Mineral Recovery System in a CEEF (2)

A unique recovery system for NaCI (salt) from urine, which consists of electrodialysis (ED) and crystallization processes is proposed. The possibility of the mineral recovery included in urine is shown in a previous report. To improve the purity of the produced salt, pH control is needed as a pretreatment. By controlling pH of the feed solution to about 10, multivalent ions such as Ca²⁺ and Mg²⁺ are crystallized as phosphate solids which can be separated by filtration. As well as raising the NaCI purity, this controls scaling b y multivalent ions.