We have created a novel resin that shows a high selectivity to a target Li (I) ion by means of a surface molecular imprinting technique. With this technique, the organic-aqueous interface of W/O emulsions is utilized as a recognition field for a water-soluble targeted metal ion. The target lithium ion forms a complex with functional host molecules at the oil-water interface, and the orientation of the functional molecules is immobilized. After the matrix is polymerized, the coordination structure is eventually“imprinted” on the polymer surface. We used β-diketone as the functional molecule and phosphine oxide as the synergistic reagent. The Li (I)-imprinted polymer with both the reagents exhibited high adsorption ability toward the target Li (I) ion. On the other hand, the Li (I)-imprinted polymer using β-diketone or phosphine oxide alone afforded no adsorption affinity to Li (I). This is the first report to utilize a synergistic effect in a molecular imprinting technique.
NaCl inhibited the activity of polyphenol oxidase (PPO) isozymes in apples, potatoes and mung bean sprouts. To elucidate the mechanism for the suppressive effect of NaCl on PPO activity in vegetables, we purified PPO from mung bean sprouts by means of ammonium sulfate fractionation and 2 column chromatographies. Six isozymes of PPO from mung bean sprouts were detected by means of SDS-polyacrylamide gel electrophoresis and chromatofocusing. The PPO isozyme of highest activity was pI 6.7. The PPO isozyme was purified as a single protein and the molecular mass was found to be 40 kDa by means of SDS-polyacrylamide gel electrophoresis. The enzyme showed an apparent Km value of 1.3 mM for chlorogenic acid. The enzyme was inhibited non-competitively by NaCl with a Ki value of 0.22M (1.27%). These results suggest that NaCl inhibits PPO activity non-competitively, and results in preventing the enzymatic browning of vegetables.
A porous polymer resin loaded with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was studied for its sorption abilities with respecto copper (II) ion taken from solar salt and underground water samples. To the porous polymeresin, PMBP in ethanol solution was added and stirred for 10 min at room temperature. Evaporation of the solvent was carried out at 45°C under reduced pressure in order to load the PMBP on the polymer resin. The product was washed repeatedly with de-ionized water and dried at room temperature, and then used as the adsorbent for the copper (II) ion. The content of the PMBP in the HP20-PMBP adsorbent was 50mg/g-resin. The copper (II) ion was quantitatively adsorbed on to the HP20-PMBP in a pH range of 2.5 to 11.0. The maximum sorption capacity was found to be 5.3×10-2mmol/g-resin. The adsorption elution cycle of HP20-PMBP for copper (II) ion can be repeated at least five times with no observable decline in the efficiency of the adsorbent. It is clear that 1.0μg/500mL copper (II) ion can be determined by the proposed method with a concentration factor of 10.
Reverse osmosis membrane processes are effecient in terms of energy and widely used in the desalination field. Recently, a new scheme of reverse osmosis seawater desalination, which is called a brine conversion twostage process, was proposed by Toray Industries, Inc. In this process, a second stage is added to a conventional RO unit, and the concentrated brine from the unit is further desalinated at the second stage to increase the water recovery ratio over 40% to 60%. The recovered energy from the first stage brine is used to pump the feed to the second stage up to approximately 10 MPa. For this purpose, a new membrane, UTC-80BCM, has been developed besides the conventional UTC-80. A test plant based on this scheme (210m3/day) was built at Ehime factory, Toray, Inc. and was operated under a wide range of conditions. The purpose of this work is to establish the calculation method for RO process for seawater desalination. In this research, first, we measured the membrane properties and the mass transfer coefficients of each spiral-type element, SU-820 and SU-820BCM, which use UTC-80 and UTC-80BCM. Next, we developed a computer program based on the concentration polarization model. In this calculation, we consider the change of the membrane itself in terms of operating conditions, the temperature, and the pressure, whose corrections are determined from the laboratory experiments. Finally, the test plant data under the various operating conditions were taken and a calculation method was successfully verified. As a result, this method enables us to obtain membrane transport parameters from running plant data to find the causes of membrane fouling under various operationg conditions, and to predict the plant performance, which is necessary for us to design the process.
A method to measure the dissolution rate of salt that can be applied to a wide range of particle sizes, and that can be used to compare values using different types of equipment and dissolution conditions, was developed. The problem with the present column method was clarified. On the other hand, using the agitation method, the measured value that suits the dissolution theory was obtained under dissolution conditions in which all particles float. Moreover, using the relative dissolution rate calculated for a cubic standard sample with a uniform particle size, a comparison of the values measured using different types of equipment and dissolution conditions was carried out.
The blocking behavior of step motion on the (100) face of an L-asparatic acid (L-Asp) crystal caused by the doping of an amino acid in an aqueous solution was investigated using an atomic force microscope. The doping of amino acids with smaller (L-alanine) and larger (L-lysine, L-phenylalanine) side chains than those of the crystallizing species (L-Asp) caused a pinning of steps that have heights equivalent to the unit cell dimension along the a axis. On the other hand, amino acids with similar-sized side chains (L-asparagine and L-glutamic acid) had little effect.