JP3992996B2 - Wastewater treatment method and apparatus - Google Patents
Wastewater treatment method and apparatus Download PDFInfo
- Publication number
- JP3992996B2 JP3992996B2 JP2002048590A JP2002048590A JP3992996B2 JP 3992996 B2 JP3992996 B2 JP 3992996B2 JP 2002048590 A JP2002048590 A JP 2002048590A JP 2002048590 A JP2002048590 A JP 2002048590A JP 3992996 B2 JP3992996 B2 JP 3992996B2
- Authority
- JP
- Japan
- Prior art keywords
- activated carbon
- ion exchange
- water
- hydrogen peroxide
- treatment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000004065 wastewater treatment Methods 0.000 title claims description 25
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 181
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 84
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 74
- 238000011282 treatment Methods 0.000 claims description 63
- 238000005342 ion exchange Methods 0.000 claims description 37
- 239000007800 oxidant agent Substances 0.000 claims description 29
- 239000002351 wastewater Substances 0.000 claims description 20
- 239000003957 anion exchange resin Substances 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 11
- 239000003729 cation exchange resin Substances 0.000 claims description 8
- 238000000354 decomposition reaction Methods 0.000 claims description 8
- 150000001768 cations Chemical class 0.000 claims description 6
- 239000011148 porous material Substances 0.000 claims description 6
- 239000003054 catalyst Substances 0.000 claims description 4
- 239000002253 acid Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 description 11
- 239000004065 semiconductor Substances 0.000 description 9
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 7
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 229910021642 ultra pure water Inorganic materials 0.000 description 6
- 239000012498 ultrapure water Substances 0.000 description 6
- 230000002378 acidificating effect Effects 0.000 description 5
- 230000001590 oxidative effect Effects 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 238000011001 backwashing Methods 0.000 description 4
- 239000003456 ion exchange resin Substances 0.000 description 4
- 229920003303 ion-exchange polymer Polymers 0.000 description 4
- 239000012528 membrane Substances 0.000 description 4
- 238000001179 sorption measurement Methods 0.000 description 4
- 239000003638 chemical reducing agent Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000008235 industrial water Substances 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 230000008929 regeneration Effects 0.000 description 3
- 238000011069 regeneration method Methods 0.000 description 3
- 239000002349 well water Substances 0.000 description 3
