環境工学研究論文集
Online ISSN : 1884-829X
Print ISSN : 1341-5115
ISSN-L : 1341-5115
36 巻
選択された号の論文の51件中1~50を表示しています
  • 中村 寛治, 鈴木 義彦, 石田 浩昭
    1999 年 36 巻 p. 1-10
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Laboratory scale soilc olumns were operated to degrade trichloroethylen (TCE) by co-metabolism with phenol. The columns were operated approximately for a year. At the end of the operation effluent and biofilm samples were taken to analyze microbial community by three methods. First, dominant phenol-utilizing strains were isolated from diluted tubes in most-probable-numbe (MPN) methods. Totally four strains were isolated, and only one strain showed the capability of degrading TCE with phenol induction. Phylogenetic analysis on these four strains was carried out, and each of four strains was found to exist at separated positions in a phylogenetic tree, suggesting the existence of variety of phenol utilizers in the columns. Second, clones of PCR-amplified 16S rDNAs were randomly obtained and analyzed. Both of suspended and attached microbialc ommunitiesc onsisted of severald ominantt ypes of 16S rDNA occupyinga pproximately 50% of total 16S rDNA clones. Furthermore, two types of 16S rDNA showed identical phylotypes, which were defined by restriction patterns, among two microbial communities. Third, rapid analysis of total microbial populations was conducted by 5' terminal restriction fragment length polymorphism (T-RFLP) of 16S rDNAs. Results of T-RFLP analysis well characterized the microbial communities, and made possible to determine a dominant 16S rDNA type in a short time.
  • 荒木 信夫, 山口 隆司, 関口 勇地, 原田 秀樹
    1999 年 36 巻 p. 11-18
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Competitive interaction between methane producing bacteria and sulfate reducing bacteria in UASB granules was investigated by applying fluorescence in situ hybridization (FISH) of DNA-targeted probes specific to five different bacterial groups. Granules grown in an UASB reactor were imposed on a stepwise perturbation of feed sulfate strength from 33 to 1, 000 mg SO4-S·L-1. Under the low sulfate condition, Methanobacterium and Methanosaeta were found to be predominant, respectively, at the outer surface layer and at the internal portion of granules. Relatively small amounts of Desulfovibrio and Desulfobulbus were observed dispersively at the outer surface layer in the form of individual singular cell. Under the high sulfate fed condition Desulfobulbus became thin layered form to cover the whole granule surface. Hydrogen consumers, mainly such as Methanobacterium and Desulfovibrio, entirely disappeared in the granules, and completely-oxidizing sulfate reducing bacteria were abundantly observed.
  • 小沼 晋, 佐藤 弘泰, 味埜 俊, 松尾 友矩
    1999 年 36 巻 p. 19-28
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    To assess the feasibility of fluorescence in situ hybridization (FISH) method for ammonia-oxidizing bacteria, three experiments were done as follows; 1) re-optimization of experimental conditions for an oligonucleotide probe Nso190 specific for most of ammonia-oxidizing bacteria, 2) enumeration of ammonia-oxidizing bacteria in lab-scale nitrification reactors, municipal wastewater treatment plants and river water by FISH and other available methods, and 3) to evaluate a correlation between ammonia-oxidizing activity and FISH observation. The results indicated that 1) optimal concentration of formamide for Nso190 probe was 25%, 2) as for the nitrification reactors, where high number of ammonia-oxidizing bacteria seem to exist, FISH, antibody bound latex coagulation and dot blot hybridization methods gave consistent results of ammonia oxidizer enumeration, whereas the MPN method showed 1-2 order lower values than other methods, 3) ammonia-oxidizing bacteria can not be quantitatively detected by FISH method in the municipal wastewater treatment plants (WWTPs) and river water where the ammonia loading is rather low, 4) in some cases, ammonia-oxidizing bacteria can not be detected by FISH whereas ammonia oxidizing activity is observed. Improvement of the FISH methods, such as pretreatment of sample and/or techniques of boosting the fluorescence from the target is needed.
  • 成田 勝, 黄 介辰, 小泉 卓哉, 山肩 健史, 遠藤 銀朗
    1999 年 36 巻 p. 29-37
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Because anaerobic mercury-resistant microorganisms have not been surveyed sufficiently and those biological features remain to be understood while anaerobic environments are common as mercury-contaminated sites such as soil and sediments, anaerobic mercury-resistant bacterial strains were isolated from Minamata Bay, Kumamoto, and characterized. We also reported identification of a mercury-resistant bacterium of the isolated strains. The genetic components for mercuryresistance of the five strictly anaerobic bacterial strains inducing the bacterium isolated from Minamata Bay were analyzed. The resistance to mercurial compounds and to other heavy metals by the five strictly anaerobic bacterial strains were also tested. Theresults showed that the anaerobic mercury-resistant bacterium isolated from Minamata Bay was identified as Clostridium butyricum Mersaru. Nucleotide sequence analysis of the mercury resistance determinant showed that C. butyricum Mersaru has merB gene (an organomercury lyase gene), identical to that of the aerobic mercury-resistant Bacillus cereus RC607. PCR-Southern hybridization showed that the two PCR products, which are amplified from chromosomal DNA of the four strictly anaerobic bacterial strains, were highly homologous to merA gene (a mercury reductase gene) and merB gene from the aerobic mercury-resistant Bacillus, respectively. The resistance spectrums to mercurial compounds and other heavy metals incicated that all Clostridia tested in this study were broad-spectrum mercury-resistant and broad-spectrum heavy-metal-resistant.
  • 山肩 健史, 黄 介辰, 成田 勝, 遠藤 銀朗
    1999 年 36 巻 p. 39-47
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The structure of a broad-spetrum mercury resistance module was shown by sequencing the Grampositive bacterial transposon TnMERII from Bacillus megaterium MB 1 that was isolated from Minamata Bay sediment. In the upstream region of a previously identified organomercurial lyase merB (merB1) region of the TnMERII, a second merR (merR2) and a second merB gene (merB2) were found. These three genes constitute a second operon (mer operon 2) following a promotor/operator (PmerR2) region. The result suggest that the consititutional genes of the broadspetrum mercury resistance module of TnMERII are organized as PmerR1-merR1-merE-like-merT-merP-merA-PmerR2-merR2-merB2-merB1.
    To characterize the functional roles of the two merB genes encoded in the broad-spetrum mercury resistance module, subcloning analysis of the merB genes using Escherichia coli DH5 α as the host strain was performed by showing their specificity for organomercury resistance. It was demonstrated that the merB genes conferred the different patterns of organomercury resistance on the host bacterial strain. Besides p-chloromercuribenzoic acid, thimerosal, and fluorescein mercuric acetate, merB1 conferred phenylmercury acetate resistance, while the merB2 did not. This is the first report to distingulish the substrates specificity for merB1 and merB2 genes and these data offers some important clues for enzymatic and environmental biotechnological interests.
