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Volume 42 (2006)
- Issue 4 Pages 159-
- Issue 3 Pages 99-
- Issue 2 Pages 45-
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Volume 42, Issue 4
Displaying 1-6 of 6 articles from this issue
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ORIGINALS
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TRAN THI HIEN HOA, LUONG NGOC KHANH, LIU ZHIJUN, TAKAO FUJII, MUNESHIG ...Article type: ORIGINALS
2006 Volume 42 Issue 4 Pages 159-168
Published: 2006
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSThis study focuses on anaerobic ammonium oxidation (anammox) treatment performance for nitrogen removal using malt ceramics (MC) as a biomass carrier. A fixed-bed reactor using MC material with 3 to 5 mm diameter pieces (Reactor 1) was operated for 368 days and another using MC material with 10 to 15 mm diameter pieces (Reactor 2) was operated for 280 days. For Reactor 1, with an HRT of 3 h, the influent concentrations of NH4－N and NO2－N were both increased stepwise from 150 mg N/l to 225 mg N/l with NH4－N removal efficiency of about 81% and NO2－N removal efficiency of 90%. Then, the influent concentrations of NH4－N and NO2－N were increased to 250~275 mg N/l, each, and removal efficiencies of NH4－N and NO2－N decreased to 75% and 85%, respectively. The T－N removal rates of Reactor 1 increased stepwise from 0.6 to 3.1 kg N/m3/day from day 187 to day 315. Ratios of T－N removal, NO2－N removal, and NO3－N production to NH4－N removal for Reactor 1 were 1.98:1.15:0.17, respectively. For Reactor 2, with an HRT of 3 h, the influent concentrations of NH4－N and NO2－N were both increased stepwise from 100 mg N/l to 225 mg N/l and removal efficiencies of NH4－N and NO2－N were high at 80% and 93%, respectively. However, when the influent concentrations of NH4－N and NO2－N were increased to 250~275 mg N/l, each, removal efficiencies of NH4－N and NO2－N decreased to 72% and 84%, respectively. The T－N removal rates of Reactor 2 were similar to those of Reactor 1 with 0.7 to 3.1 kg N/m3/day from the day 146 to day 230. Ratios of T－N removal, NO2－N removal, and NO3－N production to NH4－N removal for Reactor 2 were 2.03:1.2:0.17, respectively. In addition, distinctive red granular anammox biomass grew at the bottom parts of the reactors during both runs. By DNA analyses, both KSU－1 and KU－2 strains were detected in anammox sludge of Reactor 2, with the KSU－1 strain being dominant.View full abstractDownload PDF (3236K) -
RIE SUZUKI, KAIQIN XU, TAKAHIRO OUCHIYAMA, HIROSHI YAMAZAKI, TOSHIHIRO ...Article type: ORIGINALS
2006 Volume 42 Issue 4 Pages 169-176
Published: 2006
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSThe number of wastewater treatment systems coupled with disposers which are used in apartments in urban areas has been increasing in recent years. However, no analysis has been made as to the relationship among the microfauna/purification function in aeration tanks and the influent load in these systems. This study was aimed to analyze the relationship between influent loads and treatment performance and that between the microfauna and purification function in wastewater treatment systems using dispersion type disposers, which were introduced into rural areas. Consequently, influent loads varied greatly depending on the family, and the influent BOD load per person was 22.0 g•person−1•day−1. The BOD load was found to vary significantly, depending on the presence/absence of disposers, and a 2－fold increase in the BOD load was observed when a disposer was used. For the quality of treated water, 75% of all samples had a BOD of 30 mg•l−1 or less. For the relationship between the microfauna and purification function, the proportions of organism from activated sludge, intermediate activated sludge and non-activated sludge were found to be prone to variation, depending on influent loads into disposers. In short, these results suggest that microscopic animals that thrive in slightly aerobic and anaerobic environments when the influent load into disposers increases and they prey on decomposer bacteria and contribute to improving the purifying capacity. Moreover, microscopic animals could be used as a biological indicator to evaluate the performance of biological treatment system in terms of purification capacity.View full abstractDownload PDF (812K) -
