Adsorptive removal of aniline from aqueous solution by oxygen plasma irradiated bamboo based activated carbon

The effects of oxygen plasma irradiation on the surface properties of bamboo based activated carbon (BAC) were investigated. The adsorption characteristics of aniline on raw and irradiated BACs were also evaluated. The raw and irradiated BACs were characterized by means of SEM imaging, N2 adsorption, Boehm titration, point of zero charge (pHpzc) measurement and FTIR spectroscopy. The results showed that the surface textural properties of irradiated BACs were slightly damaged, and a gradual decrease in surface area and pore volume was observed during the irradiation. The surface chemistries of irradiated BACs were observed to be modified greatly, such as the decrease in pHpzc values and the redistribution of surface functional groups. The adsorptions of aniline on BACs were very fast initially, and the equilibriums could be reached within 480 min. The irradiated BACs significantly outperformed raw BAC for adsorption of aniline. The kinetic data of raw and irradiated BACs could be best described by the pseudo-second-order model and intra-particle diffusion model. The equilibrium data of raw and irradiated BACs followed Langmuir and R–P isothermal models more precisely. The improvements of π–π dispersive interaction and hydrogen bond effect were supposed to be responsible for the enhanced adsorption of aniline on irradiated BACs.

► Oxygen plasma was used to irradiate the bamboo based activated carbon (BAC).
► The surface textural properties of irradiated BACs were slightly damaged.
► The surface chemical properties of irradiated BACs were modified greatly.
► The improved π–π interaction enhanced the adsorption of aniline on irradiated BACs.
► The improved hydrogen bond effect enhanced adsorption of aniline on irradiated BACs.