Vesicles exhibit high-performance removal of per-and polyfluoroalkyl substances (PFAS) depending on their hydrophobic groups.

The removal of per- and polyfluoroalkyl substances (PFAS) from drinking water is urgently needed. Here, we demonstrated high performance of vesicles on PFAS adsorption. Vesicles used in this study were enclosed amphiphile bilayers keeping their hydrophobic groups inside and their hydrophilic groups outside in water.

Desorption of Ammonia Adsorbed on Prussian Blue Analogs by Washing with Saturated Ammonium Hydrogen Carbonate Solution.

Prussian blue analogs (PBAs) have been reported as promising ammonia (NH) adsorbents with a high capacity compared to activated carbon, zeolite, and ion exchange resins. The adsorbed NH was desorbed by heating and washing with water or acid. Recently, we demonstrated that desorption was also possible by washing with a saturated ammonium hydrogen carbonate solution (sat.

Ammonium salt production in NH-CO-HO system using a highly selective adsorbent, copper hexacyanoferrate.

Ammonia is a beneficial material that is widely used in agriculture, but its emission into the atmosphere causes air pollution. Recently, Prussian blue (PB) and its analogs (PBA) were found to be ammonia adsorbents with high selectivity and capacity. In this study, we utilized a highly potent PBA adsorbent, copper hexacyanoferrate (CuHCF), to desorb ammonia and turn it into a reusable form.

Ammonium removal and recovery from sewage water using column-system packed highly selective ammonium adsorbent.

One of the strategies to realize a nitrogen cycle society, we attempted to recover ammonium ions from industrial wastewater, especially sewage water with adsorbent materials. We have developed an adsorbent with high ammonium selectivity based on copper hexacyanoferrate and granulated it as pellets. Using a compact column system filled with this granule adsorbent, ammonium ions were recovered from sewage containing 1000-1500 mg-NH/L ammonium ions.

Trace Ammonia Removal from Air by Selective Adsorbents Reusable with Water.

Ammonia adsorbents effective even in trace concentrations are key to the countermeasure for air pollution of particulate matter caused by ammonia emission from agriculture sectors. We revealed that Prussian blue (PB) and its analogues (PBAs), one of the porous coordination polymers, have higher ammonia adsorption capacity in 10 ppmv of ammonia (parts per million in volume, 10 ppmv = 0.0001 volume percent), ≥8 times that of conventional adsorbents.

Pre-enrichment of radioactive cesium in muddy water separated into suspended and dissolved substances for trace analysis.

A new in-situ pre-enrichment system was developed for trace analysis of radioactive Cs in environmental water such as rivers, ponds, and seas, where the radioactive Cs is separated into suspended substances (SS) and dissolved substances (DS). The SS component was collected as the enrichment slurry by cross-flow filtration, thereby compact systems were realized. The DS component was collected in a small cartridge filled with a non-woven fiber with immobilized adsorbent nanoparticles.

Unveiling Cs-adsorption mechanism of Prussian blue analogs: Cs-percolation vacancies to complete dehydrated state.

Metal hexacyanoferrates (MHCF) or Prussian blue analogs are excellent Cs-adsorbents used for radioactive Cs-decontamination. However, the adsorption mechanism is controversial. To clarify the issue, we quantitatively investigated the Cs-adsorption behaviors of potassium copper hexacyanoferrate (KCuHCF) and A Cu[Fe(CN)] ·HO.

High-capacity and selective ammonium removal from water using sodium cobalt hexacyanoferrate.

A new NH adsorbent with high capacity and selectivity, sodium cobalt(ii) hexacyanoferrate(ii) (NaCoHCF, Na Co(ii) [Fe(CN)] ·HO), was prepared. The adsorption performance was investigated by varying the mixing ratio of [Fe(CN)] to Co during synthesis, . The ammonia capacity was found to be proportional to , indicating that the NH capacity can be increased by increasing the Na-ion content in NaCoHCF.

Inversion analysis on vertical radiocesium distribution in pond sediment from γ-ray count measurement.

Evaluation of vertical distribution of radiocesium in bottom sediment by measuring vertical γ-ray count profile was discussed. A stable inversion formula was derived based on the maximum entropy method. Efficiency of the formula was confirmed by using a low-cost apparatus composed of an array of PIN photodiodes and a single board computer with real-time inversion code.

