Combined influence of temperature and flow rate of feeds on the performance of forward osmosis

• Published in: Desalination 2016-11, Vol.398, p.98-105
• Main Authors: Hawari, Alaa H., Kamal, Nagla, Altaee, Ali
• Format: Article
• Language: English
• Subjects: Concentration polarization; Distilled water; Flow rate; Flux; Forward osmosis; Membrane flux; Membranes; Orientation; Osmosis; Polarization; Reverse solute flux; Spacers
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2016.07.023

The effect of the membrane orientation, feeds flow rate, feeds temperature, and combining effect of both temperature and flow rate on the membrane flux was investigated in order to enhance the performance of forward osmosis (FO) process. Results from experimental work demonstrated that the concentrative internal concentration polarization (CICP) could be mitigated by increasing the feed solution flow rate and using a spacer. On contrary, the severity of dilutive internal concentration polarization (DICP) phenomena was aggravated by increasing the draw solution flow rate. It was also found that when increasing the draw solution (DS) temperature from 20°C to 26°C the flux increased linearly and then started decreasing when temperature increased over 26°C due to the development of a temperature gradient. The experimental results also showed that the membrane flux increased by 93.3% due to temperature increase from 20 to 26°C and the flow rate from 1.2 to 3.2L/min using a 0.5M NaCl solution as the draw solution and distilled water as the feed solution (FS). •The impact of temperature and flow rate on the FO performance was evaluated.•At FS-AL, dilutive CP was aggravated by increasing draw solution flow rate.•Membrane flux decreased by increasing DS temperature over 26°C.•A thermo-osmosis effect was responsible for reducing the flux at high temperature.•Membrane flux increase by increasing feed temperature from 20°C to 32°C.