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sp. DN11 and its potential use for removal of radioiodine from contaminated aquifersSasamura, Seiya*; Onuki, Toshihiko*; Kozai, Naofumi; Amachi, Seigo*
Frontiers in Microbiology (Internet), 14, p.1162788_1 - 1162788_7, 2023/04
Times Cited Count：2 Percentile：75.4(Microbiology) sp. DN11 previously isolated from gasoline-contaminated groundwater contained a gene cluster involved in bacterial iodate (IO
) respiration. This study determined if strain DN11 performed iodate respiration and assessed its potential use to remove and sequester radioactive iodine (
I) from subsurface contaminated aquifers. Strain DN11 grew anaerobically with iodate as the sole electron acceptor. After the growth of strain DN11 on iodate, silver-impregnated zeolite was added to the spent medium to remove iodide from the aqueous phase. In the presence of 200 
M iodate as the electron acceptor, more than 98% of iodine was successfully removed from the aqueous phase. These results suggest that strain DN11 is potentially helpful for bioaugmentation of I-contaminated subsurface aquifers.
Uesawa, Shinichiro; Shibata, Mitsuhiko; Yoshida, Hiroyuki
Konsoryu, 37(1), p.55 - 64, 2023/03
In decommissioning Fukushima Daiichi Nuclear Power Station, the issue is confinement of radioactive aerosols in the primary containment vessel. Although a High Efficiency Particulate Air (HEPA) filter is used to collect the aerosol particles, pretreatment equipment such as a scrubber may be applied to reduce the load of HEPA filters. In the scrubber, the aerosol particles are removed by moving from gas to liquid through gas-liquid interface. Since the collection efficiency (CE) depends on gas-liquid interfacial area, fine bubbles are necessary to obtain high collection efficiency. JAEA developed a new particle removal technique by using bubble breakup phenomenon in a Venturi tube. To confirm usefulness of the technique, we performed the CE measurements and observed gas-liquid two-phase flow in the Venturi tube. In comparison with a straight pipe type, the Venturi type can have removed particles more 1,000 than it. The CE is almost the same as a HEPA filter. In addition, the Venturi type has the enough CE as the pretreatment equipment for various materials of particles such as Kanto loam, SUS and oil. Besides, we clarified that the CE of the Venturi type depended on the gas and liquid flow rates. The CE increases with the increase of the liquid flow rate but decreases with the increase of the gas flow rate. This is because the CE is affected by the bubble breakup phenomenon in the Venturi tube. In the experiment, we confirmed that cavitation number which is the parameter of the bubble breakup was related to the CE of the Venturi type.
Nankawa, Takuya; Sekine, Yurina; Yamada, Teppei*
Bulletin of the Chemical Society of Japan, 95(5), p.825 - 829, 2022/05
Times Cited Count：2 Percentile：27.64(Chemistry, Multidisciplinary)Advances in hazardous metal ion removal are essential for wastewater clean-up to tackle the global water shortage crisis. Here, we report a Pb-selective adsorbent using a Tb oxalate framework (TOF) synthesized by a one-pot hydrothermal method. The TOF has a two-dimensional sheet structure, in which the interlayer space functions as an ion exchangeable site. Sorption tests using a mixed-ion solution containing Pb
, Cd, Mn, Co, Ni, Cu, Na
, K, Mg, and Ca showed that the TOF has high selectivity for Pb among other metal ions. The saturated adsorption capacity of the TOF for Pb was 276 mg g
, which is higher than that of conventional adsorbents. Furthermore, the TOF exhibited reversible Pb adsorption/desorption and could be used for at least three cycles. The results showed that TOF has excellent potential as an adsorbent for removing Pb, and because of its reusability, it is also a promising material for wastewater clean-up.
Fukushi, Keisuke*; Sasaki, Miwa*; Sato, Tsutomu*; Yanase, Nobuyuki; Amano, Hikaru; Ikeda, Hodaka*
Applied Geochemistry, 18(8), p.1267 - 1278, 2003/08
Times Cited Count：220 Percentile：95.91(Geochemistry & Geophysics)At Nishinomaki abandoned mine district, the water is acidic and contains much amounts of arsenic. However, arsenic concentration decreases downward without any artificial treatment. To understand the mechanism of the natural attenuation, the acid mine drainage and the ochreous precipitates were collected. The samples were analyzed by XRD, IR, ICP-MS and ion-chromatograph. The precipitates were investigated by selective extraction procedure. These results were interpreted with those calculated by the geochemical code. The contamination of water has been result from oxidation of pyrite and realgar and subsequent release of iron. The released ferrous iron transforms to ferric form by bacterial oxidation and then schwertmannite forms immediately. While the arsenic concentrations in the stream are lowered to background level at downstream, these in the ochreous precipitates are up to 60 mg/g. The iron hydroxide has been known to exhibit the high sorption affinity to arsenate. Hence, arsenic is effectively removed by the schwertmannite from the contaminated water and attenuated naturally.
