Abstract
Research Subject: The presence of antibiotics in drinking water sources indicates the inefficient removal of pharmaceutical compounds by conventional methods, and the consequences of their presence in the environment cannot be ignored. The aim of this research is to fabricate a polyethersulfone nanofiltration membrane modified with titanium dioxide nanoparticles to remove amoxicillin from aqueous solutions.
Research Approach: In this research, pure polyethersulfone membranes and membranes with nanoparticles additives were fabricated by the phase inversion method. For this purpose, first, the percentage of the base polymer was optimized and the pores of the membrane were controlled to achieve maximum separation. Then, the appropriate membrane was modified with different percentages of nanoparticles (0.2, 0.5 and 1 wt%). A 22% polyethersulfone membrane with 79% rejection and a pure water flux of 1.19 l/m2.h was selected as the optimal membrane and then modification processes were performed on this membrane. Subsequently, the membranes were characterized using FTIR, water contact angle, SEM, AFM, and XRD techniques, as well as the pure water flux and amoxicillin separation efficiency.
Main Results: The results of FTIR analysis and contact angle measurements showed that the hydrophilicity of the membranes increased significantly due to the presence of hydroxyl groups in the TiO2 structure. The results of SEM images showed that the addition of nanoparticles increased the thickness and formation of small tear-like pores in the active layer, as well as the length of the tear-like pores in the substrate. Obviously, this increases the porosity and consequently the pure water flux from 1.19 to a maximum of 53.04 l/m2.h (membrane with 1wt% nanoparticles). Also, AFM images showed that the surface roughness of the synthesized membranes increased with the increase in nanoparticles. The findings show that the membrane containing 0.5% nanoparticles with a flux of 27.32 l/m2.h and a rejection of 85.72% has the best performance. The results of this study showed that the use of nanocomposite membranes for the removal of non-biodegradable contaminants such as amoxicillin antibiotics from water sources is promising.