Temperature effects of MD on municipal wastewater treatment in an integrated forward osmosis and membrane distillation process
Temperature effects of MD on municipal wastewater treatment in an integrated forward osmosis and membrane distillation process
An integrated forward osmosis (FO)-membrane distillation (MD) process is promising for the treatment and resource recovery from municipal wastewater. As higher temperature is applied in MD, it could affect the performance of both FO and MD units. This study aimed to investigate the effects of the type of draw solution (DS) and feed solution (FS) such as ammonium solution or municipal wastewater containing ammonium and draw solution (DS) at higher temperatures on membrane treatment performance. It is found that higher FS and DS temperatures resulted in a higher water flux and a higher RSF with either NaCl or glucose as DS due to the increased diffusivity and reduced viscosity of DS. However, the water flux increased by 23-35% at elevated temperatures with glucose as DS, higher than that with NaCl as DS (8-19%), while the reverse solute flux (RSF) increase rate with NaCl as DS was two times higher than that with glucose as DS. In addition, the use of NaCl as DS at higher temperatures such as 50 and FS at 42 °C resulted in increased forward ammonium permeation from the FS to the DS, whereas ammonium was completely rejected with glucose as DS at all operating temperatures. Reducing pH or lowering the temperature of DS could improve ammonium rejection and minimize ammonia escape to the recovered water, but the extra cost or reduced MD performance could be led to. Therefore, the results suggest that in an integrated FO–MD process with DS at higher temperatures such as 50 °C, glucose is better than NaCl as DS. Furthermore, a simplified heat balance estimation suggests that internal heat recovery in the FO-MD system is very necessary for treating municipal wastewater treatment. This study sheds light on the selection of DS in an integrated FO-MD process with elevated temperature of both FS and DS for the treatment of wastewater containing ammonium. In addition, this study highlights the necessity of internal heat recovery in the integrated FO-MD system.
Ammonium, Forward osmosis, Heat recovery, Membrane distillation, Municipal wastewater, Water recovery
Almoalimi, Khaled
69df5031-815b-47ea-b014-d7975dfa7829
Liu, Yongqiang
75adc6f8-aa83-484e-9e87-6c8442e344fa
February 2022
Almoalimi, Khaled
69df5031-815b-47ea-b014-d7975dfa7829
Liu, Yongqiang
75adc6f8-aa83-484e-9e87-6c8442e344fa
Almoalimi, Khaled and Liu, Yongqiang
(2022)
Temperature effects of MD on municipal wastewater treatment in an integrated forward osmosis and membrane distillation process.
Processes, 10 (2), [355].
(doi:10.3390/pr10020355).
Abstract
An integrated forward osmosis (FO)-membrane distillation (MD) process is promising for the treatment and resource recovery from municipal wastewater. As higher temperature is applied in MD, it could affect the performance of both FO and MD units. This study aimed to investigate the effects of the type of draw solution (DS) and feed solution (FS) such as ammonium solution or municipal wastewater containing ammonium and draw solution (DS) at higher temperatures on membrane treatment performance. It is found that higher FS and DS temperatures resulted in a higher water flux and a higher RSF with either NaCl or glucose as DS due to the increased diffusivity and reduced viscosity of DS. However, the water flux increased by 23-35% at elevated temperatures with glucose as DS, higher than that with NaCl as DS (8-19%), while the reverse solute flux (RSF) increase rate with NaCl as DS was two times higher than that with glucose as DS. In addition, the use of NaCl as DS at higher temperatures such as 50 and FS at 42 °C resulted in increased forward ammonium permeation from the FS to the DS, whereas ammonium was completely rejected with glucose as DS at all operating temperatures. Reducing pH or lowering the temperature of DS could improve ammonium rejection and minimize ammonia escape to the recovered water, but the extra cost or reduced MD performance could be led to. Therefore, the results suggest that in an integrated FO–MD process with DS at higher temperatures such as 50 °C, glucose is better than NaCl as DS. Furthermore, a simplified heat balance estimation suggests that internal heat recovery in the FO-MD system is very necessary for treating municipal wastewater treatment. This study sheds light on the selection of DS in an integrated FO-MD process with elevated temperature of both FS and DS for the treatment of wastewater containing ammonium. In addition, this study highlights the necessity of internal heat recovery in the integrated FO-MD system.
Text
processes-minor-04-02-2022 (5)
- Accepted Manuscript
More information
Accepted/In Press date: 4 February 2022
Published date: February 2022
Additional Information:
Funding Information:
The paper is partially supported by the National Natural Science Foundation of China (No. 51409033, 52171342), and the Fundamental Research Funds for the Central Universities (No. 3132019343).
Funding Information:
Acknowledgments: The authors thanks EBNet, BBSRC, UK, for funding the APC and Aerobic Gran‐ ules Working Group, EBNet for supporting the work. The King Saud University is also thanked for sponsoring Khaled Almoalimi for his PhD study at the University of Southampton, UK.
Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Keywords:
Ammonium, Forward osmosis, Heat recovery, Membrane distillation, Municipal wastewater, Water recovery
Identifiers
Local EPrints ID: 455297
URI: http://eprints.soton.ac.uk/id/eprint/455297
ISSN: 2227-9717
PURE UUID: cd9a0719-caf2-404a-aade-38117a96eae7
Catalogue record
Date deposited: 16 Mar 2022 18:01
Last modified: 17 Mar 2024 03:32
Export record
Altmetrics
Contributors
Author:
Khaled Almoalimi
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
