Membrane distillation-Principles, applications, configurations, design, and implementation

Membrane distillation (MD) is a promising technology for treating saline water and wastewater with high rejection factors, which cannot be accomplished by conventional technologies. MD is a thermally driven separation process in which only the vapor molecules pass through a microporous hydrophobic membrane. The driving force in the MD process is the vapor pressure difference induced by the temperature difference across the membrane surface. This chapter provides a comprehensive study of MD. The first part gives an introduction, including general information about water problems, existing water technology, and historical review for MD. MD configuration and modules, membrane properties, and membrane characterization will be illustrated in the second and third parts. The transport phenomena relating to mass and heat transfer for different MD types are also presented. Operating parameters and MD application are covered in this chapter.