Power effect of ultrasonically vibrated spacers in air gap membrane distillation: Theoretical and experimental investigations

Al-Juboori, Raed A. and Naji, Osamah and Bowtell, Les and Alpatova, Alla and Soukane, Sofiane and Ghaffour, Norreddine (2021) Power effect of ultrasonically vibrated spacers in air gap membrane distillation: Theoretical and experimental investigations. Separation and Purification Technology, 262:118319. pp. 1-12. ISSN 1383-5866


Abstract

This study investigates the efficiency of low-power ultrasound in the range of 3.5–30.0 W to improve permeate flux and alleviate membrane fouling in an air–gap membrane distillation (AGMD) system. Natural groundwater and reverse osmosis (RO) reject water were fed into the AGMD system on which fouling experiments were conducted with hydrophobic polyvinylidene fluoride (PVDF) membrane. After 35 h of AGMD system operation with groundwater and RO reject water, fouling caused the permeate flux to decrease by 30% and 40% respectively. Concentration polarization, intermediate pore blocking, and cake filtration appear to be the main reasons for flux decline with both feedwater types. Ultrasound application for a short period of 15 min resulted in flux improvement by as high as 400% and 250% for RO reject and groundwater, respectively. Modelling of the heat and mass transfers showed that the flux increase was mainly due to membrane permeability improvements under ultrasonic vibration. Fouling visualisation using Scanning Electron Microscopy revealed that ultrasound effectively removed membrane fouling without compromising the membrane’s structure. Importantly, permeate flux improvements with targeted low-power ultrasound appears to be proportionally higher than those of high-power ultrasound applied to the whole system, on a flux improvement per ultrasound W/m2 basis.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 -)
Faculty/School / Institute/Centre: Current - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 -)
Date Deposited: 26 Jan 2021 22:51
Last Modified: 22 Jun 2021 11:07
Uncontrolled Keywords: AGMD; Ultrasonically vibrated spacers; Fouling; Groundwater; RO reject
Fields of Research (2008): 09 Engineering > 0906 Electrical and Electronic Engineering > 090603 Industrial Electronics
09 Engineering > 0905 Civil Engineering > 090508 Water Quality Engineering
09 Engineering > 0906 Electrical and Electronic Engineering > 090699 Electrical and Electronic Engineering not elsewhere classified
Fields of Research (2020): 40 ENGINEERING > 4011 Environmental engineering > 401102 Environmentally sustainable engineering
40 ENGINEERING > 4009 Electronics, sensors and digital hardware > 400907 Industrial electronics
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9611 Physical and Chemical Conditions of Water > 961101 Physical and Chemical Conditions of Water for Urban and Industrial Use
D Environment > 96 Environment > 9611 Physical and Chemical Conditions of Water > 961103 Physical and Chemical Conditions of Water in Fresh, Ground and Surface Water Environments (excl. Urban and Industrial Use)
Socio-Economic Objectives (2020): 18 ENVIRONMENTAL MANAGEMENT > 1803 Fresh, ground and surface water systems and management > 180399 Fresh, ground and surface water systems and management not elsewhere classified
17 ENERGY > 1701 Energy efficiency > 170102 Industrial energy efficiency
Identification Number or DOI: https://doi.org/10.1016/j.seppur.2021.118319
URI: http://eprints.usq.edu.au/id/eprint/40783

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