Facile synthesis of amine-crosslinked starch as an efficient biosorbent for adsorptive removal of anionic organic pollutants from water

Developing applicable biosorbents for adsorptive removal of organic pollutants from water is highly demanded. However, most biosorbents suffer poor adsorption capability for anionic organic pollutants due to their negatively charged surface. Herein, we present a facile method to synthesize amine-crosslinked starch (ACS) biosorbent for removing anionic organic pollutants. The adsorption properties of ACS were thoroughly evaluated by selecting anionic brilliant blue (BB), amaranth (ART), diclofenac sodium (DS) as representatives. The results show that the ACS can selectively adsorb anionic molecules with large adsorption capacity and fast removal rate. The adsorption kinetic and isotherm behaviors can be well described by the pseudo-second-order and Langmuir models, respectively. The maximum uptake capacity of ACS for BB, ART and DS is as high as 1287.7, 724.6 and 595.2 mg g-1, respectively. Moreover, the ACS can be easily regenerated and still exhibits favorable adsorption performance even after reusing for five times.