Investigation of thin-film composite hollow fiber forward osmosis membrane for osmotic concentration: A pilot-scale study

The current study applied the forward osmosis (FO) based osmotic concentration (OC) process at the pilot-scale for concentrating synthetic feed solution (FS). The process water (PW) salinity represents effluents from the gas industry, while the draw solution (DS) mimics seawater. Besides, the performance of a hollow fiber (HF) membrane manufactured from polyamide thin film composite (PA-TFC) was evaluated. The effect of operation with various feed recovery rates, flowrates and temperatures on the OC performance was examined. Outcomes reveal that the tested membrane succeeded in recovering up to 90% of FS at water flux of 6.40 LMH. The stability of OC plant was successfully demonstrated for 48 hours long-term run at 75% feed recovery as an optimum condition, where the TFC membrane achieved average water flux of 6.00 LMH, respectively. Higher DS flowrate improved the OC performance by inducing higher water permeation and FS recovery; however, it increased the undesirable reverse solute diffusion. Lastly, the permeability coefficient of the HF membrane was estimated by 2.69 LMH/bar at 25 °C, which significantly enhanced at higher temperatures.