著者

市原 真紀子 西尾 孝之

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.34, no.12, pp.183-189, 2011

被引用文献数

1

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Alの高濃度化や不純物の精製など,改良を加えた浄水汚泥からの凝集剤回収法について検討し,そのリン除去能を検証した。回収凝集剤(再生バンド)のAl<SUB>2</SUB>O<SUB>3</SUB>濃度は0.75~9.4%であり,一部はJISに定めるAl濃度を満足していた。含水率の低い浄水汚泥を用いると,よりAl濃度の高い再生バンドを作成可能であったが,同時に不純物の高濃度化が見られた。再生バンドはT-NやT-P,Fe,Mnを高濃度含んでいたが,精製処理によりT-P以外は43.6~76.5%除去され,Alの低濃度化や鉄・マンガンの濃縮といった既報における欠点を一定克服した。モデル排水(T-P 0.85 mg・L<SUP>-1</SUP>)や地下水(T-P 1.14~1.52 mg・L<SUP>-1</SUP>)を用いたジャーテストにおいて,再生バンドは市販の硫酸バンドと同等のリン除去能を示し,1:5(PO<SUB>4</SUB><SUP>3-</SUP>:Al)のモル比で9割以上のリンが除去された。

著者

Phuc-Nguon Hong Chanreaksmey Taing Phuong-Thanh Phan Ryo Honda

出版者

Japan Society on Water Environment

雑誌

Journal of Water and Environment Technology (ISSN:13482165)

巻号頁・発行日

vol.16, no.1, pp.40-53, 2018 (Released:2018-02-10)

参考文献数

39

被引用文献数

17

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Extracellular polymeric substances (EPS) are reported to be the major foulant in membrane bioreactor (MBR) processes. It is important to understand the EPS fractions which cause irreversible fouling to reduce operation cost and energy consumption in MBR. In this study, we developed polarity-molecular weight profiling, in which EPS components were plotted on two-dimensional matrix of its polarity and molecular weight, and applied it to investigate EPS of bulk sludge and cake layers from a lab-scale MBR. The EPS components were also characterized via three-dimensional excitation-emission matrix (3D-EEM) spectroscopy. The result showed that hydrophilic substances as large as 100 − 670 kDa was found only in loosely-bound EPS (LB-EPS) of bulk sludge but not in that of cake layers nor in permeate. Hydrophobic substances smaller than 20 kDa were mainly found in soluble microbial products (SMP) in bulk sludge. Hydrophilic substances larger than 670 kDa was mainly found in tightly-bound EPS (TB-EPS) of bulk sludge and in LB- and TB-EPS of cake layers. These findings suggest that, after conditioning of micropores of virgin membrane by hydrophobic substances smaller than 20 kDa in SMP, hydrophilic biopolymers as large as 100 − 670 kDa in bulk sludge clog the narrowed micropores inside membrane, causing irreversible fouling.

著者

Sulfikar Ryo Honda Mana Noguchi Ryoko Yamamoto-Ikemoto Toru Watanabe

出版者

Japan Society on Water Environment

雑誌

Journal of Water and Environment Technology (ISSN:13482165)

巻号頁・発行日

vol.16, no.2, pp.94-105, 2018 (Released:2018-04-10)

参考文献数

51

被引用文献数

14

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The influent of municipal wastewater treatment plants (WWTP) can contain micropollutants such as antibiotics, chlorine, detergents, and biocides. In vitro studies have shown that these micropollutants may induce antibiotic resistance in bacteria. Previous studies have reported increases or decreases of antibiotic-resistant bacteria between the influent and effluent of WWTP in an unpredictable manner. Thus, the triggers of resistance induction in WWTP are largely unknown. To investigate the effects of unit operations in WWTP on antibiotic resistance induction, we incubated sixteen strains of Escherichia coli susceptible to amoxicillin or norfloxacin under simulated conditions of the primary sedimentation tank, aeration tank and final sedimentation tank in sterilized and filtered wastewater from each tank at 25°C for 1, 6 and 2 hours, respectively, which are typical hydraulic retention time of each tank. The minimum inhibition concentration towards amoxicillin or norfloxacin was compared before and after incubation to evaluate the occurrence of induction. We found that resistance to both antibiotics was more likely to increase in the aeration tank than in the primary sedimentation tank or final sedimentation tank. The longer contact time with the wastewater and the aeration are factors that appeared to induce antibiotic resistance in an activated sludge process.

