著者

今井 章雄 福島 武彦 松重 一夫

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.22, no.7, pp.555-560, 1999-07-10 (Released:2008-01-22)

参考文献数

30

被引用文献数

4 6

---

Aquatic humic substances (AHSs) from the eutrophic Lake Kasumigaura were isolated using XAD-8 resin. The effects of these isolated AHSs on the growth of Microcystis aeruginosa cultures were evaluated. M. aeruginosa was isolated from algal blooms in Lake Kasumigaura and grown in a chmically defined medium under iron limitation. The production of siderophores, iron-specific complexing agents, by M. aeruginosa was also examined. Under iron limitation, M. aeruginosa was confirmed to produce hydroxamate-type siderophores; however, they were not effective to enable substantial recovery of the growth rate. The fulvic acid (lower molecular-size fraction of AHSs) isolated from Lake Kasumigaura was found to significantly inhibit the growth of M. aeruginosa. The fulvic acid at 2 mg dry weight l-1, the same level as in the lake, significantely inhibited the growth of M. aeruginosa even though siderophores were produced. This inhibition was probably due to a deficiency of iron caused by iron complexation with the fulvic acid. These results suggest that AHSs, through their iron complexation reactions, may play an important role in formation of M. aeruginosa algal blooms.

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

---

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

---

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

佐々木 久雄 西村 修 須藤 隆一

出版者

公益社団法人 日本水環境学会

雑誌

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

巻号頁・発行日

vol.22, no.7, pp.581-586, 1999-07

被引用文献数

2

---

People usually evaluate the amenity of water environment by transparence to look at water. Water transparence is measured by transparency or transparency by cylinder test. However, these methods have some defects such as difficulties in measuring at shallow and clean waters, because transparency is limited by water depth and transparency by cylinder test is limited by length of a cylinder. Moreover, the lack of objectivity is pointed out, since transparency measuring is due to personal sensitivity. To conquer these problems, we designed a measuring method of horizontal transparency, and developed a measuring equipment by using an eye-test chart and a waterproof camera. We applied this method to water quality investigation of Matsushima Bay, Miyagi prefecture, and studied the characteristics of horizontal transparency comparing with transparency, transparency by cylinder test and so on. The results obtained were as follows; (1)Horizontal transparevcy has superior objectivity, because evaluation by plural number of people diminish personal errors. (2)Horizontal transparency is possible to express water transparence quantitatively without any limits, though conventional methods cannot apply to relatively clear and shallow waters. (3)Horizontal transparency has a very good correlation between not only transparency but also turbidity and suspended solids that are mainly affect to transparency. (4)The sense of visitors and fishermen about the water quality of Matsuhima Bay can be represented by horizontal transparency.

著者

高見 徹 丸山 俊朗 鈴木 祥広 三浦 昭雄

出版者

公益社団法人 日本水環境学会

雑誌

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

巻号頁・発行日

vol.22, no.1, pp.29-34, 1999-01-10

---

In the short-term bioassay using Porphyra yezoensis conchospores, it is basically important to clarify the most appropriate exposure period and end point to evaluate the effects of toxicants on the growth of Porphyra yezoensis conchospores. In this study, short-term bioassays (120 hours) were conducted on copper (Cu) and monochloramine (NH2Cl), which have different chemical characteristics. Three kinds of end points (survival ratio, germination ratio and growth ratio) at exposure periods every 24 hours were compared to define the most appropriate exposure period and end point.The minimum LOECs (lowest-observed-effect concentration) for Cu occurred at exposure period of 96 hours in the three kinds of end points. The 96-h LOECs from the survival ratio, the germination ratio and the growth ratio were 0.046 ± 0.026mg Cu·l-1 (n=5), 0.033 ± 0.027mg Cu·l-1 (n=5), 0.021 ± 0.019mg Cu·l-1 (n=5), respectively. The minimum LOECs for NH2Cl occurred at exposure period of 96 hours in the survival ratio and the growth ratio of 0.093 ± 0.026mg Cl2·l-1 (n=5) and 0.038 ± 0.016mg Cl2·l-1 (n=5), respectively. The minimum LOEC (0.036 ± 0.000mg Cl2·l-1, n=5) for NH2Cl from the germination ratio occurred at the exposure period of 48 hours.Therefore, taking into account of the simplicity of bioassay and its sensitivity to toxicants, it is concluded that the most appropriate exposure period and end point is 96 hours for Cu and 48 hours for NH2Cl judging from the end point of the germination ratio.

