A super biosorbent from dendrimer poly(amidoamine)-grafted cellulose nanofibril aerogels for effective removal of Cr(vi)†
Abstract
Over the past decades, heavy metal ions, especially hexavalent chromium [Cr(VI)], have substantially ravaged the aquatic environment and human health. Thus, the development of new, more efficient, and environmentally friendly methods to tackle this problem becomes very urgent. In this study, a novel dendrimer poly(amidoamine)-grafted cellulose nanofibril (PAMAM-g-CNF) aerogel was synthesized for Cr(VI) removal. The morphology, structure and adsorption properties of the PAMAM-g-CNF aerogel were investigated in detail. The results indicated that the aerogel bore abundant functional groups with a bimodal pore structure and a high specific surface area, all of which are essential for an efficient adsorbent. The maximum Cr(VI) removal capacity of the aerogel reached 377.36 mg gā1, the highest one ever reported for biosorbents. It was interesting to note that part of Cr(VI) ions had been reduced to Cr(III) during the adsorption process, which meant that PAMAM-g-CNFs could detoxify Cr(VI).