著者

金山 彦喜

出版者

Japan Society on Water Environment

雑誌

水質汚濁研究 (ISSN:03872025)

巻号頁・発行日

vol.13, no.2, pp.85-88, 1990

被引用文献数

3 1

著者

市橋 修 山本 希 廣岡 佳弥子

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.35, no.1, pp.19-26, 2012

被引用文献数

10

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養豚廃水と酪農廃水の二種類の畜産廃水を用いて,エアカソード一槽型微生物燃料電池を運転した。それぞれのリアクターの最大電力密度は,養豚廃水を用いたリアクターでは831 mW・m<SUP>-2</SUP>,酪農廃水を用いたリアクターでは59 mW・m<SUP>-2</SUP>であった。また,両リアクターのアノードにおける微生物群集構造は大きく異なり,養豚廃水および酪農廃水リアクターからそれぞれ,Acidobacteria門,Proteobacteria門に近縁な細菌が見つかった。また,アノードで主に検出された細菌は流入廃水やカソードからのものとは異なっていた。 養豚廃水を用いた系では,カソードへの塩の析出が多く観察され,析出物にはリン,マグネシウム,カルシウムが高濃度に含まれていた。

著者

中曽根 英雄 山下 泉 黒田 久雄 加藤 亮

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 = Journal of Japan Society on Water Environment (ISSN:09168958)

巻号頁・発行日

vol.23, no.6, pp.374-377, 2000-06-10

被引用文献数

10 16

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We found a special irrigation reservoir in which there are no algae, insects, or fish. Therefore, we have surveyed the water quality of an irrigation reservoir to find the reason for no living creatures. As the results of the survey, we found three factors such as high nitrate concentration, high aluminum concentration, and low pH value which will affect the lives of creatures in this irrigation reservoir. Among these three factors, the most important one is low pH in this irrigation reservoir. This low pH of the irrigation reservoir is derived from the overuse of nitrogen fertilizer at tea yards. About 1,000kg · ha^-1 · y^-1 of nitrogen fertilizer has been used to the tea yards for a long time. The remained nitrogen fertilizer which was not taken up by tea crop infiltrates through soils and enters into the ground water. This causes an over the Cation Exchange Capacity of soil and high aluminum concentration of this irrigation reservoir. To prevent this phenomenon from occurring, dozing lime under the root zone and reducing use of nitrogen fertilizer might be effective.

著者

杉崎 健司 岩田 照史 竹内 雍

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 = Journal of Japan Society on Water Environment (ISSN:09168958)

巻号頁・発行日

vol.23, no.5, pp.285-291, 2000-05-10

被引用文献数

2 4

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Eutrophication proceeds in many lakes, marshes and ponds with an unusual growth of algae so that it became a serious problem in especially urban areas. Though many approaches were made to improve the eutrophicati on in the past, e.g., oxidation treatments represented by ultraviolet radiation and ozonation showed rather high effect to reduce algae. Also, an electric disinfection treatment represented by use of electrolysis to produce strongly acidic water is attracting more attention than before, because of strongly acidic and to produce a free chlorine.<br>The authors performed an experimental study focusing on the electrolytic oxidation treatment of algae in lake and marsh water, to examine its effect on the disinfection of algae using a batch- and circulation-type apparatus of laboratory scale.<br>As for the electrolytic oxidation treatment, it showed a great effect on the disinfection of algae. It was found also that there was a correlation between the effect and the quantity of electricity. It was found, further more, that a free chlorine produced by the electrolytic oxidation enhanced the disinfection of algae. On a continuous electrolytic oxidation treatment, the electrolytic cell used for the experiment made more than 24s · A in contact reaction time necessary.

著者

辰巳 健一 中埜渡 丈嘉 成田 隆広 眞柄 泰基 橘 治国

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 = Journal of Japan Society on Water Environment (ISSN:09168958)

巻号頁・発行日

vol.25, no.5, pp.289-296, 2002-05-10

被引用文献数

1 3

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Mine wastewater and hot spring water flow into the Toyohira River, a source of water for Sapporo City. Since the concentrations of components contained in such water change with the flow regime of the river, water quality management is considered a difficult challenge. The authors focused on the dynamic state of arsenic compounds, and found that hot spring water contains these arsenic compounds in dissolved state at high concentrations and that the characteristics of pulled runoff change from point source pollution (dilution pollution) to non point source pollution (runoff load increase pollution) in the flow process of the river. This change seems to closely involve water storage in dams, and we gathered that arsenic as a component of hot spring water entering the Toyohira River accumulates in dam sediment by absorption in silt and clay and that the runoff and re-dissolution of silt and clay at times of high flow rate causes the runoff and return of arsenic to the river. It was revealed that sediment in dams is a potential source of arsenic pollution.

