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Journal Articles

A Proposed method to estimate in situ dissolved gas concentrations in gas-saturated groundwater

Tamamura, Shuji*; Miyakawa, Kazuya; Aramaki, Noritaka*; Igarashi, Toshifumi*; Kaneko, Katsuhiko*

Groundwater, 56(1), p.118 - 130, 2018/01

Groundwater saturated with gas forms bubble under atmospheric pressure, bothering most authorized methods to determine in-situ dissolved gas concentrations. To circumvent this problem, a simple theory to quantify effect of $rm bubble formation on in-situ dissolved gas concentration was developed: Pressure ({it P$_{i},rm original $}$ [bar]) of a gas component "${it i}$" (e.g., CH$$_{4}$$, CO$$_{2}$$ and H$$_{2}$$) in equilibrium with in-situ dissolved concentration (${it C $_{i},rm original $}$ [mol L $$^{-1}$$]) was related to partial pressure of the $rm bubble ({it P $_{i},rm bubble $}$ [bar]) emerged from groundwater in the form: ${it P$_{i},rm original $}$ = ${it P $_{i},rm bubble $}$ + $$Delta$$ ${it P}$ (k${it i}$' ${it P $_{i},rm bubble $}$/($$Sigma$$ ${it j}$k${it j}$' ${it P $_{ j },rm bubble $}$)), where $$Delta$$ ${it P}$ [bar] is groundwater pressure difference before and after the $rm bubble formation, and j refers to all gas components in the system including "{it i.}$" The k${it $_{i}$}$' and k${it $_{j}$}$' corresponds to the Henry's constant [bar L mol$$^{-1}$$] of ${it i}$ (k${it $_{i}$}$) and ${it j}$ (k${it $_{j}$}$), respectively, except for k$$_{CO2}$$', which is pH-dependent function. Dissolved CH$$_{4}$$ concentrations were successfully estimated by the model within the error of $$pm$$ 4.0% from the direct measurements by the sealed sampler method. Similar TIC concentration in the groundwater before and after the rm bubble formation was consistent with the model prediction. The wide application of the model is suggested without selecting sampling locations.

Journal Articles

Possibility of formic and acetic acids as active substrates for methanogenesis in the groundwater in Horonobe, Hokkaido

Tamamura, Shuji*; Endo, Ryo*; Shimizu, Satoru*; Iwatsuki, Teruki; Amano, Yuki; Omi, Yasushi*; Igarashi, Toshifumi*

Journal of MMIJ, 128(10,11), p.570 - 575, 2012/10

no abstracts in English

Oral presentation

Leaching behavior of inorganic nitrogen spiecies from diatomaceous mudstone in Horonobe Underground Research Center

Sekiya, Yoshitomo; Kitagawa, Yoshito*; Igarashi, Toshifumi*; Hokora, Hideyuki*

no journal, , 

no abstracts in English

Oral presentation

Change in chemical form of nitrogen compounds of leachate from diatomaceous mudstone

Sekiya, Yoshitomo; Kitagawa, Yoshito*; Igarashi, Toshifumi*; Hokora, Hideyuki*

no journal, , 

no abstracts in English

Oral presentation

Evaluation of nitrification of inorganic nitrogen in the leachate from diatomaceous mudstone

Sekiya, Yoshitomo; Kitagawa, Yoshito*; Igarashi, Toshifumi*; Hokora, Hideyuki*

no journal, , 

no abstracts in English

Oral presentation

Leaching behavior of nitrogen compounds from diatomaceous mudstone and its factors

Ueda, Takahiro*; Igarashi, Toshifumi*; Hokora, Hideyuki*; Sataka, Hiroyuki; Shimada, Tomohiro*

no journal, , 

no abstracts in English

Oral presentation

Factors affecting leaching behavior of nitrogen compounds from diatomaceous mudstone

Ueda, Takahiro*; Igarashi, Toshifumi*; Hokora, Hideyuki*; Sataka, Hiroyuki; Shimada, Tomohiro*

no journal, , 

no abstracts in English

Oral presentation

Factors affecting leaching behavior of nitrogen species from diatomaceous mudstone

Ueda, Takahiro*; Hokora, Hideyuki*; Igarashi, Toshifumi*; Jo, Mayumi*; Sataka, Hiroyuki

no journal, , 

Horonobe Underground Research Center, located in northern Hokkaido, Japan, has been excavating shafts of an underground research facility to establish general techniques for the assessment of deep geological environment. In this site, the groundwater seepage from the shafts and leachate from the waste rock storage site contain high concentrations of total nitrogen. Ammonium-nitrogen (NH$$_{4}$$-N), the major nitrogen species in the seepage and leachate, has been removed by a nearby treatment facility. However, NH$$_{4}$$-N is easily oxidized to nitrite-nitrogen (NO$$_{2}$$-N) and nitrate-nitrogen (NO$$_{3}$$-N) by nitrification in the excavated rock storage site, which makes the removal process employed on site less effective. Therefore, column experiments that simulated the infiltration of rainwater through the storage site were carried out to understand the phenomena and the factors affecting the leaching behavior of nitrogen species and nitrification, and to propose countermeasures for preventing nitrification. The results showed that the nitrification was inhibited when the rock layer was almost saturated, and that this process was temperature dependent. These indicate that nitrification can be mitigated by controlling hydrological conditions like water saturation.

Oral presentation

Factors affecting the leaching of nitrogen species from diatomaceous mudstone

Igarashi, Toshifumi*; Ueda, Takahiro*; Hokora, Hideyuki*; Jo, Mayumi*; Kudo, Hajime

no journal, , 

Horonobe Underground Research Center, located in northern Hokkaido, Japan, has been excavating shafts and drifts of an underground research facility to establish general techniques for the assessment of deep geological environment. In this site, the groundwater seepage from the shafts and drifts as well as leachate from the excavated rock storage site contain high concentrations of total nitrogen. Ammonium-nitrogen (NH$$_{4}$$-N), the major nitrogen species in the seepage and leachate, has been removed by a nearby treatment facility. However, NH$$_{4}$$-N is easily oxidized to nitrite-nitrogen (NO$$_{2}$$-N) and nitrate-nitrogen (NO$$_{3}$$-N) by nitrification in the excavated rock storage site, which makes the removal process employed on site less effective. Therefore, column experiments that simulated the infiltration of rainwater through the storage site were carried out to understand the leaching and nitrification of nitrogen species and the factors affecting the phenomena. The results showed that the nitrification was inhibited when the rock layer was almost saturated, and that this process was temperature dependent. These indicate that nitrification can be mitigated by controlling hydrological conditions like water saturation.

Oral presentation

Modeling of groundwater recharge and discharge for controlling radium in the mine drainage of Ningyo-toge Mine, Okayama Prefecture

Tomiyama, Shingo*; Igarashi, Toshifumi*; Odashiro, Kana*; Yamaguchi, Kohei*; Fukushima, Shigeru; Ohara, Yoshiyuki

no journal, , 

no abstracts in English

Oral presentation

Analysis of microbial community structure in deep underground diatomaceous/siliceous mudstone formations and factors determining microbial community structure

Tamazawa, Satoshi*; Ueno, Akio*; Murakami, Takuma*; Miyakawa, Kazuya; Tamamura, Shuji*; Kiyama, Tamotsu*; Inomata, Hidenori*; Naganuma, Takeshi*; Kaneko, Katsuhiko*; Igarashi, Toshifumi*

no journal, , 

no abstracts in English

11 (Records 1-11 displayed on this page)
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