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Volume 34 (1998)
- Issue 4 Pages 231-
- Issue 3 Pages 159-
- Issue 2 Pages 1-
- Issue 1 Pages 1-
Volume 34, Issue 1
Displaying 1-6 of 6 articles from this issue
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NOBUTADA NAKAMOTO, DAISUKE IKEDA, TOMOKO HOSHINO, MASUO YAMAMOTO1998 Volume 34 Issue 1 Pages 1-16
Published: March 15, 1998
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSNatural field survey was done to clarify the characteristic environment for a filamentous diatom Melosira to dominate in a slow sand filter. Four natural fields where Melosira was dominated in early spring were observed periodically. There were the basin of Shiraito waterfall at the foot of Mt. Asama, a natural pond of Sato Ike at the foot of Mt. Asama, pools in a dry river bed of River Chikuma where is a lower reach of sewerage plant and a hydroelectric power plant, a small downstream of Karasawa fall, and Soehi stream of a mountain small stream with slow water current as a contrast place where was not observed Melosira. The places where Melosira was observed at always in a year were a basin of Shiraito fall and pools in a dry river bed of River Chikuma. The basin was periodically cleaned to keep a clean basin. The pools were flushed out after the heavy rain and irregularly water discharge from the power plant. Both place are similar to a slow sand filter basin where the surface mud is scraped periodically. Small stream of Karasawa fall was hidden in the grass in summer. There was sometimes a evening shower in the mountain area and there was a sudden high water after a shower. In the pond Sato Ike, filamentous diatom was observed during the low water temperature period from fall tospring. However a filamentous green alga was dominated in summer. Filamentous diatom was apioneer plant in a stable environment with a slow water current and it was replaced tofilamentous green algae in warm period. The cause of this succession was discussed with the grazing activity of aquatic insect larvae.View full abstractDownload PDF (8306K) -
HIROKI NAKAMURA, KAZUHIRO MIKAWA, KAZUHIRO TANAKA1998 Volume 34 Issue 1 Pages 17-28
Published: March 15, 1998
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSInfluence of amount of organic matter in sludge and population density of denitrifiers on denitrification performance was studied using suspended sludge obtained from the denitrification tank of a bench plant operated by a combined nitrification / denitrification process with recycled mixed-liquor nitrified by immobilized microorganisms. In batch denitrification tests, the amount (A) of organic matter in sludge decreased according to the relation in which the metabolism rate of organic matter in sludge was proportional to A, and the denitrification rate (KDN) was obtained by an equation with KDN proportional to A. Under a condition of A of more than around 40 mg-BOD / g-SS, the population density of denitrifiers increased with decreasing A, thus the decreasing KDN was attributable to the significant decrease of the amount of organic matter per one cell of denitrifier. While, under a condition of A of less than around 40 mg-BOD / g-SS, the population density of denitrifiers decreased with A, thus the denitrification reaction was assumed to be in endogenous stage using the organic matter derived from bacterial lysis.View full abstractDownload PDF (1015K) -
BIN LE LIN, MASAAKI HOSOMI, AKIHIKO MURAKAMI1998 Volume 34 Issue 1 Pages 29-40
Published: March 15, 1998
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSEstablishing a treatment process for practical, economic disposal of photo-processing waste (PW) has become an urgent environmental concern under recently enacted revisions of LondonTreaty. This paper describes the acclimation of sulfur-oxidizing bacteria (SOB), and the PW treatment performance by acclimated SOB in conjunction with granular activated carbon (GAC), which demonstrates as an effective biological treatment method.
No distinct difference in acclimating SOB to strong dilution of PW (50-times to 12-times dilution) was observed between two acclimation methods, i.e., using diluted PW directly and using ONM medium firstly to accumulate SOB. Comparison of SOB/GAC and SOB acclimation systems for further acclimation (10-times to 3-times dilution), demonstrated that SOB/GAC systemsucceeded in acclimating SOB to 3-times diluted PW, while SOB system failed in even 6-times dilution. Meanwhile, culture of SOB in various dilutions of calcination PW system and inorganic salts of PW composition system clarified that SOB can grow even on solution of raw PW containing 12% salinity.
