Sustainable Membrane Distillation Coupled with Solar Pond

The necessity for fresh water is at the top of the international schema of serious issues. As the fresh water shortage becomes an issue, the application of desalination plants is rapidly rising on a large scale. Also, membrane technologies are gaining high importance for their great performance and their economic viability. Membrane distillation as a novel thermally-driven separation process can be adapted for water desalination, due to its simplicity and ability to couple with a sustainable source of energy. In this paper, study was conducted to develop a Sustainable Water Desalination (SWD) system by combining direct contact membrane distillation with solar ponds. A brief explanation of the solar pond concept and the concept of the membrane distillation (MD) system was illustrated. Additionally, the possibility of desalinating high saline water with zero brine discharge was investigated. Moreover, an alternative source of energy which is from the heat stored in the lower zone of the solar pond was investigated by using the combination of MD and salinity gradient solar pond (SGSP). In this work, the idea of using the surface of the solar pond as heat sink for the permeate water was considered, by introducing floating cooling pipes that are also acting as wave suppressors to reduce the surface mixing in solar pond caused by wind-driven currents. Furthermore, the present understanding and contribution to the research efforts to build a SWD technology system was analysed. In addition to the concept illustration, an indoor study was also conducted about the performance of MD with variation of the feed temperature. It concluded that as the feed temperature increases, the heat flux, mass flux, heat transfer coefficients and evaporation efficiency will increase as the temperature polarization coefficient decreases.