The Chemical Engineering Department at the College of Engineering, University of Baghdad, held a Ph.D. thesis examination titled:
“Fabrication and Performance of PAN/PSF UF Membranes Modified with Surfactant and Green Nano particles for Oily Wastewater Treatment”
By the student “Maryam Salih Karbol” and supervised by Prof. Dr. Sama M. Al-Jubouri. The examination committee consisted of Prof. Dr. Wadoud Taher Mohammed as Chairman and the membership of Prof. Dr. Zainab Yousif Shanin , Prof. Dr. Asrar Abdallah Hassan, Asst. Prof. Dr. Nada Naoum Abdul Razaq and Asst. Prof. Dr. Ziyad Tareq Ahmed. The thesis was accepted after conducting a public discussion and listening to the student’s defense. The thesis was summarized as follows:
The aim of study:
“The present study focuses on the fabrication of a polymeric membrane based on polyacrylonitrile (PAN) and polysulfone (PSF) via the phase inversion technique. To enhance the membrane’s structural and separation properties, modifications were carried out using a non-ionic surfactant (C12EO10) as an organic additive, in addition to incorporating silica (SiO₂) and alumina (Al₂O₃) nanoparticles as inorganic fillers. The developed membranes were systematically evaluated for their efficiency in treating oily wastewater through ultrafiltration (UF) under low-pressure operating conditions. The modifications aimed to improve membrane permeability, selectivity, and fouling resistance, thereby achieving high performance in oily wastewater separation applications.”
Abstract:
Recent studies have been focusing on effective ideas dealing with the treatment of wastewater polluted by oil. This study mainly presents the development of new flat sheet polyacrylonitrile (PAN)/polysulfone (PSF) blended polymer ultrafiltration membranes by decaethylene glycol monododecyl ether (C12EO10) as a non-ionic surfactant. Also, the development includes adding polyethylene glycol as a pore former, silica nanoparticles as green fillers prepared from rice husks (RHA-SiO2 NPs), and aluminium oxide nanoparticles (Al2O3 NPs) with phases (gamma and alpha) to raise the hydrophilicity and porosity of the membrane to remediate oily wastewater. Polymeric solutions containing 17 wt.% of both PAN and PSF with different ratios of 9:1, 8:2, 7:3, 2:1, 1:2, and 1:1 were modified by different mass concentrations of C12EO10 (3 wt.% and 6 wt.%) and polyethylene glycol (3 wt.% and 6 wt.%). Moreover, RHA-SiO2 NPs with varying concentrations (0.5 wt.%, 0.75 wt.%, and 1 wt.%) and Al2O3 NPs with varying concentrations (1 wt.%, 2 wt.%, and 3 wt.%) were used to improve the PAN/PSF blend, which performed successfully in the presence of the C12EO10.
The performance of the prepared membranes was tested in terms of permeate flux and vacuum gas oil (VGO) removal% expressed as chemical oxygen demand (COD) removal%. The field emission scanning electron microscope, Fourier-transform infrared spectroscopy, water contact angle, atomic force microscopy, Energy dispersive spectroscopy, surface charge, porosity, mechanical properties, and mean pore size were used to characterize the prepared membranes. Also, the effect of initial VGO concentration (150, 250, and 500 mg/L) on the permeate flux and COD removal% was investigated. The results showed the incorporation of C12EO10 in the PAN/PSF (8:2) casting solution reduced the contact angle from 63.01° to 31.14°, gave appreciable permeate flux of 77.1 L/m2.h, and distinct COD removal of 92% in comparison with the PAN/PSF blended ultrafiltration membrane.
Adding 0.5 wt.% of the RHA-SiO2 NPs to the PAN/PSF blend membrane containing 6 wt.% of C12EO10 produced the PPCS-6-0.5 membrane with an excellent permeate flux of 112 L/m2.h, favorable hydrophilicity with a contact angle of 16.21°, and a COD removal% of 95%. Further, the improvement of the PAN/PSF blend membrane containing 6 wt.% of C12EO10 using 2 wt.% of the γ-Al2O3 NPs produced the PPCA-6-2γ membrane with an excellent permeate flux of 189.2 L/m²·h, contact angle of 26.55°, and a high COD removal% of 97.15%. In addition, the antifouling features in terms of flux recovery ratio, reversible fouling ratio, irreversible fouling ratio, total fouling ratio, and the COD removal% were studied using the PPCS-6-0.5 and PPCA-6-2γ membranes during the filtration of VGO. The flux recovery ratio was 96.05% for the PPCS-6-0.5 membrane and 95.4% for the PPCA-6-2γ membrane.
The fouling mechanism that determines the flux reduction during crossflow ultrafiltration by the PPCS-6-0.5 and PPCA-6-2γ membranes was studied using the Hermia models. The cake layer formation model provided the best match for experimental behavior when analyzing the flux reduction with time for the PPCS-6-0.5 and the PPCA-6-2γ membranes. The fabrication cost was determined for PPCS-6-0.5 and PPCA-6-2γ membranes to be $3.26/20 g and $1.67/20 g, respectively. So, the local manufacturing costs of the PPCS-6-0.5 and PPCA-6-2γ membranes did not surpass 90 $/m2 of the membrane.