  • 平野 勇二郎, 一ノ瀬 俊明, 茅 陽一
    1999 年 36 巻 p. 49-59
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    This paper describes a method to estimate the spatio-temporal distribution of urban temperature and its application for evaluation of the urban thermal environment in the Tokyo metropolitan area. First, formulae to estimate the distribution of monthly and hourly mean temperatures were developed through regression analysis, using geographic conditions at meteorological stations, and then mesh temperature data were generated. Second, degree day maps based on mesh temperature data were made and energy consumption for heating and cooling of residential buildings was estimated for each mesh. It was found that energy consumption per family for heating is lower in coastal areas compared to inland. In case of cooling, the energy consumption per family is higher in the central part of Tokyo compared to other areas, because of climatic conditions.
  • 大野 浩一, 蒲生 昌志, 川本 克也, 山本 和夫
    1999 年 36 巻 p. 61-71
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Personal exposure levels to nitrogen dioxide (NO2) and volatile organic compounds (VOCs;benzene, toluene, ethyl benzene, xylenes) in the atmosphere were measured in three districts usingpassive samplers. Three districts, each 5km × 5km scale, were selected for their different populationdensities. Twenty five households were selected as the targets in each district and the exposure levels ofthe father, the mother, a child, indoor and outdoor of each household were measured. It was calculatedthat the geometric standard deviations (GSDs) of the personal exposure levels were about 1.2 for NO2and 1.6 to 1.8 for VOCs. The GSDs among the father, the mother and the child in the same district canbe regarded the same for all substances. GSDs of the father, the mother and the child were not regardedthe same among three districts except NO2 and benzene. In regard to the correlation of the exposuresbetween the subjects, good correlation relationships were shown between the mother and the child andalso between outdoor and indoor. On the other hand, only poor correlation relationships were observedbetween the father and the mother and between the father and the child.
  • 尾崎 則篤, 上野 浩平, 山口 登志子, 福島 武彦
    1999 年 36 巻 p. 73-80
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    PAHs (Polycyclic aromatic hydrocarbons) are the one of the major environmental toxic substances thatdeposit on ground surface of urban site and are discharged with precipitation runoff. To obtain more accurate knowledgeof the behavior of PAHs, phototransformation on ground surface of urban site was investigated. Transformationcoefficients, kmed (m edian of all kinds of PAHs at one measurement) were around 0.05 to 0.1 d-1, on the surface coverd with concrete, and correlated with sunlight intensity and ambient temperature. The main transformation processes were however supposed to be due to ambient chemical components generated with sunlight, not to be due to direct sunlightexposure of PAHs. Tranformation rate on the surface coverd with grass was estimated to be rather smaller than that withconcrete. This difference was supposed to be due to the differences of the properties of deposited particles.
  • 伊藤 晃佳, 村尾 直人, 太田 幸雄, 山形 定
    1999 年 36 巻 p. 81-86
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    A method for the field sampling of reduced sulfur compounds such as carbonyl sulfide (COS) and carbon disulfide (CS2) was developed and applied to sewage treatment facility. This method has-100% trapping efficiency and more than 90% recovery and shows little loss for at least 24 hr storage for these sulfur compounds. Ambient concentrations of COS and CS2 were measured at Sapporo from Oct. 1997 to Feb. 1999. During this periods COS and CS2 concentrations were typically 528 ± 77pptv (parts per trillion by volume) and 46 ± 30pptv, respectively, andoccasional high COS concentrations up to 800pptv were observed, indicating the presence of COS source in urban area.The COS concentrations of exhaust from the sewage treatment facility were several times higher than ambient concentrations, while CS2 values were larger than ambient by an order of magnitude. Estimated COS and CS2 emissions based on this results, however, suggested that sewage treatment works were minor source of COS and CS2.
  • 深澤 達矢, 荒川 豊, 浦安 功, 工藤 憲三, 橘 治国, 清水 達雄
    1999 年 36 巻 p. 87-92
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Over a half year from May 22 to December 11, 1997, We made measurements of the fluxes of methane and carbon dioxide by closed chamber techniques from 6 sites in Tukigaumi Marsh, Hokkaido, Japan. And besides, we collected and analyzed pore water and soil samples. The measured methane fluxes exhibited no daily trend, however, showed significant seasonal variations with Summer-Autumn maximum. Emissions from Tukigaumi Marsh averaged 0.8 mg-CH4/ m2h ranged from 0.6 to 1.3 mg-CH4/ m2h at Site-A. On the other hand, measured carbon dioxides fluxes showed remarkable daily and seasonal variations. The measured methane fluxes did not depend on groundwater levels and atmospheric temperature but slightly depended on soil temperature in the deep layer. Evapotranspiration processes by plants and oxidization processes by methanotrophs were not considered to affect the methane emissions from the marsh. Dissolved methane concentrations in the water, methane production potentials and number concentrations of methanogens increased with depth from the surface to 4 m depth, so that the methane emissions supposed to be controlled by the conditions at the deep layer of Tukigaumi marsh.
  • 高岡 昌輝, 大下 和徹, 武田 信生, 藤原 健史, 永原 茂
    1999 年 36 巻 p. 93-103
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    An advanced wastewater treatment system with pre-coagulation process is going to be developed and the influence of the pre-coagulation process on the sewage sludge treatment system is elucidated. In this study, an object-oriented analysis was demonstrated to optimize a sludge treatment system with pre-coagulation process. A computer program was developed to calculate mass balance of solids, costs, and site area requirement in each sludge treatment process. The optimized sludge treatment system was extracted by simulating about 100, 000 patterns of treatment system. The optimized sludge treatment system consists of pre-coagulation process with FeCl3 (6mg Fe/L) +anionpolymer (0.6mg/L), nitrification and denitrification with biofilm process granulator-thickening process, centrifuge dewatering process, circulating fluidized bed incineration process, and ash melting process.
  • 北田 久美子, 伊藤 歩, 相澤 治郎, 海田 輝之
    1999 年 36 巻 p. 105-112
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The possibility of using indigenous iron-oxidizing bacteria for biological leaching was studied to remove heavy metals from sewage sludge economically. It was confirmed that the indigenous iron-oxidizing bacteria existed in anaerobically digested sewage sludge. The oxidation activities of ferrous iron of the indigenousiron-oxidizing bacteria and the pure species, Thiobacillus ferrooxidans, were nearly equal.
    Biological leaching of heavy metals from metal sulfides such as CuS, CdS and ZnS and anaerobically digested sewage sludge was investigated at pH 3 using indigenous iron-oxidizing bacteria. The results showed that the inoculation of the bacteria accelerated the elution rate of Cu from copper sulfide and sewage sludge. It was concluded that the indigenous iron-oxidizing bacteria existing in sewage sludge has an important role to remove heavy metals from the sludge effectively.
