Application of anion removal agent derived from iron and steel slag to treatment of waste water and contaminated soil

本研究の一部は、文部科学省私立大学戦略的研究基盤形成支援事業（平成24～28年度）および関西大学・若手研究者育成経費の助成金によって行われた。ここに記して感謝の意を表す。引き続き、科学研究費補助金・基盤研究(C)(17K00630、平成29～31年度・予定)にて関連研究が行われている

Changes in biceps brachii muscle hardness assessed by a push-in meter and strain elastography after eccentric versus concentric contractions

Changes in biceps brachii muscle hardness assessed by a push-in meter (PM) and strain elastography (SE) were compared between eccentric (ECC) and concentric contractions (CON) of the elbow flexors to test the hypothesis that muscle hardness would increase greater after ECC. Ten men performed 5 sets of 10 ECC with their non-dominant arms and 5 sets of 10 CON with their dominant arms using a dumbbell corresponding to 50% of maximum voluntary isometric contraction (MVIC) force at 90º elbow flexion. Before and 1–4 days after the exercise, MVIC force, elbow joint angles, upper-arm circumference, and muscle soreness as muscle damage makers, and biceps brachii muscle hardness at maximally extended elbow joint by PM and SE were measured. Changes in these measures over time were compared between ECC and CON. All muscle damage markers showed greater changes after ECC than CON (p \u3c 0.001). Muscle hardness assessed by PM and SE increased (p \u3c 0.05) and peaked at 4 days post-ECC with 154.4 ± 90.0% (PM) and 156.2 ± 64.2% (SE) increases from the baseline, but did not change significantly after CON. The changes in muscle hardness post-ECC were correlated between PM and SE (r = 0.752, p \u3c 0.001). A correlation (p \u3c 0.001) between the normalized changes in resting elbow joint angle and changes in muscle hardness assessed by PM (r = − 0.772) or SE (r = − 0.745) was also found. These results supported the hypothesis and suggest that the increases in muscle hardness after ECC were associated with muscle damage (increased muscle stiffness), and PM and SE detected muscle hardness changes similarly

Biceps brachii muscle hardness assessed by a push-in meter in comparison to ultrasound strain elastography

© 2020, The Author(s). This study investigated the relationship between push-in meter (PM) and ultrasound strain elastography (USE) for biceps brachii (BB) muscle hardness. BB hardness of 21 young men was assessed by PM and USE during rest and isometric contractions of six different intensities (15, 30, 45, 60, 75, 90% of maximal voluntary contraction: MVC) at 30°, 60° and 90° elbow flexion. Muscle hardness (E) was calculated from the force–displacement relationship in PM, and strain ratio (SR) between an acoustic coupler (elastic modulus: 22.6 kPa) and different regions of interest (ROIs) in BB was calculated and converted to Young’s modulus (YM) in USE. In resting muscle, E was 26.1 ± 6.4 kPa, and SR and YM for the whole BB was 0.88 ± 0.4 and 30.8 ± 12.8 kPa, respectively. A significant (p \u3c 0.01) correlation was evident between E and logarithmical transformed SR (LTSR) for the ROI of whole BB (r = − 0.626), and E and converted YM (r = 0.615). E increased approximately ninefold from resting to 90% MVC, and E and LTSR (r = − 0.732 to − 0.880), and E and converted YM for the SR above 0.1 were correlated (r = 0.599–0.768, p \u3c 0.01). These results suggest that muscle hardness values obtained by PM and USE are comparable

ELECTRODIALYSIS PHENOMENA OF AQUEOUS SOLUTIONS CONTAINING PHOSPHORIC ACID AND METAL IONS

The electrodialysis phenomena of aqueous solutions containing phosphoric acid, Al and Mo ions were investigated in this study. A feasibility study of electrodialysis for treatment of waste phosphoric acid containing metal ions was also carried out. The desalination percentage of various ions shows different values through a kind of ion-exchange membrane. The voltage, solution concentration and feed temperature mainly affect electrodialysis of phosphoric acid containing Al and Mo ions. Higher voltage and feed temperature are beneficial for desalination of Al and Mo ions. At least 30% of Al ions and 7% of Mo ions can be removed from the phosphoric acid by using CMX/ AMX, CM1/ AM1 and CMX-SB/ ACS ion-exchange membranes. The electrodialysis process seems to be a promising one for use in treatment of waste phosphoric acid containing Al and Mo ions.This work was supported by the MEXT, Grant-in-Aid for Scientific Research (A)(1),(17206091).CHEMICAL, ENERGY AND ENVIRONMENTAL ENGINEERING, 50th anniversary editio

Dispersion and Flocculation Behavior of Fine Metal Oxide Particles in Various Solvents

