JP3826497B2 - Pure water production method - Google Patents
Pure water production method Download PDFInfo
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- JP3826497B2 JP3826497B2 JP16738997A JP16738997A JP3826497B2 JP 3826497 B2 JP3826497 B2 JP 3826497B2 JP 16738997 A JP16738997 A JP 16738997A JP 16738997 A JP16738997 A JP 16738997A JP 3826497 B2 JP3826497 B2 JP 3826497B2
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- water
- pure water
- membrane separation
- chelating agent
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims description 59
- 238000004519 manufacturing process Methods 0.000 title claims description 22
- 239000012528 membrane Substances 0.000 claims description 36
- 239000002738 chelating agent Substances 0.000 claims description 25
- 238000001223 reverse osmosis Methods 0.000 claims description 25
- 238000000926 separation method Methods 0.000 claims description 24
- 238000001471 micro-filtration Methods 0.000 claims description 10
- 239000003513 alkali Substances 0.000 claims description 6
- 239000005749 Copper compound Substances 0.000 claims 2
- 150000001880 copper compounds Chemical class 0.000 claims 2
- UEUXEKPTXMALOB-UHFFFAOYSA-J tetrasodium;2-[2-[bis(carboxylatomethyl)amino]ethyl-(carboxylatomethyl)amino]acetate Chemical group [Na+].[Na+].[Na+].[Na+].[O-]C(=O)CN(CC([O-])=O)CCN(CC([O-])=O)CC([O-])=O UEUXEKPTXMALOB-UHFFFAOYSA-J 0.000 claims 1
- 239000010949 copper Substances 0.000 description 35
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 24
- 238000006114 decarboxylation reaction Methods 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 8
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000003638 chemical reducing agent Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 3
- 239000000460 chlorine Substances 0.000 description 3
- 229910052801 chlorine Inorganic materials 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 3
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 230000001954 sterilising effect Effects 0.000 description 2
- 238000004659 sterilization and disinfection Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000011001 backwashing Methods 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000013522 chelant Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 239000008235 industrial water Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 238000006864 oxidative decomposition reaction Methods 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910021642 ultra pure water Inorganic materials 0.000 description 1
