Publications by authors named "Shunitz Tanaka"

Shirasu balloon (SB) is a hollow glassy sphere produced from volcanic deposits by heating that can float up on water owing to its hollow structure. In this study, a novel adsorbent for the removal of cesium ion in water was developed by the modification of the surface of the SBs with magnetite (Mag) and Prussian blue (PB). The developed adsorbent (PB-Mag-SB) was characterized by elemental analysis, X-ray diffraction, and Fourier transform infrared spectrometry and the magnetism of the adsorbent.

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The combination of electro-enhanced and hydroponic phytoremediation hereinafter referred to as electro-enhanced phytoremediation (EP) system, has been employed for rapid removal of trace metal concentration of lead (II) from contaminated water using Kentucky bluegrass ( L.) as accumulator plant. In this study, for rapid assessment the effectiveness of two-dimensional (2) electrode configuration in electro-enhanced system was evaluated by agar media for 48h period of time.

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Cesium (Cs) is known to have a strong interaction with various clay minerals; however, it is not interpreted from the structure of clay minerals and the adsorption isotherm. The adsorption interactions between Cs and hydrobiotite (H-Bio), biotite (Bio), vermiculite (Verm), and exfoliated vermiculite (E-Verm) were evaluated by analyzing adsorption isotherm, basal spacing, and adsorption/desorption experiments. The Cs adsorption of H-Bio and Verm fitted well to the Langmuir adsorption isotherm, while the Cs adsorption of Bio and E-Verm fitted well to the Freundlich adsorption isotherm.

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The removal efficiency of Cs from contaminated soil depends on its chemical species bound with the soil components. Therefore, in this study, we observed the elution behavior of Cs based on speciation analysis in a Cs removal experiment conducted on contaminated soils. The treatment method was optimized using simulated contaminated soil and applied to actual contaminated soil on a large scale as well.

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The environmentally friendly electrokinetic process was investigated using model contaminated soil with Pb and humic acid. Although humic acid has a negative charge, it moved toward the cathode side by electroosmotic flow. The removal efficiency of Pb from model contaminated soil was 48.

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Microspheres of aluminosilicate glass from volcanic sediment, whose surfaces were modified with functional groups, Shirasu-balloons (SB), were investigated as an adsorbent to remove cadmium ions from contaminated soil. The introduction of thiol groups (-SH) on the surface of SB enabled it to adsorb cadmium ions. Meanwhile, the introduction of an alkyl group (-ODS) made the surface of SB hydrophobic, and consequently increased the mechanical strength of SB.

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This paper introduces some studies on the development of separation technologies for environmental remediation that have been performed in my laboratory over the past 20 years. The studies are related mainly to the development of easily collectable adsorbents and eco-friendly remediation technologies to remove pollutants from contaminated environments. First, the investigation of pollution in the Songhua River in China is described because it was that research that gave me the opportunity to consider the necessity of an easily collectable adsorbent.

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In this research, mercapto-silica coated magnetite (Fe3O4-SiO2-SH) has been prepared in aqueous solution through a simple approach so called a one-pot process. The Fe3O4-SiO2-SH was prepared in nitrogen condition by mixing magnetite, 3-mercaptopropyltrimethoxysilane (MPTMS), and sodium silicate (Na2SiO3) solution extracted from rice hull ash, and adjusting the pH of 7.0 using hydrochloric acid.

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A low cost and environmentally friendly adsorbent was developed based on leaf of platanus sp. to adsorb cadmium ion in water. The adsorbent was modified with citric acid and then also encapsulated in agar for easy separation after the adsorption process.

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For this study, a new method was developed to electrochemically detect ovalbumin via its binding with the peptide-1(RNRCKGTDVQAW) in lysozymes. The peptide that exists at the C-terminal of a lysozyme was combined with ovalbumin. When an electroactive compound was introduced to the N-terminal side of the peptide through ethylene gycolbis(sulfosuccinimidyl succinate), the labeled peptide-1 served as a probe for the detection of ovalbumin.

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When peat forest fires happen, it leads to burn soil and also humic acids as a dominant organic matter contained in peat soil as well as the forest. The structure and properties of humic acids vary depending on their origin and environment, therefore the transformation of humic acid is also diverse. The impacts of the peat fires on peat soil from Central Kalimantan, Indonesia were investigated through the characterization of humic acids, extracted from soil in burnt and unburnt sites.

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The concentrations of PCB congeners in the blubber and liver of mother Steller sea lions (Eumetopias jubatus; SSLs) and their fetuses from the coast of Hokkaido, Japan in 2008, 2010 and 2012 were analyzed by HRGC-HRMS, in order to elucidate PCB congener profiles and maternal-to-fetal transfer of PCBs in SSLs. ΣPCBs in the fetuses were 1400 ± 660 (the mean ± SD) ng/g-fat in the blubber and 570 ± 320 ng/g-fat in the liver, respectively. There was a concern that SSLs had been contaminated by PCBs during the fetal period.

