Application of progressive freeze-concentration for desalination

There is a demand for new and effective desalination technologies, as water shortage is expected to spread all over the world in the future. Among many methods, the freeze desalination process has some advantages such as high energy efficiency, corrosive resistance, and easy operation. In this study, a progressive freeze-concentration, currently used in food processing, was applied for desalination. The progressive freeze-concentration is a method to concentrate impurities into a liquid phase and obtain a pure solid phase by controlling an ice front one-dimensionally. The effect of three parameters (the advance speed of the ice front (U), the circumferential velocity of the stirrer (Ur), and initial concentration (C0)) were investigated by conducting the laboratory experiments. In order to evaluate the efficiency of the desalination process, effective partition constant (K), and intrinsic partition constant (K0) were introduced by adopting the concentration gradient model. The results showed the effect of three parameters on desalination successfully. Furthermore, at a certain Co, K can be expressed as a function of U, Ur and K0. This function is useful for scaling up the system. [Display omitted] •Progressive freeze-concentration was adopted for desalination.•Effects of three parameters on desalination were investigated.•Two partition constants successfully evaluated the efficiency of desalination.•This system can be scaled up.