- 239000012498 ultrapure water Substances 0.000 description 1
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- Separation Using Semi-Permeable Membranes (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は銅（以下Ｃｕと言うこともある）化合物含有水から純水を製造する方法に係り、特に、Ｃｕの水酸化物による逆浸透（ＲＯ）膜分離装置の目詰りを防止して純水を効率的に回収する方法に関する。
【０００２】
【従来の技術】
半導体製造工程、液晶製造工程の使用済超純水（回収水）は、一般に、図２に示す如く、工水、市水等の原水と混合し、まず、ＮａＣｌＯ等の酸化剤を添加すると共に、ＨＣｌ等の酸を添加してｐＨ３．０〜５．０、例えばｐＨ４程度に調整して脱炭酸装置１で脱炭酸処理し、次いで還元剤を添加すると共に、ＮａＯＨ等のアルカリを添加してｐＨ６．０〜９．５、例えばｐＨ８程度に調整して紫外線酸化装置２で殺菌と有機物の酸化分解を行い、その後、精密濾過（ＭＦ）膜分離装置３及び２段に配置したＲＯ膜分離装置（第１ＲＯ膜分離装置４及び第２ＲＯ膜分離装置５）で膜分離処理することにより、純水として再利用される。
【０００３】
この純水製造工程において、ＮａＣｌＯは殺菌及び酸化のために添加され、また、ＨＣｌは水中の炭酸成分を二酸化炭素として脱炭酸装置１での脱炭酸効率を高めるために添加される。還元剤は、残留塩素の除去のために添加される。また、ＮａＯＨは脱炭酸処理後に残留する炭酸成分をイオン化し、ＲＯ膜分離装置４，５での除去効率を高めるために添加される。
【０００４】
【発明が解決しようとする課題】
回収水中にはＣｕなどの重金属が混入する場合があるが、回収水中にＣｕが存在すると、純水製造工程においてＣｕの水酸化物を生成してＲＯ膜の目詰りを引き起こし、これにより生産水量が低下する。
【０００５】
即ち、回収水中のＣｕ濃度は一般に０．５〜５ｐｐｍ程度であり、回収水のｐＨは中性程度であるため、回収水中のＣｕは水酸化物状態となっている。
【０００６】
この回収水に脱炭酸処理に先立ちＨＣｌを添加するとＣｕはＣｕ2+イオンとなるが、脱炭酸処理後にＮａＯＨを添加してｐＨ調整を行った際に、Ｃｕ2+＋ＯＨ- →Ｃｕ（ＯＨ）2 の反応によりＣｕの水酸化物が生成する。生成したＣｕ水酸化物の粒子の多くはＭＦ膜分離装置３で捕捉されるが、一部は非常に細かい粒子であるために、ＭＦ膜分離装置（通常、孔径２０μｍ程度）３を通過して第１ＲＯ膜分離装置４に流入し、ＲＯ膜の目詰りを引き起こす。
【０００７】
また、Ｃｕ水酸化物の粒子を捕捉したＭＦ膜分離装置３では頻繁に逆洗を行うことが必要となる。
【０００８】
本発明は上記従来の問題点を解決し、Ｃｕを含有する回収水から純水を製造するに当り、Ｃｕの水酸化物の生成を防止して、ＲＯ膜の目詰りによる生産水量の低下を抑えると共に、ＭＦ膜分離装置の逆洗頻度を低減して、効率的な純水製造を行う方法を提供することを目的とする。
【０００９】
【課題を解決するための手段】
本発明の純水製造方法は、Ｃｕ含有水を逆浸透膜分離処理して純水を製造する方法において、ｐＨ５以下のＣｕ含有水にキレート剤を添加した後或いはキレート剤と共にアルカリを添加し、その後逆浸透膜分離処理することを特徴とする。
【００１０】
キレート剤を添加することにより、Ｃｕイオンが化学的に安定なＣｕキレート化合物となり、Ｃｕ（ＯＨ）2 の生成は防止される。
【００１１】
また、キレート剤の添加は、ＣｕがＣｕ2+イオンの状態となっているときに添加するのが好ましく、従って、本発明ではＣｕ含有水がｐＨ５以下の酸性領域にあるときにキレート剤を添加する。
【００１２】
【発明の実施の形態】
以下に図面を参照して本発明の実施の形態を詳細に説明する。
【００１３】
図１は本発明の純水製造方法の実施の形態を示す系統図である。
【００１４】
本発明の純水製造方法は、第１ＲＯ膜分離装置４の前段でキレート剤を添加すること以外は、図２に示す従来法と同様に実施することができる。
【００１５】
本発明において、キレート剤は、ＣｕがＣｕ2+となってイオン状で存在する箇所で添加しても良いし、回収水のｐＨを酸性領域に調整した後添加し、原水と混合しても良い。
【００１６】
好ましくは、経済性の観点から、キレート剤は、脱炭酸装置１の前段のＨＣｌ添加箇所の後段から、紫外線酸化装置２の前段のＮａＯＨ添加箇所の前段までの、水のｐＨが５以下となっている部分で添加する。従って、キレート剤は、例えば、図１に示す如く、還元剤添加箇所とＮａＯＨ添加箇所との間、或いは、ＨＣｌ添加箇所と脱炭酸装置１との間で添加することができる。
【００１７】
キレート剤の添加量は、Ｃｕに対して０．５倍当量以上である。ただし、キレート剤の過剰添加は後段設備の負荷となるため、Ｃｕに対して０．７５倍当量以下とするのが好ましい。
【００１８】
キレート剤としては、ＥＤＴＡ（エチレンジアミン四酢酸）、オキシカルボン酸等が効果的であるが、他のポリマー系のキレート剤であっても良い。特に、キレート剤としてＥＤＴＡ・４Ｎａ（エチレンジアミン四酢酸ナトリウム）を用いた場合には、キレート剤自体がアルカリであるため、後段のＮａＯＨの薬注量を低減することができる。このＥＤＴＡ・４Ｎａを添加する場合は、脱炭酸装置１の後段で添加する必要がある。
【００１９】