- 235000020681 well water Nutrition 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 229920002125 Sokalan® Polymers 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 238000001223 reverse osmosis Methods 0.000 description 2
- GCLGEJMYGQKIIW-UHFFFAOYSA-H sodium hexametaphosphate Chemical compound [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 GCLGEJMYGQKIIW-UHFFFAOYSA-H 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- QDHHCQZDFGDHMP-UHFFFAOYSA-N Chloramine Chemical compound ClN QDHHCQZDFGDHMP-UHFFFAOYSA-N 0.000 description 1
- 235000013162 Cocos nucifera Nutrition 0.000 description 1
- 244000060011 Cocos nucifera Species 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- -1 anion ion Chemical class 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- QWPPOHNGKGFGJK-UHFFFAOYSA-N hypochlorous acid Chemical compound ClO QWPPOHNGKGFGJK-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 238000010525 oxidative degradation reaction Methods 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229940079827 sodium hydrogen sulfite Drugs 0.000 description 1
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Images
Description
【０００１】
【発明の属する技術分野】
本発明は、過酸化水素を含有する酸性の排水を高性能活性炭により処理する方法及び排水処理装置に係り、特に、高性能の活性炭に対する負荷を軽減して過酸化水素分解能を向上させるとともに高性能の活性炭の使用寿命を長くした排水処理方法及びこの方法に用いる排水処理装置に関する。
【０００２】
【従来の技術】
半導体製造工程等に使用される超純水は、一般に一次純水システムと二次純水システムを経て製造される。一次純水システムは、ろ過分離処理装置、吸着処理装置、逆浸透膜（ＲＯ）装置、紫外線酸化装置、脱気装置、イオン交換処理装置等で構成され、二次純水システムは、紫外線酸化装置、イオン交換処理装置、限外濾過装置等から構成されている。
【０００３】
一次純水システムには、原水として市水、井水、工業用水等が供給されるが、半導体製造工場等においては、半導体製造工程等で排出される排水も回収して原水として用いられている。
【０００４】
また、近年の傾向では、より水質の悪い排水でも回収して再利用して原水の市水、井水、工業用水等の使用量を可能な限り減少させた超純水システム（クローズドシステムという）が次第に用いられるようになってきており、原水中に占める半導体製造工程等で排出される排水の割合が高くなってきている。
【０００５】
一方、半導体製造工程等から排出され再使用される回収水は、半導体製造工程等で使用される各種の薬品や溶解成分が混入しているため市水、井水、工業用水とは含まれる成分が異なっている。通常、ふっ酸、硫酸、塩酸等の酸に含まれるアニオンとアンモニア等のカチオンともに、過酸化水素等の酸化剤および界面活性剤等の有機物成分（ＴＯＣ成分）が含有されている。
【０００６】
このため、この排水を回収して超純水システムの原水として用いる場合には、通常、排水処理工程を経てこれらの成分を取り除いたのち、原水として一次純水システムに供給している。
【０００７】
従来の一次純水システムの原水として用いるための排水処理装置は、主に、活性炭処理装置とイオン交換処理装置とから構成されている。
【０００８】
この排水処理において、過酸化水素等の酸化剤は活性炭処理装置で分解除去され、カチオンやアニオンのイオン成分はイオン交換処理装置で取り除かれ、ＴＯＣ成分も活性炭処理装置とイオン交換処理装置にて取り除かれる。
【０００９】
しかし、たとえば１０ｍｇ／ｌを越えるような高濃度の過酸化水素を処理する場合には、過酸化水素は活性炭処理装置で十分処理しきれず、１ｍｇ／ｌ（１ｐｐｍ）程度の過酸化水素が処理水に残留してしまうという問題があった。
【００１０】
このように過酸化水素等の酸化剤を含む処理水をそのまま原水として利用した場合、酸化剤は、一次純水システム、二次純水システムに設置されたＲＯ装置、イオン交換処理装置、限外濾過装置等の膜やイオン交換樹脂の酸化劣化を起こす上に、一次純水システム、二次純水システムを経てその末端に到達し、製造される超純水の水質（末端水質という）を悪化させる可能性があった。
【００１１】
このため、最近、このような排水処理装置に用いる活性炭として、酸化剤の分解性能の高い活性炭が用いられるようになってきている。
【００１２】
しかしながら、このような高性能の活性炭は、他の溶解成分に対しても優れた吸着能を有するため、使用寿命が非常に短く、逆洗再生を頻繁に繰り返す必要があって、排水量が増加し、ランニングコストも高くなってしまうという問題があった。
【００１３】
高性能活性炭による処理の前段で、これより分解能の低い汎用の活性炭により処理することも考えられる。
【００１４】
