فائز روشن ضميرچمثقالي

Global warming and the lack of water resources in the world have made it important to expand wastewater treatment and recycle water for reuse in industrial and agricultural processes. Membrane technology is particularly important among the technologies used in water and wastewater treatment. One of the relatively new methods in this field is the use of a membrane bioreactor (MBR) system, in which the activated sludge process is integrated with membrane filtration. Rapid fouling of the membrane and drop in filtration flux is one of the most challenging problems of this system. Based on the research, making hydrophilic membranes with antibacterial properties is known as an effective way to reduce constipation. In the present study, polyvinylidene fluoride/diamond ultrafiltration hollow fiber membranes were made by phase separation method by non-solvent and eva‎luated for wastewater treatment in membrane bioreactor system. In order to increase hydrophilicity, increase the interaction between polymer and diamond nanoparticles, physical stabilization of nanoparticles in the polymer matrix and also to strengthen the antibacterial properties of diamond nanoparticles, the process of modifying the surface of nanoparticles was done first by thermal oxidation and then with the natural polymer chitosan, due to which respectively Carboxyl and amine functional groups were substituted on nanoparticles. In order to check the quality of modification of diamond nanoparticles, Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Electron Microscope (FESEM) were used and the successful formation of carboxyl and amine functional groups on diamond nanoparticles as well as their size increase was observed. Further, in order to characterize the manufactured membranes, tests of pure water permeability, contact angle, porosity, mechanical resistance, field emission electron microscope and pollutant removal rate were used. According to the obtained results, it was observed that the nanoparticle-modified membranes have a thicker inner spongy wall compared to the pure sample, which is due to their proper interaction with the polymer and the higher viscosity of the polymer solution compared to the pure membrane. The modified samples were more hydrophilic due to the presence of functional groups containing oxygen and amine, and the contact angle decreased by 20° compared to the membrane without nanoparticles. The flux of pure water increased by 81.6% in the modified sample compared to the membrane without nanoparticles. Increasing the hydrophilicity and antibacterial properties of the membranes led to the repulsion of microorganisms and prevented the formation of colony secretions on the surface of the membrane. Therefore, by examining the performance of membranes containing modified nanoparticles in membrane bioreactors, it was observed that the pollutant removal rate is 99.8%, the flux recovery is 97.8% and the total fouling is 7.9%, which shows the improvement of the anti-fouling and antibacterial performance of the membrane compared to the membrane It is without nanoparticles.

بيوراكتورغشايي , غشاهاي اولترافيلتراسيون , پلي‌وينيليدن‌فلورايد , نانوذره الماس , كيتوسان

membrane bioreactors , ultrafiltration membranes , polyvinylidene fluoride , diamond nanoparticles , chitosan

Faez roshanzamir

Dr.Toraj mohammadi