  • 岩部 秀樹, 小松 敏宏, 小出 典宏, 宗宮 功
    1999 年 36 巻 p. 113-120
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The behavior of phosphorus in sewage sludge from various kinds of activated sludge processes was investigated by laboratory-scale experiments. Using an extract-fractionation method, insoluble phosphorus in sludge was divided into three fractions: the metal phosphate fraction, the polyphosphate fraction and the other fraction. In the experiments, more than 40% of insoluble phosphorus was rapidly transformed within 24 hours under anaerobic conditions to soluble phosphate in mixed sludge from an anaerobic-aerobic activated sludge process. In the sludge, the transformed phosphorus was originated from the polyphosphate fraction and the other fraction. On the other hand, only 16% of insoluble phosphorus was slowly dissolved over 72 hours in sludge from a conventional activated sludge process, because there are a less amount of phosphorus in the polyphosphate fraction and the other fraction than that in sludge from other activated sludge processes. Little phosphorus was dissolved when excess coagulants existed in sludge after added metal salts in activated sludge processes, because dissolved phosphorus from the polyphosphate fraction and the other fraction was converted to insoluble metal phosphate. From the experimental results, amounts of soluble phosphorus after 72 hours were recognized to have a close correlation with the molar ratio of metal component to phosphorus of the polyphosphate fraction and the other fraction at 0 hour.
  • プラシトヨシン ジテップ, 渡辺 義公, 亀田 修平, 但野 利秋
    1999 年 36 巻 p. 121-128
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The most important nutrient elements required for food production by crops are nitrogen, phosphorus and potassium. Among these elements, however, amount of rock phosphorus remained in the world is limited. Therefore, it is important to develop the technology and construct the social system for recycling use of phosphorus. Municipal wastewater contains phosphorus of 5-10 mg/l as the suspended and soluble forms. This paper deals with the separation of phosphorus from municipal wastewater by the coagulation/flocculation/sedimentation process using a jet mixed separtor (JMS) which is a simple but effective solid-liquid separtor. A new coagulant, Poly Silicato Iron (PSI), was used together with polyaluminum chloride and FeCl3. The PSI has a molar ratio of Fe to Si with 1: 1 to 1: 5 anda molecular weight of 200, 000 to 500, 000 Da. The JMS removed about 80% phosphorus with the addition of 5 mg Al or Fe/l. Classification of phosphorus forms in the coagulated sludge was carried out, and the effectiveness of the acid phosphatase and citric acid secreted from the plant roots for releasing orthophosphate from the organic and inorganic phosphorus compounds contained in the sludge was examined. It was shown that the inorganic phosphorus coagulated by FeCl3, and organic phosphorus in the sludge released orthophosphates by the acid phosphatase.
  • 中島 広樹, 榊原 豊
    1999 年 36 巻 p. 129-136
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The possibility of removing and recovering phosphate from wastewater by a novel electrochemical method was investigated experimentally. In this electrochemical method, iron electrodes are immersed in phosphate solution and DC is applied to coagulate the phosphate onto the surface of anode. Experimental results demonstrated that at electric current densities ranged from about 0.001 to 0.1 mA/cm2, phosphate was well coagulated on the surface of anode, satisfying the mass balance on P at the bulk liquid and the electrode surface. Furthermore, a model heavy metal ion, Cu2+, deposited on the counter electrode, cathode; therefore, it was thought a relatively high quality of phosphate is obtainablein the present electrochemical method.
  • 高畠 寛生, 佐藤 弘泰, 味埜 俊, 松尾 友矩
    1999 年 36 巻 p. 137-144
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Recently, PHAs (Polyhydroxyalkanoates) are focused on as biodegradable plastics. In this research, the potential capabilities of PHA production in activated sludges treating real wastewater were surveyed. In this survey, conventional, anaerobic-aerobic and A2O activated sludges at 4 wastewater treatment plants in Tokyo were taken, and PHA production capability from acetate as carbon source in each activated sludge was investigated. Asresults, all activated sludges could accumulate PHA from acetate. This indicated that even conventional activated sludge can also accumulate PHA. The different capabilities of PHA production in activated sludges were different with dependenton the wastewater treatment plant, 20-30% PHA contents to MLSS were observed for 2 of 4 wastewater treatment plant. Throughout this survey, about 29.5% PHA contents was achieved at maximum.
  • コフイボスクハミルトン エジャ, 池本 良子, 小森 友明, 武隈 貴裕
    1999 年 36 巻 p. 145-154
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Simultaneous sulfur and iron oxidation-reduction in anaerobic-oxic activated sludge were examined using activated sludge of a municipal wastewater treatment plants (WWTP) and two laboratory scale plants (AO) and (O). Batch experiments were carried out using artificial wastewater. For the WWTP sludge, the sulfate reducing rates increased with maximum released phosphate but did not show the same relationship with the AO and O sludge. Sulfate reduction rates tended to increase with sulfide oxidation rates for both wastewater treatment and laboratory scale sludge. Under oxic conditions, both sulfide and iron oxidation occurred simultaneously and iron was responsible for lowering sulfide oxidation rates. In anaerobic conditions, sulfate and iron reduction occurred simultaneously with sulfate inhibition by the iron bacteria. Phosphate release tended to increase with a decrease in iron reduction. The results from the electron flow and activity calculations suggested that although the sulfate reducing bacteria utilized more substrate electrons than iron reducing bacteria, the iron reducing activity was enough to cause inhibition of sulfate reduction.
  • 流入下水の有機物組成と撹拌工程に残存する硝酸性窒素の影響
    藤田 昌史, 古米 弘明, 中島 典之
    1999 年 36 巻 p. 155-165
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    An anaerobic/aerobic sequencing batch activated sludge reactor was operated by using synthetic wastewater consisted of peptone and glucose as carbon sources. The response of phosphorus release and uptake to different carbon sources was investigated by conducting three different experiments. After achieving a good biological phosphorus removal, the organic substrates were changed solely to glucose, to peptone and to sodium acetate respectively. It was found out that the wastewater having sodium acetate yielded highest phosphorus release and that peptone gave the lowest. The difference in the phosphorus release and uptake was appeared to be strongly dependent on organic substrate composition in relation to hydrolysis and fermentation process.
    Other sets of experiment were also performed to investigate the effect of remaining nitrate at mixing phase on phosphorus removal. Nitrate concentrations were adjusted to 10 and 20 mg-N/L at the initial mixing phase. It was found out that the nitrate addition suppressed phosphorus release during a whole mixing phase, the less phosphorus release with limited PHA storage seemed to increase effluent phosphorus concentration afterwards. Therefore in order to achieve reliable phosphorus removal, the nitrate at the beginning of initial feed/mixing phase should be as low as possible. A SBR model based on IAWQ ASM2 was applied to explain the phosphorus and nitrate dynamics in the response experiments that were carried out for continuous period of 28 days. The long-term simulation results well explain the dynamics of phosphorus and nitrogen during a cycle as well as effluent water quality, when denitrification process by Poly-phosphate Accumulating Organisms was considered and kinetic parameters were adjusted for the synthetic organic substrates.
