A low-cost crosslinked polystyrene derived from environmental wastes for adsorption of phenolic compounds from aqueous solution

Waste polystyrene (WPS) and CCl4 are typical environmental wastes. They belong to white pollution resource and ozone depleting substance, respectively. A porous crosslinked polystyrene (CPS). which was successfully synthesized by WPS and CCl4, can effectively adsorb various phenolic compounds from aqueous solution. The adsorption performance of CPS originated from its Lewis basicity. hydrophobicity, and coexistent micro- and mesopores. The Lewis basidty and the hydrophobicity facilitated deep removal for 2,4-dimethylphenol, salicylic acid, and tannic add (TA). The coexistent micro- and mesopores enabled the simultaneous removal for 4-chlorophenol and TA. For the adsorption mechanism, the interaction between CPS and the phenolic compounds was confirmed as H-bonding and pi-pi stacking. For the better understanding of adsorption behaviour of CPS to various phenolic compounds, functional relationships between the Freundlich parameters K-F and n were studied for several sorbents. The relationships indicated that the Lewis basicity of CPS might be deactivated by its mesopores and needed to be activated by the phenolic acids. (C) 2020 Elsevier B.V. All rights reserved.