co₂; specifically, polyethyleneimine (PEI) is a polymer-based product which has a behavior of adsorbing Co₂ directly from ambient air. A carbon-neutral technology for eliminating anthropogenic CO₂ emissions has been proposed, trapping CO₂ from the atmosphere. The major concern including Co₂ adsorption rate and methods to evaluate the volume of adsorption with time has been reviewed. Trend analysis depends on the reason that can foresee what will occur later on by seeing what has happened beforehand. The trend analysis method was used in this study to model the adsorption rate of PEI based on their pore diameter. When it comes to designing regression analysis, R² values of 0.2 to 0.3 indicate that statistical tests have no meaningful impact and further research is needed. For adsorption of No_X, a lot of adsorbents are used namely sodium bentonite, zeolite, activated carbon, and other natural minerals. Among them, activated carbon enhances the adsorption rate of No_x. Vast research has been conducted to analyze the adsorption rate, advantages, disadvantages, and the behavior of different adsorbent with the concrete. Literally for SO_x, the adsorbents that are widely used are coal ash, copper oxide, and silicate. The characterization of different adsorbents with their adsorbate can be analyzed by some test methods as follows: Fourier-transform infrared spectroscopy (FTIR), BET analysis, scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) analysis, surface area, X-ray diffraction (XRD), porosity analysis, and more according to the requirement. The quantity of adsorbent and adsorbate could be evaluated for facing the real-time constraints through a detailed research by review.