水環境学会誌
Online ISSN : 1881-3690
Print ISSN : 0916-8958
ISSN-L : 0916-8958
22 巻, 4 号
選択された号の論文の9件中1~9を表示しています
論文
  • 津野 洋, 宗宮 功, 柳瀬 仁志, 河村 正純
    1999 年 22 巻 4 号 p. 275-281
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    Soil samples were collected from A and A0 horizons at 38 points in Shiga Prefecture under consideration of geological feature, soil type and vegetation. The samples were analyzed and used in artificial acid rain added experiments to clear soil characteristics and effects of acid rain. Ca, Mg and Al included in the extracted solution with buffer solution of 0.5M acetic acid and ammonium acetate (pH4.7) are shown to be available as indices for discussion on effects of acid rain on soil. According to these indices, forests with broad-leafed trees are shown to be stronger against acid rain than those with red pine, Japanese cypress and Japanese cedar. It is also shown that Al is afraid to be eluted from granite soil and that dune soil is typically weak against acid rain.
  • 橋本 温, 河井 健作, 西崎 綾, 松本 かおり, 平田 強
    1999 年 22 巻 4 号 p. 282-287
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    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.
  • 平田 静子, 冨永 衛, 寺島 滋
    1999 年 22 巻 4 号 p. 288-293
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    Antimony was designated as one of the Requiring Surveillance Items in the Japanese Environmental Quality Standards for Water which was renewed in 1993. Total amounts of antimony {antimony(III) + antimony(V)} solubilizcd from the polluted soils added antimony compounds were determined under the various conditions of pH, temperatures and extracting times by hydride generation-atomic absorption spectrometry. The total amounts of antimony solubilized from the polluted soils increased with rising pH, temperature and extracting time of samples. The order of largeness of solubilization from the polluted soils was sulfide < oxide < salt of antimony. Also, the total amounts of antimony solubilized from polluted soils with distilled water were 0.27% of total antimony in the soil containing oxide antimony (S-2), 0.19% of that in the soil containing antimony sulfide (S-3) and 0.40% of that in the soil containing soluable salt of antimony (S-4), respectively. From the results of comparing the analytical data using one tenth of official sample amounts with the data based on the official rule, it was proved that the solubilization experiment could be done with one tenth of official sample amounts of soils.
  • 本村 輝正, 宮内 信文
    1999 年 22 巻 4 号 p. 294-300
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    Waterhyacinth (Eichhornia crassipes (Mart.) Solms) is known as one of the most troublesome aquatic weeds in the world. The plant naturally grows in eutrophic freshwater habitats of both tropical and temperate regions. The nutrient status of various habitats offers a much wider range and the plant multiplies so rapidly that it often forms dense stands covering a large surface area of the habitats. In this work, 20 community habitats of the plant in Kagoshima Prefecture were investigated with regards to the reproduction of the plant and physicochemical characteristics of the water in these habitats.
    The reproduction of the plant and the development of the habitats were related with the concentrations of pollutants (NO3-N, PO4-P) in the water.
    The origin of NO3-N in water at the hahitas was considered to be N of polluted with mainly animal waste, because N values of animal waste in Kagoshima Prefecture is several times higher than the values in other prefectures.
  • 石井 誠治, 浦野 紘平
    1999 年 22 巻 4 号 p. 301-307
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    The COD is a principal water quality index to manage water environment in Japan. However, much labor and large amounts of hazardous reagents are needed to measure by the conventional method in Japan Industrial Standard (JIS). In this study, we developed an improving method of JIS CODMn by colorimetry. This method was much easy procedure and could reduce amounts of the hazardous reagents and energy consumption to one twentieth of the conventional method.
    Five ml of sample water and 0.50ml of 5.0mmol·l-1 KMnO4 were put into a test tube contained sulfuric acid and silver nitrate. It was heated at 100°C for 30 minutes with block heater. Since it was found that formed Mn2+ from MnO4- was reacted with residual MnO4- to Mn02 in the ratio of 3 : 2, we determined the residual concentration of MnO4- from absorbance at 525nm after filtration of Mn02, and calculated the CODMn.
    It was confirmed that CODMn values by this developed method for 60 various water samples were equal to the values by the JIS method with r=0.998. The scatter of data and the measurable concentration range of this method were nearly equal to them of the JIS method.
