Membrane Preparation for Unconventional Desalination by Membrane Distillation and Pervaporation

The treatment of concentrated saline effluent has been a great challenge in the industry, where traditional desalination techniques and membrane processes can be energy-intensive with high operational cost. In the past decade, research and development into alternative membrane processes and technologies that are energy-efficient for desalination purposes have been thoroughly explored. For example, membrane distillation and pervaporation are driven by the temperature gradient across the membrane. This special feature has shed lights on the potential utilization of low-grade energy as the driving force of these membrane processes and suggested a prospective application of concentrated saline effluents treatment. The desirable characteristics of the membranes dedicated to membrane distillation and pervaporation have very distinctive features than membranes for traditional membrane processes. Herein, we present a comprehensive review on the current state of unconventional desalination scenarios, along with their obstacles. This chapter will explore the desired characteristics of membranes, the preparation of membranes, and surface engineering, in order to serve the special requirements of membrane distillation and pervaporation. In the end, we will share some perspectives into the future trend of membrane distillation and pervaporation, regarding the design and preparation of the membranes specific to these technologies, as well as other potential applications as concentration technology in food engineering and pharmaceutical industries.