しかしながら、このように、高性能の活性炭の処理の前段に汎用の活性炭による処理を行った場合でも、通水につれて処理水中の過酸化水素濃度が増加して２４時間後には４０μｇ／ｌ（４０ｐｐｂ）を越えてしまうという問題があった。
【００１５】
このように過酸化水素の分解能が低下した場合でも高性能活性炭の逆洗再生を行えば過酸化水素処理性能は通水開始当初と同等に回復するが、過酸化水素処理性能を維持するためには逆洗再生を頻繁に行なわなければならないため洗浄排水が増加し、ランニングコストも増加してしまうという問題があった。
【００１６】
なお、酸化剤を処理する方法としては、亜硫酸水素ナトリウム等の還元剤を用いる処理方法も考えられるが、このような還元剤を使用した処理方法では酸化剤を完全に分解することは困難であり、処理水中に酸化剤が残留してしまう上に、多量の試薬が必要となり、さらに還元剤注入によるイオン成分の増加で末端水質が悪化してしまうという問題があった。
【００１７】
【発明が解決しようとする課題】
本発明は、上記した従来の問題を解決すべくなされたもので、過酸化水素等の酸化剤の処理性能を向上させて、回収水中の酸化剤をほぼ完全になくするとともに、活性炭処理装置の逆洗頻度を少なくして、排水を減少させ、ランニングコストも低減させた排水処理方法及び排水処理装置を提供することを目的とする。
【００１８】
【課題を解決するための手段】
本発明者は、上記の課題を解決すべく鋭意研究を重ねた結果、高性能活性炭で排水を処理する際に、排水を高性能活性炭より酸化剤に対する分解能の低い通常の活性炭で処理し、次いでイオン交換処理を行った後に、高性能の活性炭で処理するようにすると、過酸化水素等の酸化剤の分解性能が著しく向上するともに酸化剤処理性能をより長時間維持させることができることを見出した。
【００１９】
本発明は、かかる知見に基づいてなされたもので、本発明の排水処理装置は、過酸化水素その他の酸化剤を含有する酸性の排水を高性能活性炭により処理する方法において、前記排水を前記高性能活性炭より酸化剤に対する分解能の低い活性炭により処理する第１の活性炭処理工程と、前記第１の活性炭処理工程で処理した処理水を、イオン交換装置により処理するイオン交換処理工程と、前記イオン交換処理工程で処理された処理水を、前記高性能活性炭で処理する第２の活性炭処理工程と含むことを特徴としている。
【００２０】
本発明の処理対象である排水は再度原水として使用される排水であって、例えば、半導体製造工程において排出される１〜３０ｍｇ／ｌの過酸化水素、次亜塩素酸、クロラミン、オゾン等の酸化剤を含有し、ふっ酸、硫酸、塩酸等の酸を含有するｐＨ２〜５の酸性のものであるが、半導体製造工程に限らず、ほぼ同等の組成の排水であれば処理可能である。
【００２１】
本発明の第１の活性炭処理工程で使用される高性能の活性炭よりも酸化剤に対する分解能の低い活性炭は、通常の水処理に用いられているもので、例えばやし殻活性炭、石炭系活性炭等が例示される。これらの活性炭は、内部に１０〜１００００Ａ程度（その大半は１０〜２０Ａである）の細孔が無数に形成されており、５００〜１５００ｍ2 程度の比表面積を有している。なお、本明細書における活性炭の細孔分布及び比表面積は、窒素ガス（Ｎ2 ）、アルゴンガス（Ａｒ）等による吸着法もしくは水銀圧入法により測定した値である。
【００２２】
これら通常の水処理に用いられている活性炭は、純水中１０ｍｇ／ｌの過酸化水素をＳＶ＝１０ ｈ-1で通水したとき処理水中の過酸化水素を０．１〜１ｍｇ／ｌ（＝×１０００μｇ／ｌ）程度にまで減少させる分解能をもっている。なお、上記のＳＶは、空間速度(Space Velocity)の意味であり、ＳＶ＝流速（ｌ（リットル）／ｈ（時間））／充填活性炭量（ｌ）で表される。
【００２３】
本発明の第２の活性炭処理工程で用いられる活性炭は、２０〜１０００Ａの細孔の割合を１０ Ｖｏｌ％以上、好ましくは２０ Ｖｏｌ％以上に高くするか、又は白金、パラジウム、銀のような分解触媒を担持させて酸化剤に対する分解能を高くしたもので、純水中１０ｍｇ／ｌの過酸化水素をＳＶ＝１０ ｈ-1で通水したとき、処理水中の過酸化水素を５０μｇ／ｌ、好ましくは１０μｇ／ｌ、より好ましくは５μｇ／ｌ未満にまで分解する性能を有るものである。
【００２４】
細孔分布を変えて酸化剤に対する分解能を高めた活性炭としては、例えば、東洋カルゴンや米国カルゴン カーボン コーポレーション(Calgon Carbon Corporation) から販売されているセンタウ(CENTAUR)(商品名）が例示される。また、過酸化水素高分解触媒を担持させた活性炭としては、クラレケミカル株式会社製 Ｔ−ＳＢ（商品名）が例示される。
【００２５】
本発明のイオン交換処理に用いられるイオン交換装置としては、カチオン・アニオン交換樹脂を用いた混床式イオン交換塔もしくはカチオン交換樹脂を用いた単床塔とアニオン交換樹脂を用いた単床塔の組み合わせ、イオンの吸着と再生を連続的に行う電気式イオン交換樹脂装置が例示される。
【００２６】
なお、高性能活性炭の酸化剤分解性能は、被処理水のｐＨに依存し、酸性よりも中性やアルカリ性のほうが酸化剤の分解性能が高くなる。一般に、イオン交換装置として、カチオン・アニオン交換樹脂もしくはアニオン交換樹脂を用いたイオン交換処理装置の処理水のｐＨは６〜７、もしくはそれ以上になるため、高性能の活性炭装置の上流にカチオン・アニオン交換樹脂もしくはアニオン交換樹脂を用いたイオン交換処理装置を配置するようにすることによって、過酸化水素分解性能が向上する。
【００２７】
さらに、第１の活性炭処理工程、イオン交換処理工程、第２の活性炭処理工程は、必ずしも連続して行う必要は無く、他の処理工程、たとえば溶解する炭酸ガスや酸素を脱気する脱気工程、逆浸透膜等による膜処理工程、ＴＯＣ（有機質不純物等）を分解するための紫外線（ＵＶ）照射工程等を上記の処理工程の間に設けることも可能である。
【００２８】
本発明の排水処理方法は、高性能活性炭を用いた排水処理装置であって、前記高性能活性炭より酸化剤に対する分解能の低い活性炭を用いた第１の活性炭処理装置と、前記第１の活性炭処理装置の下流に配置されたイオン交換処理装置と、前記イオン交換処理装置の下流に配置された前記高性能活性炭を用いた第２の活性炭処理装置とからなる排水処理装置を用いて実行される。
