Microbially formed Mn(IV) oxide as a novel adsorbent for removal of Radium.

Radioactivity of Ra isotopes in natural waters is of serious concern. Control of Ra concentrations in tailings ponds, which store waste from U ore extraction processes, is an important issue in mill tailings management. In this study, we tested microbially formed Mn(IV) oxide as an adsorbent for removal of Ra in water treatment.

Chemical species of cesium and iodine in condensed vaporized microparticles formed by melting nuclear fuel components with concrete materials.

In this study, we report chemical species of Cs and I in condensed vaporized particles (CVPs) produced by melting experiments using nuclear fuel components containing CsI with concrete. Analyses of CVPs by SEM with EDX showed the formation of many round particles containing Cs and I of diameters less than ∼20 μm. X-ray absorption near-edge-structure and SEM-EDX analyses showed two kinds of particles: one containing large amounts of Cs and I, suggesting the presence of CsI, and the other containing small amounts of Cs and I with large Si content.

Iodate respiration by sp. DN11 and its potential use for removal of radioiodine from contaminated aquifers.

sp. DN11 was previously isolated from gasoline-contaminated groundwater as an anaerobic benzene-degrading bacterium. Genome analysis of strain DN11 revealed that it contained a putative gene cluster ( ), which was recently found to be involved in bacterial iodate (IO ) respiration.

Improvement of the Stability of IO-, SeO-, and SeO-Coprecipitated Barite after Treatment with Phosphate.

Coprecipitation of radionuclides with barite has been studied to remove radionuclides from radioactive liquid waste because of its excellent removal efficiency; however, little information exists concerning the stability of the ions coprecipitated with barite. This study systematically investigated the stability of iodate, selenite, and selenate coprecipitated with barite via leaching tests. These oxyanions were gradually leached from the oxyanion-bearing barite into ultrapure water over time.

Sewage sludge ash contaminated with radiocesium: Solidification with alkaline-reacted metakaolinite (geopolymer) and Portland cement.

This study contributes toward developing measures for the disposal of radiocesium-contaminated sewage sludge ash (SSA). Here, we prepared two types of solidified bodies containing 30 wt% radiocesium-bearing SSA. The material used for the two solidified bodies were alkaline-reacted metakaolinite (geopolymer) and ordinary Portland cement (OPC).

Radiocesium in Shiitake mushroom: Accumulation in living fruit bodies and leaching from dead fruit bodies.

In this paper, cesium (Cs) accumulation by the saprophytic fungus Lentinula edodes (Shiitake) was investigated to contribute to the elucidation of radiocesium-cycling mechanisms in forest environments. Although the Cs in the mushroom bed before culture was bioavailable, the transfer factor (TF) of Cs (Cs and Cs) from the mushroom bed to fruit bodies was low (approximately 1) and the TFs of K (5) and Na (1.5) were higher.

Effect of bacterial siderophore on cesium dissolution from biotite.

In this study, the adsorption of cesium (Cs) on biotite and dissolution of Cs from Cs-bearing biotite using a siderophore were investigated aiming to contribute to the elucidation of radiocesium migration mechanisms in the soil environment. Thus, a siderophore was extracted and purified from the culture medium of Pseudomonas sp., and the purified siderophore was used in five consecutive dissolution experiments of biotite samples.

Effective removal of iodate by coprecipitation with barite: Behavior and mechanism.

Radioactive iodine (I) is of great concern owing to its high mobility in the environment and long-term radiotoxicity. However, there is a lack of effective techniques for removing iodate (IO) from aqueous solution. This study aims to develop a new technique for removing radioactive iodate from contaminated solution by using barite (BaSO).

Spectroscopic and first-principles investigations of iodine species incorporation into ettringite: Implications for iodine migration in cement waste forms.

Low-level radioactive wastes are commonly immobilized in cementitious materials, where cement-based material can incorporate radionuclides into their crystal structure. Specifically, ettringite (CaAl(OH)(SO)∙26HO) is known to stabilize anionic species, which is appealing for waste streams with radioactive iodine (I) that persists as iodide (I-) and iodate (IO-) in the cementitious nuclear waste repository. However, the structural information and immobilization mechanisms of iodine species in ettringite remain unclear.

Reduction behaviors of permanganate by microbial cells and concomitant accumulation of divalent cations of Mg, Zn, and Co.

Permanganate treatment is widely used for disinfection of bacteria in surface-contaminated water. In this paper, the fate of the dissolved permanganate in aqueous solution after contact with cells of Pseudomonas fluorescens was studied. Concomitant accumulation of divalent cations of Mg, Zn, and Co during precipitation of Mn oxides was also studied.

Role of filamentous fungi in migration of radioactive cesium in the Fukushima forest soil environment.

The fate of radioactive Cs deposited after the Fukushima nuclear power plant accident and its associated radiological impacts are largely dependent on its mobility from surface soils to forest ecosystems. We measured the accumulation of radioactive Cs in the fruit bodies of wild fungi in a forest at Iitate, Fukushima, Japan. The transfer factors (TFs) of radioactive Cs from soil to the fruit bodies of wild fungi were between 10-2 and 102, a range similar to that reported for the fruit bodies collected in Europe after the Chernobyl accident and in parts of Japan contaminated by the nuclear bomb test fallout.

