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Volume 31 (1995)
- Issue 3 Pages 137-
- Issue 2 Pages 63-
- Issue 1 Pages 1-
Volume 31, Issue 1
Displaying 1-7 of 7 articles from this issue
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[in Japanese]1995 Volume 31 Issue 1 Pages 1-13
Published: March 15, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDownload PDF (5677K) -
TSUNEO YOSHINO, TOHRU IYO, SHIGERU OHNO1995 Volume 31 Issue 1 Pages 15-23
Published: March 15, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSSynthetic inorganic NH4-N wastewater with a load of 0.06, 0.12 and 0.24g/l·d were drculated through a nitrification tank equipped with a lace-like contact medium. At water temperatures of 20 and 30°C, high nitrification efficienaes (more than 90%) were obtained irrespective of the loading condition. At a water temperature of 10°C, a nitrification efficsency of approximately 80%was obtained under a low loading condition of 0.06 g-NH4-N/l⋅d. The maximum nitrifcation rates were 22.6mg-N/g-VSS·hr at a water temperature of 30°C, 11.0mg-N/g-VSS·hr at a water temperature of 20°C and 6.2mg-N/g-VSS·hr at a water temperature of 10°C.Temperature coeffiaents (θ) for nitrification were calculated to be 1.023-1.084.As the NH4-N loading rate was lowered, the influence of water temperature on nitrification effiaency was smaller. These results show that the nitrogen load should be limited to 0.06g/l⋅d or lower for nitrification treatment using the submerged bed process at a low water temperature.View full abstractDownload PDF (857K) -
TSUNEO YOSHINO, TOHRU IYO, SHIGERU OHNO1995 Volume 31 Issue 1 Pages 25-31
Published: March 15, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe effects of nitrogen load and water temperature on the treatment efficiency were studied using an anoxic rector equipped with a lace-like contact media. Experiments were conducted under various nitratenitrogen (NO3-N) loads and water temperatures. Temperature coefficients (θ) of 1.046-1.064 were calculated. An equation expressing the relationship between NOx-N removal efficiency, the NOx-N load and water temperature was obtained. From the equation, the NOx-N load that allows a high NOx-N removal efficiency in the anoxic reactor can be estimated, and the value was greatly effected by water temperature. Denitrification rates of 2.4-4.5 mg-N/g-SS·hr under water temperature of 30°C were obtained.View full abstractDownload PDF (657K) -
NOBUYUKI TANAKA, YUHEI INAMAORI, ZEN'ICHIRO KAWABATA, TADAHIKO MORI, T ...1995 Volume 31 Issue 1 Pages 33-41
Published: March 15, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe population dynamics of a genetically engineered microorganism (GEM) in a microcosm was analysed using computer simulation models. The GEM Escherichia coli HB101/pBR325 was inoculated into the microcosm containing algae Chlorella vulgaris, bacteria Pseudomonas putida and protozoa Cyclidium glaucoma 14 days after cultivation of the microcosm was initiated. When the GEM was added at 108cells·ml-1 (high density), protozoa grew and then decreased rapidly. It recovered to the same population density as the protozoa in the microcosm without addition of the GEM. The GEM also rapidly decreased until it leveled out at the density about 104cells·ml-1 when protozoa increased. On the other hand, in the microcosm into which GEM was added at 104cells·ml-1 (low density), the population density of neither the indigenous bacteria nor the GEM changed. Based on empirical data, the differential equation which represents the indigenous bacteria and GEM population dynamics was developed and solved numerically. The simulation corresponded well with the empirical data. There was, however, a difference between high and low density introduction of the GEM in the values of parameter which represent theexchange of bacteria between the predated GEM by protozoa and non-predated GEM by protozoa. This indicated that the values of parameter changed when the GEM aggregated or when cell morphology of GEM occurred.View full abstractDownload PDF (897K) -
KEISUKE IWAHORI, SHIGERU TATSUTA, KOICHIRO YAMAKAWA, MASANORI FUJITA1995 Volume 31 Issue 1 Pages 43-50
Published: March 15, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSBased on the results of batch culture experiments on the starch wastewater treatment using Aspergillus niger pellets, parameter fitting and model simulation were carried out in order to apply to the process design, operation and control. Starch was hydrolyzed into glucose and the resulting glucose was immediately metabolized by pellets, while a part accumulated in the form of citric acid. Kinetic parameters were found to be approximately identical regardless of the pellet diameter when calculated using a starch decomposition model for A. niger. From the results of model simulation, it was estimated that SRT and HRT needed to be set at 10 days and 12 hrs, respectively, in order to attain over 90% of the starch decomposition efficiency.View full abstractDownload PDF (796K) -
MASAHARU TADOKORO, TAKEHIKO OGAWA, TOSHIRO SAKURAI, SHIGERU OHNO1995 Volume 31 Issue 1 Pages 51-58
Published: March 15, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDeterioration of final effluent from small-scale onsite wastewater treatment plants (SOWTPs) for individual houses frequently occurs due to their malfunction if the family has a patient with diabetes. However, since little is known about the causes of this deterioration, no effective countermeasures have been taken. To understand the causes, we analyzed and evaluated the effects of glucosuria on the performance of the plants. The BOD of glucosuria was found to be markedly high, and the BOD in the urine of the patients with severe diabetes (3.0% or more saccharides) was about 10 times higher than that of the normal urine. The BOD load in the urine of the severe diabetics was calculated to be 61-142g/cap/day, equivalent to 20-47 times higher urinary BOD load of normal persons. The BOD load of night soil containing the urine of severe diabetics was estimated to be 71-152 g/cap/day, which was 5.5-12 times higher than the corresponding BOD of normal person of the night soil. It was suggested that the malfunction of the plants by glucosuria was caused by a significant increase in the BOD load.View full abstractDownload PDF (838K) -
ZAFAR IQBAL BHATTI1995 Volume 31 Issue 1 Pages 59-62
Published: March 15, 1995
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSOperational problems during the start-up of upflow anaerobic sludge blanket (UASB) reactors are little reported in the literature. In this study, operational problems during the initial operation of UASB reactors are discussed. Major problems encompass the gas entrapment in the granular sludge bed, formation of scum and crustation, and maintenance of hydraulic retention times (HRTs) at very low flow rates. The experience related to the effect of these problems is addressed in this study together with insight into the remedial measures. Gentle mixing at regular intervals during the initial period is stressed.View full abstractDownload PDF (3441K)
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