【００２９】
本発明においては、第１の活性炭処理工程において、過酸化水素の相当部分が水と酸素に分解されるとともに、次段のイオン交換工程において、第２の活性炭処理工程に用いられる高性能の活性炭に対して負荷となる有機酸のようなイオン成分が除去されるので、高性能活性炭は、第１の活性炭処理工程において分解されなかった酸化剤に対して長期にわたり効果的に作用する。
【００３０】
【発明の実施の形態】
次に、本発明の実施例について詳細に説明する。
【００３１】
【実施例１】
図１は、本発明の排水処理装置の実施例である。この装置は、第１の活性炭処理装置（ＡＣ（１））１１、イオン交換処理装置（混床式イオン交換樹脂装置）１２、第２の活性炭処理装置（ＡＣ（２））１３を、それぞれ配管系１４で接続して構成されている。なお、第１の活性炭処理装置１１、イオン交換処理装置１２、第２の活性炭処理装置１３には、それぞれ次の活性炭又はイオン交換樹脂が用いられている。
第１の活性炭処理装置：Ｆ４００（商品名）（東洋カルゴン社製）２００ｌを充填；イオン交換処理装置：アニオン交換樹脂：弱塩基性アニオン交換樹脂デュオライトＡ３７８Ｄ（住友化学工業株式会社製）４０ ｌ、カチオン交換樹脂：強酸性カチオン交換樹脂デュオライトＣ−２０（ローム＆ハース社）２０ ｌ、これらの樹脂を予め再生してＨ型とＯＨ型に変換した後に混合充填したもの；第２の活性炭処理装置：センタウ（商品名）（東洋カルゴン社製）を２００ ｌ充填
【００３２】
なお、上記活性炭（Ｆ４００及びセンタウ）は、純水中１０ｍｇ／ｌの過酸化水素をＳＶ＝１０ ｈ-1で通水したとき、Ｆ４００は１１０μｇ／ｌ、センタウは０μｇ／ｌの過酸化水素分解能を有している。
【００３３】
このように構成された排水処理装置を用いて、半導体製造工程排水を模擬した次の組成の模擬排水について実験を行った。
【００３４】
模擬排水：純水に硫酸２９０ｍｇ／ｌ、フッ酸９ｍｇ／ｌ、炭酸アンモニウム２ｍｇ／ｌ、過酸化水素１０ｍｇ／ｌ、界面活性剤（ノニオン系：和光純薬（株）製 ＮＣＷ−６０１Ａ）０．１５ｍｇ／ｌを添加した水（ｐＨ２．３、導電率１８００μＳ／ｃｍ）；上記の超純水製造装置に、上記の模擬排水を、２ｍ3 ／ｈの流量で通水して第２の活性炭装置１３の入口のｐＨ及びＴＯＣ濃度を測定したところ、それぞれｐＨは６．５、ＴＯＣ濃度は０．１ｍｇ／ｌであった。また、通水４５分後の最終処理水の過酸化水素濃度を測定したところ、過酸化水素濃度は０ μｇ／ｌであった。さらに、最終処理水の過酸化水素濃度を経時的に測定したところ、表１に示す通りの結果が得られた。
【００３５】
【実施例２】
実施例１の超純水製造装置の混床型イオン交換装置１２の代わりに２塔の単床式イオン交換装置（実施例１で使用したカチオン交換樹脂の単床とアニオン交換樹脂の単床）を用いた以外は、実施例１と同一構成とした排水処理装置を用いて、実施例１と同一条件で模擬排水を通水して第２の活性炭装置の入口のｐＨ及びＴＯＣ濃度を測定したところ、それぞれｐＨは７．５、ＴＯＣ濃度は０．１ ｍｇ／ｌであった。また、通水４５分後の最終処理水の過酸化水素濃度を測定したところ、過酸化水素濃度は０ μｇ／ｌであった。さらに、最終処理水の過酸化水素濃度を経時的に測定したところ、表１に示す結果が得られた。
【００３６】
【比較例１】
実施例１で使用した装置から、活性炭処理装置２を除去した以外は、実施例１と同一構成とした装置を用いて、実施例１と同様の条件で模擬排水の処理を行い、通水４５分後の最終処理水の過酸化水素濃度を測定したところ、過酸化水素濃度は１３０ μｇ／ｌであった。さらに、最終処理水の過酸化水素濃度を経時的に測定したところ、表１に示す結果が得られた。
【００３７】
【比較例２】
実施例１で使用した装置におけるイオン交換処理装置１２と第２の活性炭処理装置１３の通水順序を逆にした点を除いて、実施例１と同一構成とした装置を用いて、実施例１と同様の条件で模擬排水を通水して第２の活性炭装置の入口のｐＨ及びＴＯＣ濃度を測定したところ、それぞれｐＨは２．４、ＴＯＣ濃度は０．１６ ｍｇ／ｌであった。また、通水４５分後の最終処理水の過酸化水素濃度を測定したところ、過酸化水素濃度は７ μｇ／ｌであった。さらに、最終処理水の過酸化水素濃度を経時的に測定したところ、表１に示す結果が得られた。
【００３８】
【表１】
【発明の効果】
以上の実施例及び比較例の結果からも明らかなように、本発明によれば、回収した排水中の酸化剤濃度を著しく低減することができ、一次純水システムへ流入する酸化剤濃度を抑制して一次純水システムへの負担を軽減することができる。
【００４０】
また、回収水中に残留した酸化剤は、一次純水装置、二次純水装置を経て末端に到達するので、この方法を用いることによって末端水質の悪化も抑制することができる。さらに、高性能活性炭の逆洗間隔が長くなるので、逆洗による排水量の抑制およびコストダウンをはかることができる。
【図面の簡単な説明】
【図１】 本発明の一実施例の排水処理装置の構成を概略的に示す図である。
【符号の説明】
１１………第１の活性炭処理装置、１２………イオン交換処理装置、１３………第２の活性炭処理装置、 １４………配管系[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and a wastewater treatment apparatus for treating acidic wastewater containing hydrogen peroxide with high-performance activated carbon, and in particular, reduces the load on high-performance activated carbon to improve hydrogen peroxide resolution and high performance. The present invention relates to a wastewater treatment method having a longer service life of activated carbon and a wastewater treatment apparatus used in this method.
