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Volume 48 (2012)
- Issue 4 Pages 133-
- Issue 3 Pages 81-
- Issue 2 Pages 29-
- Issue 1 Pages 1-
Volume 48, Issue 4
Displaying 1-4 of 4 articles from this issue
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ORIGINALS
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KOUGA SHIGEIZUMI, CHIKAKO MARUO, MUNEHIRO NOMURA, YOSHIO AIKAWA, OSAMU ...Article type: ORIGINALS
2012 Volume 48 Issue 4 Pages 133-140
Published: 2012
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSAdsorptive removal of PFOS in the order of ng/l was investigated using model road runoff water containing NO3-, PO43-, and Cr2O72- in different orders of concentration. Since PFOS is an anionic surfactant, effective removal by means of anion exchange can be expected. The removal efficiencies of PFOS with anion exchange materials were, however, lower than that with activated carbon, suggesting the difficulty of application of anion exchange materials. Removal of PFOS with activated carbon was effective not only under pure condition, but also under contaminated condition with coexisting anions in road runoff. Furthermore, PFOS removal was not inhibited by presence of NO3-, PO43-, and Cr2O72- which concentration were, 10 - 104 times as high as PFOS, while adsorption of NO3- and Cr2O72- competed with coexisting anion, resulting in a low removal efficiency. The results that a high removal efficiency of PFOS with activated carbon was obtained and the adsorptive removal performance was not affected by coexisting anions suggest that the hydrophobicity of PFOS become a significant factor when PFOS in the order of ng/l is removed from road runoff by means of adsorption.View full abstractDownload PDF (1659K) -
MEGUMU FUJIBAYASHI, WOO-SEOK SHIN, YUMI NAGAHAMA, YOSHIO AIKAWA, OSAMU ...Article type: ORIGINALS
2012 Volume 48 Issue 4 Pages 141-144
Published: 2012
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSPriming effect is known as a phenomenon that the decay of inputted labile organic compounds enhances the decomposition of native organic matter in sediment. In this study, pedal mucus of pond snail Bellamya chinensis was examined whether it induced priming effect. Agar medium with sucrose and paddy field sediment were used as organic carbon sources in our laboratory experiments. Each sample was coated with pedal mucus by mean of letting snails crawl on the surface. Decomposition rate of each sample was compared with controls which doesn’t contain pedal mucus as oxygen consumption rate using by a coulometer. Oxygen consumption rates of samples which were coated with pedal mucus were larger than that of control. These results indicate pedal mucus of B. chinensis possess ability to induce priming effect.View full abstractDownload PDF (1216K) -
Nguyen Ai Le, Daisuke Inoue, Kazunari Sei, Satoshi Soda, Michihiko IkeArticle type: ORIGINALS
2012 Volume 48 Issue 4 Pages 145-156
Published: 2012
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSIron-based adsorbents are attractive agents for remediation of arsenic contaminated water. This study characterized biogenic iron oxides (BIO) samples, which were obtained from a biological water treatment plant, from the physicochemical and biological aspects, and examined their As(V) and As(III) adsorption capability in comparison to that of chemogenic iron oxides (CIO). The BIO samples contained large amounts of Fe, Mn and PO43- and were dominated with Leptothrix spp., a typical iron-oxidizing bacteria, suggesting the formation of Fe and Mn oxides precipitation with large surface area on Leptothrix cell surface. Batch adsorption experiments of As(V) and As(III) (100 to 1500 μg/L each) with BIO and CIO (5 mg-Fe/L), and the regression of the experimental data by Langmuir and Freundlich isotherms revealed that BIO is more effective than CIO regarding the aqueous arsenic removal, irrespective of the species and concentrations of arsenic. The maximum arsenic adsorption capacities of BIO were 34.25 μg-As(V)/mg-Fe and 28.99 μg-As(III)/mg-Fe, respectively, which were 2.7 times larger than those of CIO. Because BIO can be generated continuously by biological oxidation of Fe coexisting in arsenic contaminated water, it can be concluded that BIO-based adsorption would be a promising arsenic remediation technology for Asian developing countries where drinking water source is heavily contaminated with arsenic and contains a high concentration of iron.View full abstractDownload PDF (1637K) -
KUNIKO TAKEMOTO, AKITSUGU YAMAMOTO, GO MIZUTA, SATOSHI ICHISE, MASASHI ...Article type: ORIGINALS
2012 Volume 48 Issue 4 Pages 157-163
Published: 2012
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSOne of the causative substances of musty odors which have frequently occurred in Lake Biwa were identified as 2-methylisoborneol (MIB), and the causative organisms were identified as Phormidium tenue. Musty odor producing and non-producing Phormidium tenue were observed with a soft x-ray microscope (XM), a transmission electron microscope (TEM), and a low temperature/low vacuum scanning electron microscope (low temperature/low vacuum SEM). While MIB producing strain (green strain) was composed of thick cells without mucilaginous sheath, MIB non-producing strain (brown strain) was composed of slender cells with mucilaginous sheath. Although carboxysomes and polyphosphate granules were observed in both green and brown strains, the polyphosphate granules were larger than the carboxysomes in green strain. Morphological differences between the green and the brown strains suggest a possibility that the green and the brown strains are different species. The experimental results lead to the conclusion that it is possible to distinguish musty odor producing and non-producing strain based on the morphological feature using XM, TEM, and low temperature/low vacuum SEM.View full abstractDownload PDF (16278K)
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