  • 中川 創太, 三島 浩二
    1999 年 22 巻 4 号 p. 308-312
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    Coagulation process is usually used as a method of treating refractory substances in wastewater. But, it can't often satisfy target water quality within practical coagulant dosage. In case of treating the effluent from coagulation process, the AOP (Advanced Oxidation Process), an oxidation/decomposition process which combines ultraviolet, ozone, and hydrogen peroxide, is looked upon as a method of treating the effluent from coagulation process. However, the abundant amount of oxidant and ultraviolet irradiation needed for oxidation are hampering the practicalization of this process. The authors conducted a research on the application of the AOP (ozone/hydrogen peroxide treatment) for pretreatment of secondary coagulation process using the effluent from coagulation process of a landfill site leachate treatment plant as raw water. The D-TOC removal by coagulation treatment using AOP treated water of raw water was higher than that using raw water, despite the D-TOC of the former was lower than that of the latter. Considering that the D-TOC removal was occurred during the AOP, it was assumed that the organic compound underwent changes to more susceptible to reaction with coagulant during oxidative decomposition. From this result, it was considered that using the AOP for pretreatment of coagulation process could achieve a significant decrease in coagulant dosage, a space-saving in the sludge treatment facility, and a saving in sludge disposal costs.
  • 竹内 正美, 村上 定瞭, 北尾 高嶺
    1999 年 22 巻 4 号 p. 313-319
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    Photographic wastewater bears high levels of pollutants being composed of various organic and inorganic chemicals which are difficult to be reduced to the levels permitted for discharge with a single biological or chemical method. The authors have proposed a three-stage treatment system of the 1st biological, chemical and 2nd biological process. The purpose of the chemical stage is to reform the refractory chemicals into biodegradable ones. In this study, electrochemical oxidation with a ferrite anode is applied to the chemical stage to improve their biodegradabilities.
    Electrolysis of the photographic wastewater, which had been biologically treated at the 1st stage, enhanced BOD of the wastewater. Mechanism has been discussed on the upgrade in biodegradabilities of chemicals, used in photographic processing, by electrochemical oxidation. The 1st biological-electrochemical-2nd biological process removed 95% in COD; the contributions to COD removal were 42%, 11% and 42% by 1st biol., electro. and 2nd biol. stages, respectively. 48% of TN was removed and 94% among the remaining N-compounds was NO3-. The principal process for COD removal from photographic wastewater have been established, but the additional N removal process is necessary to discharge the processed wastewater into the N regulated water bodies.
ノート
  • 原田 茂樹, E. エリック アダムズ, ロザリンド K. タカタ
    1999 年 22 巻 4 号 p. 320-322
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    Mixing inside free floating mesocosms (marine enclosures) is essential to reproduce the marine surface environment. Thus, two devices, a disc and a pump were developed and deployed into a reduced scale (about 1/10) mesocosm. The disc device is comprised of a wooden seesaw, a float and five perforated discs. The pump device is comprised of the same seesaw and float and a plastic pipe with a check valve. Both devices transfer energy into the mesocosm in response to the movement of the float outside the mesocosm. These two devices provided turbulent mixing and/or upward vertical advection, resulting in stronger mixing than in the control case (with no device). On the other hand, when waves were strong, enough mixing was occurred in the control case. Optimal design of mesocosms in terms of selection and/or combination of such devices (including the do nothing case) depends highly on the strength of wave fields.
  • 酒井 保藏, 高橋 不二雄
    1999 年 22 巻 4 号 p. 323-326
    発行日: 1999/04/10
    公開日: 2008/01/22
    ジャーナル フリー
    The aim in this paper is to clarify that the apparatus of rotating magnetic disk separation (apparatus of RMDS) is useful to remove filamentous bacteria from the activated sludge during the waste water treatment. The bulking sludge was mixed with ferromagnetic powder (Fe3O4) to prepare magnetic sludge (SVI: 430ml·g-1 VSS) containing 2 g·l-1 MLVSS and 2 g·l-1 Fe3O4. The apparatus of RMDS composed of the aeration tank knd the magnetic separation tank equipped rotating magnetic disk with scraper was compared with that of gravitational sedimentation (apparatus of GS) composed of the aeration tank and the sedimentation tank on the separation of magnetic sludge. Six days experiments were carried out with adding 200mg·l-1 CODCr as the influent at HRT=6h using both apparatuses of RMDS and GS. In case of GS method, the SVI kept constant at around 250ml·g-1 VSS after 70h. On the other hand, the SVI with RMDS method decreased to about 200ml·g-1 VSS after 30h, and about 100ml·g-1 VSS after 90h. It was found by microscopic observation that filamentous bacteria remained in the apparatus of GS, but almost not in that of RMDS after the 6 d experiments.
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