Grant: Research Tools and Instruments

Separating dilute oil contaminations from wastewater is a practical problem in various industries such as food, metal processing, and petroleum industries. The presence of low concentration oil in wastewater challenges the efficiency of conventional separation methods, especially when the oil is viscous, dispersed, and has a density similar to water. We propose to fabricate a customized and integrated system for oil-water separation, using advanced and engineered materials. Unlike alternative systems, our proposed equipment can separate all forms of oil contaminations, including free oil, dispersed oil, and emulsified oil. Using superhydrophobic and superoleophilic membranes, in the first step of separation, the free oil and large oil droplets are passively separated from the water. In this stage, superhydrophobic and superoleophilic membranes capture free and dispersed oil contaminations. Our proposed membranes are less prone to fouling as the solid particles are usually in the water phase that do not wet our hydrophobic membranes. In the second stage, functionalized stainless steel brushes that are operated under a slight vacuum condition will separate the oil droplets when they are in contact with the high capillary pressure areas between the wires. There is a possibility of having micro- and nano-emulsified oil contaminations left in the aqueous phase that is not separated in the previous two stages. We will use functionalized magnetic nanoparticles to encapsulate the nano-sized oil droplets to be separated upon applying a magnetic field. The emulsions are usually separated through energy-intensive processes such as ultrafiltration, dissolved air floatation, and coagulation. Our proposed method of using the magnetic nanoparticles is a passive separation method that uses a magnetic field supplied by permanent magnets, having a minimum energy demand. The magnetic field increases the driving force in separating the emulsified oil droplets. This can be of great interest to the Canadian heavy oil and bitumen, where the density of the oil can be similar to that of the water phase, leading to a significant delay in the separation process. The equipment can be customized to tolerate the harsh fluid characteristics of the Canadian hydrocarbons, such as heavy crude oil, high asphaltene, and resin contents, by choosing wetted materials that resist harsh chemicals. The proposed oil-water separation system will enable research studies in areas such as flow hydrodynamics of dispersed oil-water flow and flow assurance strategies related to emulsions, wax, hydrate, and asphaltene precipitation/deposition and removal. Also, the proposed experimental set up will have a great impact on the separation of oily wastewater and oil spill removal at low energy input. Additionally, the proposed system will enable training HQPs, including undergraduate and graduate students in the areas of chemical engineering, environmental engineering, and mechanical engineering.********