Weak dilution of PW (5-times to 4-times dilution) was treated by using SOB in conjunction with 10 g/l GAC in a long-term (98 d) continuous treatment (HRT=1.9-7.7d) such that mass-reduced sulfur compounds were completely oxidized to sulfate, while biodegradable organics in dissolved organic carbon (DOC) were simultaneously degraded at a removal rate of 55%, andresulted in 68% removal rate in chemical oxygen demand (COD) .
Selective culture of the SOB sludge by using seven kinds of medium revealed that about 90% of the SOB was facultative chemoautotrophic bacteria and also two kinds of heterotrophicbacteria were present.View full abstractDownload PDF (1178K) -
MASAFUMI TATEDA, YOUNGCHUL KIM, WESLEY O. PIPES1998 Volume 34 Issue 1 Pages 41-55
Published: March 15, 1998
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSOne of the most important functions of the settling tanks in an activated sludge process is thickening the sludge to a high enough suspended solids concentration so that the return sludge flow will maintain the desired mixed liquor suspended solids concentration. The settling phenomena which result in the thickening are zone settling and sludge compression. Both zone settling and sludge compression have been studied extensively. However, the transition from zone settling to compression has previously received only superficial treatmen
The objective of this study was to characterize the transition of activated sludge from zone settling to compression by using simple laboratory methods. Batch settling tests were conducted using samples of activated sludge from one treatment plant. The samples were obtained over a period of fourteen month and the sludge volume index (SVI) values ranged from 80 ml/g to 213 ml/g. A model for predicting a first order rate constant for the transition from zone settling to compression was developed by analyzing the experimental data By classifying the sludges into six groups according to the SVI range, the transition from zone settling to compression was successfully characterized with respect to the initial suspended solids concentratfonView full abstractDownload PDF (1166K) -
MINORU SHIMURA, TOSHIO HAYAKAWA, GOURI MUKERJEE-DHAR, MASAO FUKUDA, KA ...1998 Volume 34 Issue 1 Pages 57-65
Published: March 15, 1998
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe degradation of polychlorinated biphenyls (PCBs) in a 10-liter fermentor by Comamonas testosteroni strain TK102 was investigated. The efficient degradation of 100mg/l Kaneclor 300 by strain TK102 was achieved in 1/3 diluted Luria-Bertani (LB) medium in the absence of biphenyl.Eighty seven percent of Kaneclor 300 was transformed within 72h. This is the first report onthe biodegradation of PCBs in a fermentor. During 24h of incubation, PCBs at the initial concentration of 100mg/l were most efficiently degraded. At the concentration of 150 and 200mg/l, the efficient degradation of PCBs began after a 18-h lag period.View full abstractDownload PDF (825K) -
HIDEAKI UCHIDA, TAKANORI KOUCHIWA, KAORI WATANABE, AYAKO KAWASAKI, YOS ...1998 Volume 34 Issue 1 Pages 67-75
Published: March 15, 1998
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSAn assay system was described for studying the mechanism for the lysis of cyanobacteria, which consists of (1) the improved soft-agar overlayer (SAO) method, and (2) the chlorophyll absorbance (CA) method. In the SAO, the activity was observed on a following double-layer agar plate; the agar was covered with a soft agar containing precultured Microcystis aeruginosa in a schale. Lytic plaques on the agar plate were observed using the disk method and/or cup method. In the CA, the cultured cyanobacterium was centrifuged and an aliquot of the concentrated suspension was poured into each well of a 96-well microplate. Subsequently, sample solution was added to the well and the plate was settled. The plates were daily measured for observing any increase or decrease in the OD665. CA has the number of advantages over SAO when considering practical use, however, SAO is indispensable for qualitative analysis, the elucidation of the mode of action and relationship between structure and activity. This method was applied to screen lytic compounds in a lake and two amino acids were found to have lytic activity.View full abstractDownload PDF (2772K)
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