tailieunhanh - Influence of operating conditions and membrane fouling on water flux during seawater desalination using air gap membrane distillation

The results reported in this study manifest that seawater AGMD desalination can be a practical process to supply drinking water to small and remote communities in Vietnam. | Vietnam Journal of Chemistry, International Edition, 55(5): 638-644, 2017 DOI: Influence of operating conditions and membrane fouling on water flux during seawater desalination using air gap membrane distillation Duong Cong Hung1,2*, Huynh Thai Nguyen2, Pham Manh Thao2, Trinh Thi En2, Luong Trung Son2 1 Strategic Water Infrastructure Laboratory, School of Civil Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522, Australia 2 School of Environmental Engineering, Faculty of Physics and Chemical Engineering, Le Quy Don Technical University, 236 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam Received 14 March 2017; Accepted for publication 22 October 2017 Abstract Membrane distillation (MD) has emerged as a promising process for seawater desalination applications to augment fresh water supply in remote coastal areas. Amongst four basic MD configurations, air gap membrane distillation (AGMD) exhibits the highest thermal efficiency, and thus is the most used configuration for small-scale seawater desalination. In this study, the influences of operating conditions and membrane fouling on water flux of a lab-scale AGMD process with actual seawater feed were systematically investigated. The experimental results demonstrated strong impacts of feed temperature, circulation rates, and membrane fouling on the process water flux. Increasing feed temperature exponentially raised water flux but also aggravated polarization effects of the AGMD process. Elevating water circulation rates, particularly of the feed stream, helped alleviate polarization effects, hence improving the process water flux. During the AGMD process of raw seawater feed, the accumulation of organic matters on the membrane reduced its active surface for water evaporation, increased polarization effects, and therefore significantly reduced the process water flux. Pretreatment of the seawater feed by μm paper filters removed organic foulants from