Japanese Journal of Water Treatment Biology
Online ISSN : 1881-0438
Print ISSN : 0910-6758
ISSN-L : 0910-6758
Volume 39, Issue 4
Displaying 1-6 of 6 articles from this issue
  • HIROSHI OGAWA, KEISUKE IWAHORI
    2003 Volume 39 Issue 4 Pages 157-165
    Published: December 15, 2003
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    As more than 90 % of the installed Gappei-shori Johkasous, a kind of domestic wastewater treatment plant, are made of fiber-glass reinforced plastics (FRP) or dicyclopentadiene (DCPD), there is an environmental risk resulting from the elution of bisphenol A (BPA) and phthalic acid ester from such johkasous. A study on elution of the endocrine disrupting chemicals from FRP/DCPD-made johkasous was carried out using test-piece of the johkasous and a johkasou in operation.
    The results showed that di- (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) was detected in the elution experiment, implying that those endocrine disrupting chemicals eluted into the water from the test-piece and the johkasou in operation. However, DEHP and DBP in water seem to be adsorbed by activated sludge, and then DEHP and DBP were biodegradated in the activated sludge. The residual rates of DEHP and DBP after 30 days was found to be 28%, 33% respectively.
    Download PDF (1093K)
  • SATOSHI TSUNEDA, TAKASHI SHIONO, KAZUYUKI NAKAMURA, AKIRA HIRATA
    2003 Volume 39 Issue 4 Pages 167-174
    Published: December 15, 2003
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    An upflow anaerobic sludge blanket (UASB) reactor was successfully applied to continuous degradation of ferric ethylene diamine tetra acetate (Fe-EDTA) as a typical xenobiotic substance contained in photo-processing wastewater. The sludge in the UASB reactor had an abundance of sulfate-reducing bacteria (SRB), which had been anaerobically cultivated in a sulfate-rich culture medium including Fe-EDTA and yeast extract as the carbon sources. Since the prominent reductions of Fe-EDTA and sulfate ion were observed, the contribution of SRB to Fe-EDTA degradation in the UASB reactor was confirmed. The aggregated sludge in the UASB rector became gradually large, reaching steady state with an equivalent diameter of 60-90, μm after 92 days operation. An increase of the amount of yeast extract addition to feed solution, which contained 100 mg-C/l of Fe-EDTA, improved the Fe-EDTA removal efficiency up to 90%. Moreover, approximately 80% of intermediate compounds were mineralized by O3/H2O2 oxidation process. When the combination of SRB treatment and O3/H2O2 was applied to an actual fixing wastewater, approximately 80% of Fe-EDTA and 70% or more of dissolved organic carbon (DOC) in thefixing wastewater were degraded.
    Download PDF (2646K)
  • TAKASHI KONDO, TOMOAKI ITAYAMA, SATOSHI TSUNEDA, AKIRA HIRATA, YUHEI I ...
    2003 Volume 39 Issue 4 Pages 175-181
    Published: December 15, 2003
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    In this study, effects of phosphorus concentration on aquatic microcosms were evaluated in terms of microbial population dynamics and the photosynthetic activity that is the starting point of the material flux. Microcosms that consist of algae Chlorella vulgaris, bacteria Pseudomonas putida and ciliate Cyclidium glaucoma were incubated using media that contain various concentrations of KH2PO4. At 14-16 days after the incubation started, sodium [14C] bicarbonate was added to each microcosm, and then microbial uptake of radioactive substrate was monitored. The population density of C. uulgaris and C. glaucoma increased, as initial phosphorus concentration was higher, while that of P.putida was constant. The photosynthetic activity of C. vulgaris also increased, as initial phosphorus concentration becomes higher. In the microcosm, P. putida uses metabolites produced by C. vulgaris and is preyed by C. glaucoma. Therefore, the growth activity of P.putida increased as the photosynthetic activity of C. vulgaris increased, but predation pressure by C. glaucoma also increased. Consequently, the population of P. putida kept constant. These findings lead to the conclusion that phosphorus concentration strongly affects the microbial population dynamics and material flux in the microbial loop in the aquatic ecosystem. However, the mass balance of each organism should keep steady state in the environment where the population of predator such as protozoa, invertebrates, fish and so on was kept suitable.
