Study on the treatment of Sb(III)-containing wastewater by reduced graphene oxide supported nano zero-valent iron composites

To address the problem of heavy metal Sb(III) pollution, a liquid phase reduction method was used to prepare a highly efficient reduced graphene oxide supported nano zero-valent iron composite (nZVI/rGO), and the composites were characterized using a variety of technologies. Meanwhile, the influence of loading amounts of nZVI, nZVI/rGO dosages, initial pH values, and reaction temperatures on the adsorption effect of Sb(III) was investigated comprehensively. Furthermore, the adsorption isotherm model and the adsorption kinetics model are used to study the removal process of Sb(III) by nZVI/rGO. The results show that with a nZVI loading capacity of 70% and a nZVI/rGO dosage of 0.5g/L at 25°C and pH=3.0, the maximum Sb(III) removal efficiency can reach 99.7%. The adsorption mechanism is well fitted to the quasi-second-order kinetic model and the Langmuir isotherm adsorption model, thus, the nZVI/rGO was demonstrated to be an efficient composite adsorption material. © 2022 Chinese Society for Environmental Sciences. All rights reserved.