Thesis (MSc.) - Cyprus International University. Institute of Graduate Studies and Research Environmental Science Department

Includes bibliography (sheets 65-70)

ABSTRACT
In membrane technology, membrane surface modification using nanoparticles have been used to improve membrane performance and reduce membrane fouling in the recent years. With the advantages and limited use of CuO particles in membrane surface modification, this research used already synthesized CuO/SDS and CuO/CTAB in concentrations of 50 mg/L, 100 mg/L, 500 mg/L and 1000 mg/L which were deposited on the membrane surface using an active dead end ultrafiltration setup at 3bar at different solutions of pH 4, pH 7 and pH 10 to investigate the effect on the PES membrane. Any possible changes on the membrane surface after filtration were characterized using the Fourier Transform Infrared (FTIR) spectrophotometer. The pure membrane gave a flux of 281±30 L/m2.hr. In this study, there was no influence of particle deposition on the membrane at various concentrations at solution pH 7. The PES membrane had a high percentage rejection of 95% and 98% for both CuO/SDS and CuO/CTAB respectively. The findings also shows that at pH 7 and pH 4 acid solution for both CuO/SDS and CuO/CTAB, there was no increase or decrease in membrane flux for all particle concentrations used. In opposite, CuO/SDS and CuO/CTAB 100 mg/L at pH 4 buffer solution had 34% and 30% decrease in membrane flux respectively as compared to the 80% and 74% decrease in flux at pH 10 alkaline buffer solutions for both particles. In addition, fouling models were applied to the flux data. The constant pressure filtration laws confirm complete pore blocking as the dominant fouling mechanism with an R2 of 1 for the deposition of CuO/SDS and CuO/CTAB on the PES membrane. Altering the pH to pH 10 with buffer solution had the most effect on the PES membrane performance.