Ino, Kohei*; Hernsdorf, A. W.*; Konno, Yuta*; Kozuka, Mariko*; Yanagawa, Katsunori*; Kato, Shingo*; Sunamura, Michinari*; Hirota, Akinari*; Togo, Yoko*; Ito, Kazumasa*; et al.
ISME Journal, 12(1), p.31 - 47, 2018/01
In this study, we found the dominance ofanaerobic methane-oxidizing archaea in groundwater enriched in sulfate and methane from a 300-m deep underground borehole in granitic rock.
Iwatsuki, Teruki; Munemoto, Takashi*; Kubota, Mitsuru*; Hayashida, Kazuki; Kato, Toshihiro*
Applied Geochemistry, 82, p.134 - 145, 2017/05
This study investigated the behavior of rare earth elements (REEs) associated with suspended particles in deep granitic groundwater and in a sealed drift at a depth of 500 m in the Mizunami Underground Research Laboratory (URL) in Japan. Approximately 10%60% of REEs in groundwater are associated with suspended particles. Carbonate particles in groundwater are most likely derived from in situ precipitation of supersaturated carbonate minerals such as calcite. Thermodynamic calculations show that the dissolved REE carbonate complexes in the closed drift decreased in the drift closure period. These complexes may have been absorbed or co-precipitated within the shotcrete on the drift wall. The usage of cement based materials would generate environmental conditions in which REEs are fundamentally immobile in and around the underground facilities.
Ino, Kohei*; Konno, Yuta*; Kozuka, Mariko*; Hirota, Akinari*; Togo, Yoko*; Fukuda, Akari*; Komatsu, Daisuke*; Tsunogai, Urumu*; Tanabe, Akifumi*; Yamamoto, Satoshi*; et al.
Environmental Microbiology Reports (Internet), 8(2), p.285 - 294, 2016/04
To understand the subsurface biosphere, borehole investigation was conducted for 300-m deep granitic rocks at the Mizunami underground research laboratory, Japan. The initial biomass was the highest with the flourish of aerobic H-oxidizing Hydrogenophaga spp., whereas an uncultivated lineage of the phylum Nitrospirae became predominant after three years with decreasing biomass. The common occurrence of many species of Nitrospirae and Chlorobi phyla at the geographically distinct sites and the exclusive detection of their phylogenetically related environmental sequences from deep groundwaters and terrestrial hot springs, suggest that these bacteria are indigenous and potentially adapted to the deep terrestrial subsurface.
Saito, Takumi; Terashima, Motoki; Aoyagi, Noboru; Nagao, Seiya*; Fujitake, Nobuhide*; Onuki, Toshihiko
Environmental Science; Processes & Impacts, 17(8), p.1386 - 1395, 2015/08
The deep groundwater HSs were different from surface HSs, having high aliphaticities, sulfur contents, and small molecular sizes. The amounts of their acidic functional groups were comparable to or slightly larger than those of surface HSs; however, the magnitude of Cu binding to the deep groundwater HSs was smaller. The NICA-Donnan model attributed this to the binding of Cu to chemically homogeneous carboxylic-type sites via mono-dentate coordination at relatively low pH. The binding mode tended to shift to multi-dentate coordination with carboxylic-type and probably more heterogeneous alcoholic hydroxide-type groups at higher pH. This study shows the particularity of the deep groundwater HSs in terms of their physicochemical and ion-binding properties, compared with surface HSs.
Sasamoto, Hiroshi; Yui, Mikazu; Arthur, R. C.*
JNC-TN8400 99-033, 153 Pages, 1999/07
The results of hydrochemical investigations of groundwaters in the Kurihashi granodiorite at JNC's Kamaishi in-situ tests site indicate that these solutions are: (1)meteoric in origin, (2)chemically reducing (at depths greater than a few hundreds meters), (3)relatively young [residence times in the Kurihashi granodiorite generally less than about 40 years, but groundwaters older than several thousand years BP (before present) are also indicated by preliminary carbon-14 dating of samples obtained from the KH-1 borehole], (4)Ca-HCO type solutions near the surface, changing to Na-HCO type groundwaters with increasing depth. The evolution of groundwater compositions in the Kurihashi granodiorite is modeled assuming local equilibrium for selected mineral-fluid reactions, taking into account the rainwater origin of these solutions. Results suggest it is possible to interpret approximately the "real" groundwater chemistry (i.e., pH, Eh, total dissolved concentrations of Si, Na, Ca, K, AI, carbonate and sulfate) in the Kurihashi granodiorite if the following assumptions are adopted: (1)CO concentration in the gas phase contacting pore solutions in the overlying soil zone = 10 bar, (2)minerals in the rock zone that control the solubility of respective elements in the groundwater include; chalcedony (Si), albite (Na), kaolinite (Al), calcite (Ca and carbonate), microcline (K) and pyrite (Eh and sulfate). Discussions with international experts suggest a systematic approach utilizing reaction-path models of irreversible water-rock interactions in open systems may be needed to more realistically model groundwater evolution at the Kamaishi test site. Detailed information characterizing certain site properties (e.g., fracture mineralogy) may be required to adequately constrain such models, however.
Saito, Takumi; Terashima, Motoki; Onuki, Toshihiko
no journal, ,
Redox properties of humic substances extracted from deep sedimentary groundwater was investigated by cyclic voltammetry and bulk electrolysis with a mediator organic molecule. Reversible current-potential curves were observed with the mediator, although electrode reaction of humic substances are slow in general. The redox capacities of various humic substances exhibited positive correlation with their aromaticity; those of deep groundwater humic substances were appreciably smaller than those of surface humic substances.
Terashima, Motoki; Saito, Takumi*; Ishii, Tomoko*; Ito, Miki*; Akagi, Yosuke*; Tachi, Yukio
no journal, ,
no abstracts in English
Terashima, Motoki; Saito, Takumi*; Ito, Miki*; Akagi, Yosuke*; Tachi, Yukio
no journal, ,
no abstracts in English
Terashima, Motoki; Amano, Yuki
no journal, ,
Effects of microbial activity and coexisting cations on association of selenium (Se) with humic substance (HS) in deep groundwater were investigated by means of incubation experiments, DAX-8 extraction, and size-exclusion chromatography combined with UV-Vis and ICP-MS detections (SEC-ICP-MS). Selenite added into the groundwater was effectively reduced to elemental Se(0) by microbial activity stimulated by a nutrient. The DAX-8 extraction showed the existence of Se fraction that is extracted with HS. The SEC-ICP-MS analysis for alkaline extracts of the DAX-8 showed that the chromatogram of Se, HS and Fe are well corresponded each other, and were obtained regardless of the sterilization of groundwater. These indicate the possibility that Se can associate with HS in deep groundwater via the interaction with Fe.