Developing innovative technologies to achieve water-energy sustainability is a top priority challenge of the nearest future. We propose a novel renewable energy source, which provides simultaneous production of clean water and electrical energy from wastewater by utilizing a naturally occurring osmotic process. Our objective is to develop emerging and cost-efficient Pressure Retarded Osmosis (PRO) process, equipped with our smart PRO membranes, to provide excellent water and energy recovery from Alberta’s Oil Sands. This will be done by incorporating stimuli-responsive nanomaterials into the host membrane matrix. Our PRO process, apart from water reclamation function, provides high power density to harness electrical energy from wastewater.
We fabricated 4 types of specialty PRO thin-film composite (TFC) membranes and constructed a unique bench-scale PRO setup. The fabricated membranes possessed sufficient mechanical stability to generate a minimum power density of 5 W/m2 under long-term PRO conditions. We characterized the developed membranes in terms of morphology, permeation properties, and generated power density. The high water permeability (> 40 L/m2h in the optimized membrane) and excellent contamination selectivity (<7 g/m2h reverse salt passage) confirmed the suitability of these membranes for the PRO process. The optimum amount of extractable energy from the PRO process using our synthesized membranes was more than 18 W/m2 at 20 atm hydraulic pressure and 1.5 M draw solution.