Effect of graphene oxide blended in poly (vinylidene fluoride-co-hexafluoropropene (PVDF-CO-HFP)) polymer inclusion membrane for silver ion removal

One of the valuable metals present in electronic wastewater is silver. Removal of silver ions from wastewater is important in water management. Traditional methods of removing silver ions can be expensive and would generate large amounts of toxic sludge. Recently, membrane technology has gained high attention in wastewater treatment and is widely used in many ranges of applications. A growing number of researchers are exploring polymer inclusion membranes (PIMs) as they provide improved stability, the ability for selective separation, and the possibility of various applications. In this study, poly (vinylidene fluoride-co-hexafluoropropene) (PVDF-co-HFP) base polymer with different concentrations of Aliquat 336 as a membrane carrier and different concentrations of Graphene Oxide (GO) as an additive were studied for their ability to remove silver ions from aqueous solutions. The characteristic of fabricated PIMs was studied using Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance (FTIR-ATR), Scanning Electron Microscope (SEM), Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD), contact angle, porosity and water uptake analysis. The performances of fabricated PIMs were evaluated by determining the high removal of silver ions from the aqueous phase. From this study, it was found that M6 with 45% of Aliquat 336 in 50 mg/L of initial concentration of silver ions with pH 6 for 8 hours at room temperature and N2 with 0.5% of GO in 100 mg/L of initial concentration of silver ions with pH 6 for 8 hours at room temperature have shown the highest percentage of silver ion removal respectively. At optimum conditions, M6 was able to remove 94.00% of silver ions while N2 removed 99.65% of silver ions. Moreover, the kinetic modelling of all the parameters is best fitted with a pseudo-first-order kinetic model. In addition, the permeability and flux of the M6 membrane at optimum condition are 0.048 ms-1 and 2.379 molm−2s−1, respectively while the permeability and flux of the N2 membrane at optimum condition are 0.096 ms-1 and 9.563 molm−2s−1, respectively. This result proved that the transport mechanism of the silver ions improved with the addition of GO.