Mesoporous biohybrid epichlorohydrin crosslinked chitosan/carbon clay adsorbent for effective cationic and anionic dyes adsorption

Abstract

Epichlorohydrin crosslinked chitosan/carbon–clay (CSCC) biohybrid adsorbent was prepared for the adsorption of cationic methylene blue (MB) and anionic azo acid blue 29 (AB 29). The 40:60 wt% of chitosan (CS) and carbon–clay (CC) was selected as the best biohybrid adsorbent (CS40CC60) for the adsorption of both dyes. The adsorption of MB and AB 29 on CS40CC60 was carried out in a batch process to investigate the effects of initial dye concentration (25–400 mg/L), initial pH (3−11), contact time and adsorption temperature (30, 40 and 50 °C). The kinetics results of dyes adsorption onto CS40CC60 fit well to the pseudo-second-order model. The isotherms analysis demonstrated that the Freundlich isotherm described the adsorption data, and the qmax (mg/g) were 95.31 for MB and 167.35 for AB29 at 50 °C. These findings reveal the potential and effectiveness of the newly prepared biohybrid adsorbent for the adsorption of both dyes.