Mohammadali Baghbanzadeh
University of Ottawa, Canada
Title: Enhancement of the structural properties of membranes by hydrophilic nanoparticles for vacuum membrane distillation
Biography
Biography: Mohammadali Baghbanzadeh
Abstract
Desalination has been demonstrated to be an appropriate technology in compensating the lack of fresh water in different areas of the world. Among the processes which are used for treating the saline water, membrane-based technologies have been placed on top due to their energy-saving and cost-effective nature. Presently, desalination load is mainly dominated by reverse osmosis (RO), i.e. a pressure driven process which fairly demands large amount of electrical energy and works in harsh operating conditions. Membrane distillation (MD) has been shown to be a serious competitor with RO in obtaining the desalination market owing to its low tendency to fouling and scaling which further results in a simplified pre-treatment process, its ability in processing the high concentration feeds and working in mild operating conditions. Although, huge thermal energy consumption within the process along with the low performance MD membranes have been led to this fact that reaching the fresh water by MD is not economically feasible. One approach in reducing the thermal energy consumption could be the development of high performance MD membranes which works efficient at low temperatures. In other words, MD needs durable membranes which are able to achieve the high flux i.e. that of the MD membranes in typical operating conditions, at low temperatures. To improve the membrane performance and considering the outstanding characteristics of the nanocomposite membranes, in this study, hydrophilic nanomaterials, i.e. CaCO3, CuO, and SiO2 were incorporated in a polyvinylidene fluoride(PVDF) membrane for vacuum membrane distillation (VMD). According to the results, hydrophilic nanoparticles could improve the membrane structure via enlarging the surface pores and increasing the membrane porosity through reducing the thickness of the sponge-like layer, i.e. the major contributor to mass transfer resistance in the membrane. The permeability of the neat PVDF membrane at 27.5 ºC increased by 102.3%, 153.4%, and 2456.0% via using the appropriate amount of CaCO3, CuO, and SiO2 nanoparticles respectively. All the nanocomposite membranes possessed suitable contact angle and liquid entry pressure (LEPw) along with perfect rejection to be employed in desalination by VMD.