Kojima, Takuji
Hoshasen, 29(2), p.77 - 85, 2003/04
The radiation technologies for environment conservation are useful for purification of pollutants contained in flue gas or wastewater at very low concentration which is difficult to perform by conventional methods: removal using fine filter or charcoals and decomposition using catalysis at high temperature, etc. This paper reviews some examples of radiation application to removal of SO
and NO
from coal-combustion flue gases, decomposition of dioxin in gas emitted through the incinerator, decomposition of gaseous toxic volatile organic compounds in off gas, reuse of agricultural wastes.
Odano, Naoteru; Ishida, Toshihisa
Journal of Nuclear Science and Technology, 37(Suppl.1), p.584 - 588, 2000/03
no abstracts in English
Enoeda, Mikio; Kawamura, Yoshinori; Okuno, Kenji
Fusion Technology, 30(3), p.885 - 889, 1996/12
no abstracts in English
Murakami, Yoshio
Purazuma, Kaku Yugo Gakkai-Shi, 68(5), p.467 - 479, 1992/11
no abstracts in English
Arai, T.; Yamamoto, Masahiro; Akino, N.; ; Nakamura, H.; *; ; ; Okubo, Minoru; ; et al.
Journal of Nuclear Materials, 145-147, p.686 - 690, 1987/00
Times Cited Count：6 Percentile：55.64(Materials Science, Multidisciplinary)no abstracts in English
Yamamoto, Masahiro; Nakamura, H.; ; ; Arai, T.; ; *; *; *; *; et al.
Shinku, 29(4), p.187 - 193, 1986/00
no abstracts in English
; *;
JAERI-M 7594, 113 Pages, 1978/03
no abstracts in English
;
Hoken Butsuri, 9(4), p.223 - 231, 1974/04
no abstracts in English
; ;
Hoken Butsuri, 9(2), p.81 - 86, 1974/02
no abstracts in English
Onuki, Toshihiko; Kozai, Naofumi; Sakamoto, Fuminori; Yu, Q.; Yamashita, Mitsuo*; Horiike, Takumi*; Utsunomiya, Satoshi*
no journal, ,
We have studied the elimination of Sr from sea water into biogenic calcite. Biogenic calcite were produced at 30
by a maline microbe of TK2d. SEM and TEM analyses showed that needle shaped precipitates containing Ca and Sr was formed when 1.0 mM Sr was added in the solution with TK2d strain. XAFS analysis indicates that coordination environment of Sr in the biotic coprecipitates differs from that in the abiotic one.
Kawamoto, Keisuke*; Ochiai, Asumi*; Takeda, Ayaka*; Nakano, Yuriko*; Yokoo, Hiroki*; Oki, Takumi*; Onuki, Toshihiko*; Ohara, Yoshiyuki; Fukuyama, Kenjin; Utsunomiya, Satoshi*
no journal, ,
In the Ningyo-toge uranium mine, Okayama, Japan, various toxic elements such as U, As, and Ra are present in the mine wastewaters, of which the concentration except for Ra in the wastewater decrease below the regulatory limit by transport to the slag dumping pond. The mechanisms of decreasing their concentrations in the wastewaters are not fully understood. In order to understand the fundamental processes of natural attenuation at this site, we have investigated the wastewaters and solids from upstream to the pond at the downstream. Wastewater was contacted with oxygenated water and the amount of dissolved oxygen increased. Simultaneously dissolved ferrous iron was oxidized to form ferrihydrite nanoparticles, which are associated with silica colloids, As and U. The ferrihydrite nanoparticles as suspended colloids were transported to the pond in downstream, where the waste stream is completely oxidized. In the slag dumping pond, Mn dioxide, birnessite, dominantly occurs forming a mixture with ferrihydrite + silica colloid, which has a potential to adsorb Ra. Consequently, Fe hydroxides nanoparticles and Mn dioxides in Ningyo-toge play a key role on removing U, As and Ra from the wastewater.
Yokoo, Hiroki*; Kawamoto, Keisuke*; Oki, Takumi*; Uehara, Motoki*; Onuki, Toshihiko*; Ohara, Yoshiyuki; Fukuyama, Kenjin; Hochella, M. F. Jr.*
no journal, ,
no abstracts in English
RaKato, Tomoaki; Onuki, Toshihiko; Yu, Q.*
no journal, ,
In this research, we have demonstrated the uptake of alkaline earth metals toward elimination of Ra during the formation of biomass-MnOx. I concluded that higher elimination of Ba in solution was observed at initial stage of biomass MnOx production within 2h after KMnO
addition and decreased of surf ace area associated with aggregation of colloidal MnOx occur the decreased of elimination efficiency of Ba. We also found that positive correlation is observed between the removal of alkaline earth metal and ionic radius.
