Seawater desalination concentrate—a new frontier for sustainable mining of valuable minerals

The ocean has often been announced as a sustainable source of important materials for civilization. Application of the same extraction processes to desalination concentrate, rather than to unconcentrated seawater, will necessarily be more energetically favorable, so the expansion of seawater desalination in recent decades brings this dream closer to reality. However, there is relatively little concrete commercial development of 'concentrate mining'. This review assesses the technical and economic prospects for utilization of commercially viable products from seawater. The most important technologies for economic use of products from desalination plant concentrate are technologies for more economic separation and technologies for more economic concentration. The most promising separation technologies are those, such as nanofiltration, which separate brine into streams enriched/depleted in entire classes of constituents with minimal input of energy and reagents. Concentration is becoming more economic due to rapid advances in Osmotically-Assisted RO technology. Despite very active research on many aspects of desalination concentrate utilization, it is likely that commercial development of the non-NaCl components of desalination brine will depend on the available market for NaCl, as the challenges and costs of extracting the other mineral components from bitterns in which they are highly enriched are so much less than those faced in direct treatment of brines

Biological and corrosion aspects of a multi-stage flash seawater desalination plant after deaerator modification

Deaeration units of a commercial multi-stage flash (MSF) cogeneration facility underwent venting modifications to increase system distillate productivity without increasing energy consumption or elevating top brine temperatures. Three MSF units were investigated after oxygen levels of deaerators spiked above design limits (20 ppb). The investigation found a significant biotic presence in the deaerator unit’s MSF heat rejection sections that included algae, bacteria, bivalves, and bivalve larvae. The bivalve taxa consists of Barbatia parva, Diodora funiculata, Pinctada margaritifera, Amiantis umbonella, and Acrostergma assimile. Galvanic corrosion exacerbated by biofilm was also observed in heat rejection sections. While attesting to the tenacity and adaptability of marine life, the presence of biological communities is symptomatic of the abnormally high oxygen levels in deaerator units. Elevated oxygen levels contribute to systems performance declines resulting from biological fouling of deaerator packing materials, partially responsible for inefficiencies in reducing the gas solubilities of MSF process feed waters and elevated concertation ratios [1,2]. Several thermal desalination units presented similar process issues, but one was selected for detailed inspection and evaluation

Performance investigation of advanced adsorption desalination cycle with condenser-evaporator heat recovery scheme

10.1080/19443994.2012.693659Desalination and Water Treatment511-3150-16