[0002]
[Prior art]
Ultrapure water used in semiconductor manufacturing processes and the like is generally manufactured through a primary pure water system and a secondary pure water system. The primary pure water system is composed of a filtration separation treatment device, an adsorption treatment device, a reverse osmosis membrane (RO) device, an ultraviolet oxidation device, a deaeration device, an ion exchange treatment device, etc., and the secondary pure water system is an ultraviolet oxidation device. , An ion exchange treatment device, an ultrafiltration device, and the like.
[0003]
City water, well water, industrial water, etc. are supplied to the primary pure water system as raw water, but wastewater discharged from semiconductor manufacturing processes etc. is also collected and used as raw water in semiconductor manufacturing factories, etc. .
[0004]
Also, in recent trends, ultrapure water systems (called closed systems) that reduce the amount of municipal water, well water, industrial water, etc. used as much as possible by collecting and reusing wastewater with poor water quality. Is increasingly used, and the proportion of wastewater discharged in the semiconductor manufacturing process and the like in the raw water is increasing.
[0005]
On the other hand, the recovered water that is discharged from the semiconductor manufacturing process, etc. and reused contains various chemicals and dissolved components used in the semiconductor manufacturing process, etc., and is included in city water, well water, and industrial water. Is different. Usually, both an anion contained in an acid such as hydrofluoric acid, sulfuric acid, and hydrochloric acid and a cation such as ammonia contain an oxidant such as hydrogen peroxide and an organic component (TOC component) such as a surfactant.
[0006]
For this reason, when this waste water is recovered and used as raw water of an ultrapure water system, these components are usually removed through a waste water treatment process and then supplied to the primary pure water system as raw water.
[0007]
A waste water treatment device for use as raw water of a conventional primary pure water system is mainly composed of an activated carbon treatment device and an ion exchange treatment device.
[0008]
In this wastewater treatment, the oxidizing agent such as hydrogen peroxide is decomposed and removed by the activated carbon treatment device, the cation and anion ion components are removed by the ion exchange treatment device, and the TOC component is also removed by the activated carbon treatment device and the ion exchange treatment device. It is.
[0009]
However, when high-concentration hydrogen peroxide, for example, exceeding 10 mg / l is treated, hydrogen peroxide cannot be sufficiently treated by the activated carbon treatment apparatus, and about 1 mg / l (1 ppm) of hydrogen peroxide is treated water. There was a problem that it remained.
[0010]
In this way, when treated water containing an oxidizing agent such as hydrogen peroxide is used as raw water as it is, the oxidizing agent is used for the primary pure water system, the RO device installed in the secondary pure water system, the ion exchange treatment device, the limit In addition to causing oxidative degradation of membranes such as filtration devices and ion exchange resins, the quality of the ultrapure water produced (called terminal water quality) is deteriorated by reaching the end through the primary pure water system and the secondary pure water system. There was a possibility of letting.
[0011]
For this reason, recently, activated carbon having a high ability to decompose an oxidant has been used as the activated carbon used in such a wastewater treatment apparatus.
[0012]
However, such high-performance activated carbon has an excellent adsorption capacity for other dissolved components, so the service life is very short, and it is necessary to repeat backwash regeneration frequently. There was a problem that the running cost also became high.
[0013]
It is conceivable to treat with general-purpose activated carbon having a lower resolution than the treatment with high-performance activated carbon.
[0014]
However, even when the treatment with general-purpose activated carbon is performed before the treatment of the high-performance activated carbon in this way, the hydrogen peroxide concentration in the treated water increases as the water flows, and after 24 hours, 40 μg / l (40 ppb) There was a problem of going over.
[0015]
In this way, even if the resolution of hydrogen peroxide is reduced, the performance of hydrogen peroxide treatment recovers to the same level as the beginning of water flow if backwashing of high-performance activated carbon is performed. However, there is a problem that the drainage of washing increases and the running cost also increases because backwash regeneration must be performed frequently.
[0016]
As a method for treating the oxidizing agent, a treating method using a reducing agent such as sodium hydrogen sulfite is also conceivable, but it is difficult to completely decompose the oxidizing agent by such a treating method using a reducing agent. In addition, the oxidizing agent remains in the treated water, and a large amount of reagent is required. Further, there is a problem that the quality of the terminal water is deteriorated due to an increase in ion components due to the injection of the reducing agent.
