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Takeshi Itakura Kazumasa Hirata Masanori Aoki Ryo Sasai Hisao Yoshida Hideaki Itoh 《Environmental Chemistry Letters》2009,7(4):343-345
We demonstrated a complete decomposition method for ionic liquids (ILs; organic cation part: butyl-methyl or ethyl-methyl
imidazolium, and inorganic anion part: PF6 −, BF4
− or Br−) in aqueous media by combining a hydrothermal mineralization method with a photocatalytic decomposition (PD) method. As a
result, the hydrothermal treatment with Ca(OH)2 mineralizer could effectively remove the inorganic anion part, such as PF6
− or BF4
− and the PD could decompose the organic cation part effectively. Therefore, the detoxification of ILs in aqueous media was
accomplished by the present method. 相似文献
2.
Arsenic accumulation in duckweed (Spirodela polyrhiza L.): a good option for phytoremediation 总被引:2,自引:0,他引:2
Some unavoidable drawbacks of traditional technologies have made phytoremediation a promising alternative for removal of arsenic from contaminated soil and water. In the present study, the potential of an aquatic macrophyte Spirodela polyrhiza L. for phytofiltration of arsenic, and the mechanism of the arsenic uptake were investigated. The S. polyrhiza L. were grown in three test concentrations of arsenate and dimethylarsinic acid (DMAA) (i.e. 1.0, 2.0 and 4.0microM) with 0 (control), 100 or 500microM of phosphate. One control treatment was also set for each test concentrations of arsenic. The PO(4)(3-) concentration in control treatment was 0.02microM. When S. polyrhiza L. was cultivated hydroponically for 6d in culture solution containing 0.02microM phosphate and 4.0microM arsenate or DMAA, the arsenic uptake was 0.353+/-0.003micromolg(-1) and 7.65+/-0.27nmolg(-1), respectively. Arsenic uptake into S. polyrhiza L. was negatively (p<0.05) correlated with phosphate uptake when arsenate was applied to the culture solutions owing to similar in the sorption mechanism between AsO(4)(3-) and PO(4)(3-), and positively (p<0.05) correlated with iron uptake due to adsorption of AsO(4)(3-) onto iron oxides. Thus, the S. polyrhiza L. accumulates arsenic by physico-chemical adsorption and via the phosphate uptake pathway when arsenate was added to the solutions. These results indicate that S. polyrhiza L. would be a good arsenic phytofiltrator. In contrast, DMAA accumulation into S. polyrhiza L. was neither affected by the phosphate concentration in the culture nor correlated (p>0.05) with iron accumulation in plant tissues, which indicates that S. polyrhiza L. uses different mechanisms for DMAA uptake. 相似文献
3.
Okamoto Taka-aki Tanaka Kenta Matsumoto Kazumasa Someya Tomohiro 《Environmental Fluid Mechanics》2021,21(3):693-711
Environmental Fluid Mechanics - Transport of driftwood during heavy rainfall events can intensify the flood hazard. Driftwood accumulates at a bridge and backwater rises. Accumulated logs sink... 相似文献
4.
Wittaya Chuajiw Mitsuru Nakano Kazumasa Takatori Toshiya Kojim Yoshiki Wakimoto Yoshiaki Fukushima 《环境科学学报(英文版)》2013,25(12):2507-2515
The amount of carbon dioxide (CO2) absorption and calcium ion (Ca^2+) concentration besides the pH of aqueous solution were observed during the COz absorption to precipitate calcium carbonate (CaCO3) from calcium hydroxide (Ca(OH)2). A reaction rate-limiting effect of an amount of CO2 absorption without any organic additives in the early stage of the precipitation was observed, which was attributed to an interruption effect of bicarbonate ion (HCO3) on the precipitation of CaCO3. The improvement for the reaction rate was achieved not only by amine additives but also by neutral additives such as ε-caprolactam or amine salt. When the hexamethylene diamine was dissolved in the solution, successive change of crystal forms of CaCO3 aragonite to calcite in aqueous suspensions, confirmed by Ca^2+ concentration change and X-ray diffraction, was concluded that a local environment around the amine group in aqueous solution and an interaction of the diamine with precipitated CaCO3 particles were important factors for these reactions. 相似文献
5.
Evaluation of antimicrobial agents for veterinary use in the ecotoxicity test using microalgae 总被引:12,自引:0,他引:12
Eguchi K Nagase H Ozawa M Endoh YS Goto K Hirata K Miyamoto K Yoshimura H 《Chemosphere》2004,57(11):1733-1738
The influence of antimicrobial agents approved as veterinary drugs in Japan on the growth of green algae, Selenastrum capricornutum and Chlorella vulgaris, was studied in accordance with the OECD guidelines for testing chemicals. Among the agents tested, growth inhibitory activity was very varied, i.e. erythromycin showed the strongest activity (EC50, 50% effective concentration, =0.037 mg/l), sulfa drugs had activity to some extent (EC50s of sulfamethoxazole, sulfadiazine, and sulfadimethoxine were 1.5, 2.2, and 2.3 mg/l, respectively), but ampicillin and cefazolin did not inhibit growth (EC50s > 1000 mg/l). We also investigated synergistic effect of combining sulfa drugs with trimethoprim or pyrimethamine, which are commonly used as a combined drug. By adding trimethoprim, the growth inhibitory activity of sulfamethoxazole and sulfadiazine was significantly enhanced. Growth inhibition by sulfa drugs was reduced by the addition of folic acid, indicating that they inhibit folate synthesis in green algae. 相似文献
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