LOW ENERGY SYSTEM AND METHOD OF DESALINATING SEAWATER

摘要

A low energy system and process for seawater desalination wherein the system has at least an electrodialysis apparatus that produces partially desalinated water and a brine by- product, an ion exchange softener, and at least one electrodeionization apparatus. The softener treats the partially desalinated water stream to remove or reduce the amount of scaling material in order to maintain deionization apparatus efficiency and reduce energy consumption. The softener has the capability of removing a higher ratio of calcium ions to magnesium ions than is in the partially desalinated stream, thereby reducing softener size and energy use. The deionization apparatus produces product water of the desired properties. The brine stream may be used to regenerate the softener.