Facile preparation of agaraldehyde chitosan-based composite beads as effectual adsorbent especially towards amido black

Agaraldehyde and chitosan (CHI) functional beads as dye adsorbent were prepared under aqueous medium under ambient temperature and used for removing seven dyes from aqueous solutions. The resulting porous CHI-A_ald (R-A_ald-CHI) bio-beads were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscope. The dye removal efficiency was studied using seven dyes (amido black AB], bromophenol blue, crystal violet, bismarck brown, cotton blue, methyl orange, methylene blue), but detail study was done on AB. AB adsorption was followed the Langmuir-isotherm and pseudo-second order kinetics. The effects of adsorption parameters were investigated, and maximum AB 1506 mg/g was adsorbed under the optimum conditions. The linear and nonlinear forms of Langmuir and Freundlich isotherms and two kinetic models pseudo-first-order and pseudo-second-order were studied. The results show that adsorption follow both isotherm model while for kinetics of adsorption follow pseudo-second-order. The results of this work showed that R-A_ald-CHI was encouraging adsorbent to remove dyes from wastewater, especially AB.