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Humic acid (HA) has been implicated as a contributory factor for blackfoot disease, which is an endemic peripheral vascular disease. We investigated the effect of HA on the regulation of endothelial nitric oxide (NO) synthase (eNOS) in human umbilical vein endothelial cells (HUVECs) to evaluate the involvement of eNOS and related factors in peripheral vascular impairment with HA exposure. Treatment of HUVECs with HA induced upregulation of eNOS.

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The concentrations of PCB congeners in the blubber and liver of male and female Steller sea lions (Eumetopias jubatus; SSLs) collected from the Shakotan Peninsula and the Nemuro Strait, Hokkaido, Japan in 2008 and 2010 were measured by HRGC-HRMS, in order to express the concentration profiles in SSLs at these regions. #153 predominated in both organs, followed by #138, #99 and #118. In males, #28 and #31 were concentrated particularly in the blubber, while #177 and #199 were accumulated specifically in the liver.

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Humic acid (HA), a group of high-molecular weight organic compounds characterized by an ability to bind heavy metals, is normally found in natural water. Although the impairment of vascular endothelial cells in the presence of humic substances has been reported to be involved in some diseases, the mechanisms responsible for this involvement remain unclear. In this study, we examined the cytotoxicity of HA obtained from peatland in Central Kalimantan, Indonesia, to human vascular endothelial cells, as well as the mechanisms behind these effects.

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To determine the water environment and pollutants in West Java, the contents of metals and general water quality of the Ciliwung River in the Jakarta area were measured. High Escherichia coli number (116-149/mL) was detected downstream in the Ciliwung River. In addition to evaluate mercury pollution caused by gold mining, mercury contents of water and sediment samples from the Cikaniki River, and from paddy samples were determined.

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In this study, a hydrophobic magnetite coated with an alkyl chain or a phenyl group on the surface was prepared and used as an adsorbent to investigate the adsorption behavior of aromatic compounds having various values of log P(ow) (phenol 1.46, benzonitrile 1.56, nitrobenzene 1.

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Boron doped graphite nano particles were used as functioning elements for creation of electrodes for the detection of uric acid in biological samples. The electrode obtained in this manner was capable of oxidizing ascorbic acid at lower potentials. This provided a desirable solution to the interfering problem encountered in the detection of uric acid in biological samples caused by ascorbic acid.

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In this study, nitrobenzene in water and ice samples collected from the Songhua River after the explosion of a petrochemical plant was determined by GC/MS. The results showed that nitrobenzene was detected in most of the water and ice samples taken from the Songhua River. However, the concentration of nitrobenzene in all water and ice samples was from 0 to 0.

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The present study investigated the adsorptive ability of carbon materials (C1 and C2) released during the combustion of woody biomass. The physical and chemical properties, adsorption dynamics and adsorption isotherms of the adsorbents were compared with those of commercially available carbon that was powdered and activated. The percent nitrobenzene adsorption from an aqueous solution (nitrobenzene: 50mg/L) after 3h of adsorption using C1 was 92% compared with 81% when using the activated carbon powder.

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A new fluorometric enzyme immunoassay for 17beta-estradiol (E2) using biotinylated estradiol (BE) as a probe ligand, is described. In this method, E2 is detected indirectly by a solid-phase avidin-biotin binding assay, in which the biotin is immobilized on a microtiter plate (biotin-plate). After the competitive reaction between E2 and BE for the anti-E2 antibody in solution, the free E2 and BE are separated from the bound forms by means of ultrafiltration.

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In Java and Kalimantan in Indonesia, river water plays important roles in human life; for example, for transportation, and economic activities of the inhabitants. However, industrial, agricultural and domestic water is discarded into rivers directly in many developing countries, including Indonesia, since drainage systems have not been completely constructed. In this study, to evaluate the water quality and to compare those levels of environmental contaminants in developing and developed countries, water quality and contents of endocrine disrupters were measured in a total of 64 water samples (Indonesia; 28 samples and Japan; 36 samples) from 53 sites.

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A new type of adsorbent which is capable of selectively adsorbing lead(II) ions (Pb(2+)) was developed. The adsorbent was generated by reaction of sodium alginate with NB-9000B, a polyisocyanate type of prepolymer of polyurethane. The adsorbent was a hydrophilic and flexible alginate/polyurethane composite foam (ALG/PUCF) with the alginate chemically immobilized in the cell walls of the foam.

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To suppress the coagulation of humic acid (HA) in aqueous solutions, HA was modified with hydrophilic amines, such as glucosamine or taurine. These amines were attached to carboxyl groups in HA via amide bond formation. The degree of modification (R(m)) was estimated to be 21-38%.

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The usefulness of the combined use of the electrokinetic (EK) remediation and a ferrite treatment zone (FTZ) was demonstrated for a treatment of the contaminated soil with heavy metal ions. Copper ions in contaminated soil were transferred into the FTZ by the EK technology and were ferritized in this system. The distribution of copper in a migration chamber after EK treatment with FTZ for 48h showed the large difference in the total and eluted concentration of copper.

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