Adsorption of Cd(II) and Cu(II) by Epichlorohydrin and Cysteine Modified Bagasse

Abstract

A new adsorbent for heavy metal ions removal was obtained by modifying bagasse with epichlorohydrin and cysteine. Bagasse was reacted with epichlorohydrin then grafted with cysteine to produce modified-bagasse. Adsorption behaviours of original-bagasse and modifiedbagasse for Cd²⁺ and Cu²⁺ were studied. The cysteine modification was effective at introducing carboxyl and sulfhydryl groups into bagasse. SEM, XPS and FTIR were used to determine the characteristics of original-bagasse and modified-bagasse. The results showed that modifiedbagasse had a porous and loose surface covered with carboxyl and sulfhydryl groups, which was beneficial to removing Cd²⁺ and Cu²⁺ from wastewater. In the range of experiments, modifiedbagasse can reach a maximum saturated adsorption capacity (Qmax) of 1.092 and 1.122 mmol/g, compared with 0.233 and 0.272 mmol/g of original-bagasse for Cd²⁺ and Cu²⁺ at 25 ºC, respectively. Lower temperature was favourable for the process of adsorption of modified-bagasse. The results indicated that the adsorption property of modified-bagasse had been enhanced obviously, which could be utilized as a potential and promising metal ion adsorbent.