[0017]
[Problems to be solved by the invention]
The present invention has been made to solve the above-described conventional problems, improves the treatment performance of oxidants such as hydrogen peroxide, eliminates oxidants in recovered water almost completely, An object of the present invention is to provide a wastewater treatment method and a wastewater treatment apparatus that reduce the frequency of backwashing, reduce wastewater, and reduce running costs.
[0018]
[Means for Solving the Problems]
As a result of intensive research to solve the above-mentioned problems, the present inventor treated wastewater with ordinary activated carbon having a lower resolution to oxidizing agents than high-performance activated carbon when treating wastewater with high-performance activated carbon, It was found that, after ion exchange treatment, treatment with high-performance activated carbon significantly improved the decomposition performance of oxidants such as hydrogen peroxide and maintained the oxidizer treatment performance for a longer time. .
[0019]
The present invention has been made based on such knowledge, and the waste water treatment apparatus of the present invention is a method for treating acidic waste water containing hydrogen peroxide and other oxidizing agents with high-performance activated carbon, wherein A first activated carbon treatment step for treating with activated carbon having a lower resolution than an activated carbon, an ion exchange treatment step for treating the treated water treated in the first activated carbon treatment step with an ion exchange device, and the ion exchange The treatment water treated in the treatment step includes the second activated carbon treatment step of treating with the high-performance activated carbon.
[0020]
The wastewater to be treated according to the present invention is wastewater that is used again as raw water, for example, 1 to 30 mg / l of hydrogen peroxide, hypochlorous acid, chloramine, ozone, etc. discharged in the semiconductor manufacturing process. Although it is an acidic one having a pH of 2 to 5 containing an agent such as hydrofluoric acid, sulfuric acid, hydrochloric acid, etc., it is not limited to the semiconductor manufacturing process and can be treated as long as it has substantially the same composition.
[0021]
The activated carbon having a lower resolution with respect to the oxidizing agent than the high-performance activated carbon used in the first activated carbon treatment step of the present invention is used for ordinary water treatment, such as coconut shell activated carbon, coal-based activated carbon, etc. Is exemplified. These activated carbons have innumerable pores of about 10 to 10000 A (most of which are 10 to 20 A) inside and have a specific surface area of about 500 to 1500 m 2 . In addition, the pore distribution and specific surface area of the activated carbon in this specification are values measured by an adsorption method using a nitrogen gas (N 2 ), an argon gas (Ar) or the like, or a mercury intrusion method.
[0022]
The activated carbon used for these normal water treatments is 0.1 to 1 mg / l of hydrogen peroxide in treated water when 10 mg / l of hydrogen peroxide in pure water is passed at SV = 10 h −1. = × 1000 μg / l). In addition, said SV is the meaning of space velocity (Space Velocity), and is represented by SV = flow velocity (l (liter) / h (time)) / filled activated carbon amount (l).
[0023]
The activated carbon used in the second activated carbon treatment step of the present invention increases the proportion of pores of 20 to 1000 A to 10 Vol% or more, preferably 20 Vol% or more, or like platinum, palladium, silver, etc. The decomposition catalyst is supported to increase the resolution with respect to the oxidizing agent. When 10 mg / l of hydrogen peroxide in pure water is passed at SV = 10 h −1 , the hydrogen peroxide in the treated water is 50 μg / l, It preferably has the ability to decompose to 10 μg / l, more preferably to less than 5 μg / l.
[0024]
Examples of the activated carbon that has improved pore resolution and improved resolution to the oxidizing agent include CENTAUR (trade name) sold by Toyo Calgon and Calgon Carbon Corporation. Moreover, as activated carbon which carried | supported the hydrogen peroxide high decomposition catalyst, Kuraray Chemical Co., Ltd. T-SB (brand name) is illustrated.
[0025]
The ion exchange apparatus used for the ion exchange treatment of the present invention includes a mixed bed type ion exchange tower using a cation / anion exchange resin or a single bed tower using a cation exchange resin and a single bed tower using an anion exchange resin. An electric ion exchange resin apparatus that continuously performs combination, ion adsorption and regeneration is exemplified.
[0026]
In addition, the oxidizing agent decomposition performance of high-performance activated carbon depends on the pH of the water to be treated, and neutral and alkaline decomposition performance of oxidizing agent is higher than acidic. In general, as an ion exchange apparatus, the pH of treated water of a cation / anion exchange resin or an ion exchange treatment apparatus using an anion exchange resin is 6 to 7 or more, so that a cation / anion exchange resin is placed upstream of a high-performance activated carbon apparatus. By disposing an anion exchange resin or an ion exchange treatment apparatus using an anion exchange resin, the hydrogen peroxide decomposition performance is improved.
[0027]
Furthermore, the first activated carbon treatment step, the ion exchange treatment step, and the second activated carbon treatment step are not necessarily performed continuously, and other treatment steps, for example, a deaeration step for degassing dissolved carbon dioxide and oxygen. It is also possible to provide a membrane processing step using a reverse osmosis membrane or the like, an ultraviolet (UV) irradiation step for decomposing TOC (organic impurities, etc. ) , etc. between the above processing steps.