YUKUO SHUTO, YOUSHI SUZUKI, KAZUHIRO NAGAHAMA, MASAYOSHI MATSUOKA, TAK ...Article type: ORIGINALS
2006 Volume 42 Issue 4 Pages 177-184
Published: 2006
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSTriphenyltin (TPT), an endocrine disruptor, was successfully quantified by gas chromatography using a newly developed method consisting of propylation of TPT after conversion to a tropolone complex. Increased volatility by propylation as well as high efficiency of extraction into an organic solvent phase by tropolone allowed for measuring degradation by-products of TPT with grater sensitivity and accuracy. Screening of microbial strains capable of degrading TPT resulted in isolation of a promising strain from soil. This strain, identified as a Pseudomonas sp., was tolerant to TPT at 50 mg/l and grew well in the presence of 0.16% ethanol as a carbon source. In a synthetic medium containing 1 mg/l TPT and 0.16% ethanol, the strain degraded TPT at a maximum of 50% over 5 days, and the by-products were 48.5% tri-phenyl, 38% di-phenyl, 12% mono-phenyl and 1.5% inorganic tin. Degradation of TPT did not occur in nutrient medium, thus suggesting that TPT might be co-metabolized with ethanol.View full abstractDownload PDF (1348K) -
RYUHEI INAMORI, KAI-QIN XU, PING GUI, YOSHITAKA EBIE, YUHEI INAMORI, M ...Article type: ORIGINALS
2006 Volume 42 Issue 4 Pages 185-197
Published: 2006
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESS -
KENGO YASUHIRA, MASAHIRO TAKEO, SEIJI NEGOROArticle type: ORIGINALS
2006 Volume 42 Issue 4 Pages 199-205
Published: 2006
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSWe isolated alkalophilic bacterium, Agromyces sp. KY5R, which degrades 6-aminohexanoate (Ahx)-oligomer (by-product of nylon-6 manufacture, designated as nylon-oligomer), from activated sludge of sewage disposal plant. The strain KY5R exhibited good growth on LB-plate containing insoluble Ahx-oligomer (pH10), and produced clear zone by hydrolysis of the oligomers. 6-Aminohexanoate-oligomer hydrolase from KY5R (A-EIII) had optimum pH at 7.5-8.0. This value was 0.5 point higher than the optimum pH of P-EIII (EIII encoded on plasmid pOAD2 in Arthrobacter sp. KI72). In addition, thermostability test revealed that the A-EIII was stable up to 60 ℃, while the P-EIII was stable up to 50 ℃ under the same condition. Cloning and sequencing analysis demonstrated that the amino acid sequence of the two EIII enzymes differs only at 5 positions among 355 amino acid residues. These results suggest that at least one of the five alterations affects the differences in the enzyme characteristics.View full abstractDownload PDF (1128K)
NOTE
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DAISUKE HOURI, MINORU MORIMOTO, KENJI MATSUMOTOArticle type: NOTE
2006 Volume 42 Issue 4 Pages 207-213
Published: 2006
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESS"Contemporary society is naturally interested in drinking water, needless to say with a focus on the safety, taste and healthfulness of water in Japan today.Three brands of bottled mineral water Rokkou-no-oishii-mizu, Tennen-sui-Aso, Mori-no-mizu-dayori secure a high share in the Japan mineral water market. These three brands plus another brand Yonago-no-mizu were tested for elements included in the water using water indexes on taste (O-index) and health (K-index).We compared the results obtained with the standards and prerequisites of high quality city water published by the Japanese Ministry of Health and Labor, and evaluated the level of water quality.The Rokkou-no-oishii-mizu and the Tennen-sui-Aso brands showed an O-index of > 2.0 and a K-index of > 5.2, which we classified as tasty/healthy water. The Mori-no-mizu-dayori and the Yonago-no-mizu brands showed an O-index of > 2.0 and a K-index of < 5.2, classified as tasty/non-healthy water.These results showed that these four kinds of natural bottled mineral water each have their own special characteristics and were classified as tasty water.View full abstractDownload PDF (744K)
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