LAUSR

Forward osmosis has a great potential to be applied in treating biomass containing streams. However, the reverse salt permeation and the high energy consumption in draw solutes recovery pose two main obstacles. In this work, a porous FO membrane water extraction system is proposed to overcome these shortages. Using polyelectrolytes as draw solution and a porous PAN FO membrane, the system could recover water from a biologically treated wastewater (from a pilot anaerobic fluidized-bed bioreactor) with a stable flux of 7 L/m2.h using only 0.94 bar of osmotic pressure generated by 0.8% PSS draw solution. Compared with the dense FO membranes provided by HTI, the porous FO membrane could sustain a much higher flux due to its significantly higher water permeability. Meanwhile, the porous FO membrane has high rejection (99.5%) for PSS polyelectrolytes. Finally, draw solutes could be efficiently recovered (∼99%) using a low pressure UF process between each FO cycle.