Synthesis of Nanozeolite and its Efficiency in Reducing the Ca2+ of Shiraz Oil Refinery Wastewater

The production of industrial wastewater with a variety of compounds is one of the major environmental challenges of human societies, posing a great threat to the health of society. In this study, synthesis of Y-type nanozeolite and its efficiency in reducing the Ca2+ of Shiraz oil refinery effluent compared to acid treated natural zeolite was investigated. Synthensis of nanozeolites was performed by sol-gel method using sodium silicate and sodium aluminate solution. The synthesized samples were analyzed by X-ray diffraction analysis, scanning electron microscopy, and Brunauer-Emmett-Teller (BET) test. The X-ray diffraction results confirmed the crystalline structure of Y-type nanozeolites. The scanning electron microscopy images showed the formation of mesoporous particles. The specific porosity of the synthesized nanozeolite and also the total porosity were determined as 805.4m2/g and 0.4222 m3/g, respectively by BET analysis. Based on the nitrogen gas absorption / desorption isotherm, the presence of mesopores along the micro-pore in synthesized nanozeolite was confirmed. Kinetic studies showed the adsorption kinetics of both adsorbents are fit well with pseudo-second-order model, indicating that the interaction between the absorber surface and the adsorbent is the determining factor in adsorption process and diffusion of the Ca2+ ions to the inside of mesoporous zeolite canals is fast. The removal amount of Ca2+ from wastewater of oil-refinery for natural zeolite(50 g) and nano zeolite(5 g) in 1 L wastewater  after equilibrium time was determined as 60% and 95%, respectively and pH=7 was determined as the optimum pH.