Abstract

Modified corn straw, MCS, was prepared by pretreatment and esterification modification technology. The optimisation and mechanism of Cr(VI) adsorption performance was critically investigated via orthogonal experimental design and single-factor comparison experiments. Experimental results indicated that the MCS dosage and pH value had the greatest effect on the Cr(VI) adsorption process. Moreover, the Cr(VI) adsorption rate (CrAR) and maximum adsorption capacity (CrAC) were 96.8 % and 121mg/g respectively under the optimal condition (MCS dosage: 0.04g, adsorption time: 45 minutes, pH3, adsorption temperature: 40°C, Cr(VI) initial concentration: 10mg/L), which was an increase of 10.3 times compared to unmodified corn straw. FTIR analysis testified that carboxyl and ester groups were introduced into the MCS. Meanwhile, it turned out that the cellulose structure of MCS was found to be more orderly by SEM analysis than that of CS. The MCS might show great potential for application in the adsorption of Cr(VI) in tannery wastewater as a new type of biosorbent.