Preparation of magnetic carbon nanotube nanocomposite for enhancing the separation of dissolved hydrocarbon from petroleum wastewater

Abstract

Multi-walled carbon nanotubes decorated with magnetite (MMWCNTs) were prepared then modified with silicon oxide (MMWCNTs/SiO2) and characterized using high-resolution transmission electron microscope (HRTEM), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), Fourier transform infrared photometer (FTIR), and X-Ray diffraction techniques (XRD). A bench scale experimental setup was designed for the oil in water mixture separation of the prepared materials. Subsequently, individual and interaction effects of operational parameters, e.g., MMWCNTs and MMWCNTs/SiO2 doses, initial oil concentration, pH and water salinity were investigated and optimized using response surface methodology (RSM) and ANOVA analysis at α = 0.05. The results of experimental data were fitted with polynomial models developed using RSM, and the regression analysis with an R2 value of 0.99 showed the goodness of fit for the experimental results with predicted values. The experimental results showed higher oil/water separation for MMWCNTs/SiO2 than MMWCNTsitself with a separation rate of 92.8% and 72.4%, respectively at 1 g/l of initial oil concentration. Compared with other approaches for fabricating oil-water materials, the as-prepared MMWCNTs/SiO2 is a promising candidate for efficient oil-water separation even after 5 cycles.