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Kumagai, Yuta; Kimura, Atsushi*; Taguchi, Mitsumasa*; Watanabe, Masayuki
Radiation Physics and Chemistry, 191, p.109831_1 - 109831_8, 2022/02
Times Cited Count：0 Percentile：0.01(Chemistry, Physical)In this study, we investigated and compared the effects of a high-silica zeolite (HMOR) on the radiation-induced degradation of three aromatic chlorides, 2-chlorophenol (2-ClPh), 2-chloroaniline (2-ClAn), and 2-chlorobenzoic acid (2-ClBA), in order to examine its potential to reduce the influence of ions in water matrix in the irradiation treatment of water-soluble organic compounds. In the presence of ions reactive to radicals, the degradation of 2-ClPh in water was inhibited, but the combined use of HMOR much improved the degradation yield. This improvement was attributed to high performance of HMOR in adsorption of 2-ClPh. Similarly, HMOR was effective for adsorption of 2-ClAn and facilitated the 2-ClAn degradation by irradiation. In contrast, HMOR was poor at adsorption of 2-ClBA and consistently the degradation of 2-ClBA in the water-HMOR mixture was inhibited by the radical scavenger. These results demonstrate that HMOR can mitigate the influence of radical scavengers in water.
Taguchi, Mitsumasa*; Kumagai, Yuta; Kimura, Atsushi*
IAEA-TECDOC-1855, p.106 - 116, 2018/00
The technology for the decomposition of trace amounts of halogenated pharmaceuticals/antibiotics was developed in wastewater by use of the combination method of zeolite adsorbent and ionizing radiation. HMOR, a hydrophobic high-silica mordenite-type zeolite, was employed to concentrate 2-chlorophenol (2-ClPh) as a simple model of halogenated pharmaceuticals/antibiotics. HMOR adsorbed above 99% of 2-ClPh from dilute aqueous solutions. The yield of Cl
production in HMOR mixture corresponded to the aqueous solution containing 10 fold higher concentration of dissolved 2-ClPh. Clofibrate and triclosan, one of chlorinated pharmaceuticals/antibiotics, in real wastewater were treated by use of the combination method of HMOR and ionizing radiation. Production yield of Cl by use of the adsorbent was about twice higher than that in aqueous solution, and HMOR was contributed for effective reduction of chlorinated pharmaceuticals/antibiotics in real wastewater.
Yahata, Taneaki*; Kihara, Shinji;
JAERI-Research 96-035, 24 Pages, 1996/06
JAERI-Research-96-035.pdf:0.97MB
no abstracts in English
-ray irradiation in zeolite-water mixtureSugawara, Atsushi*; Kumagai, Yuta; Watanabe, Masayuki; Kimura, Atsushi*; Taguchi, Mitsumasa*; Fujisawa, Kiyoshi*
no journal, ,
Radiation-induced decomposition of three chlorinated aromatic compounds in zeolite-water mixture was studied, in order to evaluate decomposition yields of the aromatics adsorbed on the zeolite. The adsorption and condensation in zeolite pore structure has a possibility to improve the decomposition yield of aqueous organics in treatments of environmental water using ionizing radiations. In this study, the decomposition yields of 4-chlorophenol (4-ClPh), 4-chlorobenzoic acid (4-ClBAc), 4-chlorobenzylamine(4-ClBAm) were examined. The decomposition yield of adsorbed 4-ClBAm was lower than that in pure water. On the other hand, adsorbed 4-ClPh decomposed at a yield as high as in pure water. Moreover, a slight increase in the yield was overserved for 4-ClBAc. These results suggest that the decomposition yields of adsorbed aromatics are dependent on the reactivity with carriers of energy transfer from solid zeolite framework to water in the pore.
Kumagai, Yuta; Sugawara, Atsushi; Segawa, Yukari; Watanabe, Masayuki
no journal, ,
Nanoscale porous structure of zeolites provides attractive environment for radiation-induced reactions. Efficiency of the reactions potentially improves owing to high yields of reactive radicals inside the pores, which would lead to an application of ionizing radiation for decomposition of organic substances of concern. Hence, this study examined degradation of a chlorinated organic compound, 2-chlorophenol (2-ClPh), as a model compound in aqueous solution by the combined use of gamma irradiation and adsorption by zeolite. Degradation efficiency of 2-ClPh by irradiation was improved when a hydrophobic zeolite was used as adsorbent. On the other hand, a hydrophilic zeolite showed an insignificant effect on the degradation efficiency. The difference between these zeolites is expected to be due to different performances for adsorption of 2-ClPh. The results indicate that degradation of aqueous organics can be promoted by the use of zeolites having high performance for adsorption.
