著者

毛利 光男 加瀬 隆雄 貫上 佳則

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.4, pp.281-286, 2005-04-10 (Released:2008-01-22)

参考文献数

23

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The grain-size distribution of turbidity, water chemistry, and the size of fine particles associated with contaminants in turbid groundwater were investigated in existing monitoring wells. Groundwater monitoring wells are used in obtaining general information on groundwater quality and specific information on concentrations and specification of mobile contaminants in the vicinity of a monitoring well. This information is used in determining whether a given facility is currently in compliance with regulations. Turbidity (fine particles) are present in monitoring wells as a result of well installation in a stratum containing many fine particles (e.g., clay and silt) at a depth of less than GL-10m, well development, prior purging, sampling events, and natural colloidal transport and deposition over time. It is crucial that samples obtained from monitoring wells accurately reflect in situ mobile contaminant concentrations. The filtration of groundwater samples may remove both mobile fine particles/colloids and artifact particles. The most common groundwater purging method is to purge a monitoring well using bailers or pumps to remove 3 to 5 casing volumes to obtain formation water. In this paper, the concept and numerical formulas of a well-purging model are introduced and discussed. The calculation result shows that prepurging more than 3 casing volumes ensures a sampling of well water which is similar to formation water. The differences between filter pack and gravel pack (filter media #2 - #4) and the method of selecting the sizes of filter media were surveyed and discussed with the aim of installing a monitoring well in a stratum containing many fine particles.

著者

毛利 光男 馬場 直紀 青木 陽士 平澤 卓也

出版者

公益社団法人 土木学会

雑誌

土木学会論文集 (ISSN:24366021)

巻号頁・発行日

vol.79, no.11, pp.23-00045, 2023 (Released:2023-11-20)

参考文献数

19

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本研究は,実機による枯葉剤ダイオキシン汚染土壌の実証試験において土壌洗浄の浄化性能を定量的に評価したものである.サイクロンによるダイオキシン除去率は67~87%(平均79.2%)であったが,後段のフローテーションによって除去率は91~97%(平均94.0%)へ大きく向上した.土壌洗浄によって16,000pg-TEQ/gまでの汚染土壌から住宅地(300),緑地・公園(600),商業地・工業地(1,200)のいずれかの基準を満足する浄化土を実際に産出できることを実証した.回収される浄化産物(浄化土+粗粒分)の割合は元土壌の59~74%(平均65%),濃縮残渣の割合は26~41%(平均35%)であり十分な減容化効果が認められた.濃縮残渣の濃縮倍率は1.3~3.8の範囲にあり平均は2.4であった.