著者

蒔苗 靖子 渡部 徹 大村 達夫 遠藤 銀朗

出版者

日本水環境学会

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.12, pp.771-777, 2000-12-10

---

Outbreaks of infectious diseases by new pathogenic microorganisms through water utilization have been reported in recent years. Especially, Legionnaires' disease has been recognized as a serious problem in modern societies since a high concentration of <i>Legionella pneumophila</i> often exist in water environment (such as cooling tower, bath water, recreational water) close to human activities. In this study, the quantitative detection method (colony-hybridization) for <i>L. pneumophila</i> was developed by combining the hybridization with the plate culture method. The developed detection method enabled <i>L. pneumophila</i> to be enumerated in various water samples. It was possible to quantify <i>L. pneumophila</i> without interferences of other bacteria by this method in case that the number of total coliforms on the plate was less than 10³ CFU.

著者

臼井 恵次 進藤 晴夫 丸本 卓哉 岸野 拓男

出版者

日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.17, no.9, pp.596-599, 1994

被引用文献数

2 1

---

A release of phosphorus from calcium phosphate, iron(III) phosphate, and aluminum phosphate owing to the complex formation of their metals with fulvic acid was examined. Fulvic acid was extracted from lake sediments and treated with Amberlite XAD-8 resin. The non-adsorbed fraction of fulvic acid on the resin, which has highly Cu2+-complexing capacity, was used in this study, because the adsorbed fraction has only little Cu2+-complexing capacity as reported in our previous paper. The non-adsorbed fraction was able to release phosphorus from calcium phosphate, but not from iron(III) phosphate, and aluminum phosphate. The application of X-ray analysis to the calcium phosphate indicated that the major component is hydroxyapatite. The stability constant of the Cu2+-fractionated fulvic acid was determined to be 2×10(5) (log K=5.3) and the average molecular weight of the fulvic acid was 1,026.

著者

臼井 恵次 岸野 拓男 東 俊雄 進藤 晴夫 丸本 卓哉

出版者

日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.16, no.10, pp.690-695, 1993

被引用文献数

3 3

---

Fulvic acid extracted from lake sediments was treated with Amberlite XAD-2 and XAD-8 resins. The metal complexing ability of the fulvic acid was measured at pH 6.0 with a Cu2+ titration method, in which free Cu2+ was determined with an ion selective electrode. A two binding site model, in which there are two kinds of the molecules having strong and weak complexing ability and they complex with metal ion at the ratio of 1:1, was employed for the determination of the stability constant and complexing capacity of the fulvic acid, because the hyperbolic approxmation could apply to the Scatchard plot of the found values. The stability constants of the fulvic acids having strong complexing ability and weak complexing ability were in the range of 6.33-7.12 and 4.35-4.66, respectively. Both colorless fractions of the fulvic acid which were not adsorbed on XAD-2 and XAD-8 resins had such a high complexing ability as 44 and 32 μmol・g-1, respectively. On the other hand, both colored fractions of the fulvic acid which were adsobed on the resins had only little complexing capacity.

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

---

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

高見 徹 丸山 俊朗 鈴木 祥広 三浦 昭雄

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.22, no.1, pp.29-34, 1999-01-10 (Released:2008-01-22)