キレート剤は、流入水のＣｕ濃度に応じて薬注制御するのが好ましいが、Ｃｕ濃度がほぼ一定である場合には、キレート剤とＮａＯＨ等のアルカリとを予め混合して一液製剤として注入することにより、注入設備（ポンプ、タンク、配管等）の削減が可能となり経済的である。
【００２０】
【実施例】
以下に実施例及び比較例を挙げて本発明をより具体的に説明する。
【００２１】
実施例１
Ｃｕ１．５ｐｐｍを含む回収水を図１に示す方法（ただし、ＲＯ膜分離装置は１段のみ）で処理して純水の製造を行った。
【００２２】
まず、回収水にＮａＣｌＯを有効塩素として１ｐｐｍ添加した後、ＨＣｌでｐＨ４に調整し、脱炭酸処理した。その後、還元剤としてヒドラジンを０．３５ｐｐｍ添加し、残留塩素が無くなったのを確認した後、キレート剤としてＥＤＴＡ・４Ｎａを８．０ｐｐｍ添加し、ＮａＯＨでｐＨ８に調整し、紫外線酸化処理した後、孔径２０μｍのＭＦ膜分離装置に通水し、透過水を平膜（ポリアクリルアミド系）を装着したＲＯ膜分離装置に、回収率９０％、運転圧力１５ｋｇ／ｃｍ2 で通水した。
【００２３】
通水初期のＲＯ膜分離装置の生産水量（透過水量）と通水１５時間後の生産水量を調べ、結果を表１に示した。
【００２４】
比較例１
実施例１において、キレート剤を添加しなかったこと以外は同様に処理を行い、結果を表１に示した。
【００２５】
比較例２
実施例１において、ＨＣｌを添加しなかったこと以外は同様に処理を行い、結果を表１に示した。
【００２６】
この比較例２では、キレート剤を添加しているが、ＨＣｌを添加せず、ｐＨ７の条件下で添加しているために、キレート化合物の生成効率が、ｐＨ４の水にキレート剤を添加した実施例１の場合に比べて劣り、このためＣｕ（ＯＨ）2 生成の抑制効果が十分でなかったために、比較例１よりは改善されているものの、生産水量の低下がみられる。
【００２７】
【表１】
なお、通水後、各ＲＯ膜分離装置のＲＯ膜面を調べたところ、実施例１では、ＲＯ膜に付着物は見られなかったが、比較例１，２では、緑灰色の付着物が見られ、これにより生産水量が低下していることが確認された。
【００２９】
【発明の効果】
以上詳述した通り、本発明の純水製造方法によれば、Ｃｕを含有する回収水から純水を製造するに当り、Ｃｕの水酸化物の生成を防止して、ＲＯ膜の目詰りによる生産水量の低下を抑えると共に、ＭＦ膜分離装置の逆洗頻度を低減して、効率的な純水製造を行うことができる。
【図面の簡単な説明】
【図１】本発明の純水製造方法の実施の形態を示す系統図である。
【図２】従来法を示す系統図である。
【符号の説明】
１ 脱炭酸装置
２ 紫外線酸化装置
３ ＭＦ膜分離装置
４ 第１ＲＯ膜分離装置
５ 第２ＲＯ膜分離装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing pure water from copper (hereinafter sometimes referred to as Cu) compound-containing water, and in particular, prevents clogging of a reverse osmosis (RO) membrane separation apparatus by Cu hydroxide. The present invention relates to a method for efficiently recovering water.
[0002]
[Prior art]
In general, spent ultrapure water (recovered water) in the semiconductor manufacturing process and liquid crystal manufacturing process is mixed with raw water such as industrial water and city water as shown in FIG. 2, and first, an oxidizing agent such as NaClO is added. Then, an acid such as HCl is added to adjust the pH to 3.0 to 5.0, for example, about pH 4, and then decarboxylated with the decarboxylation apparatus 1, and then a reducing agent is added and an alkali such as NaOH is added. The pH is adjusted to 6.0 to 9.5, for example, about pH 8, and sterilization and oxidative decomposition of organic matter are performed by the ultraviolet oxidation device 2, and then the microfiltration (MF) membrane separation device 3 and the RO membrane separation device arranged in two stages. It is reused as pure water by performing a membrane separation process with the (first RO membrane separation device 4 and the second RO membrane separation device 5).
