Research Subject: Synthesis of functionalized magnetic nanosorbent and determination of adsorbent properties, optimization of adsorption laboratory conditions, modeling and optimization of adsorption laboratory conditions, and determination of the kinetics of monoethylene glycol adsorption in wastewater samples by magnetic nanosorbent cobalt ferrite-triaminopropyltriethoxysilane-chitosan
Research Approach: In this research, a functionalized magnetic nanosorbent was used to remove the pollutant monoethylene glycol (MEG) from wastewater. This adsorbent was synthesized by attaching chitosan to the surface of magnetic cobalt ferrite nanoparticles CoFe2O4, and through the intermediate triaminopropyltriethoxysilane (APTES). Chitosan has a high ability to absorb organic pollutants such as monoethylene glycol due to its amino and hydroxyl functional groups. Also, the use of chitosan increases the contact surface and consequently increases the capacity of the adsorbent. The magnetic property of cobalt ferrite leads to easy separation of the adsorbent from the wastewater sample by creating a magnetic field. The properties of the synthesized adsorbent were investigated using Fourier Transform Infrared (FTIR) spectroscopy, Vibrating Sample Magnetometer (VSM), Thermogravimetric Analysis (TGA), and Scanning Electron Microscope (SEM). The optimal adsorption conditions, including pH, adsorbent saturation time, and adsorbent recovery through the adsorption and desorption cycle, were investigated.
Main results: The optimal pH value for glycol adsorption from a wastewater sample by functionalized magnetic nanosorbent was determined to be 6, and the contact time for apparent equilibrium of the adsorbent was determined to be 5 minutes, which indicates the availability of adsorbent sites for glycol. Also, the change in adsorption capacity after 10 stages of adsorption and desorption cycle was less than 21%, which indicates the high recovery capability of the adsorbent and its economic efficiency. Adsorption kinetic data were investigated by three kinetic models: pseudo-first order, pseudo-second order, and Intra-particle diffusion. Considering the higher correlation coefficient in the pseudo-second-order model (R2 = 0.9951), it can be concluded that the adsorption of glycol on the synthesized adsorbent is most consistent with this model.