The Natural Vacuum Desalination Technology in Seawater Desalination

Seawater desalination technology is an important way to solve the freshwater shortage problem. Natural vacuum desalination (NVD) technology generates very low pressure environment in the headspace of 10 meters high water column. The weight of the water column is balanced by atmospheric pressure, and low-temperature desalination proceeds in the headspace. NVD technology drives the desalination process without any mechanical pumping, and requires relatively inferior quality of device material and simple structures. In this paper, the basic theory of NVD technology is introduced and physical model is described. Research progresses of different types of NVD technologies are summarized, and the method of increasing freshwater production is pointed out. This paper also illustrates the outlook on future development of NVD technology.