Abstract
Three activated carbons were prepared from biomass (agriculture and wood industry by-products) and subsequently modified by treatment with liquefied petroleum gas at 900°C. The primary properties of the activated carbons before and after modification were investigated by nitrogen adsorption isotherms and FT-IR techniques. Modification of the activated carbons by liquefied petroleum gas led to a significant decrease in the content of micropores with diameters less than 1 nm. The prepared activated carbons exhibited improved adsorption capacities towards benzene due to their non-polar surface chemical groups and narrower micropore distributions; however, their adsorption capacities towards ammonia were diminished. The adsorption extent of iron ion was determined by the surface chemical properties of the activated carbons and showed a smaller relationship to the pore volume. The adsorption extent of Direct Red 23 was influenced by micropore sizes in the range 1–1.5 nm.