Selective adsorption of aromatic sulfonic acid from wastewater using a surface imprinted polymer: H-acid as a representative contaminant

Abstract

Aromatic sulfonic acids (ASAs) play a pivotal role as essential intermediates in numerous industrial manufacturing, while a large amount wastewater with various ASAs and high concentration of inorganic salts is subsequently generated. The effective separation and removal of ASAs from wastewater is challenging due to their complex chemical composition and the limited selectivity of common adsorbents. Herein, a novel surface imprinted polymer (H-SIP) with high selectivity and excellent salt resistance was designed with PEI/Cl-PS-DVB as the carrier and 1-amino-8-naphthol-3,6-disulfonic acid (H-acid) as the target pollutant. Compared to non-imprinted polymer (NIP), H-SIP exhibited superior salt resistance in the presence of Na₂SO₄ concentration ranging from 20 to 80 mg/L. The relative selectivity coefficients determined in the binary-solutes experiments proved that H-SIP demonstrated favourable selectivity towards H-acid in binary systems of H-acid/T-acid or H-acid/2-NSA. Moreover, H-SIP could effectively treat the simulated complex wastewater within 24 bed volume (BV) in the column adsorption, and the desorption rate exceeded 90% when eluted by NaOH solution and distilled water, respectively. Therefore, these results confirmed that surface imprinting technique was a promising method for effectively and selectively removal of ASA wastewater in the application.