  • 日高 平, 津野 洋, 宗宮 功
    1999 年 36 巻 p. 167-177
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    A kinetic model of an aerated filter is developed. The aerated filter has the combined functions of biofilm reactor for biodegradation of organic matter and filter for removal of SS under aeration. The filter considered here is an upflow type filter with a sedimentation part at the bottom part. The developed model is applied to an aerated filter incorporated into the pre-coagulation and biofilm reactor process, in which removal of nitrogen and phosphorus as well as organic matter is intended. The aerated filter is applied after the position of denitrification tank in the nitrification-denitrification biofilm process to be expected to remove residual organic matter and SS and to restore DO concentration. The developed model is verified by comparing calculated results with the experimentally obtained data. It is clarified by using this model that the ideal height of the filter is about 2700 mm and the operational HRT of 1 h in the aeratedfilter can be available in this process.
  • 花田 茂久, 佐藤 弘泰, 味埜 俊, 松尾 友矩
    1999 年 36 巻 p. 179-186
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The Activated Sludge Model No.3 (ASM No.3) proposed by the IAWQ Task Group includes the process of storage of organic substrates. But, it is not experimentally verified that the storage of organic substrates has principal significance in actual activated sludge processes. Moreover, the parameters for the storage of organic substrates in ASM No.3 are not selected on experimental bases. In this research, polyhydroxyalkanoate (PHA) is assumed as the principal storage product, and the capacity of storage of PHA in activated sludges obtained from seven full scale plants in Tokyo, including conventional activated sludge processes as well as those designed for nutrient removal, was examined. Sodium acetate was fed under either aerobic or anaerobic conditions to the activated sludges, and the behavior of internally stored PHA was measured. It was experimentally demonstrated that under the aerobic condition the storage process significantly affect the substrate uptake rate not only in activated sludges from the anaerobic-aerobic process for biological enhanced phosphate removal but also in those from conventional activated sludge rocesses. Parameters for storage (the synthesis rate constant: KSTO and the aerobic yield of synthesized product per Ss: YSTO, O2)were about 0.7 to 1.3 gCOD/gCOD-Ed and about 0.6 to 0.7 gCOD/gCOD, respectively.
  • 中村 みやこ, 片山 浩之, 李 錫憲, 大垣 眞一郎
    1999 年 36 巻 p. 187-197
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Disinfecting characteristics of viruses in water treatment with chlorine and TiO2 photocatalyst were studied. RNA coliphage Qβ and poliovirus type 1 were used as model viruses. Viral inactivation was measured using plaque assay technique. Two kinds of RT-PCR methods combined with the MPN method were used to determine viral RNA damage. The SDS-PAGE was applied to determine the degradation of viral protein molecules. According to RT-PCR values, the viral RNA was damaged with 0.9 mg Cl/l free chlorine but not significantly damaged with 0.3 mg Cl/l combined chlorine concentration. Though RT-PCR results for both of Qβ and poliovirus showed no damage with a combined chlorine concentration of 0.3 mg Cl/l, according to plaque assay results, Qβ was inactivated llog in 20min. The results of SDSPAGE showed that Qβ protein molecules were degraded only with 400 mg Cl/l free chlorine concentration but not with 400mg Cl/l combined chlorine concentration. By TiO2 photocatalyst combined with UV irradiation, the results of RT-PCR for Qβ showed Hog decrease in 3min, but showed no decrease even in 12min with UV irradiation alone.
  • 矢古宇 靖子, 高橋 明宏, 東谷 忠, 田中 宏明
    1999 年 36 巻 p. 199-208
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    This study is aiming at examining the conditions of a testing method for comprehensive environmental-like activity in wastewater using recombinant yeast. Using this method, 43 chemicals that are suspected to have the estrogen-like effects measured. Then, their estrogen-like activities were evaluated as the 17 β-estradiol equivalent by comparison with the assay results of 17β-estradiol. 17β-estradiol equivalent of influent and effluent sampled from 10 wastewater treatment plants in summer and autumn were measured with this method. The endocrine disruptors (EDs) concentrations in the wastewater were calculated into the theoretical17 β-estradiol equivalents based on the chemical evaluation. The results suggest that w astewater treatment plants effectively reduce estrogen-like substances during treatment, and that there weresome differences between 17β-estradiol equivalent with the recombinant yeast and the theoretical 17β-estradiol equivalent based on the chemical evaluation. Therefore, it is implied that unknown estrogen-like substances or antagonists might exist in wastewater.
  • 亀田 豊, 橘 治国, 清水 達雄
    1999 年 36 巻 p. 209-215
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Various samples from lakes, rivers, secondary effluents and renovated water following coagulation-sedimentation treatment were characterized by fluorescence spectroscopy using excitaion-emission matrix. Our results suggest that dissolved organic matter can be categorized into three distinct groups. Groupl is distinguished by a fulvic acid-type fluorescence (excitation about 270nm and emission about 435nm). Fulvic acid-type substances concentration can be calculated using this relative fluorescence intensity. Group 2 is distinguished by a protein-type fluorescence (excitation about 280nm and emission about 340nm). This substance consisted of protein from secondary effluent and that released by algae. Group 3 is distinguished by a fluorescence caused by organic matter in secondary effluent (excitation about 495nm and emission about 515nm). This substance was hydrophobic and not biodegradable. The relative fluorescence intensity in excitation 495nm and emission 515nm may be an indicator of the influence of secondary effluent.
  • 山田 俊郎, 清水 達雄, 井上 隆信, 橘 治国
    1999 年 36 巻 p. 217-224
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The water qualityo f two forest rivers in central Hokkaidow as surveyedi n the period of storm events in thesummero f 1997t o understandt he run-offc haracteristicosf the loads of waterq ualityc omponenftr omt he rivers.
    As the result, t he run-ofcf haracteristicos f the waterc omponentsw ere classifiedin tof our groups:
    1) WASH OUT type (SS, PN, PP); Most of loads are discharged with increased flow rate.
    2) STEADYR UN-OFtFy pe (Poolt ype)(NO3-ND, O C, D P);R un-oflfo ads increasew ithi ncreaseo f flowr ate but there is a lowcorrelationb etweenf lowr ate and run-offl oads.
    3) STEADYR UN-OFFty pe (Non-pootly pe)(Na+, K+, Ca2+, Cl-, SO42-);There is a high correlationb teween flow rate and the run-offl oads.
    4) UNSTEADRYU N-OFFty pe (silicica cid, NH4+-N);There is a low correlation between flowrate and the run-off loads.
  • 岸本 直之, カク地 賢二, 宗宮 功, 中村 敏昭
    1999 年 36 巻 p. 225-236
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    In the present study, we investigated influence of turbid water on water environment in the Asahireservoir, Nara prefecture, Japan, by some field surveys and experiments.
