All issues
Volume 43 (2007)
- Issue 4 Pages 169-
- Issue 3 Pages 121-
- Issue 2 Pages 63-
- Issue 1 Pages 1-
Volume 43, Issue 1
Displaying 1-6 of 6 articles from this issue
- |<
- <
- 1
- >
- >|
OLIGINALS
-
AKARI FUKUDA, MOTOO UTSUMI, KUNIHIRO OKANO, NORIO SUGIURA, TAKAAKI SAT ...Article type: ORIGINALS
2007 Volume 43 Issue 1 Pages 1-8
Published: 2007
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSBatillaria snails are a dominant group in the tidal wetlands along the Japanese coast. In this study, we monitored the metals concentration in the sediments and in the soft tissue of B. cumingii, which is the direct-developing snail, collected from Kasai-oki and Banzu tidalflats located in Tokyo Bay and Nakatsu tidalflats at Oita Prefecture. The metals concentration such as Cr, Co, Ni, Cu and Zn in the sediment of Kasai-oki was higher than that of other's. The Cd concentration in sediments of Banzu was lower than that of Nakatsu, but the Cd in the soft tissue of the snails from Banzu tidalflat showed higher concentration than that of Nakatsu. The snails of Banzu tidalflat represented higher amounts of MTLPs (metallothionein-like-proteins), which were calculated by using Cd-chelex assay, than the snails of Nakatsu tidalflats. It is seemed that some environmental stress might be force the snails to represent MTs (metallothioneins) in their body, therefore, the relationship between metals concentration in the sediments and in the snail bodies was not confirmed.View full abstractDownload PDF (1119K) -
AKARI FUKUDA, MOTOO UTSUMI, NORIO SUGIURA, TAKAAKI SATAKEArticle type: ORIGINALS
2007 Volume 43 Issue 1 Pages 9-18
Published: 2007
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSFreshwater snails, physid (Physa acuta) and lymnaeid (Austropeplea ollula), are in an interspecific competitive relationship occupying a same niche, both of them grazing periphyton attached to the surface of aquatic macrophyte. It is known that the some species feeding a same resource can avoid the interspecific competition by food segregation resulting from differentiation of their size. In Matsumi-ike Bog at University of Tsukuba, however, it was cleared that their sizes did not have significant difference through the year. In this research, it was considered whether two snails living a same habitat have the strategy to segregate their food habitats or not by comparison between seasonal changes of generic composition of the attached and planktonic diatoms and the diatoms in snails’ gut contents. By detrended correspondence analysis of the generic compositions of diatoms in snails’ gut contents and attached and planktonic diatoms from June to December, it was showed that the individual variety of two snails’ food habitat was larger than seasonal fluctuations of the diatoms. By analysis of selective indices, it was showed that the number of diatom genera that lymnaeid grazed by selective grazing was more than that of physid did. In this research, it was revealed lymnaeid had a little different food habitat compared with physid. It is supposed that there isn’t distinct food segregation between two species, but the different food habitats between two species might be one of the causes of the coexistence in Matsumi-ike Bog.View full abstractDownload PDF (1143K) -
TAKASHI KONDO, YOSHITAKA EBIE, NAOHIRO NODA, NORIO IWAMI, SATOSHI TSUN ...Article type: ORIGINALS
2007 Volume 43 Issue 1 Pages 19-29
Published: 2007
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSPolyphosphate-accumulating organisms (PAOs) indicators in enhanced biological phosphorus removal (EBPR) process evaluated by conventional analyses and that by microautoradiography- fluorescence in situ hybridization (MAR-FISH) analysis were compared and discussed. Two types of activated sludge, EBPR sludge and non-EBPR sludge, were mixed in the different ratios and operated in the acetate-fed sequencing batch reactors (SBRs). During the start-up phase, three conventional indicators, the phosphorus content in biomass, the population density of Rhodocyclus-related PAO (RPAO) and the anaerobic phosphorus release, were analyzed. The increase of the population density of RPAO and the phosphorus content exhibited different behavior. This difference might be derived from the change in physiology of RPAO. The anaerobic phosphorus release also showed different result from the other two indicators. It might result from the low acetate assimilation activity of PAOs and from the acetate assimilation by other bacteria. Both the acetate assimilation by α-Proteobacterial G-bacteria and no acetate assimilation by some RPAO were visualized by MAR-FISH analysis whereas the acetate assimilation by most of RPAO was also visualized. Conventional indicators evaluated in this study gave the different results because 1) each indicator is based on each activity of PAOs, such as acetate assimilation, phosphorus uptake and growth activity, and 2) the activities of other organisms should affect each indicator. MAR-FISH analysis is more appropriate for the determination of the actual substrate uptake activities, but the further identification of their phylogenetic affiliation and the determination of the biochemistry of PAOs and glycogen-accumulating organisms (GAOs)/G-bacteria are also still needed.View full abstractDownload PDF (1555K) -
