Achievements in membrane distillation processes for wastewater and water treatment

Abstract Membrane distillation (MD) is a membrane-based thermal separation process. Vapor pressure difference between both sides of the membrane is the driving force for mass transfer of volatile compounds via the gas phase. A hydrophobic porous membrane is generally used as a barrier to isolate the feed from the volatiles permeated across the membrane. Although MD is a thermally energy-intensive process, it can be coupled with low-grade/waste heat sources to increase the overall thermal energy utilization efficiency or reduce thermal pollution. In this chapter, five aspects of MD were studied: • Configurations of MD and their applications in wastewater and water treatment • MD performance enhancement and employment scope broadening by membrane material and structure modifications • MD commercialization • Treatment cost analysis • Conclusion and future trends