The objective of this study is to investigate the relation between the flocculation and dispersion of Al2O3, TiO2 and Fe2O3 particles and the properties of solvents such as dielectric constant and solubility parameters. The median diameter of these metal oxide perticles was measured in many organic solvents. The effect of the kind of solvent on the flocculation/dispersion behavior of metal oxide particles was evaluated from these results. Hansen\u27s solubility parameters with three dimensions were applied to the evaluation of the flocculation/dispersion behavior for fine metal oxide particles in organic solvents. The numeral balance among the Hansen\u27s solubility parameters of various solvents was plotted in a triangular chart, and then the points of solvents with similar median diameter of the particle were linked. In the triangular chart, these linked lines were not intersected each other and there was the specific point at which the best dispersibility of the particles was obtained.http://www.kona.or.jp/search/20_263.pd

Regeneration technology of tetramethylammonium hydroxide using ion exchange resin

Tetramethylammonium hydroxide is used in various electric and electronic parts production processes, such as those for making semiconductors, liquid crystal displays and printed circuit boards. The discharged amount of this chemical reaches about 2,500 ton/year from one factory in Japan. The waste liquor discharged from the liquid crystal display production contains 0.53 wt% tetramethylammonium hydroxide, 60 mg/d3 phenol and a ppb order of metal ions. In the cation exchange reaction, tetramethylammonium ion is captured on the cation exchange resin. Other non-ionic organic matter, such as phenol, goes through the resin without being captured on it, the separation being attained in this step. In the elution step, tetramethylammonium ion captured on the resin is released as tetramethylammonium chloride into aqueous solution by the action of dilute hydrochloric acid. Tetramethylammonium chloride is converted to tetramethylammonium hydroxide by the reaction between tetramethylammonium chloride and OH type anion exchange resin. The process is composed of three steps, that is，cation exchange, elution and conversion. The experiments were carried out using an ion exchange resin column of 20 mmφ and 735 mm height, in order to investigate the recovery and purity of percents tetramethylammonium hydroxide at each step

Hydrothermal synthesis of potassium-type zeolite from coal fly ash and evaluation of its physical properties

Hydrothermal syntheses of potassium-type zeolite from coal fly ash were carried out under various KOH concentrations and reaction temperatures, and crystal structure and cation exchange capacity (CEC) of the reaction products were investigated. Both acid resistance and heat resistance of the reaction products were considered, as these are important for use as a cation exchanger,a catalyst or an absorbent. When hydrothermal synthesis from coal fly ash is conducted at a reaction temperature of 393K, potassium chabazite (K-CHA) begins to form for 5h of reaction time. K-CHA and K-H zeolite are formed as zeolite species at 393K and 453K,respectively. Both K-CHA and K-H zeolite are synthesized simultaneously at 433K. CEC values of the obtained K-CHA and K-H zeolite are 208meq/100g and 104meq/100g. respectively. The CEC of reaction products decreases with increasing reaction temperature, and this phenomenon dictates the kind of formed zeolite. X-ray diffraction intensities of K-CHA gradually decrease with decreasing pH in the range above pH4. Whereas, in the range below pH 4, this intensity decreases rapidly and the elution amount of Al3+ from K-CHA with proton increases remarkably. In the case of heat treatment below 873K, the X-ray diffraction intensity of K-CHA decreases with increasing calcined temperature, but thermal decomposition of K-CHA and production of new crystalline materials do not take place in these treatments. With a heat treatment of 1273K,the K-CHA peaks disappear in the XRD pattern, and those of leucite generate anew

RECOVERY OF PHOSPHORIC ACID FROM WASTE ACID MIXTURE WITH SOLVENT EXTRACTION

By applying a solvent extraction method for the etching waste solution discharged from the manufacturing process of liquid crystal display, the removal of acetic acid and nitric acid were carried out from the waste acid mixture containing phosphoric, acetic and nitric acids to obtain phosphoric acid as the raffinate. Fundamental studies on the recovery of phosphoric acid were conducted by using Tri-octyl phosphate (TOP) as the extractant for acetic acid and nitric acid. From the results, demonstration tests using a mixer-settler equipment were carried out to obtain crude phosphoric acid. Acetic and nitric acids were selectively extracted by TOP from the waste acid mixture, which contains phosphoric acid as a main component. From the McCabe Thiele analysis, almost all of the acetic and nitric acids were removed by a countercurrent multi-extraction operation of phase ratio(A/O) 0.4 and 6-stage. When TOP loading acids was contacted with the water under the countercurrent operation conditions of phase ratio (0/A) 1.0 and 4-stage, 99% of acetic acid and 99.5% of nitric acid were stripped from the organic phase, respectively. From these results obtained by the fundamental studies, a demonstration test was carried out for the extraction of acetic and nitric acids by using a mixer-settler equipment. Consequently, the extractions of acetic and nitric acids in the waste acid mixture were about 95% and 98%, respectively, and crude phosphoric acid can be obtained as a raffinate after the solvent extraction