[0003]
In this pure water production process, NaClO is added for sterilization and oxidation, and HCl is added to increase the decarboxylation efficiency in the decarboxylation apparatus 1 using carbonic acid components in water as carbon dioxide. A reducing agent is added to remove residual chlorine. Further, NaOH is added to ionize the carbonic acid component remaining after the decarboxylation treatment and to enhance the removal efficiency in the RO membrane separation devices 4 and 5.
[0004]
[Problems to be solved by the invention]
Heavy metals such as Cu may be mixed in the recovered water. However, if Cu is present in the recovered water, Cu hydroxide is generated in the pure water production process, causing the RO membrane to be clogged. Decreases.
[0005]
That is, since the Cu concentration in the recovered water is generally about 0.5 to 5 ppm and the pH of the recovered water is neutral, Cu in the recovered water is in a hydroxide state.
[0006]
When HCl is added to this recovered water prior to decarboxylation, Cu becomes Cu 2+ ions. However, when pH is adjusted by adding NaOH after decarboxylation, Cu 2+ + OH − → Cu (OH) The reaction of 2 produces a Cu hydroxide. Most of the generated Cu hydroxide particles are captured by the MF membrane separator 3, but some of them are very fine particles, so that they pass through the MF membrane separator (usually about 20 μm in pore diameter) 3. It flows into the first RO membrane separation device 4 and causes clogging of the RO membrane.
[0007]
Further, the MF membrane separation device 3 that has captured the Cu hydroxide particles needs to be backwashed frequently.
[0008]
The present invention solves the above-mentioned conventional problems, and in producing pure water from recovered water containing Cu, the production of Cu hydroxide is prevented, and the production water volume is reduced due to clogging of the RO membrane. An object of the present invention is to provide a method for efficiently producing pure water while suppressing the frequency of backwashing of the MF membrane separation apparatus.
[0009]
[Means for Solving the Problems]
The pure water production method of the present invention is a method of producing pure water by subjecting Cu-containing water to reverse osmosis membrane separation, and after adding a chelating agent to Cu-containing water having a pH of 5 or less, or adding an alkali together with the chelating agent, Thereafter, reverse osmosis membrane separation treatment is performed.
[0010]
By adding a chelating agent, Cu ions become a chemically stable Cu chelate compound, and the formation of Cu (OH) 2 is prevented.
[0011]
The chelating agent is preferably added when Cu is in the state of Cu 2+ ions. Therefore, in the present invention, the chelating agent is added when the Cu-containing water is in the acidic region of pH 5 or lower. To do.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 1 is a system diagram showing an embodiment of the pure water production method of the present invention.
[0014]
The pure water production method of the present invention can be carried out in the same manner as the conventional method shown in FIG. 2 except that a chelating agent is added before the first RO membrane separation device 4.
[0015]
In the present invention, the chelating agent may be added at a place where Cu is Cu 2+ and is present in an ionic state, or may be added after adjusting the pH of recovered water to an acidic region and mixed with raw water. good.
[0016]
Preferably, from the economical point of view, the chelating agent has a pH of water of 5 or less from the stage after the addition of HCl at the front stage of the decarboxylation apparatus 1 to the stage before the addition of NaOH at the front stage of the ultraviolet oxidation apparatus 2. Add in the part where it is. Therefore, for example, as shown in FIG. 1, the chelating agent can be added between the reducing agent addition site and the NaOH addition site, or between the HCl addition site and the decarboxylation device 1.
[0017]
The addition amount of the chelating agent is 0.5 times or more equivalent to Cu. However, since excessive addition of a chelating agent causes a load on the subsequent equipment, it is preferable to make it 0.75 equivalent or less with respect to Cu.
[0018]
As the chelating agent, EDTA (ethylenediaminetetraacetic acid), oxycarboxylic acid and the like are effective, but other polymer-based chelating agents may be used. In particular, when EDTA · 4Na (sodium ethylenediaminetetraacetate) is used as the chelating agent, the chelating agent itself is alkaline, so that the amount of NaOH injected in the latter stage can be reduced. When this EDTA · 4Na is added, it is necessary to add it at the subsequent stage of the decarboxylation device 1.