Anammox Treatment Potential in an Up-Flow Column Reactor using a Novel Acrylic Fiber Biomass CarrierSEN QIAO, YINGJUN CHENG, ZHIJUN LIU, YASUNORI KAWAGOSHI, AYA FUJIMOTO, ...Article type: ORIGINALS
2007 Volume 43 Issue 1 Pages 31-41
Published: 2007
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSIn this study, a novel acryl fiber biomass carrier (ABC) was applied for anammox research in an up-flow column reactor. This material could retain anammox microorganism efficiently and the average weight of attached sludge in the bottom part of the reactor was calculated to be 0.14 g－TSS/cm3 ABC. High removal efficiencies of ammonium, nitrite and TN were obtained at a high volumetric loading rate of 2.0 kg－TN/m3/d. Furthermore, anammox activity did not decrease significantly with decreasing temperature, e.g., when the temperature decreased from 33.0℃ to 26.2℃, nitrite removal efficiencies decreased only about 5% (from 94% to 89%). Scanning electronic microphotographs revealed that the microorganisms were in a compacted state when attached on the support material. Based on the analysis of 16S rDNA, two close matches of anammox bacteria, KSU－1 and KOLL2a, were detected. This material showed potential for treatment of wastewater with low concentrations of nitrogen using a short hydraulic retention time.View full abstractDownload PDF (2386K) -
NGUYEN NHU SANG, SATOSHI SODA, KAZUNARI SEI, TOMONORI ISHIGAKI, LAM MI ...Article type: ORIGINALS
2007 Volume 43 Issue 1 Pages 43-49
Published: 2007
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSThis study examined characteristics of leachate from the Go Cat landfill in Ho Chi Minh City, Vietnam and the performance of a lab-scale bioreactor equipped with a microfiltration unit (membrane bioreactor; MBR) for leachate treatment. The COD concentrations of leachate were 39.6–59.8 g l–1 and 1.1–4.0 g l–1 in the dry season (Nov. 2003 – Apr. 2004) and the rainy season (May – Aug. 2004), respectively, indicating that intensive precipitation of the monsoon climate in summer promotes leachate generation and changes in its quality because of the enhanced degradation and increased dilution. The BOD/COD ratio over 0.68 through the year suggested that biological wastewater treatment processes are promising for leachate treatment. The MBR was operated for 90 days at volumetric loading rates of 1.9–4.2 g－COD l–1 d–1. The microfiltration membrane kept the sludge concentration high in the MBR. The specific loading rate remained at 0.097–0.616 g－COD g－VSS–1 d–1 because of the high MLVSS concentration. The MBR showed high COD removal of 84–97% throughout the experimental period. Those results suggest that the effluent COD standard of 100 mg l–1 is probably achieved in the rainy season, but some post-treatment processes are needed, especially for the dry season.View full abstractDownload PDF (734K) -
TAKASHI KONDO, YOSHITAKA EBIE, SATOSHI TSUNEDA, YUHEI INAMORIArticle type: ORIGINALS
2007 Volume 43 Issue 1 Pages 51-62
Published: 2007
Released on J-STAGE: March 10, 2018
JOURNAL FREE ACCESSTo evaluate the effectiveness of the separation of polyphosphate-accumulating organisms (PAOs) and glycogen accumulating organism (GAOs)/G-bacteria from the phylogenetically high-diverse activated sludge using the buoyant density separation, activated sludge was collected from the acetate-fed SBR and the microbial community was determined. The activated sludge sample collected at the end of the aerobic phase was subjected to the buoyant density separation. The microbial communities of separated sludge were fingerprinted by terminal restriction fragment length polymorphism (T－RFLP) analysis. The microbial community analysis exhibited that Candidatus ‘Accumulibacter phosphatis’ known as PAOs, Defluvicoccus- relative G-bacteria and the group GB known as GAOs and some organisms playing an important role for nitrogen removal existed in the SBR. The T－RFLP analysis for each fraction of the buoyant density separation revealed that Cand. ‘Accumulibacter phosphatis’ was selectively concentrated in the high-density fraction. Although some unidentified peaks were also the prominent, Defluvicoccus vanus-relative G-bacteria were failed to concentrate. The unique T－RF derived from organisms including the group GB was the prominent in the high-density fraction. The Acidobacteria, the Bacteroidetes and the Nitrospira were disappeared in the high-density fraction. Even though some bacteria related to phosphorus removal were eliminated, most of bacterial strains which do not play an important role for phosphorus removal could be eliminated by the buoyant density separation.View full abstractDownload PDF (843K)
- |<
- <
- 1
- >
- >|