زهرا اسماعيلي

Oil wastewater is one of the most dangerous and resistant types of wastewater that cannot be treated by conventional and traditional methods. Membrane separation is always one of the most widely used methods in the wastewater treatment industry, including oily wastewater, but the most important problem is fouling in the membranes, which leads to the weakening of the membrane performance, the increase of the process costs, and the impossibility of continuous processes. Photocatalytic technology is one of the promising methods to reduce membrane fouling. In this study, visible light- driven photocatalysts BiVO4/rGO and BiVO4/g-C3N4 were synthesized by hydrothermal method, and then, a ceramic photocatalytic ultrafiltration membrane with excellent self-cleaning and antifouling ability was prepared through sol-gel method for efficient treatment of oily waste water was built. The properties of photocatalysts were determined using FESEM, XRD, FTIR, DRS, nitrogen absorption and desorption and zeta potential analyses. The microfiltration ceramic membrane was converted into an ultrafiltration membrane by coating with alpha alumina and silica layers, and after the photocatalytic surface modification of the membrane, filtration tests were performed for oily wastewater. The presence of rGO and g-C3N4 carbon compounds in the structure of BiVO4 led to the improvement of its photocatalytic activity. The antifouling properties of the membrane were eva‎luated by testing the underwater oil contact angle and measuring the antifouling parameters, and surface roughness. The use of BiVO4/rGO combination with 20 wt% rGO in membrane coating caused the underwater oil contact angle to be 158 degrees. Also, in the filtration of synthetic oily wastewater with a concentration of 3000 ppm, after 3 hours, the flux showed double compared to the UF membrane without photocatalytic coating, and the TOC removal efficiency was more than 99%. In the measurement of antifouling parameters, the flux recovery was 89% compared to 51% in the ultrafiltration membrane also the irreversible fouling ratio decreased from 48% to 11% and the total fouling ratio decreased from 57% to 21%.

غشاهاي فوتوكاتاليستي , غشاي ضدرسوب , تصفيه پساب هاي نفتي , اولترافيلتراسيون

Photocatalytic membranes , Antifouling membrane , Oily wastewater treatment , ultrafiltration

Zahra Esmaeili

Dr. Ashrafizade