干旱区生态环境知识资源中心

To this study bench pilot WAIV units (similar to 1 m(2) evaporation area loaded on 0.17 m(2) footprint) were operated on two different desalination brines (RO and ED) as well as on a mineral brine concentrate under arid conditions of the Negev Highlands. The evaporation rate with the WAIV unit on these feeds often gave evaporation rates per footprint that were 10-fold or greater than the pan evaporation rate obtained from the local meteorological station at Sde Boker. Desalination brines were concentrated up to 23% TDS when operating on ED concentrate. The evaporation from the WAIV unit demonstrated enrichment in the magnesium ion compared to the calcium and the sodium ion, including over a two-fold enrichment of magnesium relative to calcium as would be expected by the equilibrium solubilities of the different minerals. Despite precipitation of minerals, there is not a large buildup of deposit on the flexible evaporation surface, and this helps establish the feasibility for recovering minerals from the desalination brine by using WAIV unit. For the ED-RO hybrid desalination process which provided one of the feeds to the WAIV unit, WAIV capital costs will only be about 5.5% of the annualized desalination costs (CAPEX and OPEX).