Tailored N,N,N-triethyl ammonium-functionalized cross-linked chitosan beads: A versatile matrix for enhanced chromium and lead adsorption for batch and fixed bed adsorption.

There are significant health hazards associated with heavy metal contamination of water such as lead and chromium. In this paper, chitosan beads are modified and cross-linked with glutaraldehyde to acquire N,N,N-triethyl ammonium-functionalized cross-linked chitosan beads (TEACCB) which adsorb chromium and lead from water. Batch and column studies were carried out to evaluate adsorption conditions. The characterization FTIR, SEM and EDAX are implied to explicate the structure of TEACCB. The adsorption study showed that Cr(VI) and lead removal by TEACCB was highest in acidic to neutral pH conditions. The results showed that the adsorption capacity of TEACCB from 1000 mg/L of aqueous solution, for Cr(VI) adsorbed were 146 mg/g at pH 4, 40 °C and for lead adsorbed were 130 mg/g at pH 5, 40 °C. Increasing the adsorbent dosage from 0.05 to 1 g resulted in greater removal percentages, while the presence of anions like SO42- and CO32- influenced the adsorption capacity, with CO32- having the most significant impact. The adsorption results better coordinated with Langmuir isotherm and pseudo-first order kinetics model. The adsorption requirements for continuous removal of mixture of Cr(VI) and lead from aqueous solution by TEACCB showed removal to be 92 % and 78 % respectively.