The impact of surface properties and dominant ions on the effectiveness of G-nZVI heterogeneous catalyst for environmental remediation.

Abstract The surface properties of nanocomposites are influenced by the existence of inorganic species that may affect its performance for specific catalytic applications. The impact of different ionic species on particular catalytic activity had not been investigated to date. In this study, the surface charge (zeta potential) of graphene-oxide-supported nano zero valent iron (G-nZVI) was tested in definitive cationic (Na+, K+, Ca2+ and Mg2+) and anionic (Br−, Cl−, NO 3 −, SO 4 2−, and HCO 3 −) environments. The efficiency of G-nZVI catalyst was inspected by measuring the generation of reactive oxygen species (ROS) for the degradation of 1,1,1-trichloroethane (TCA) in sodium percarbonate (SPC) system. Tests conducted using probe compounds confirmed the generation of OH and O 2 − radicals in the system. In addition, the experiments performed using scavenging agents certified that O 2 − were primary radicals responsible for TCA removal, along with prominent contribution from OH radicals. The study confirmed that G-nZVI catalytic capability for TCA degradation is notably affected by various cationic species. The presence of Ni2+ and Cu2+ significantly enhanced (94%), whereas Na+ and K+ had minor effects on TCA removal. Overall, the results indicated that groundwater ionic composition may have low impact on the effectiveness of G-nZVI-catalyzed peroxide TCA treatment. Graphical abstract Unlabelled Image Highlights • Dominant groundwater cations effect the performance efficiency for degradation • Surface charge and organic ions effect investigated for the degradation of TCA a persistent contaminant in hydrosphere. • Generation of reactive oxygen species for remediation of TCA in percarbonate system • The ionic composition of groundwater has a relatively minor effect on TCA removal for the G-nZVI catalyzed system. [ABSTRACT FROM AUTHOR]