Radiocesium removal system for environmental water and drainage.

With the development of the nuclear power generation, it is expected that severe pollution of environmental water by radiocesium (r-Cs) may occur. We developed a r-Cs removal system with a continuous stirring tank reactor (CSTR) and r-Cs adsorbent of non-woven fiber immobilizing Prussian blue nanoparticles (PBN). Results confirmed that this system can remove r-Cs from environmental water with a removal rate higher than 80% at processing speed of 2 m/h.

Historical Pigment Exhibiting Ammonia Gas Capture beyond Standard Adsorbents with Adsorption Sites of Two Kinds.

Prussian blue is a historical pigment synthesized for the first time at the beginning of 18th century. Here we demonstrate that the historical pigment exhibits surprising adsorption properties of gaseous ammonia. Prussian blue shows 12.

Thermal dewetting behavior of polystyrene composite thin films with organic-modified inorganic nanoparticles.

The thermal dewetting of polystyrene composite thin films with oleic acid-modified CeO2 nanoparticles prepared by the supercritical hydrothermal synthesis method was investigated, varying the nanoparticle concentration (0-30 wt %), film thickness (approximately 50 and 100 nm), and surface energy of silanized silicon substrates on which the composite films were coated. The dewetting behavior of the composite thin films during thermal annealing was observed by an optical microscope. The presence of nanoparticles in the films affected the morphology of dewetting holes, and moreover suppressed the dewetting itself when the concentration was relatively high.

Dealing with the aftermath of Fukushima Daiichi nuclear accident: decontamination of radioactive cesium enriched ash.

Environmental radioactivity, mainly in the Tohoku and Kanto areas, due to the long living radioisotopes of cesium is an obstacle to speedy recovery from the impacts of the Fukushima Daiichi Nuclear Power Plant accident. Although incineration of the contaminated wastes is encouraged, safe disposal of the Cs enriched ash is the big challenge. To address this issue, safe incineration of contaminated wastes while restricting the release of volatile Cs to the atmosphere was studied.

Supercritical hydrothermal synthesis and in situ organic modification of indium tin oxide nanoparticles using continuous-flow reaction system.

ITO nanoparticles were synthesized hydrothermally and surface modified in supercritical water using a continuous flow reaction system. The organic modification of the nanoparticles converted the surface from hydrophilic to hydrophobic, making the modified nanoparticles easily dispersible in organic solvent. The addition of a surface modifier into the reaction system impacted the crystal growth and particle size as well as dispersion.

Estimation of local density augmentation and hydrogen bonding between pyridazine and water under sub- and supercritical conditions using UV-vis spectroscopy.

The local density around pyridazine was evaluated by examining the UV-vis spectral shift of pyridazine in a high-pressure liquid state and supercritical water from 25 to 450 degrees C and from 20 to 45 MPa. Augmentation of the local density was observed from 380 to 420 degrees C, and showed the maximum at a lower density than the critical density of water. The degree of hydrogen bonding was estimated in consideration of the local density augmentation.

Determination of Kamlet-Taft solvent parameters pi* of high pressure and supercritical water by the UV-Vis absorption spectral shift of 4-nitroanisole.

Kamlet-Taft solvent parameters, pi*, of high pressure and supercritical water were determined from 16-420 degrees C based on solvatochromic measurements of 4-nitroanisole. For the measurements, an optical cell that could be used at high temperatures and pressures was developed with the specification of minimal dead space. The low dead space cell allowed us to measure the absorption spectra of 4-nitroanisole at high temperature conditions before appreciable decomposition occurred.

Melting point depression of ionic liquids confined in nanospaces.

A new physical method was proposed to control the liquid properties of room temperature ionic liquids (RT-ILs) in combination with nanoporous materials; the melting point of ILs confined in nanopores remarkably decreases in proportion to the inverse of the pore size.

Amination of n-hexanol in supercritical water.

The amination of 1-n-hexanol followed by amidation was carried out in supercritical water at 380, 400, and 420 degrees C and water densities of 0.1, 0.3, and 0.