Rapid removal of Cr(VI) ions by densely grafted corn stalk fibers: High adsorption capacity and excellent recyclable property.

Hexavalent chromium (Cr(VI)) is a highly toxic pollutant which widely exists in industrial wastewater. Here, an adsorbent, corn stalk fibers (CSF) grafted poly(dimethylaminoethyl methacrylate) (PDMAEMA), was prepared via atom transfer radical polymerization (ATRP). Polyvinyl alcohol (PVA) was used to enrich the hydroxyl groups of CSF, thus increasing PDMAEMA grafting density. Compared with the general grafting, the adsorption capacity of high-density grafting CSF increased from 56 to 145 mg/g. The PDMAEMA chains stretched in the water like brushes, resulting in very fast adsorption rate—about 10 min to achieve adsorption equilibrium. The adsorbent was stable and would not be oxidized by Cr(VI), and the adsorption performance was still excellent after 20 cycles. [ABSTRACT FROM AUTHOR]