Return flow ion concentration polarization desalination: A new way to enhance electromembrane desalination.
Water Res
; 159: 501-510, 2019 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-31129480
ABSTRACT
In electromembrane desalination processes such as electrodialysis (ED) and ion concentration polarization (ICP) desalination, ion-depleted boundary layers constitute the desalted, product stream, yet also cause high resistivity and voltage drop. Directly manipulating fluid flow streams is a new method to break this fundamental trade-off for electromembrane desalination. In this work, we are introducing a novel electromembrane desalination architecture that allows a feed stream to return to the feed inlet side of the membrane (hereby named as return-flow (RF) architecture) to improve the energy efficiency by re-distributing and controlling the depleted boundary layer, even at high current values. The technical feasibility of this idea was examined in ICP desalination process (RF-ICP) with a wide range of feed salinity from 10 to 70â¯g/L. For a partial desalination, RF-ICP (â¼75â¯cm2 of membrane area) has achieved similar power consumption compared to batch-ED with 3 times bigger membrane area (200â¯cm2) with a higher area efficiency for salt removal, which translates into lower optimal desalination cost. The techno-economic analysis of RF-ICP have been performed for the treatment of 70â¯g/L brine waste. For partial desalination of 70â¯g/L brine down to 35â¯g/L, RF-ICP desalination achieved overall water cost as low as $2.57/m3 ($0.41/barrel). This could translate into reduction in total water cost up to 31% for zero brine release scenarios, depending on the concentrated brine treatment cost. These results show that return-flow architecture can improve the performance of electromembrane desalination, enabling more flexible water treatment for many real-world applications.
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Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Purificación del Agua
Idioma:
En
Revista:
Water Res
Año:
2019
Tipo del documento:
Article
País de afiliación:
Estados Unidos