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Volume 35 (1999)
- Issue 4 Pages 225-
- Issue 3 Pages 143-
- Issue 2 Pages 67-
- Issue 1 Pages 1-
Volume 35, Issue 3
Displaying 1-7 of 7 articles from this issue
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KWEON JUNG, YOUNG C. CHANG, YOUNG S. YOO, KAZUHIRO TAKAMIZAWA1999 Volume 35 Issue 3 Pages 143-155
Published: September 15, 1999
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA method for prediction of leachate amount and analysis of leachate characteristics at an open-dumping landfill site, Nanji-do, Seoul, Korea were studied to help designing of leachate treatment facility and planning for adequate utilization of produced land. Water content capable of maintaining by wastes was introduced to water balance equations for prediction of leachate amount, resulted that 4, 339 m3/day in average was computed. Despite HELP model gave more leachate amount, similar value was obtained by using Stegmann model applicable for condition of unfavorable soil covering at sanitary landfills. Cl-concentration profile in leachate suggested that behavior of leachate production at an open-dumping site was likely to those of at semiaerobic landfill sites and sea-based waste disposal sites. Air could penetrate into inner layer, if dumping height was 95 m. Rate of oraganics decomposition could be slower than that of sanitary landfill, was understandable from analysis of BOD and nitrogen concentrations in leachate. Heavy metals detected were mainly form of suspended solids and values of leachate effluent are higher than those of internal leachate. Cadmium, mercury, and lead were seldom detected in leachate. It was found that sulfate-reducing bacteria were widely distributed in leachates and more number of sulfate-reducing bacteria showed lower values of heavy metals in leachate, besides, number of sulfate-reducing bacteria were highly correlated (r=0.523, n=36) with TBOD values of leachate.View full abstractDownload PDF (1552K) -
NAOSHI FUJIMOTO, NAOYUKI SUENAGA, MASAHARU SUZUKI, RIKIYA TAKAHASHI, K ...1999 Volume 35 Issue 3 Pages 157-163
Published: September 15, 1999
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSProtozoa and metazoa isolated from aeration tank of biological wastewater treatment facility were cultivated with hollow polyethylene media to test growth characteristic under presence of the media. The number of Ciliata Vorticella cupifera and Rotatoria Philodina erythrophthalma attached to the media was 166 N⋅cm-2 and 50 N⋅cm-2 respectively, resulting population density of these microanimals in cultivation 9-fold and 2.5-fold higher than those without media. With media, the number of these microanimals in liquid phase was also higher than those without media. Oligochaeta Aeolosoma hemprichi did not attach on the media. It was proved that application of the media could heighten area for attach and also create suitable environment for growth resulting population density of microanimal much higher.View full abstractDownload PDF (603K) -
YUKIO KAWAGUCHI, YOSHIO SAKAI, MASANORI FUJITA1999 Volume 35 Issue 3 Pages 165-176
Published: September 15, 1999
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe four-stage denitrification-nitrification system with step-inlet was developed in order to prevent operational troubles in activated sludge plants, such as filamentous bulking, pH drop of the effluent because of advanced nitrification, and so on. Pilot-scale treatment experiments using municipal wastewater were conducted to clear the treatment characteristic and the optimum operating condition of this process.
The equations were introduced to simulate microbial behavior in this process based on population dynamics. Then, the coefficients of these equations were determined by the results of pilot-scale treatment experiments and some reference, and it was revealed that the simulated water qualities in the reactor agreed with the results of pilot-scale treatment experiments. The simulation results suggested that this process is more suitable than the conventional activated sludge process to prevent the filamentous bulking and pH drop of the effluent because of advanced nitrification, within wide operation range of primary settling tanks. The nitrification-suppressed operation was more effective than the nitrification-enhanced operation to prevent the filamentous bulking, also, the shorter solids retention time (SRT) was effective to prevent it.The four-stage denitrification-nitrification process with step-inlet can also prevent the filamentous bulking, if nitrification-suppressed or nitrification-enhanced operation was switched according to the nitrification activity with wide range of water temperature.View full abstractDownload PDF (1290K) -
YASUO TANAKA, KAZUSHIGE KITAYAMA, SAKAE FUKUNAGA, KIYONORI HAGA1999 Volume 35 Issue 3 Pages 177-188
Published: September 15, 1999
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe performance of a swine wastewater treatment process composed of an upflow sedimentation tank for pretreatment, an UASB reactor, and a trickling filter for post treatment was examined using a pilot plant. The UASB reactor has a volume of 1 m3 (0.6 m diameter × 3.5 m height), 48 hrs for hydraulic retention time (HRT) and 25°C in reactor temperature. The trickling filter was 0.6 m in diameter and 2 m in height. The operation of the pilot plant was carried out from February 1998 to July 1998 with supplying 0.5 m3/day wastewater discharged from a swine barn. Water quality of influent was 5, 000-30, 000 mg/l for suspended solids, 10, 000-30, 000 mg/I for CODCr, 3, 000-10, 000 mg/l for BOD, 200-400 mg/l for total phosphorus, and 600-1, 500 mg/l for total nitrogen. Effluent water quality was 200-600 mg/l for suspended solid, 500-2000 mg/l for CODCr, 100-300 mg/l for BOD, 80-100 mg/l for total phosphorus and 400-600 mg/l for total nitrogen. The removal efficiency of BOD was 80-95% by the UASB reactor and 97-99% by the total process. Methane gas production was about 1 m3/m3-reactor·day during the initial stage and declined gradually with the dropping of influent BOD. Sulfide contained in biogas was removed from 3, 000 ppm to less than 2 ppm by a packed column type H2S remover in which the effluent was spreaded continuously.View full abstractDownload PDF (1095K) -
