Advantages
- By simply adding highly water-soluble high-concentration sodium / potassium ions, this product enables rapid and selective precipitation separation.
- Achieved over 80% sodium chloride removal rate in seawater-equivalent aqueous solutions
- No complex column flow solution required. A highly efficient/low-cost pretreatment process completed solely by adding removers and filtration.
Current Stage and Key Data
Chart of ion chromatography for $text{Na}^+$ during the removal of sodium ions from an aqueous solution with a salt concentration of 30 g/L.
The concentration of sodium ions in the aqueous solution was measured by ion chromatography and compared with the result of the solution before treatment to determine the removal rate. The results indicated that Na+ was removed with a removal rate of approximately 80%.
Partnaring Model
[Analytical Equipment Manufacturer]
- Collaboration to make this agent an optional 'autosampler reagent kit for high-salinity samples' such as ICP-MS.
- Joint development as a simple desalination cartridge for fieldwork (on-site analysis).
[Water Treatment Manufacturer]
- OEM supply of 'coarse desalination agent' or 'powder reagents' used just before injecting high-concentration salt samples into our equipment.
- Integration into inline pretreatment units on wastewater analysis lines.
Background and Technology
In trace metal analysis of seawater and other sources (such as ICP analysis), high concentrations of sodium chloride are the biggest factor significantly reducing measurement accuracy, making simple masking agents highly sought after. However, organic small molecules with sodium ions are generally highly soluble in water, making them difficult to capture and precipitate, and removers capable of precipitating alkali metal ion salts from aqueous solutions have not yet been developed.
The laboratory developed an original organic small molecule that incorporates sodium ions into higher-order frameworks (with activity confirmed in multiple derivatives), and was the first in the world to succeed in precipitating and removing sodium ions from aqueous solutions. In demonstration tests, it has been demonstrated through ion chromatography and electrical conductivity measurements that about 70% of sodium ions can be precipitated and removed in a sodium chloride aqueous solution at the same concentration as seawater. The mechanism for forming higher-order skeleton structures through trapping and precipitation is structurally supported by single-crystal X-ray analysis. Additionally, when using silver complexes synthesized with this molecule, in addition to sodium ion removal, chloride ions precipitate as AgCl (confirmed by powder X-ray analysis). In other words, it has been shown that a removal rate of over 80% of NaCl from seawater as a sediment can be achieved, promising rapid and consistent pretreatment and desalination technologies.
The main ligand/silver complex can be synthesized at low cost due to its simple process, and going forward, development will need to be tailored to the supply form of treatment agents tailored to scale-up and throughput depending on the application scenario.
Principal Investigator
Professor Mitsuru Kondo
Green Science and Technology Research Institute, Shizuoka University, National University Corporation