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Seko, Noriaki; Kasai, Noboru; Shimizu, Takao*; Tamada, Masao
Nihon Kaisui Gakkai-Shi, 59(5), p.316 - 319, 2005/10
Braid adsorbent having functional group of amidoxime is a promising material for the recovery of uranium dissolved in the seawater. This long braid adsorbent was made by polyethylene multi-fibers in which amidoxime groups were introduced by radiation-induced graft polymerization and subsequent chemical treatment. The braid adsorbent obtained was moored at the offing of Okinawa Island. The average U adsorption of the adsorbent became 1.5 g-U/kg-adsorbent for 30 d soaking. The mooring system for braid adsorbent has possibility which reduced the cost for the recovery of uranium from seawater. Annual product of 1200 tons of uranium needs 134 km
of mooring area. In addition, there is 6000 km and more of suitable sea area for the collection of the uranium in the regions from Okinawa Islands to Tosa Bay in Japan.
Seko, Noriaki; Tamada, Masao; Yoshii, Fumio
Nuclear Instruments and Methods in Physics Research B, 236(1-4), p.21 - 29, 2005/07
Times Cited Count：104 Percentile：98.76(Instruments & Instrumentation)Removal of toxic metals from streaming water and ground water is important task to preserve environment. Radiation processings of grafting and crosslinking can synthesis adsorbent having high performances. Graft adsorbent can be synthesized by using the conventional polymer like polyethylene having variety shapes such as membrane, cloth, and fiber. Especially, the obtained fibrous adsorbent has 100 times higher rate of adsorption than that of commercialized resin. Novel fibrous adsorption for arsenic was synthesized by direct grafting of phosphoric monomer and following zirconium-loading. Fibrous adsorbents of amidoxime and iminodiacetate were applied to the removal of cadmium from the scallop waste. Furthermore, the amidoxime adsorbent is useful to recover rare metal such as uranium and vanadium in seawater. Crosslinked natural polymers like chitin-chitosan in the paste-like state are applicable for the metal adsorbent. This adsorbent can be biodegraded after usage.
Katakai, Akio; Tamada, Masao; Nagamoto, Hiroyuki*; Miyagawa, Hiroshi*
Nihon Ion Kokan Gakkai-Shi, 16(2), p.122 - 126, 2005/05
A chelating fiber containing an amidoxime group as a chelate-forming group was prepared by radiation-induced cograft polymerization of acrylonitrile and methacrylic acid and subsequent conversion of the produced cyano group into the amidoxime group. The effect of repeated use of monomers for radiation-induced graft copolymerization on the composition of the graft chain and its adsorption capacity for metal ions was determined. The degree of cografting decreased by as low as 10% at the fourth cycle of cografting, compared with an initial degree of cografting of 170%, because the amount of homopolymer formed in cografting was negligibly small at 0.15 g/L of the monomer solution. The repeated use of monomers did not affect the amidoxime group density and the adsorption capacities of zinc and cadmium ions, resulting in the cost reduction of the preparation of the chelating fiber.
Tamada, Masao; Seko, Noriaki; Kasai, Noboru; Shimizu, Takao*
FAPIG, (169), p.3 - 12, 2005/03
Braid adsorbent having functional group of amidoxime is a promising material for the recovery of uranium dissolved in the seawater. This braid adsorbent was made by polyethylene multi-fibers in which amidoxime groups were introduced by radiation-induced graft polymerization and subsequent chemical treatment. Reaction time for graft polymerization was 5 h and the resulted braid adsorbent had 2.8 mmol/g-adsorbent of amidoxime group. The braid adsorbent obtained was moored at the offing of Okinawa Island. The adsorption of uranium reached 1.5g/kg-adsorbent for 30 d soaking. The mooring system for braid adsorbent has possibility which reduced the cost for the recovery of uranium from seawater. It is shown that 134 km of mooring area is needed for annual product of 1200 tons of uranium. In addition, there is 6000 km and more of suitable sea area for the collection of the uranium in the regions from Okinawa Islands to Tosa Bay in Japan.
Seko, Noriaki; Kasai, Noboru; Tamada, Masao; Hasegawa, Shin; Katakai, Akio; Sugo, Takanobu*
JAERI-Tech 2004-076, 78 Pages, 2005/01
JAERI-Tech-2004-076.pdf:17.11MB
In September 1999, we have soaked 200 kg of fibrous amidoxime adsorbents, synthesized by radiation-induced graft polymerization, into seawater to evaluate their performance. Fractional elution facility was set effectively to elute the rare metals on adsorbents in Mutsu-Establishment. This facility consists of two parts of pre-washing and elution. The present report dealt with planning, manufacture and setting of fractional facility. Marine organism and slime on adsorbent cassette (290
290160 mm) were washed out and every 72 cassettes were set in elution unit (12101210H1460 mm) with nonwoven materials as a packing to avoid elution loss. In the elution process alkaline and alkaline earth metals were eluted with low concentration hydrochloric acid (0.01M) and rare metals were eluted with high concentration (0.5M) after the packing of elution unit into fractional elution facility.
Seko, Noriaki; Tamada, Masao; Yoshii, Fumio
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(4), p.340 - 345, 2004/12
Fibrous adsorbents having chelate agent such as amidoxime (AN/MAA-ad), iminodiacetic acid (IDA-ad), and phosphoric acid (HMPA-ad) were prepared by radiation-induced graft polymerization. AN/MAA-ad was synthesized by co-grafting of acrylonitrile and methacrylic acid. Then the introduced functional group of CN was converted to the amidoxime with chemical treatment. Grafting of glycidyl methacrylate and chemically introducing the IDA group synthesized IDA-ad. HMPA-ad was directly synthesized by grafting of phosphoric acid monomer. The densities of the chelate agency were 3.5 mol/kg for AN/MAA-ad, 2.0 mol/kg for IDA-ad and 2.0 mol/kg for HMPA-ad after the grafting time of 2, 1.5 and 8 hours, respectively. HMPA-ad had 200 times higher distribution coefficient for uranium than that of a commercial adsorbent (Diaion-PK216) at pH 0.5. The distribution coefficient for AN/MAA-ad became 500 times higher than that of Diaion-CR11 more than pH 8. These chelate adsorbents are promising materials for removal of uranium from acid or alkali treated waste sludge contaminated uranium.
