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Volume 39 (2003)
- Issue 4 Pages 157-
- Issue 3 Pages 99-
- Issue 2 Pages 49-
- Issue 1 Pages 1-
Volume 39, Issue 1
Displaying 1-6 of 6 articles from this issue
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TAKESHI SAITO, TOMOAKI ITAYAMA, YUHEI INAMORI, NORIO SUGIURA, MASATOSH ...2003 Volume 39 Issue 1 Pages 1-8
Published: March 15, 2003
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe biodegradability of microcystins produced by water-bloom was examined using the river die-away test. Although microcystin LR was not degraded during the first eight days after starting the test, after the eighth day, it began to be degraded rapidly, suggesting that microcystin LR was degraded by inductive metabolism and specific biodegradation. The activity of specific degradation of microcystin LR in the samples from a pond in which water-bloom was occurring was higher than from a pond with no water-bloom. Furthermore, the activity of specific degradation of microcystin LR in the samples taken during the water-bloom season (July 2001) was higher than on no water-bloom season (June 2001) . These results show that the bacteria that can degrade microcystin LR act accompanying the occurrence of water-bloom. Also, under the alkaline condition, microcystin LR was not degraded in the sample from the pond without water-bloom, but was degraded rapidly in the sample from the pond with water-bloom. We suggest that alkaliphilic or tolerant alkaline bacteria are strongly involved in the degradation of microcystin LR in the pond with water-bloom. We concluded that the fate of microcystin in the environment depend on specific bacteria which could adapt to two requirements, specific degradation metabolism for microcystin and tolerance to alkaline environment.View full abstractDownload PDF (969K) -
SEIICHIROU KUROKI, MOTONOBU NAKAOKA, TADAO SHIOTANI, KENJI FURUKAWA2003 Volume 39 Issue 1 Pages 9-16
Published: March 15, 2003
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSFor efficient treatment of textile wastewater, continuous treatment using PVA gel beads was conducted. The photo-dependent denitrifying sludge (PDDS) consisting of a symbiotic consortium of denitrifying and dye-degrading photosynthetic bacteria attached on polyviniyl alcohol (PVA) gel beads. The results of batch experiments indicated that immobilized PDDS has denitrification and decolorization capability under illuminated and anoxic conditions. A continuous-flow system consisting of nitrification and denitrification processes was constructed, and treatment experiments using a synthetic textile wastewater were conducted. The specific nitrification rate was influenced by inorganic carbon concentration and the relation of specific nitrification rate to organic nitrogen concentration followed Michaelis-Menten kinetics. The PDDS attached immobilized on PVA gel beads successfully removed color intensity and NOx-N in the denitrification reactor.View full abstractDownload PDF (3886K) -
IKBAL, YUEQIN TANG, TORU SHIGEMATSU, SHIGERU MORIMURA, KENJI KIDA2003 Volume 39 Issue 1 Pages 17-24
Published: March 15, 2003
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSHigh rate thermophilic methane fermentation using a gas circulation-type reactor was explored for its potential to reduce the volume of and make beneficial use of municipal solid waste (MSW) . Treatment without addition of mineral nutrients allowed for a maximum TS volumetric loading rate of only 1 g/l⋅d. However, with addition of mineral nutrients, a high TS volumetric loading rate of 8 g/l⋅d was achieved. At a TS loadingrate of 1 g/l⋅d, the methanogenic activity with addition of mineral nutrients was 4-fold higher than that without mineral nutrients. The concentrations of coenzymes F430 and corrinoids were 0.12 μmol/g-VSS and 0.07 μmol/g-VSS, respectively, at a TS volumetric loading rate of 8 g/l⋅d. Carbon recovery at each TS volumetric loading was nearly 100%, and about 50% of the carbon in raw waste was converted to methane gas. The degradation efficiency of lipid, protein, holocellulose and lignin were 90.7%, 59.4%, 91.9% and 66.0%, respectively. To repress the evolution of hydrogen sulfide, air was supplied to the anaerobic reactor, by which the concentration of hydrogen sulfide in biogas was reduced nearly 100% when air at 7.5% of the amount of evolved biogas was used.View full abstractDownload PDF (1041K) -