    Chemical contents in new sediments collected with sediment traps were analyzed throughout the year. As aresult, carbon, nitrogen and phosphorus contents in sediments during storm run off period were 30-40%lower than those during dry period. In addition, it was proved that nitrogen in the sediments was decomposedinto dissolved nitrogen, but phosphorus was not decomposed practically. Oxygen consumption rate in bottomsediment in December, 1997 after storm events was in the range from 0.27 to 2.07 mgO2 m-2 h-1 which was lessthan one-fifteens of the rate in December, 1996. This was thought to be caused by new sediments coveringlake bottom. Turbid waters also transformed an aspect of phytoplanktons in the reservoir, namely, dominantspecies changed in turns into Cryptophyceae Rhodomonas sp. and Cryptomonas sp., Chlorophyceae Eudrinaelegans and Pandrina morum, and Bacillarisphyceae Melosira spp. after the rise in turbidity. Thesephytoplanktons except Melosira spp. have two flagellum, and can stay in water surface by swimming withthem. Therefore, it was inferred that the rise in turbidity decreasing underwater light intensity caused thetransition of dominant species to the flagellates.
    It is no doubt that inflow of turbid waters shallow lakes and reservoirs, and promote eutrophication in the longterm. In the short term, however, it may also have anti-eutrophication effect such as decrease of nutrientsloading from lake sediment. In any case, turbid waters flowing into lakes and reservoirs lead their waterenvironment into unstable state, and impact on water quality, benthic environment and aspect ofphytoplanktons in a short period.
  • 牧野 育代, 小川 進, 斎藤 元也
    1999 年 36 巻 p. 237-242
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Land cover change and discharge fluctuation for the past 12 years in the Doki River catchmentwere examined using multi-temporal satellite data. This catchment is composed of mainly forest andsome agricultural fields along the streams, the ratio of which is more than 10% of the total area. Usingthe multi-temporal satellite data, Landsat TM, in 1986 and 1990, approximately 3% of the total area hadchanged from forest to the agricultural fields during this period. From the water budget from 1981 to1992 in the catchment, evapotranspiration decreased and runoff ratio increased. Short-term waterbudget led to monthly evapotranspiration before and after 1986, which showed the evapotranspiration in April and October decreased. Such change means agricultural activities, seeding and harvest. Moreover, statistical tests for hydrological data before and after 1986 showed that runoff ratio increasedsignificantly with its significant level of 0.05. Therefore, one of the factors that caused the increase ofrunoff ratio in the catchment should be the land cover change from forest to agricultural fields.
  • 羅 漢金, 坂本 康, 久保田 喜裕
    1999 年 36 巻 p. 243-251
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Groundwater qualities were geochemically examined for As-rich wells in Chuetsu area of Niigata Prefecture. The results showed the partial overlap of high As concentration zone and high temperature zone caused by hydrothermal effect. Well waters were classified by water qualities. As-rich groundwaters mainly belonged to Na-HCO3 type. But neither hydrothermal Na-HCO3 type groundwater of higher temperature nor hydrothermal Na-Cl type groundwater originating from fossil seawater showed high As concentration. These results suggested that As was dissolved from As compounds in alluvia into hydrothermal Na-HCO3 type water. This hypothesis was supported by the correlation between As and SO42-concentrations of As-rich Na-HCO3 type waters.
  • 田中 周平, 藤井 滋穂, 山田 淳, 市木 敦之
    1999 年 36 巻 p. 253-261
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    This study aims to find out influences of planting methods and site conditions on reed growth. Reed growth was observed at an experimental field in Lake Biwa every month from December 1997 to August 1998. Influences of several factors on reed growth, such as planting method, water depth, erosion, were examined from the results of the observations, and the following results were drawn: 1) Out of 1081 pieces of reeds planted on October 1997, 449 pieces failed to grow, which were mainly planted with the Bittmann Method and the Root Method, while the other methods produced 89% in survival ratio, especially, high percentage (98%) in the Mat Method. 2) Average density of reeds in the autumn is 86.6, 67.8, 65.3 and 20.6 stalks/m2, respectively for the Mat Method. the Pot Method. the Sandbag Method and the Big Stump Method. 3) The erosion exceeding 12cm depth had adverse effects on reed growth, while the erosion less than 4cm did not show abstraction on reed growth apparently. 4) All of the factors (methods, sites, dates, and any of their combinations) are statistically proved to have some significant influence on the reed growth variation with a risk less than 0.1%. The contribution of planting method on reed growth was 20% of the whole variation
  • 小浜 暁子, 金 主鉱, 山田 一裕, 西村 修, 稲森 悠平, 須藤 隆一
    1999 年 36 巻 p. 263-269
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Positive effects of protozoa on mineralization of the organic compounds were clarified in the wastewater treatment process. In particular, bacterivorous protozoa are known to be the most important grazers and predators ofbacteria and cause a decrease of biomass in wastewater. However, the role of carnivorous protozoa in a wastewater treatment process has so far not been reported. In order to know the role of carnivorous protozoa in micro-ecosystem, the effect of protozoan species as prey organisms, concentration of prey organisms, and temperature on the growth characters of carnivorous protozoa, Dileptus anser were investigated. The results can be drawn.
    Dileptus anser was found to be a wide ranging polyphags. The calculated predation rate for Tetrahytnena pyriformis was 140 cells·day-1·cell-1. The maximum specific growth rate of Dileptus anset using Tetrahyrnena pyriformis was 1.22day-1 at 30°C and ΔE was 74.0kJ·mol-1. Removal rate of DOC (Dissolved Organic Carbon) in batch culture experiment by adding Dileptus anser was 40.2% and biodegradability was higher than that of no addition (23.3%). The presence of Dileptus anser enhanced the degradation activities of DOC in the detritus food web.
  • 川本 泰生, 関根 雅彦, 楊 継東, 小林 宏正, 浮田 正夫
    1999 年 36 巻 p. 271-276
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Recently, the purposes of river restoration works have became not only the protection for flood but also the restoration of ecosystem quality. In this context, habitat evaluation procedures are becoming important. The Instream Flow Incremental Methodology (IFIM) is one of the most popular habitat evaluation method, but still there is little application in Japan. In this paper, we study the accuracy and applicability of fish habitat evaluation method by IFIM. At first, we surveyed habitat variables, such as velocity, depth and substrate during the summer and the autumn in 1998 in the kiba River, Yamaguchi prefecture, to derive suitability-of-use curves, which are the core technique in IFIM. Then, we compare the observed fish distribution with calculated habitat distribution by using the suitability-of use curves obtained from the same river, which showed a good accordance. Next, we compare the observed fish distribution with calculated habitat distribution by using the suitability-of-usecurves obtained from literature and laboratory. The former showed a bad accordance, the latter showed a good accordance. Those results imply that the suitability-of-use curves obtained from a river will show a good accordance when it is used in the same river, and suitability-of use from laboratory can apply to other rivers.