[0019]
The chelating agent is preferably controlled according to the Cu concentration of the influent water, but when the Cu concentration is almost constant, the chelating agent and an alkali such as NaOH are mixed in advance and injected as a one-part preparation. This makes it possible to reduce the number of injection facilities (pumps, tanks, piping, etc.) and is economical.
[0020]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
[0021]
Example 1
The recovered water containing 1.5 ppm of Cu was treated by the method shown in FIG. 1 (however, the RO membrane separator was only one stage) to produce pure water.
[0022]
First, after adding 1 ppm of NaClO as effective chlorine to the recovered water, the pH was adjusted to 4 with HCl and decarboxylation was performed. Then, after adding 0.35 ppm of hydrazine as a reducing agent and confirming that there was no residual chlorine, 8.0 ppm of EDTA · 4Na was added as a chelating agent, adjusted to pH 8 with NaOH, and after UV oxidation treatment, Water was passed through an MF membrane separator having a pore diameter of 20 μm, and the permeate was passed through an RO membrane separator equipped with a flat membrane (polyacrylamide system) at a recovery rate of 90% and an operating pressure of 15 kg / cm 2 .
[0023]
The production water volume (permeated water volume) of the RO membrane separation apparatus at the initial stage of water flow and the production water volume after 15 hours of water flow were examined, and the results are shown in Table 1.
[0024]
Comparative Example 1
In Example 1, it processed similarly except not adding a chelating agent, and the result was shown in Table 1.
[0025]
Comparative Example 2
In Example 1, the same treatment was performed except that HCl was not added, and the results are shown in Table 1.
[0026]
In Comparative Example 2, a chelating agent was added, but HCl was not added, and the addition was performed under the condition of pH 7. Therefore, the efficiency of chelating compound formation was increased by adding the chelating agent to pH 4 water. This is inferior to the case of Example 1, and therefore, the effect of suppressing the formation of Cu (OH) 2 was not sufficient.
[0027]
[Table 1]
In addition, when the RO membrane surface of each RO membrane separation apparatus was examined after passing water, in Example 1, no deposit was found on the RO membrane, but in Comparative Examples 1 and 2, a greenish gray deposit was found. As a result, it was confirmed that the amount of water produced decreased.
[0029]
【The invention's effect】
As described above in detail, according to the method for producing pure water of the present invention, in producing pure water from recovered water containing Cu, formation of Cu hydroxide is prevented, and RO membrane is clogged. While suppressing the fall of the amount of production water, the backwash frequency of MF membrane separation apparatus can be reduced, and efficient pure water manufacture can be performed.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an embodiment of a pure water production method of the present invention.
FIG. 2 is a system diagram showing a conventional method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Decarbonation apparatus 2 UV oxidation apparatus 3 MF membrane separation apparatus 4 1st RO membrane separation apparatus 5 2nd RO membrane separation apparatus
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16738997A JP3826497B2 (en) | 1997-06-24 | 1997-06-24 | Pure water production method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16738997A JP3826497B2 (en) | 1997-06-24 | 1997-06-24 | Pure water production method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1110150A JPH1110150A (en) | 1999-01-19 |
| JP3826497B2 true JP3826497B2 (en) | 2006-09-27 |
Family
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16738997A Expired - Fee Related JP3826497B2 (en) | 1997-06-24 | 1997-06-24 | Pure water production method |
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| JP (1) | JP3826497B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070084793A1 (en) * | 2005-10-18 | 2007-04-19 | Nigel Wenden | Method and apparatus for producing ultra-high purity water |
| KR100758380B1 (en) * | 2006-09-14 | 2007-09-18 | 주식회사 디엠퓨어텍 | Concentrated Water Recycling Equipment using Reverse Osmosis |
| JP6106943B2 (en) * | 2012-04-17 | 2017-04-05 | 栗田工業株式会社 | Reverse osmosis membrane treatment method and reverse osmosis membrane treatment apparatus |
| JP2023058359A (en) * | 2021-10-13 | 2023-04-25 | 野村マイクロ・サイエンス株式会社 | Medicament injection system, pure water production system, and pure water production method |
-
1997
- 1997-06-24 JP JP16738997A patent/JP3826497B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1110150A (en) | 1999-01-19 |
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