Submerged membrane distillation for inland desalination applications

• Comparison of submerged vacuum membrane distillation with conventional configurations
• Permeate flux increased with the application of transverse vibration.
• Periodical aeration and air backwash may be detrimental to scaling mitigation with complex feeds.

Submerged vacuum membrane distillation is an alternative to conventional membrane distillation configurations which offers lower energy consumption and higher thermal efficiency. The feasibility of a submerged vacuum membrane distillation system for inland desalination was investigated. Relatively similar flux could be achieved compared to cross-flow vacuum membrane distillation, but a lack of agitation led to a faster rate of wetting. Transverse vibration was applied to limit crystal deposition on the membrane surface. While an increase in permeate flux was observed, scaling was not significantly reduced. Further attempts at scaling mitigation with periodical air backwash and aeration suggested that bubble generation may lead to more crystal deposition on the membrane when using a mixed feed solution containing sparingly soluble salts.