Root-endophytic Chaetomium cupreum chemically enhances aluminium tolerance in Miscanthus sinensis via increasing the aluminium detoxicants, chlorogenic acid and oosporein.

Miscanthus sinensis Andersson is a pioneer plant species that grows naturally at mining sites. Miscanthus sinensis can detoxify aluminium (Al) by producing phytosiderophores, such as chlorogenic acid, citric acid, and malic acid, and localizing Al in cell walls. Root-endophytic Chaetomium cupreum, which produces microbial siderophores, enhances Al tolerance in M.

A new technique for removing strontium from seawater by coprecipitation with barite.

Strontium (Sr) removal from seawater has recently attracted attention from an environmental perspective after the Fukushima Nuclear Power Plant accident, but there is a lack of effective removal techniques for removing Sr from seawater. In the present study, we looked at the removal efficiency of Sr by using barite (BaSO) under various experimental conditions to develop techniques for the direct removal of Sr from seawater. The effects of pH, saturation state, ionic strength, competitive ions, and [Ba]/[SO] ratio in the initial aqueous solution were examined.

A fluorometric skin-interfaced microfluidic device and smartphone imaging module for in situ quantitative analysis of sweat chemistry.

The rich composition of solutes and metabolites in sweat and its relative ease of collection upon excretion from skin pores make this class of biofluid an attractive candidate for point of care analysis. Wearable technologies that combine electrochemical sensors with conventional or emerging semiconductor device technologies offer valuable capabilities in sweat sensing, but they are limited to assays that support amperometric, potentiometric, and colorimetric analyses. Here, we present a complementary approach that exploits fluorometric sensing modalities integrated into a soft, skin-interfaced microfluidic system which, when paired with a simple smartphone-based imaging module, allows for in situ measurement of important biomarkers in sweat.

Complexation of Eu(III), Pb(II), and U(VI) with a Paramecium glycoprotein: Microbial transformation of heavy elements in the aquatic environment.

This study investigated the interaction of inorganic aqueous Eu(III), Pb(II), and U(VI) with Paramecium sp., a representative single-celled protozoan that lives in freshwater. Living and prekilled Paramecium cells were tested.

Calcium-deficient Hydroxyapatite as a Potential Sorbent for Strontium.

A calcium (Ca)-deficient hydroxyapatite was investigated for its potential to remove Sr from environmentally relevant water. We conducted sorption tests on solutions containing magnesium ion (Mg) and calcium ion (Ca) as competing cations at a strontium ion (Sr) concentration of 0.05 mmol/L.

Direct accumulation pathway of radioactive cesium to fruit-bodies of edible mushroom from contaminated wood logs.

This paper presents the accumulation process of radioactive Cs in edible mushrooms. We here first report the direct accumulation pathway of radioactive Cs from contaminated wood logs to the fruit-bodies of shiitake mushrooms through the basal portion of the stipe. In this pathway, radioactive Cs is not transported through the hyphae.

Effect of minerals on accumulation of Cs by fungus Saccaromyces cerevisiae.

The accumulation of Cs by unicellular fungus of Saccharomyces cerevisiae in the presence of minerals has been studied to elucidate the role of microorganisms in the migration of radioactive Cs in the environment. Two different types of experiments were employed: experiments using stable Cs to examine the effect of a carbon source on the accumulation of Cs, and accumulation experiments of radioactive Cs from agar medium containing (137)Cs and zeolite, vermiculite, phlogopite, smectite, mica, or illite as mineral supplements. In the former type of experiments, the Cs-accumulated cells were analyzed by scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDS).

Radioactive fallout cesium in sewage sludge ash produced after the Fukushima Daiichi nuclear accident.

The radioactive fallout cesium (¹³⁷Cs) in the sewage sludge ashes (SSAs) produced in Japan after the Fukushima Daiichi Nuclear Accident was tested. Five samples of SSAs produced in 2011 and 2012 were tested. Two of the samples contained ¹³⁷Cs (23 and 9.

Characterization of saline groundwater at Horonobe, Hokkaido, Japan by SEC-UV-ICP-MS: speciation of uranium and iodine.

The saline groundwater collected at a depth of about 500 m in Horonobe, Japan, where an underground research laboratory (URL) has been built, is rich in saline (Na 4900 ppm, Cl 7600 ppm), iodine (42 ppm), and methane gas. We analyzed the colloids and ions of this groundwater mainly by employing a size exclusion chromatography (SEC) coupled on-line to ultraviolet-visible (UV-Vis) detection and inductively coupled plasma mass spectrometry (ICP-MS) technique and focused on the speciation of uranium and iodine, both of which are of particular importance for radioactive waste disposal. For this purpose, the groundwater sample was introduced to SEC columns after being passed through a 0.

Chemical speciation and association of plutonium with bacteria, kaolinite clay, and their mixture.

We investigated the interactions of Pu(VI) with Bacillus subtilis, kaolinite clay, and a mixture of the two to determine and delineate the role of the microbes in regulating the environmental mobility of Pu. The bacteria, the kaolinite, and their mixture were exposed to a 4 x 10(-4) M Pu(VI) solution at pH 5.0.