  • 相模川原水による実証実験
    黄 建元, 滝沢 智, 藤田 賢二
    1999 年 36 巻 p. 277-286
    発行日: 1999/11/15
    公開日: 2010/11/30
    ジャーナル フリー
    Pilot-plant studies were carried out to verify the applicability of a newly developed microfilter (MF) thickener for treatment and thickening of retentate coming out from membrane water treatment processes. The membrane thickener, which made use of the concentration polarization phenomena in the dead-end filtration process, was proved to be applicable to thickening of retentate having an average turbidity of 100 units and a maximum turbidity of up to 400 units at a filtrationflux of 0.5 m/day. The water recovery ratio against raw water from Sagami River was more than 99 percent in the whole process of combined membrane water treatment and MT thickening. However, a high turbidity over 420 units caused a sudden increase of filtration resistance. The filtration resistance was maintained lowerat a high filtration flux of 0.5 mlday than at a low flux of 0.3 m/day because turbid water was more rapidly excluded down to the bottom of the thickener at a higher filtration flux. Particle size distribution measurement revealed that the smaller particles with diameters of less than 3μm tended to remain suspended inthe thickener and attached to the membrane, causing an increase of the filtration resistance.
  • 木村 克輝, 渡辺 義公
    1999 年 36 巻 p. 287-294
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The authors have proposed a novel membrane process for drinking water treatment in which nitrifiers are fixed on the membrane surface. With this proposed membrane process, strict solid-liquid separation by membrane filtration and oxidation of ammonia can be performed simultaneously. Fixed nitrifiers are supposed to cause membrane filtration resistance to some extent. The magnitude of the filtration resistance caused by the fixed nitrifiers for oxidizing low concentrations of ammonia was evaluated in this study. Experimental results showed that the fixation of the nitrifiers on the membrane surface had a little influence on the increase of the filtration resistance. Most of the resistance was caused by trace inorganic and organic substances contained in the feed water (tap water). The filtration resistance was divided into the cake resistance and the irreversible fouling resistance. The nitrifiers for the oxidation of low concentrations of ammonia seemed to increase the cake resistance a little and hardly cause the irreversible fouling.
  • 久保 利晃, Begum Shaila LUXMY, 中島 典之, 山本 和夫
    1999 年 36 巻 p. 295-302
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The objective of this study was to investigate intra- and extra-cellular materials of membrane separation activated sludge (MSAS). From the result, we discussed on the relationship between extra-cellular materials and floc size of MSAS and compared five different kinds of activated sludge process: a conventional process, a sequential batch process, an A2O process and two MSAS processes with and without wasting excess sludge. The MSAS process without wasting excess sludge treated real sewage for 9 months. It was found out that most of the microbial flocs in MSAS were smaller than 45μm, and that smaller flocs in MSAS had more extracellular materials per MLSS than larger flocs. From the result of comparison among five different kinds of activated sludge, although there was little difference of the amount of intra-cellular materials, MSAS without wasting excess sludge had the least extra-cellular materials.
  • 胡 俊杰, 寺島 泰, 磯辺 良介, 西川 貴政, 大河内 由美子, 越川 博元
    1999 年 36 巻 p. 303-311
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Several environmental factors influencing the growth of two kinds of Actinomycetes (S.chromofuscus All, S.setonii 75Vi2), and their ability of removing 2, 4-dichlorophenol (2, 4-DCP) were investigated in batch cultures.The characterization of extracellular peroxidases produced by the objective fungi was also investigated. Optimal p H, temperature and nutritional conditions for the growth of each fungi and the basic feature of extracellular peroxidases were obtained. And it was concluded that 2, 4-DCP hindered growth of fungi and it could be removed by the objective fungi. The extracellular peroxidase produced by S.chromofuscus All may contribute to the removal of 2, 4-DCP.
  • アギーレ カルメン, 渡辺 智秀, 榊原 豊, 黒田 正和
    1999 年 36 巻 p. 313-322
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Reductive dechlorination of tetrachloroethylene (PCE) was investigated in a bio-electro reactor system. It consisted of cathodic electrodes on which methane fermentative microorganisms were immobilized and anodic carbon electrodes. Methane fermentative microorganisms used in this study were cultured from a mixture of lake sediment and anaerobic treatment sludge as inoculum source. PCE dechlorination, supported either by hydrogen gas or by organic compounds fed as primary energy source and electron donor, was also investigated at 35°C in small vials used as bioreactors. In the bioelectro reactor system, hydrogen generated by electrolysis of water supports PCE dechlorination. PCE was transformed mainly into ethylene (ETH) and trans-1, 2-dichloroethylene (trans -DCE). On the other hand, when PCE dechlorination was supported by hydrogen gas or organic compounds, PCE was dechlorinated mainly up to cis-1, 2 dichloroethylene (cis-DCE) and vinyl chloride (VC) respectively. The fact that PCE was dechlorinated into harmless metabolites such as ETH in the bio-electro reactor system, suggested that such process investigated would be applied for PCE contaminated groundwater remediation.
  • ファラカ Z., 榊原 豊, 黒田 正和
    1999 年 36 巻 p. 323-332
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Performance of a combined biofilm-electrode reactor/adsorption process for the removal of nitrate and trace pesticide from contaminated drinking water has been investigated. In long-term (more than 200 days) continuous experiments, influentand effluent concentrations of nitrate, nitrite, isoprothiolane and gas composition were measured at different electric current and pesticide loading conditions. Experimental results showed that complete and stable denitrification was achieved in BER without accumulation of nitrite and nitrous oxide. Nitrate removal ranges from O to 100% depending on electric current and inhibition by isoprothiolane was not observed. Isoprothiolane is removed by adsorption onto either granular activated carbon or silicone resin in the adsorption column. Removal efficiency of isoprothiolane exceeding 97 % was achieved and effluent concentration was below the guideline value (40μg/l). The adsorption of isoprothiolane onto GAC and silicone conformed to Langmuir isotherm model. From these results, it is concluded that the combined process is applicable to treat nitrate and pesticide contaminated drinking water. More over, from comparison with former studies, possible methods to further enhance the decomposition of pesticide were suggested.
  • 博多湾流域を対象として
    厳 斗鎔, 楠田 哲也
    1999 年 36 巻 p. 333-340
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Abstract; In arid and semi-arid watersheds, water resources management is of importance to maintain water supply for water works, irrigation, industry, and so on. Because water shortage occurs stochastically, stochastic approaches are inevitable to estimate precipitation and storage in reservoirs and to estabilish countermeasures for water shortage. Requirements of the water resources management are minimizing cost and LCE, and maximizing user's benefit. Objectives of this study, in which the Hakata bay watershed is the area of interest, are to develop astochastic model on precipitation, to analyze annual precipitation distribution, to design precipitaion patterns on 10, 25, 50 and 100 return years, and to establish water supply alternatives for water shortage. We select water supply alternatives at each water shortage period as follows: First, reservoir storage is simulated by using a tank model, secondly, intakes from reservoirs are calculated, thirdly, water resource alternatives are selected, and finally countermeasures are determined at each water shortage. In conclusion, desalination or other alternative measures, in addition to utilizing groundwater, is inevitable to avoid water shortage in this watershed. Desalination, however, has demerits of high LCE and cost, so that neat technologies to obtain alternative water resources and toreduce water consumption are to be developed.