著者

中井 智司 山根 小雪 細見 正明

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 = Journal of Japan Society on Water Environment (ISSN:09168958)

巻号頁・発行日

vol.23, no.11, pp.726-730, 2000-11-10

参考文献数

11

被引用文献数

3 4

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Four polyphenols, gallic acid (GA), ellagic acid (EA), pyrogallic acid (PA), and (+)-catechin (CAT), released from <i>Myriophyllum spicatum</i>, are anti-algal allelochemicals. In this paper, we investigated the inhibitory effects of each of these polyphenols on blue-green algae (<i>Microcystis aeruginosa</i> and <i>Phormidium tenue</i>), green algae (<i>Selenastrum capricornutum</i> and <i>Scenedesmus quadricauda</i>), and diatoms (<i>Nitzschia palea</i> and <i>Achnanthes minutissima</i>). We also determined the collective actions of the 4 polyphenols on the inhibition of algal growth.<br>Among the 6 algae, <i>M. aeruginosa</i> was the only one whose growth was significantly inhibited by each of the 4 polyphenols, while PA, GA, and EA each caused some degree of growth inhibition in <i>P. tenue</i> and the 2 green algae. Because none of the 4 polyphenols showed any inhibitory effect on growth of <i>N. palea</i> and growth of <i>A. minutissima</i> was not inhibited by PA, GA or CAT, diatoms appear to have strong resistance to such polyphenols. The algal assays we used to investigate the collective effects of polyphenols showed that (<i>i</i>) blue-green algae, <i>M. aeruginosa</i> and <i>P. tenue</i> were most sensitive to the synergistic actions of PA, GA and CAT, and (<i>ii</i>) the synergistic actions toward the 2 green algae and the 2 diatoms were concentration-dependent. These results indicate the possible feasibility of selectively controlling growth of blue-green algae through use of these polyphenols and/or the allelopathic effects of <i>M. spicatum</i>. Measurement of the autoxidation rates of the 4 polyphenols suggests that (<i>i</i>) their inhibitory effects on the growth of <i>M. aeruginosa</i> could be caused by products of their autoxidation, such as radicals, and (<i>ii</i>) the synergistic action of PA, GA and CAT might be due to acceleration of their autoxidation resulting in increasing production of such autoxidation products.

著者

沼辺 明博 井上 隆信 海老瀬 潜一

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.15, no.10, pp.662-671, 1992

被引用文献数

25 30

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The runoff loadings and characteristics of pesticides applied to paddy fields after transplanting of rice plant were estimated by means of analysis of pesticides in drainage river water in weekly and at the rainfall events.<br>The largest loadings of herbicides were found between one and two weeks after transplanting of rice plant. On the other hand, the largest loadings of insecticides were found at about ten days later than that of herbicides.<br>The runoff loadings of herbicides during one rainfall event ranged 20 to 25% of total runoff amounts. Therefore, the runoff investigation of pesticides in river water at and after the rainfall are very important for estimation of pesticides runoff from agricultural fields to drainage river.<br>The runoff characteristics of insecticides and herbicides were differed, and it was recognized that the runoff loadings of insecticides were decreased more rapidly than herbicides at the rainfall event.<br>The runoff rates of pesticides were ranged from 25% for fenobucarb to 0.02% for fenitrothion.<br>From this results concerned in rainfall event, the runoff rates of pesticides from agricultural fields to river were more higher than that of the previous literature.

著者

大橋 優子 亀屋 隆志 小林 剛

出版者

Japan Society on Water Environment

雑誌

水環境学会誌 = Journal of Japan Society on Water Environment (ISSN:09168958)

巻号頁・発行日

vol.31, no.9, pp.533-539, 2008-09-10

被引用文献数

1

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Soil contamination by toxic anions has become a serious problem, because of their persistence for a longtime and their diffusion into underground water. In this study, the adsorption equilibria for three hazardous anions of As(V), Se(IV), and Cr(VI) were investigated in a wide concentration range for four types of soilunder the condition of coexisting of competitive anions. The adsorption amount of toxic anions was altered by 20∼40 fold depending on the type of soil, Ando soil, Brown Forest soil >> Glay Upland soil> Terrestrial Rego soil. Metal anion adsorption was hindered by coexisting anions, particularly hydroxide ion, and competitive adsorption could be quantitatively expressed using the multiple isotherm equation proposed in this study. From the quantitative investigation analysis, the effect of the concentration change in liquid phase did not depend on the type of soil, but could be approximated by a constant for each anion. On the basis of experimental results, the behavior of the toxic metal anions in contaminated soils could be estimated by examining the adsorption isotherms for the soils and its pH dependence.