[0028]
The waste water treatment method of the present invention is a waste water treatment apparatus using high-performance activated carbon, and includes a first activated carbon treatment apparatus using activated carbon having a lower resolution against an oxidizing agent than the high-performance activated carbon, and the first activated carbon treatment. This is carried out using a wastewater treatment device comprising an ion exchange treatment device arranged downstream of the device and a second activated carbon treatment device using the high-performance activated carbon arranged downstream of the ion exchange treatment device.
[0029]
In the present invention, in the first activated carbon treatment step, a substantial portion of hydrogen peroxide is decomposed into water and oxygen, and in the next ion exchange step, high-performance activated carbon used in the second activated carbon treatment step. Since an ionic component such as an organic acid serving as a load is removed, the high-performance activated carbon effectively acts over a long period against an oxidizing agent that has not been decomposed in the first activated carbon treatment step.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Next, examples of the present invention will be described in detail.
[0031]
[Example 1]
FIG. 1 shows an embodiment of the waste water treatment apparatus of the present invention. In this apparatus, a first activated carbon treatment device (AC (1)) 11, an ion exchange treatment device (mixed bed ion exchange resin device) 12, and a second activated carbon treatment device (AC (2)) 13 are respectively piped. The
First activated carbon treatment device: F400 (trade name) (made by Toyo Calgon Co., Ltd.) 200 l filled ; ion exchange treatment device: anion exchange resin: weakly basic anion exchange resin Duolite A378D (Sumitomo Chemical Co., Ltd.) 40 l Cation exchange resin: Strongly acidic cation exchange resin Duolite C-20 (Rohm & Haas) 20 l, mixed and filled with these resins after being regenerated in advance and converted to H type and OH type ; second activated carbon Processing equipment: 200 l of Centau (trade name) (manufactured by Toyo Calgon Co., Ltd.)
The activated carbon (F400 and Centau) has a hydrogen peroxide resolution of 110 μg / l for F400 and 0 μg / l for Centau when 10 mg / l hydrogen peroxide in pure water is passed at SV = 10 h −1. have.
[0033]
Using the wastewater treatment apparatus configured as described above, an experiment was conducted on simulated wastewater having the following composition simulating semiconductor manufacturing process wastewater.
[0034]
Simulated wastewater: 290 mg / l sulfuric acid in pure water, 9 mg / l hydrofluoric acid, 2 mg / l ammonium carbonate, 10 mg / l hydrogen peroxide, surfactant (nonionic: NCW-601A manufactured by Wako Pure Chemical Industries, Ltd.) Water added with 15 mg / l (pH 2.3, conductivity 1800 μS / cm) ; the simulated activated water was passed through the ultrapure water production device at a flow rate of 2 m 3 / h, and the second activated carbon device When the pH and TOC concentration at 13 inlets were measured, the pH was 6.5 and the TOC concentration was 0.1 mg / l, respectively. Further, when the hydrogen peroxide concentration of the final treated water after 45 minutes of water flow was measured, the hydrogen peroxide concentration was 0 μg / l. Furthermore, when the hydrogen peroxide concentration of the final treated water was measured over time, the results shown in Table 1 were obtained.
[0035]
[Example 2]
Single bed
[0036]
[Comparative Example 1]
Except for removing the activated
[0037]
[Comparative Example 2]
Example 1 using an apparatus having the same configuration as Example 1 except that the water exchange order of the ion
[0038]
[Table 1]
【The invention's effect】
As is clear from the results of the above examples and comparative examples, according to the present invention, the oxidant concentration in the recovered waste water can be significantly reduced, and the oxidant concentration flowing into the primary pure water system is suppressed. Thus, the burden on the primary pure water system can be reduced.
[0040]
Further, since the oxidant remaining in the recovered water reaches the end through the primary pure water device and the secondary pure water device, deterioration of the end water quality can be suppressed by using this method. Furthermore, since the backwashing interval of the high-performance activated carbon becomes long, the amount of drainage by backwashing and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a configuration of a wastewater treatment apparatus according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF
Claims (6)
前記排水を前記高性能活性炭より酸化剤に対する分解能の低い活性炭により処理する第１の活性炭処理工程と、
前記第１の活性炭処理工程で処理した処理水を、イオン交換装置により処理するイオン交換処理工程と、
前記イオン交換処理工程で処理された処理水を、前記高性能活性炭で処理する第２の活性炭処理工程とを含むことを特徴とする排水処理方法。Acid waste water containing hydrogen peroxide and other oxidizing agents is treated with 10 mg / l hydrogen peroxide in pure water at SV = 10 In a method of treating with high-performance activated carbon having a resolution for an oxidizing agent that reduces hydrogen peroxide in treated water to less than 10 μg / l when water is passed at h −1 ,
A first activated carbon treatment step in which the waste water is treated with activated carbon having a lower resolution with respect to an oxidizing agent than the high-performance activated carbon;
An ion exchange treatment step of treating the treated water treated in the first activated carbon treatment step with an ion exchange device;
A wastewater treatment method comprising: a second activated carbon treatment step of treating the treated water treated in the ion exchange treatment step with the high-performance activated carbon.