  • 荒巻 俊也, 杉本 留三, 花木 啓祐, 松尾 友矩
    1999 年 36 巻 p. 341-352
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    In this study, the GIS based artificial water cycle model was developed, and the influences of rainwater and reclaimed wastewater reuse systems on urban water cycle were evaluated in each area of Tokyo. The model consists of building and land use data with grid form, and digital data of sewerage system and river with vector form. From the model, many information for planning and management of these systems were obtained as the following;(1) 10% of annual water supply were replaced and 25% of annual stormwater runoff were reduced by the installation of rainwater reuse systems in 1993.(2) In the case that intstall the suitable system on economic aspects in each area, 17% of the total water demand in Tokyo can be replaced.
  • 荒尾 慎司, 楠田 哲也
    1999 年 36 巻 p. 353-360
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The energy loss at manholes is often compared with the friction loss of pipes under surcharge flow. One of the methods to avoid inundation is the reduction in energy loss at storm sewer manholes. The purpose of this study is to develop new types of manhole structure for energy loss reduction. Experiments were carried out by using five types of manhole; Type A with straight-through pipes as used currently in Japan, Type B with a guide-cover on the invert of Type A, Type C with 90°Cbending pipes as also used currently in Japan, Type D with an improved invert profile of Type C, and Type E with full-benching of Type D. The experimental results showed that the energy losses for Types B, D and E considerably decreased than the other Types.
  • 鈴木 憲明, 高桑 哲男, 船水 尚行
    1999 年 36 巻 p. 361-369
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Although the numerical analysis is one of the most effective tools to evaluate the existing urban drainage networks, the scale of calculation might be a trouble for analysis of large-scale networks. Therefore main pipe analysis by modeling outflow from sub pipe is generally applied. But sub pipe analysis is necessary to evaluate urban drainage networks because the water level of main pipes doesn'trepresent that of sub pipe areas in some cases. In this report a new method forsimulation of large-scale networks including sub pipe analysis are proposed. The procedure consists of two stages. The first is the process of main pipe analysiswith modeling sub pipe areas as simple tanks. The second is the process of sub pipe analysis with the main water levels as boundary conditions.
  • 細井 由彦, 城戸 由能, 市平 雅美
    1999 年 36 巻 p. 371-378
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    The theories and policies for the maintenance and renewal of water supply systems are required. The occurrence of water distribution pipe breakage and water leakage is influenced by pipe material, size and age as well as soil characerristics and transportation. The water leakage has to be found as soon as possible from the point of minimizing water loss. However, it costs greater to increase investigations for water leakage. In this study, the model to determine the optimal investigation interval for water leakage of water distribution network was examined. The nonlinear optimization model was theoretically derived. The leakage investigation method with optimal intervals obtained from the presented model was more effective than that with constant interval for all investigation areas.
  • 山内 正仁, 平田 登基男, 松藤 康司, 増田 純雄, 前野 祐二, 桃井 清至
    1999 年 36 巻 p. 379-389
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    As an effective utilization of waste stillage which will be banned to dump into sea from the year of 2001, authors have studied and succeeded to make soseipaper by using waste stillage from shochu distillery.
    This research is tried to compare the physical and mechanical properties of sosei paper produced by using sweet potato waste stillage (hereafter, SPWS), barley waste stillage (hereafter, BWS) and old newspaper, and to consider the weight and property of waste water after compressing samples (waste stillage + old newspaper). Further, this research is applied to the growth test of Chingensai in a pot made of sosei paper.
    Following results were obtained;
    1) Barley soseipaper was greater in density and less in strength than sweet potato soseipaper. 2) After compressing samples, in the case of the sample whose ratio ofold newspaper to waste stillage is 1%, more than 70 % of the CODCr, TOC, T-N components can be removed from waste water in the case of SPWS, and so can more than 45% of them in the case of BWS.3) In the growth test ofChingensaiin a pot made of soseipaper, the plant absorbed components in soseipaper, and the paper proved to be effective as a fertilizer.
    N. B.soseipaper (soseimeans reborn)
  • 谷口 美希, 藤原 健史, 武田 信生
    1999 年 36 巻 p. 391-401
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Air pollutants generated in municipal waste incinerator, such as chlorinated organic compounds, are closely related to combustion behavior of waste in the furnace. The behavior is very complicated because the wastc consists of various kinds of components and the reaction develops to the direction from surface to inside of the solid with tune. In this paper, as a fundamental study on pyrolysis and combustion of solid waste, experiment for combustion and pyrolysis of sample was conducted and then the weight loss and flow rate of produced gas were measured on line. As a result, weight loss curve showed a combustion term clearly consists of pyrolysis and char combustion terms. A peak of CO gas production was found in each term. In particular, CO gas flow rate increased gradually in char combustion term, and the rate of increase depended on physical factors, such as density, moisture, and shape of the sample. As the temperature of carrier gas surrounding the sample became higher, total amount of CO gas decreased. Moreover, the rate of increase in CO gas production for a sample with 40% moisture was smaller than that for samples with 20% and 10% moisture.
  • トラベルシ イスマイル, 松藤 敏彦, 田中 信寿, 松尾 孝
    1999 年 36 巻 p. 403-411
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    A detailed physico-chemical characteristics of 23 years old municipal solid waste disposed of in a landfill was investigated. The results are compared with other investigations and degree of stabilization of about 20 years old landfilled waste is discussed. After about 20 years being disposed of, landfilled waste may be considerably stabilized but a minor fraction of slowly biodegradable organic matter still remains.
  • 李 玉友, 佐々木 宏, 鳥居 久倫, 奥野 芳男, 関 廣二, 上垣内 郁夫
    1999 年 36 巻 p. 413-421
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Influences of the hydraulic retention time (HRT) and the organic loading rate onmesophilic and thermophilic anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) were investigated by using a semi-continuous flow completely-mixed reactor. Theexperiments were conducted at a constant influent total solid (TS) of 10% by changing the HRT from 5days to 30 days under mesophilic (35°C) and thermophilic (55°C) conditions, respectively. Both themesophilic and the thermothilic digestion reactors were successfully operated even at a short HRT of 5days corresponding to a volumetric loading rate of 31.8 g-CODCr/L · day by adding mineral nutrient tothe feed. The results indicate that there was no significant difference between mesophilic andthernophilic digestion in terms of VS reduction, CODCr removal and methane production at the HRTs oflonger than 15 days, and the comparative merits of thermophilic digestion was found only at the HRTshorter than 15days. The water quality of the supernatant of the thermophilic digestion was worsethan that of the mesophilic digestion at the all conditions. Based on the comparison betweenmesophilic and thermophilic digestion at various HRTs, it is concluded that the HRT of thermophilicdigestion could be reduced to 7.5 days, but the mesophilic digestion should be operated at the HRT of 15days or longer for maintaining a high degradation efficiency of 75%.
