be important . Kante et al. studied adsorption of NO2 using wood-based activated carbon impregnated with chemicals such as sodium, cerium and lanthanum chlorides. Overall, introducing these chemicals onto the activated carbon surfaceresultedin higher adsorption capacity for NO2. The adsorption capacity of sodium chloride (283 mg NO2/g) was the highest and lanthanum chloride (143 mg NO2/g) showed the lowest adsorption.Impregnation resulted in a significant decrease in the structural arrangement via the addition of nonporous materials. The chlorides were deposited in the pores and decreased the pore volume. In this case, addition of sodium chloride reduced the BETsurface area and total pore volume from 2143 to 1952 m2/g and1.494 to 1.372 cm3/g, respectively