Dendrimer functionalized graphene oxide for selenium removal

Selenium is an essential trace element nutrient for human life; but it can be extremely toxic if taken excess. Various adsorbents have been applied for the removal of selenium from water but performed poorly in Se (VI) removal, which is more bioavailable and more difficult to remove. Herein, we reported a new method to prepare the dendrimer, a different generations of poly (amido amine), functionalized graphene oxide (PAMAM-GO). The PAMAM-GO was characterized by XPS, FTIR, XRD, TGA and TEM. The resulting products were applied in selenium removal from simulated waste water, showing an increasing capacity with increasing the generation of dendrimers. The 4th generation of PAMAM-GO (GO-G4) shows a removal capacity of 60.9 mg g−1 in Se (IV) and 77.9 mg g−1 in Se (VI) at pH 6. The adsorption mechanism is mainly attributed to the electrostatic interaction between selenium oxyanions and the amine groups, proved by the effect of initial pH on removal capacity and zeta potential measurement. Our study shows that PAMAM-GO is an excellent adsorbent in selenium removal from waste water.