HIROFUMI IZAWA, TAKU OKAMOTO, TOSHIKO HASHIMOTO1999 Volume 35 Issue 3 Pages 189-197
Published: September 15, 1999
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSIn order to eliminate nitrogen from wastewater, simple and stable method was developed using methanol permeable polymer bag containing methanol inside. Polyethylene membrane was suited as the methanol permeable polymer in comparison with polyvinylchloride in a point of endurance. Permeation rate of methanol through polyethylene membrane 0.1mm thickness, was 2.1g-McOH/m2/day at 20°C. The permeation rate increased in proportion to temperature and decreased in proportion to thickness of the membrane. Effect of temperature, hydraulic retention time and nitrate concentration on the denitrification of this process using polyethylene membrane was examined. The results showed that the denitrification proceeded on the surface of the membrane including biofilm, and the rate depended on the methanol permeation rate which was affected with temperature. And also, denitrification rate was affected in proportion to nitrate concentration below 15mg-N/l, but the rate was held approximately 1g-N/m2/day of maximum revel above 20mg-N/l of nitrate concentration, using 0.1mm polyethylene membrane at 20°C. We actually applied this process as a denitrifying reactor to small-scale on site wastewater treatment plant for human waste. We got similar results of denitrifying ability, 1.25g-N/m2/day and 80% nitrogen removal at 20-25°C, under actual condition.View full abstractDownload PDF (944K) -
NORIO SUGIURA, KEO INTABON, TAKAAKI MAEKAWA1999 Volume 35 Issue 3 Pages 199-209
Published: September 15, 1999
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSCausative offensive odor from water bloom formed by Microcystis species in two eutrophicated lake waters (L. Kasumigaura, L. Tsukushi) in decaying process was examined and evaluated using sensory test method, gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) . After incubation, analysis for water parameters of the two lakes indicated remarkable increase in dissolved organic carbon (DOC) with much higher level by L. Kasumigaura, coinciding with high content of chlorophyll-a (chl.a) owing to the growth of cyanobacteria, Microcystis during summer. In identifying the causative odors, hydrogen sulfide (HS), methyl mercaptan (MM), isopropyl mercaptan (IPM), dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) were mainly contained before and after incubation, and the levels of MM and IPM from L. Kasumigaura after incubation were above 2.5 fold those in water from L. Tsukushi.
In measuring type and intensity of the odors with sensory test method, the odor from L. Kasumigaura before and after incubation was earthy, drainage or marshy, whereas L. Tsukushi had a marshy or a drainage with much less than the value of thresh-hold odor number (TON) of L. Kasumigaura. The sensory test method was available for identifying type of the causative odors and measuring their intensity.
The cause of the offensive odors from the two lakes with the high density of Microcystis during the decomposition mainly attributed to IBM, IPM and MM emitting strong odor at very low concentration, paralleling with the increase in ammonia and HS.View full abstractDownload PDF (1207K) -
SHIGERU TAKEDA, AKIRA INABA, SETSUKO KITAHARA, KEISUKE IWAHORI1999 Volume 35 Issue 3 Pages 211-223
Published: September 15, 1999
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSTotal coliforms, fecal coliforms, and pathogenic Escherichia coli O157: H7 were measured in domestic wastewater and biologically treated wastewater from 75 treatment plants serving various types of buildings. The means for the influents of all the plants were 3.7×105 CFU/ml of total coliforms, 1.4×105 CFU/ml of fecal coliforms, and pathogenic E. coli O157 was not detected. The means for the effluents were 4.6×103 CFU/ml of total coliforms, and 1.1×103 CFU/ml of fecal coliforms. Seventy-nine percent of the plants complied with the effluent standards, revealing that efficient treatment can considerably reduce total coliforms even before disinfection. In Johkasous serving multiple dwelling houses, total coliforms in the influents showed relatively small time-serial and seasonal variations, and flow equalization tanks contributed to efficient treatment, resulting in the constant presence of few bacteria in the effluents.
A high correlation was obtained between total coliforms and fecal coliforms. A correlation was also found between BOD and total coliforms in the effluents. Total coliforms can be decreased by extending the retention time in a biological reactor, where nitrification can proceed. So operation methods which promote nitrification can reduce total coliforms effectively. The mean removal efficiency of total coliforms was higher using the activated sludge process than the contact aeration process.View full abstractDownload PDF (1050K)
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