Desalination - Research Notes

 There are some interesting research efforts underway to provide alternate ways of performing desalination of seawater (vs. the energy-intensive reverse-osmosis mechanisms carried aboard many cruising boats).

This blog post is intended as a helpful collection point for organizing the links to articles I happen to come across, from time-to-time

2022

• https://interestingengineering.com/science/membrane-desalination-potable-water-seawater
• "Researchers have developed an ultrathin polymer-based ordered membrane that can effectively remove salt from seawater and brine while allowing quick water transport. The KAUST-led team showed their separation membranes could offer a viable alternative to the water desalination systems currently in use."
• "as reported in Nature Materials [Shen et al. Nat. Mater. (2022) DOI: 10.1038/s41563-022-01325-y], the use of 2D conjugated polymer frameworks (2D CPF) to make membranes was investigated as they offer high molecular permeability and their sub-nm channels provide a sieving effect for high selectivity."
  
• https://scitechdaily.com/new-device-purifies-saltwater-over-a-1000-times-faster-than-standard-industrial-equipment/
• "The researchers developed test filtration membranes by chemically manufacturing nanoscopic fluorine rings that were stacked and implanted in an otherwise impenetrable lipid layer, similar to the organic molecules found in cell walls. They developed multiple test samples with nanorings ranging in size from 1 to 2 nanometers. A human hair is almost 100,000 nanometers wide for comparison. Itoh and his colleagues evaluated the presence of chlorine ions, one of the major components of salt (the other being sodium), on either side of the test membrane to determine the effectiveness of their membranes." 
• Refrence: Ultrafast water permeation through nanochannels with a densely fluorous interior surface” by Yoshimitsu Itoh, Shuo Chen, Ryota Hirahara, Takeshi Konda, Tsubasa Aoki, Takumi Ueda, Ichio Shimada, James J. Cannon, Cheng Shao, Junichiro Shiomi, Kazuhito V. Tabata, Hiroyuki Noji, Kohei Sato and Takuzo Aida, 12 May 2022, Science.
  DOI: 10.1126/science.abd0966
  
• https://news.mit.edu/2022/portable-desalination-drinking-water-0428 
• "MIT researchers have developed a portable desalination unit, weighing less than 10 kilograms, that can remove particles and salts to generate drinking water."
• "requires less power to operate than a cell phone charger, can also be driven by a small, portable solar panel" 
• "unlike other portable desalination units that require water to pass through filters, this device utilizes electrical power to remove particles from drinking water. Eliminating the need for replacement filters greatly reduces the long-term maintenance requirements."
• "The research has been published online in Environmental Science and Technology."
• "Senior author Jongyoon Han, a professor of electrical engineering and computer science and of biological engineering, and a member of the Research Laboratory of Electronics (RLE).. Joining Han on the paper are first author Junghyo Yoon, a research scientist in RLE; Hyukjin J. Kwon, a former postdoc; SungKu Kang, a postdoc at Northeastern University; and Eric Brack of the U.S. Army Combat Capabilities Development Command (DEVCOM)."
• "relies on a technique called ion concentration polarization (ICP)"
• "ICP does not always remove all the salts floating in the middle of the channel. So the researchers incorporated a second process, known as electrodialysis, to remove remaining salt ions." 
• "The resulting water exceeded World Health Organization quality guidelines, and the unit reduced the amount of suspended solids by at least a factor of 10. Their prototype generates drinking water at a rate of 0.3 liters per hour, and requires only 20 watt-hours per liter." 
• "The research was funded, in part, by the DEVCOM Soldier Center, the Abdul Latif Jameel Water and Food Systems Lab (J-WAFS), the Experimental AI Postdoc Fellowship Program of Northeastern University, and the Roux AI Institute."
• ... 

2023