Polyethylenimine-Grafted-Corncob as a Multifunctional Biomaterial for Removing Heavy Metal Ions and Killing Bacteria from Water

Currently, there is an increasing interest in adding value to corncob, since corncob is a low-cost, green, and reliable cellulose material that is often discarded as waste without utilization. To increase the value of corncob, we developed a multifunctional corncob-based material by grafting polyethylenimine on oxidized corncob (PEI-g-OC). The PEI-g-OC was then used to remove the heavy metal ions and kill bacteria from water. We found that PEI-g-OC presented high adsorptive capabilities to Cu2+, Cd2+, and Pb2+ at 159.5, 212.6, and 224.0 mg/g in water, more potent than the other corncob-based biosorbents. Moreover, the PEI-g-OC is able to kill the model bacteria of S. aureus, P. aeruginosa, and E. coli with minimal inhibitory concentrations (MIC) at 3.5, 12.0, and 8.5 mg/mL, indicating its effect on antibacteria. Hence, PEI-g-OC with multiple functions improved the recyclability of corncob and added its value for application in water treatment.