Ultrafiltration Membranes Modified with Reduced Graphene Oxide: Effect on Methyl Green Removal from Aqueous Solution

Abstract

In this work, three types of ultrafiltration membranes with different characteristics (GR60PP, RC70PP and GR80PP) have been tested for the removal of the dye methyl green. The tests were first carried out with the three membranes without any modification and then with the membranes’ surfaces modified with reduced graphene oxide (rGO). The modification was achieved through physical treatment. The CR70PP membrane did not support the modification treatment and was discarded. The other membranes were initially characterized with distilled water tests to study the permeability to the solvent, and later, the permeate fluxes and the values of rejection coefficients were obtained at different working pressures with a fixed dye initial concentration. In addition, SEM images and SEM-EDX spectra of the native and modified membranes were obtained before and after the dye tests. The GR60PP membrane has shown the best results in relation to the modification because it has increased its rejection levels. On the opposite, the GR80PP membrane performs better without surface modification, achieving the highest rejection values and the highest permeate fluxes in its native form.

Graphene’s Role in the Clean-Up Act: Progress in Industrial Wastewater Treatment

“…The endothermic adsorption process followed the Langmuir isotherm and the adsorption kinetics conformed to pseudo-second-order kinetics. Murcia et al [151] modified membrane surfaces with reduced graphene oxide (rGO) for the effective removal of methyl green dye. Later on, Li et al [152] employed SP-PVA (sulphonated graphene enhanced polyvinyl alcohol) for adsorbing methyl green dye, and GOdoped NiFe2O4 was utilized for catalyzing the photodegra-dation of methyl green dye under visible light and in the presence of oxalic acid.…”