Seawater and Brackish‐Water Desalination with Membrane Operations

A perspective on reverse osmosis water desalination: Quest for sustainability

“…10,77,78 To avoid wasting the pressure energy of the discharged brine stream, energy recovery devices (ERDs) can be integrated with the RO system. 10,79 Typically, single stage RO processes are integrated with ERDs ( Figure 6) such as a pressure intensifier/booster or parallel feed pumping, 10,78,79 which presently are mostly limited to seawater desalination applications. Reduction in energy consumption through the use of multi-stage RO with inter-stage (booster) pumps is also possible and is most suitable for BW desalination in which a high product level of product recovery is needed.…”

“…11,16,32 The SEC is strongly affected by water product recovery, energy recovery (from the high pressure RO concentrate), pumping energy (including feed intake), operating conditions (e.g., RO feed channel velocity and feed-side pressure), and plant configuration in terms of membrane modules arrangements. 10,11,16,31,78,[83][84][85] The various contributions to the total energy consumption for a seawater RO desalination plant typically includes the desalination stage and discharge ($67%), RO feed pre-treatment ($13%), intake ($7%) and Figure 5. Typical arrangements of pressure vessels for RO/NF membrane elements.…”

“…10,12,16 However, unlike seawater RO plants, the management of the RO concentrate from inland brackish desalination can represent a major challenge given the often limited options for concentrate disposal. 10,12,20,30 Inland concentrate management costs can be as high as 0.40-1.78 $/m 3 and in certain cases represent more than 50% of the cost of water production. 86 Hence, there is a significant drive to increase RO recovery so as to minimize the volume of generated RO residual stream.…”

“…In addition to the various approaches to increasing the utilization of water resources (e.g., water use efficiency, water recycling, and reuse), there has been increased interest in augmenting potable water supplies through desalination of seawater and inland brackish water (BW). [9][10][11][12] Water salinity is typically categorized based on the concentration of total dissolved solids (TDS; i.e., mineral salts) as shown in Table 1. The recommended salinity level for drinking water is 500 mg/L TDS, 13 while seawater salinity is typically in the range of $33,000-42,000 mg/L TDS.…”

Low-cost inorganic cation exchange membrane for electrodialysis: optimum processing temperature for the cation exchanger

“…The ionexchange membranes currently being manufactured are mainly polymeric membranes, in which the polymer itself either contains groups that are able to ionise (such as sulphonium, carboxyl, or quaternary ammonium) or the polymer acts as a support, in which an ionexchange resin is dispersed [3]. Although polymeric ion-exchange membranes perform well, they usually exhibit stability problems when they work in media with extreme pH, at high temperatures, or in the presence of strong oxidisers or ionising radiations [4,5].…”