YOSHIKATSU ABE, MASAHIRO TAKEO, AKIHISA SAKAKIBARA, SEIJI NEGORO2003 Volume 39 Issue 1 Pages 25-31
Published: March 15, 2003
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA 4-nitrophenol (4-NP) degrading bacterium Rhodococcus sp. strain PNI can degrade polynitrophenols such as 2, 4-dinitrophenol (2, 4-DNP) and 2, 4, 6-trinitrophenol (picric acid) . To characterize picric acid degradation by this bacterium, degradation tests were carried out using resting PN1 cells. The results revealed that picric acid degradation by strain PN1 is induced by 2, 4-DNP and the hydride Meisenheimer complex of picric acid accumulates as a metabolite, suggesting that the initial reaction is a hydride transfer to the aromatic-ring of picric acid. The same resting cells could degrade 2, 4-DNP, 2, 5-dinitrophenol and 4, 6-dinitro-o-cresol (DNOC), but not 2, 6-dinitrophenol and 2-sec-butyl-4, 6-dinitrophenol (Dinoseb) . These results describe that strain PN1 has a reductive degradation mechanism for polynitrophenols in addition to an oxidative one for 4-NP.View full abstractDownload PDF (921K) -
JOSEPH D. ROUSE, NORIHARU YOSHIDA, HAYATO HATANAKA, URARA IMAJO, KENJI ...2003 Volume 39 Issue 1 Pages 33-41
Published: March 15, 2003
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSUsing a nonwoven material for biofilm attachment in a continuous flow reactor, conversions of nitrogenous compounds closely following the stoichiometry of the recently discovered anaerobic ammonium oxidation (anammox) process were developed and maintained for over one year of operation. Removal rates of ammonium (NH4+) and total nitrogen as high as 31 and 63 mg N/ (l⋅h), respectively, were demonstrated over several weeks of operation and removals of approximately 24 and 47 mg N/ (l⋅h), respectively, were maintained over most of the study, which are in a suitable range for industrial applications. With a HRT of 8.5 hours, influent NH4+ and nitrite (NO2-) concentrations of over 300 mg N/l, each, were successfully treated with removal efficiencies of approximately 70%. However, very little benefit could be attributed to the use of recycle in attempts to work with higher influent concentrations where NO2- toxicity would be of concern.View full abstractDownload PDF (3416K) -
YASUO TANAKA2003 Volume 39 Issue 1 Pages 43-48
Published: March 15, 2003
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSIn a wastewater treatment process consisting of a UASB reactor and aerobic post treatment, excess biogas is produced during the warm season. Methane-dependent nitrate removal using a biogas scrubber would be an efficient way to utilize the excess biogas. The performance of the plastic media-filled packed-bed reactor was examined for biogas scrubbing and methane-dependent nitrate removal. A bench-scale packed-bed reactor was installed in a swine wastewater treatment plant consisting of a UASB reactor and a trickling filter. The biogas from the UASB reactor was supplied from the bottom (3.4-9.4 m d-1), and the trickling filter effluent was spread from the top (9.4-26.1m3 m-2 d-1) . The concentration of H2S dropped from 1200-2500 ppm to less than 2 ppm. The plastic media covered with biofilm were then collected from the reactor and filled into a laboratory scale packed-bed reactor. Inorganic medium containing 40 mg-N l-1 nitrate was spread from the top of this reactor (1.4 m3 m-2 d-1), and gas was supplied from the bottom (25-36.5 m d-1) . The nitrate concentration dropped significantly when CH4 (93%v/v) and O2 (7%v/v) were supplied simultaneously. In contrast, nitrate removal scarcely occurred when only CH4 or He was supplied. These results suggest that simultaneous biogas scrubbing and methane-dependent nitrate removal are possible with the packed-bed reactor.View full abstractDownload PDF (685K)
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