  • 水野 修, 大原 健史, 新谷 真史, 野池 達也
    1999 年 36 巻 p. 423-429
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    Characteristics of organic wastes decomposition in hydrogen fermentation were investigated using batch reactor at35 °C Bean curd manufacturing waste, rice bran and wheat bran were used as the organic wastes. The organic wastes weresoaked in distilled water for dissolving carbohydrate and protein, and then the solution containing carbohydrate and protein wasused as the substrate for batch experiment. Although carbohydrate was rapidly consumed during hydrogen fermentation, nodecomposition of soluble protein was observed. It was suggested that the most of hydrogen was produced from carbohydratedecomposition. Hydrogen-producing microflora easily decomposed soluble carbohydrate of 46, 000 molecular weight. Hydrogenyields of bean curd manufacturing waste, rice bran and wheat bran were 2.54, 1.29 and 1.73 mol H2/mol hexose, respectively.Volatile fatty acids and alcohols were produced as the by-products from decomposition of substrate. Acetate, butyrate, ethanol, 2-propanol and 2-pentanol were the main substances.
  • 多川 正, 原田 秀樹, 高橋 弘希, 大橋 晶良, 関口 勇地
    1999 年 36 巻 p. 431-441
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    An on-site pilot-scale experiment was conducted to investigate the process performance of our newly proposed multi-staged UASB reactor by feeding with a food industrial wastewater containing high strength of lipid and protein. The reactor was operated at a thermophilic condition (55°C) for a period of 300 days. The reactor accomplished finally 50 kgCOD·m-3·L-1 at a soluble COD removal of 90%(corresponding to the influent COD strength of 7, 000 mgCOD·L-1 and HRT of 3.4 h), while the overall COD removal (based on the effluent COD-total) was considerably unsatisfactory at only around 50%. The presence of lipid, protein along with Mg and Ca ions in the raw wastewater caused a severe scum formation in the pre-acidification tank and UASB sludge bed, resulting in lessening the contact efficiency between substrate and sludge. Replacement of granules in the sludge bed by insolubilized lipid and protein caused deterioration of sludge methanogenic activity. The most optimum operational mode we established through 300 days experiment was to intentionally reject the retainment of insoluble lipid and protein fractions from UASB reactor by imposing a relatively high liquid velocity. It is recommended that for treatment of a kind of wastewater as used in this study the UASB process should serve as pretreatment for elimination of soluble organic fractions, and the subsequent activated sludge process serve as post-treatment for removal of remaining insoluble lipid/protein fractions.
  • 片岡 直明, 鈴木 隆幸, 鈴木 芳郎, 石田 健一, 山田 紀夫, 本多 勝男
    1999 年 36 巻 p. 443-453
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    A methane fermentation system for treating animal wastes was developed and substantiated successfully in a field test plant (0.5 m3/d). The system is composed of a screw-press dehydrator, an acidification digester, a methanogenic digester, an anaerobic sludge separator, an oxidation ditch, and a composting equipment. Pretreatment of swine wastes to remove the solid impurities was carried out using the screw-press dehydrator without chemical grouting. TS and CODCr removal by the screw-press treatment was 38% and 22%, respectively. Properties of the screenings were as follows: water content 57%, ignition loss 93%, specific gravity 0.33. Main ingredients of the screenings were undigested organics and swine bristles. The pretreated strong slurry (CODCr 9.0%, BOD 3.0%, TS 5.5%, T-N 0.48%) was digested under mesophilic conditions; HRT of 15.4 d; volumetric organic loading rate of 4.4-4.8 kg CODCr/m3-d. It was found that CODCr and BUD removal at 35°C was 64% and 78%, respectively; digestion gas production rate was 25 Nm3/m3-slurry; methane content of the digestion gas was 67%. The effluent from the methanogenic digester was separated into supernatant and thickened sludge in the anaerobic sludge separator and subsequently treated using the oxidation ditch and the screw-press dehydrator. The oxidation ditch for treating the supernatant was controlled by intermittent aeration for the purpose of nitrogen removal. The quality of effluent from the oxidation ditch (>20°C) was BOD 90 mg/L, CODCr 360 mg/L, SS 40 mg, /L, and T-N 220 mg/L. However, organic colored substances (dark-brown) remained in the effluent. The thickened sludge was dehydrated using the same screw-press dehydrator as mentioned above. Polymer feeding rate was 0.54% to TS. Water content of the dehydrated cake was 77.5%. Mixture of the screenings and the dehydrated cake was composted without bulking agents. It was confirmed that the present system is applicable to treatment of animal wastes.
  • 金 主鉱, 片山 悦治郎, 藤田 泰広, 山田 一裕, 西村 修, 須藤 隆一
    1999 年 36 巻 p. 455-464
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    A sequencing batch reactor process by adding aluminium sulfate was operated with a different BOD/T-N ratio and Al/P molar ratio to investigate the removal characteristics of nitrogen and phosphorus, and nitrous oxide (N2O) emission from the swine wastewater treatment. The following results can be drawn:
    (1) The percentage removal of T-N and T-P were 63.6-78.0% and 83.9-97.3% respectively, and their treatment performance were significantly affected by BOD/T-N ratio of influent and the amount of chemical dosage. Nitrification inhibition by the dosage of coagulant in the addition of 0.2 and 0.5 as Al/P molar ratio was not observed during operational periods.(2) N20 conversion rate decreased with increasing of percentaged enitrification. In particular, N2O emission of low BOD/T-N ratio was more significant than that of high BOD/T-N ratio during the anaerobic process.
  • 長谷川 聖, 花木 啓祐, 松尾 友矩
    1999 年 36 巻 p. 465-476
    発行日: 1999/11/15
    公開日: 2010/03/17
    ジャーナル フリー
    To demonstrate the efficiency of sulfur as denitrification electron donor, the column and the batch experiments were carried out. Nitrate-nitrogen was sufficiently removed by the soil column packed with elemental sulfur. When denitrification proceeded insufficiently, the high concentration of N2O was detected. On the other hand, when denitrification proceeded sufficiently, N2O formation was kept low. The batch experiments indicated that high water content and CaCO3 addition for pH adjustment are effective methods to proceed denitrification sufficiently and decrease N2O emission. In the case of adding each electron donor (S0, FeS, glucose, or cellulose), produced N2O was more readily reduced than the case of soil alone. When inorganic sulfur was used as electron donor, the maximum concentration of produced N2O in the gas phase was very low (about 50 ppm), which was 2 order lower than the concentration in the case that organic compounds were used as electron donor. This indicated the possibility to suppress N2O emission by adding sulfur into the soil and proceeding sulfur denitrification.
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