scholarly journals Rotating carbon nanotube membrane filter for water desalination

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Qingsong Tu ◽  
Qiang Yang ◽  
Hualin Wang ◽  
Shaofan Li
Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 527 ◽  
Author(s):  
Ali Aldalbahi ◽  
Mostafizur Rahaman ◽  
Mohammed Almoiqli ◽  
Abdelrazig Hamedelniel ◽  
Abdulaziz Alrehaili

Acid-functionalized single-walled carbon nanotube (a-SWCNT)-coated reticulated vitreous carbon (RVC) composite electrodes have been prepared and the use of these electrodes in capacitive deionization (CDI) cells for water desalination has been the focus of this study. The performance of these electrodes was tested based on the applied voltage, flow rate, bias potential and a-SWCNT loadings, and then evaluated by electrosorption dynamics. The effect of the feed stream directly through the electrodes, between the electrodes, and the distance between the electrodes in the CDI system on the performance of the electrodes has been investigated. The interaction of ions with the electrodes was tested through Langmuir and Freundlich isotherm models. A new CDI cell was developed, which shows an increase of 23.96% in electrosorption capacity compared to the basic CDI cells. Moreover, a comparison of our results with the published results reveals that RVC/a-SWCNT electrodes produce 16 times more pure water compared to the ones produced using only CNT-based electrodes. Finally, it can be inferred that RVC/a-SWCNT composite electrodes in newly-developed CDI cells can be effectively used in desalination technology for water purification.


2008 ◽  
Vol 1106 ◽  
Author(s):  
Francesco Fornasiero ◽  
Hyung Gyu Park ◽  
Jason K Holt ◽  
Michael Stadermann ◽  
Costas P Grigoropoulos ◽  
...  

AbstractCarbon nanotubes offer an outstanding platform for studying molecular transport at nanoscale, and have become promising materials for nanofluidics and membrane technology due to their unique combination of physical, chemical, mechanical, and electronic properties. In particular, both simulations and experiments have proved that fluid flow through carbon nanotubes of nanometer size diameter is exceptionally fast compared to what continuum hydrodynamic theories would predict when applied on this length scale, and also, compared to conventional membranes with pores of similar size, such as zeolites. For a variety of applications such as separation technology, molecular sensing, drug delivery, and biomimetics, selectivity is required together with fast flow. In particular, for water desalination, coupling the enhancement of the water flux with selective ion transport could drastically reduce the cost of brackish and seawater desalting. In this work, we study the ion selectivity of membranes made of aligned double-walled carbon nanotubes with sub-2 nm diameter. Negatively charged groups are introduced at the opening of the carbon nanotubes by oxygen plasma treatment. Reverse osmosis experiments coupled with capillary electrophoresis analysis of permeate and feed show significant anion and cation rejection. Ion exclusion declines by increasing ionic strength (concentration) of the feed and by lowering solution pH; also, the highest rejection is observed for the salts (A=anion, C=cation, z= valence) with the greatest zA/zC ratio. Our results strongly support a Donnan-type rejection mechanism, dominated by electrostatic interactions between fixed membrane charges and mobile ions, while steric and hydrodynamic effects appear to be less important. Comparison with commercial nanofiltration membranes for water softening reveals that our carbon nanotube membranes provides far superior water fluxes for similar ion rejection capabilities.


2020 ◽  
Vol 22 (44) ◽  
pp. 25747-25759
Author(s):  
Yunzhe Jia ◽  
Xiya Lu ◽  
Zhen Cao ◽  
Tianying Yan

Hydrophobic porous materials with nano-pores are critical in many processes such as water desalination and biological membrane transportation.


2012 ◽  
Vol 1407 ◽  
Author(s):  
R. Enright ◽  
R. Mitchell ◽  
H. Mutha ◽  
C. Lv ◽  
M. Christiansen ◽  
...  

ABSTRACTUncertainty about future energy and water supplies suggests a pressing need to develop efficient technologies for water desalination. Capacitive deionization (CDI), a method that captures ions in the electrical double layer (EDL) of an electrochemical capacitor, is a promising technology that can potentially fulfill those requirements. Similar to supercapacitors, ideal CDI electrodes should have a large electrolyte-accessible specific surface area available for ion adsorption with rapid charging/discharging characteristics. Unlike supercapacitors, CDI electrodes are required to operate in aqueous electrolytes with low ionic concentrations in a non-linear charging regime. To explore this practically and theoretically important regime, we developed robust, electrochemically-compatible carbon nanotube (CNT) carpet electrodes that posses a well-defined and uniform pore structure that is more readily analyzed in comparison to the random and multi-scale pore structure of typical carbon electrodes. The fabricated electrodes were characterized using cyclic voltammetry and potentiostatic charging in aqueous NaCl solutions (no = 20 - 90 mM) using a three electrode setup. Examination of the CV and potentiostatically-measured capacitances were consistent with EDL behavior dictated by the Stern layer. However, some deviations from the expected behavior were observed with increasing salt concentration during potentiostatic testing.


2010 ◽  
Vol 3 (2) ◽  
pp. 110-114 ◽  
Author(s):  
Ken Gethard ◽  
Ornthida Sae-Khow ◽  
Somenath Mitra

Desalination ◽  
2010 ◽  
Vol 258 (1-3) ◽  
pp. 182-186 ◽  
Author(s):  
Maryam Ahmadzadeh Tofighy ◽  
Toraj Mohammadi

Desalination ◽  
2014 ◽  
Vol 336 ◽  
pp. 97-109 ◽  
Author(s):  
Rasel Das ◽  
Md. Eaqub Ali ◽  
Sharifah Bee Abd Hamid ◽  
Seeram Ramakrishna ◽  
Zaira Zaman Chowdhury

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