    Download PDF (2592K)
  • HU JIN, TEIZI URAKAMI, KENJI FURUKAWA
    2003 Volume 39 Issue 4 Pages 183-188
    Published: December 15, 2003
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    The addition of a hydrogen donor is essential for heterotrophic biological denitrification treatment. Experiments were conducted on the denitrification treatment of groundwater using biodegradable plastic poly-β-hydroxybutyrate (PHB) . Batch denitrification tests using denitrifying activated sludge and continuous treatment using a soil column were carried out. Results showed that denitrifying activity improved with time and that the surface of PHB pellets changed unevenly in the batch tests. The soil column with PHB could remove influent NO3-N completely, but the soil column without PHB could not remove influent NO3-N at all. Effluent TOC concentrations from the soil column, in which 342g of PHB pellets were buried, were high (max: 38mg-TOC/l), but effluent TOC concentrations from soil columns in which 171 and 86 of g-PHB pellets were low.
    Download PDF (5707K)
  • IKBAL, YUEQIN TANG, YUTAKA FUJIMURA, TORU SHIGEMATSU, SHIGERU MORIMUR ...
    2003 Volume 39 Issue 4 Pages 189-197
    Published: December 15, 2003
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Acontinuous-flow methane fermentation process was operated using acetate as the sole organic substrate. The phylogenetic analysis showed that 72% of the 16S rDNA clones were amliated with aceticlastic methanogens, Methanosaeta and Methanosarcina. The effects of pH, NH4+, acetic acid, propionic acid, S2-, Co2+, Ni2+, and NO3- concentrations on methanogenic activity were investigated in batch assays using the culture broth from the acetate reactor. The results showed that the patterns of specific gas evolution rate with and without pH control were different. Under the condition with pH control, the specific gas evolution rate decreased drastically when the pH was below 6.5 and over 7.5. The optimum pH was fbund to be 7 for mesophilic aceticlastic reaction. The specific gas evolution rate decreased sharply when the concentration of free NH3 exceeded 100-150mg/l; acetic acid and propionic acid did not interfere with the stability of anaerobic treatment when their concentrations were less than 3, 500mg/l and 4, 000mg/l, respectively. S2-had a toxic effect on methanogenic activity, such that the gas production rate was nearly zero at a Na2S concentration of 300mg/l; the additions of Ni2+ and Co2+ increased the gas production rate and they had almost no negative effects on methane fermentation even when their concentrations reached 10mg/l. The specific gas evolution rate also decreased sharply when the concentration of NO3- exceeded 500 mg/l which corresponded to about 110 mg-N/l.
    Download PDF (1120K)
  • YOSHITAKA EBIE, HIDETOMO MIURA, NAOHIRO NODA, MASATOSHI MATSUMURA, SAT ...
    2003 Volume 39 Issue 4 Pages 199-207
    Published: December 15, 2003
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Expression of ammonia monooxygenase (amoA) gene in domestic wastewater treatment process was monitored by combination analysis of reverse transcription (RT) -PCR and denaturing gradient gel electrophoresis (DGGE) . Sludge samples were collected from a bench-scale reactor treating synthetic domestic wastewater. After total RNA was extracted, RT-PCR was performed. DGGE analysis was used to separate the amplified products according to their sequence and thereby to visualize individual community members. Ammonia oxidizers that were demonstrated by the presence of amoA mRNA were regarded as metabolically active ones. The DGGE profiles of amoA mRNA RT-PCR products obtained at the initial stage of the operation showed decrease of the diversity of amoA mRNA. When influent load was changed with reduction of hydraulic retention time (HRT) or increase of concentration of wastewater, new DGGE bands newly appeared on only the short HRT condition. The amoA sequences of DGGE bands disappeared in the beginning of the operation affiliated to the Nitrosomonas eutropha lineage. On the other hand, all the amoA sequences of new DGGE bands affiliated to the genus Nitrosomonas, and formed phylogenetic lineage for which no cultured representative exists.
    Download PDF (2766K)
feedback
Top