Dye removal from single and binary systems using gel-like bioadsorbent based on functional-modified cellulose

A novel type of gel-like bioadsorbent was prepared by crosslinking thiourea-modified sugarcane bagasse cellulose with carboxymethyl cellulose, and used for the removal of methylene blue (MB) and crystal violet (CV) in single and binary systems. The resulting bioadsorbent was characterized with FTIR, XRD, SEM and thermogravimetric analysis. The porous structure of hydrogels significantly improved the adsorption capacity towards dyes. The effects of pH, temperature, initial concentration of dyes and adsorbent dosage on the adsorption behavior were systematically investigated. The maximum adsorption capacity for MB and CV reached as high as 632.9 and 574.7 mg/g in single system; and 555.6 and 427.4 mg/g in binary system, respectively. The kinetic data fitted well to the pseudo-second-order model in both systems; and the dye adsorption on bioadsorbent was mainly governed by intraparticle diffusion. Meanwhile, the isotherm data fitted well to Langmuir models. Moreover, the bioadsorbent showed excellent recycling ability over the desorption tests, thus leading to a promising and green-based adsorbent for the removal of dyes.