参考文献数

22

被引用文献数

1

---

In the short-term bioassay using Porphyra yezoensis conchospores, it is basically important to clarify the most appropriate exposure period and end point to evaluate the effects of toxicants on the growth of Porphyra yezoensis conchospores. In this study, short-term bioassays (120 hours) were conducted on copper (Cu) and monochloramine (NH2Cl), which have different chemical characteristics. Three kinds of end points (survival ratio, germination ratio and growth ratio) at exposure periods every 24 hours were compared to define the most appropriate exposure period and end point.The minimum LOECs (lowest-observed-effect concentration) for Cu occurred at exposure period of 96 hours in the three kinds of end points. The 96-h LOECs from the survival ratio, the germination ratio and the growth ratio were 0.046 ± 0.026mg Cu·l-1 (n=5), 0.033 ± 0.027mg Cu·l-1 (n=5), 0.021 ± 0.019mg Cu·l-1 (n=5), respectively. The minimum LOECs for NH2Cl occurred at exposure period of 96 hours in the survival ratio and the growth ratio of 0.093 ± 0.026mg Cl2·l-1 (n=5) and 0.038 ± 0.016mg Cl2·l-1 (n=5), respectively. The minimum LOEC (0.036 ± 0.000mg Cl2·l-1, n=5) for NH2Cl from the germination ratio occurred at the exposure period of 48 hours.Therefore, taking into account of the simplicity of bioassay and its sensitivity to toxicants, it is concluded that the most appropriate exposure period and end point is 96 hours for Cu and 48 hours for NH2Cl judging from the end point of the germination ratio.

著者

橋本 温 河井 健作 西崎 綾 松本 かおり 平田 強

出版者

公益社団法人 日本水環境学会

雑誌

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

巻号頁・発行日

vol.22, no.4, pp.282-287, 1999-04

被引用文献数

5

---

In order to investigate the occurrence and indicator of protozoa in water, water samples were collected from 11 points along the Sagami River and its tributaries for 9 months. The concentrations of Cryptosporidiurn oocysts, Giardia cysts and potential indicators (presumptive Clostridium perfringens spores, Escherichia coli, coliforms, aerobic spores and turbidity) were analyzed. Cryptosporidium oocysts were detected at 10 of the 11 sampling points (GM 34 presumptive oocysts·100l-1, 24 confirmed oocysts·100l-1) and Giardia cysts were detected at all sampling points (GM 30 presumptive cysts·100l-1, 12 confirmed cysts·100l-1). Based on a regression analysis, the concentrations of presumptive C.perfringens spores and E.coli were significantly correlated with the concentrations of protozoa. In a multiple regression analysis, the concentration of presumptive C.perfringens spores, E.coli and aerobic spores were selected as explanatory variables for the protozoan concentrations. The results indicated that presumptive C.perfringens spores, aerobic spores and E.coli were useful indicators for protozoan contamination.

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

---

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

堀越 壮一 飯島 明宏 冨岡 淳 関 順司 加藤 政彦 小澤 邦壽

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.30, no.5, pp.283-286, 2007 (Released:2010-01-09)

参考文献数

28

被引用文献数

2 2

---

Recently, nitrate-nitrogen (NO3-N) pollution in groundwater was identified as a serious problem in Gunma prefecture. The rate of satisfying the environmental quality standard(EQS) for NO3-N concentration in Gunma prefecture was lowest in Japan from 2000 to 2004. However, a significant decrease in NO3-N concentration was observed in 2005. Therefore, the factors contributing to the decrease were statistically examined. The results suggest that the area of dry field, livestock head count, and agricultural population significantly contributed to the decrease in NO3-N concentration. The enforcement of the Law on Promoting Proper Management and Use of Livestock Excreta might reduce NO3-N discharge into groundwater.

著者

山本 富久 中曽根 英雄 松沢 康宏 黒田 久雄 加藤 亮

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.27, no.5, pp.329-336, 2004-05-10 (Released:2008-01-22)

参考文献数

27

被引用文献数

1 1

---

The water quality and discharge from a tea field area in Shizuoka were measured daily and the outflow loads of fertilizer components in runoff water estimated. The results are as follows: The amount of nitrogen fertilizer applied was about 1000kg·ha-1·yr-1 in the tea field. The annual of T-N effluent load from the tea field was 531kg·ha-1·yr-1 and it was 49% of the amount nitrogen fertilizer applied. 97% of the T-N load was composed of the NO3-N load. Its outflow load, which consisted of storm water, was 51%. The outflow NO2-N and NH4-N loads were small in the first half of the investigation period. The T-P outflow load from the tea field was 0.18kg·ha-1·yr-1 and the leaching rate was very low, at 0.05%. Most of the phosphate fertilizer was absorbed by the red-yellow soil in the tea field. The average T-P concentration was as low as 0.01 mg·l-1. However, the T-P concentration was very high after heavy rain in June and September of 2000. Storm water had a T-P outflow load concentration of 64%. The K+ outflow load was estimated to be 89kg·ha-1 for the year. The leaching rate was 14%. The percentage was very low because K+ was absorbed by surface soil containing clay minerals. The annual Mg2+ and Ca2+ outflow loads were 292kg·ha-1·yr-1 and 266kg·ha-1·yr-1, respectively. Their leaching rates were 63% and 26%, respectively.

