Controllable synthesis of bifunctional corn stalk cellulose as a novel adsorbent for efficient removal of Cu2+ and Pb2+ from wastewater

Abstract

A corn stalk cellulose-based adsorbent with bifunctional groups of -NH−/-NH2 and C-S/C=S for efficient removal of Cu2+ and Pb2+ was successfully synthesized. Under specific alkali and reaction conditions, 4.58 mmol/g of C-S/C=S groups were further introduced on surface of aminated cellulose with 6.99 mmol/g of amino groups. The introduced CS2 would only participate in the esterification with -NH2 groups to form special dithiocarbamate (DTC) structures containing -NH- groups (-NHCS2−). The synthesized DTC structures would not reduce total amount of -NH−/-NH2 groups on aminated cellulose to keep its excellent adsorption performance for Cu2+, and the introduced appropriate number of C-S/C=S groups could ensure the efficient removal of Pb2+. It was suitable for removal of coexisting Cu2+ and Pb2+ with low initial concentration in real wastewater, and the removal rates were both close to 100%. The application of the bifunctional cellulose offered a novel way for purpose of ‘waste treatment by waste’.