Seko, Noriaki; Tamada, Masao; Kasai, Noboru; Yoshii, Fumio; Shimizu, Takao*
Kaiyo Kaihatsu Rombunshu, 20, p.611 - 616, 2004/06
Development of the recovery technology of uranium of storing all over seawater can stable supply of mineral resources over the future. The amidoxime adsorbents used by nonwoven fiber of the shape of cloth produced by the radiation graft polymerization technique. It became clear that their adsorbents of the high form of contact efficiency with seawater are important. Therefore, the braid adsorbents by which contact efficiency with seawater is improved were devised. Moreover, by the mooring system using braid adsorbents, since it counted upon lightweight-ization, i.e., rationalization of the marine structure which occupies the great portion of total cost, in this research, while developing the producing method, performance evaluation was performed, and the production method and the applicability of a recovery system were examined.
Seko, Noriaki; Katakai, Akio; Tamada, Masao; Sugo, Takanobu*; Yoshii, Fumio
Separation Science and Technology, 39(16), p.3753 - 3767, 2004/00
Times Cited Count：82 Percentile：89.98(Chemistry, Multidisciplinary)Fibrous amidoxime adsorbents were prepared by radiation-induced co-grafting of acrylonitrile (AN) and methacrylic acid (MAA) and subsequent amidoximation. Adsorption of uranium in seawater was evaluated by pumping seawater into the adsorbent column. The best monomer ratio of AN and MAA was 7:3 for continual usage of uranium adsorption. Though hydrochloric acid is an effective eluting agent for the metals adsorbed on the adsorbent, amidoxime groups were simultaneously damaged after five cycles of adsorption-desorption. This deterioration was reduced by an alkaline treatment of the adsorbents after each elution. Furthermore, various organic acids were examined as elution agents. It was found that the 80% of adsorption activity was still maintained after five cycles of adsorption-desorption when tartaric acid was used for eluting agent.
Seko, Noriaki; Tamada, Masao; Sugo, Takanobu
Kaiyo Kaihatsu Nyusu, 31(1), p.8 - 11, 2003/04
no abstracts in English
Shiraishi, Tomoyuki*; Tamada, Masao; Saito, Kyoichi*; Sugo, Takanobu
Radiation Physics and Chemistry, 66(1), p.43 - 47, 2003/01
Times Cited Count：50 Percentile：93.91(Chemistry, Physical)no abstracts in English
Tamada, Masao
Enerugi Rebyu, 22(4), p.24 - 26, 2002/03
The Black Current conveys 5.2 million tons of uranium toward the offing of Japan, though uranium concentration is only 3.3 ppb in seawater. Recovery of 0.2% of this resources can supply the uranium for all atomic power plants in Japan. Graft polymerization is a promising technique to prepare adsorbent having high selectivity to uranium in seawater and enough durability in severe sea conditions. To evaluate the activity of the adsorbents the equipment for the recovery of rare metals from seawater was set at the 7 km offing of Mutsu-Sekine, Aomori prefecture on September, 1999. In three years (1999 - 2001) 9 mooring experiments of adsorbents were carried out and 1 kg uranium as yellow cake was recovered. This experiment suggested that hydrophilic monomer and trunk polymer should be improved to realized the higher activity for uranium recovery from seawater.
Katakai, Akio; Seko, Noriaki; *; *; Sugo, Takanobu
Nihon Kaisui Gakkai-Shi, 53(3), p.180 - 184, 1999/06
no abstracts in English
Katakai, Akio; Seko, Noriaki; *; *; Sugo, Takanobu
Nihon Genshiryoku Gakkai-Shi, 40(11), p.878 - 880, 1998/00
Times Cited Count：24 Percentile：85.15(Nuclear Science & Technology)no abstracts in English
*; Katakai, Akio; Sugo, Takanobu; *
Journal of Applied Polymer Science, 49, p.599 - 607, 1993/00
Times Cited Count：59 Percentile：89.92(Polymer Science)no abstracts in English
Omichi, Hideki; Katakai, Akio; Okamoto, Jiro
Sep. Sci. Technol., 23(14-15), p.2445 - 2450, 1988/00
Times Cited Count：4 Percentile：67.83(Chemistry, Multidisciplinary)no abstracts in English
; Katakai, Akio; ;
Sep.Sci.Technol., 21(3), p.299 - 313, 1986/00
Times Cited Count：72 Percentile：95.24(Chemistry, Multidisciplinary)no abstracts in English
; Katakai, Akio; ;
Sep.Sci.Technol., 21(6-7), p.563 - 574, 1986/00
Times Cited Count：73 Percentile：95.37(Chemistry, Multidisciplinary)no abstracts in English
; ; Katakai, Akio;
J.Appl.Polym.Sci., 30, p.2967 - 2977, 1985/00
Times Cited Count：104 Percentile：96.81(Polymer Science)no abstracts in English
; Katakai, Akio; ;
Sep.Sci.Technol., 20(2-3), p.163 - 178, 1985/00
Times Cited Count：80 Percentile：96.1(Chemistry, Multidisciplinary)no abstracts in English