著者

山本 富久 中曽根 英雄 松沢 康宏 黒田 久雄 加藤 亮

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.28, no.6, pp.399-404, 2005-04-10 (Released:2008-01-22)

参考文献数

51

被引用文献数

1 1

---

The study area was located in the Makinohara collective tea fields in Shizuoka, Japan. There are flourishing tea industries in this area. The quality and level of the groundwater were observed from Jun. 2002 to Sept. 2003 and examined on the basis of hydrogeology. The Makinohara plateau comprises of clay layers between gravel beds. It yielded discontinuous water qualities caused by perched water in a geological structure. The average concentrations of T-N and NO3-N in the surface water were 26.4 mg·l-1, 23.8mg·l-1, respectively. In contrast, for the groundwater, these concentrations were 17.2 mg·l-1 and 12.6 mg·l-1, respectively. The average concentrations of T-P were 0.012 mg·l-1 in the surface water and 0.022 mg·l-1 in the groundwater. This difference is caused by the dilution effect and release of phosphorus from on aquifer. The annual groundwater effluent loads of nitrogen and phosphorus from the catchments of the Makinohara plateau were 406 t·y-1 and 0.7 t·y-1, respectively.

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

---

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

臼井 恵次 進藤 晴夫 丸本 卓哉 岸野 拓男

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.17, no.9, pp.596-599, 1994-09-10 (Released:2008-01-22)

参考文献数

13

被引用文献数

2 1

---

A release of phosphorus from calcium phosphate, iron(III) phosphate, and aluminum phosphate owing to the complex formation of their metals with fulvic acid was examined. Fulvic acid was extracted from lake sediments and treated with Amberlite XAD-8 resin. The non-adsorbed fraction of fulvic acid on the resin, which has highly Cu2+-complexing capacity, was used in this study, because the adsorbed fraction has only little Cu2+-complexing capacity as reported in our previous paper.The non-adsorbed fraction was able to release phosphorus from calcium phosphate, but not from iron(III) phosphate, and aluminum phosphate. The application of X-ray analysis to the calcium phosphate indicated that the major component is hydroxyapatite. The stability constant of the Cu2+-fractionated fulvic acid was determined to be 2×105 (log K=5.3) and the average molecular weight of the fulvic acid was 1,026.

著者

臼井 恵次 岸野 拓男 東 俊雄 進藤 晴夫 丸本 卓哉

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 (ISSN:09168958)

巻号頁・発行日

vol.16, no.10, pp.690-695, 1993-10-10 (Released:2008-04-21)

参考文献数

19

被引用文献数

5 3

---

Fulvic acid extracted from lake sediments was treated with Amberlite XAD-2 and XAD-8 resins. The metal complexing ability of the fulvic acid was measured at pH 6.0 with a Cu2+ titration method, in which free Cu2+ was determined with an ion selective electrode. A two binding site model, in which there are two kinds of the molecules having strong and weak complexing ability and they complex with metal ion at the ratio of 1 : 1, was employed for the determination of the stability constant and complexing capacity of the fulvic acid, because the hyperbolic approxmation could apply to the Scatchard plot of the found values.The stability constants of the fulvic acids having strong complexing ability and weak complexing ability were in the range of 6.33-7.12 and 4.35-4.66, respectively. Both colorless fractions of the fulvic acid which were not adsorbed on XAD-2 and XAD-8 resins had such a high complexing ability as 44 and 32 μmol·g-1, respectively.On the other hand, both colored fractions of the fulvic acid which were adsobed on the resins had only little complexing capacity.

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

---

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

---

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.