前記高性能活性炭より酸化剤に対する分解能の低い活性炭を用いた第１の活性炭処理装置と、
前記第１の活性炭処理装置の下流に配置されたイオン交換処理装置と、
前記イオン交換処理装置の下流に配置された前記高性能活性炭を用いた第２の活性炭処理装置とからなることを特徴とする排水処理装置。 10 mg / l hydrogen peroxide in pure water with SV = 10 a wastewater treatment apparatus using high-performance activated carbon having a resolution with respect to an oxidizing agent that reduces hydrogen peroxide in treated water to less than 10 μg / l when water is passed at h −1 ;
A first activated carbon treatment apparatus using activated carbon having a lower resolution for oxidizing agents than the high-performance activated carbon;
An ion exchange treatment device disposed downstream of the first activated carbon treatment device;
A wastewater treatment apparatus comprising a second activated carbon treatment apparatus using the high-performance activated carbon disposed downstream of the ion exchange treatment apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002048590A JP3992996B2 (en) | 2002-02-25 | 2002-02-25 | Wastewater treatment method and apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002048590A JP3992996B2 (en) | 2002-02-25 | 2002-02-25 | Wastewater treatment method and apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003245659A JP2003245659A (en) | 2003-09-02 |
| JP3992996B2 true JP3992996B2 (en) | 2007-10-17 |
Family
ID=28661350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002048590A Expired - Lifetime JP3992996B2 (en) | 2002-02-25 | 2002-02-25 | Wastewater treatment method and apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3992996B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4977970B2 (en) * | 2005-06-22 | 2012-07-18 | ダイキン工業株式会社 | Method for producing nonionic surfactant aqueous composition |
| JP2007185581A (en) * | 2006-01-12 | 2007-07-26 | Nomura Micro Sci Co Ltd | Purification method and purification apparatus for oxidizing agent |
| JP5232059B2 (en) * | 2009-03-27 | 2013-07-10 | 日本錬水株式会社 | Wastewater recovery method and wastewater recovery device |
| JP7065723B2 (en) * | 2018-07-31 | 2022-05-12 | オルガノ株式会社 | Water treatment system, its operation method, and protection device |
-
2002
- 2002-02-25 JP JP2002048590A patent/JP3992996B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2003245659A (en) | 2003-09-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0634364B1 (en) | Pure water manufacturing method | |
| JP5617231B2 (en) | Method and apparatus for purifying ion exchange resin | |
| JPH0790219B2 (en) | Pure water production apparatus and production method | |
| JP2003205299A (en) | Hydrogen dissolved water manufacturing system | |
| KR101476864B1 (en) | Method and apparatus for removing organic matters | |
| JP3864934B2 (en) | Pure water production equipment | |
| JP4447212B2 (en) | Ultrapure water production method and ultrapure water production apparatus | |
| JP2000354729A5 (en) | ||
| JP5320723B2 (en) | Ultrapure water manufacturing method and apparatus, and electronic component member cleaning method and apparatus | |
| JP5499433B2 (en) | Ultrapure water manufacturing method and apparatus, and electronic component member cleaning method and apparatus | |
| JP3992996B2 (en) | Wastewater treatment method and apparatus | |
| JPH0649190B2 (en) | High-purity water manufacturing equipment | |
| JP4810757B2 (en) | Ultrafiltration membrane for ultrapure water production and its pre-cleaning method | |
| JP2000301005A (en) | Method for reutilizing effluent in regeneration of ion exchange resin | |
| US20060201882A1 (en) | Method and system for treating wastewater containing hydrogen peroxide | |
| JPH07313994A (en) | Production of ultrapure water | |
| WO2022024815A1 (en) | Pure water production apparatus, ultrapure water production apparatus, pure water production method, and ultrapure water production method | |
| JP2007098268A (en) | Method and apparatus for disposing waste water | |
| JPH10202296A (en) | Ultrapure water producer | |
| JP3259557B2 (en) | How to remove organic matter | |
| JP5782675B2 (en) | Water treatment method and ultrapure water production method | |
| JP3727156B2 (en) | Desalination equipment | |
| JP3304412B2 (en) | Pure water production method | |
| JP3528287B2 (en) | Pure water production method | |
| JP7171671B2 (en) | Ultrapure water production system and ultrapure water production method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050131 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20061226 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070109 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070226 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20070226 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20070724 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070725 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 3992996 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100803 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110803 Year of fee payment: 4 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110803 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120803 Year of fee payment: 5 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130803 Year of fee payment: 6 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |