JP3602640B2 - New water purifier combining hollow fiber membrane and non-woven fabric - Google Patents
New water purifier combining hollow fiber membrane and non-woven fabric Download PDFInfo
- Publication number
- JP3602640B2 JP3602640B2 JP06763796A JP6763796A JP3602640B2 JP 3602640 B2 JP3602640 B2 JP 3602640B2 JP 06763796 A JP06763796 A JP 06763796A JP 6763796 A JP6763796 A JP 6763796A JP 3602640 B2 JP3602640 B2 JP 3602640B2
- Authority
- JP
- Japan
- Prior art keywords
- nonwoven fabric
- hollow fiber
- fiber membrane
- lead
- water
- 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 - Fee Related
Links
Landscapes
- Treatment Of Water By Ion Exchange (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、次世代の浄水器となるところの重金属除去用不織布を組み込んだ浄水器に関するものである。特に、本発明は、重金属を除去する機能を有する不織布と多孔質中空糸膜とを組み込んだ浄水器に関するものである。
【０００２】
【従来の技術】
近年、水道水質の悪化が問題となっており、それに伴って家庭用浄水器の売上げ高も伸びている状況にある。汚染物質として認識されているものには、かび臭、カルキ臭、鉄さび等があるが、現状では鉛に関してはさほど問題にされていない。ところで、鉛に関する問題は従来給水管として敷設されていた鉛管に起因するものであるが、現在では新規に鉛管を敷設することはなくなっている。
【０００３】
しかし、全国４０００万戸の住宅のうち約１０００万戸（２５％）の家庭では未だ鉛管を通過した水が上水道として使用されている。鉛は必須元素ではなく、ＷＨＯによる飲料水水質ガイドラインでは飲料水として望ましいレベルとして１０μｇ／ｌ以下に設定している。このガイドライン値を越える飲料水を採取しても直ちに健康に影響が生ずるものではないが、特に小児の摂取量が増した場合には知能障害等につながる可能性が指摘されている。
【０００４】
日本の水質基準は１９９３年１２月に改正され、鉛は、１００μｇ／ｌ以下であったものが５０μｇ／ｌに強化され、さらに１０年後には１０μｇ／ｌにすることがうたわれている。
【０００５】
以上の如く、上水中の鉛の問題は認知され、敷設された鉛管を塩ビ管に取替える対策は行われつつあるが、全国で１／４の鉛管を全てすぐに取替えるには多大なる労力と費用を要する。故に、一般市民が当面なすべき対策の一つは浄水器を設置し、それにより鉛管から溶出した鉛を除去すればよいと考えられる。
【０００６】
【発明が解決しようとする課題】
ところが、現在使用されている浄水器は、鉄さび及び雑菌等は除去しても、鉛を十分に除去する機能を有するものは無い。浄水器で鉛成分を除去する機能をうたったものがあるが、初期の除去能は高くても、その能力は不十分で、すぐに除去能が低下することが、詳細な検討の結果明らかになった。その浄水器は、活性炭の後段（下流）側に鉛除去機構を設置、さらにその後段側に中空糸膜を設置するという構造をとっていた。しかし、その初期除去能は９０％近くあっても通水していくうちにすぐに８０％以下に低下し、寿命がはなはだ短いという問題点があった。
【０００７】
また、鉛除去用浄水器はその仕様を考慮した場合、鉛を十分に除去する性能が長寿命であることはもちろんであるが、従来備わっていた機能を損ねるようなことがあってはならない。例えば処理流量を十分に確保できること、圧力損失をできるだけ小さくできること等は当然備わるべき機能である。
【０００８】
【課題を解決するための手段】
本発明では、上記問題点を解決することを目的として詳細に検討し、以下の結果を得た。即ち、本発明の浄水器は、不織布が多孔質中空糸膜の水路の下流に位置され、その不織布が、放射線グラフト重合法により重金属除去機能を有するイミノジ酢酸官能基を導入されたものであり、飲料水として適切な水質を提供するために、２％水酸化ナトリウム水溶液、５％塩化カルシウム水溶液を順に通水させることによってその官能基をカルシウム型に置換しておくものである。
【０００９】
【発明の実施の形態】
本発明では、十分な鉛除去能力を有した機能を有する不織布を中空糸膜の後段に配置する浄水器により鉛成分を完璧に除去するものである。本発明者らが鋭意検討した結果、浄水器に鉛除去機能を有する不織布を組み入れる場合、中空糸膜の前段（上流）では初期性能は９０％近くあるが、すぐに性能が低下した。これは既に述べた現在使用されている鉛除去用浄水器と同等の特性であった。
【００１０】
しかし、本発明における中空糸膜の後段に不織布を配置した場合においては、長期間にわたって鉛除去率は９７％以上であった。これに対し、中空糸膜だけを備えたものでは鉛除去率は１０％以下であり、また当該不織布だけを備えた場合には鉛除去率は初期で８８％であったが、次第にその除去率が低下したため、鉛除去用浄水器として使用するには不適切であった。ゆえに中空糸膜と本発明の不織布との組み合わせからなる構成は不可欠である。
【００１１】
また本発明の不織布を浄水器に組み込んで使用する場合には、飲料水を作るという目的から、適切なｐＨ範囲の水を作る必要がある。そのためにはイミノジ酢酸基を導入しただけの不織布では不適切で、前処理として２％水酸化ナトリウム水溶液、５％塩化カルシウム水溶液を順に通水させることによって官能基をカルシウム型に置換する必要があり、これを怠ると不織布を通過した透過液のｐＨが著しく低下し、飲料水として不適切なものとなることを見いだした。
【００１２】
以下、実施例により本発明の構成および効果を具体的に述べるが、いずれも本発明を限定するものではない。
【００１３】
【実施例１】
ポリプロピレン製の不織布（目付３０ｇ／ｍ２、繊維径１．８μｍ）に電子加速器（加速電圧２ＭｅＶ、電子線電流１ｍＡ）を用いて、窒素雰囲気下で２００ｋＧｙを照射したのち、減圧下でグリシジルメタクリレートを接触させ、グラフト重合反応を行い、質量増加率（グラフト率）３６１％の不織布を得た。このグラフト膜をジメチルスルホキシドが５０％含まれるイミノジ酢酸水溶液に浸し、８０℃で２４ｈ反応させ、イミジノ酢酸基量が基材１ｇあたり２．０ｍｍｏｌの、キレート形成基を有するキレート不織布を得た。
【００１４】
このキレート不織布を中空糸膜の後段（下流）に組み入れて透水試験を行った。まず前処理として２％水酸化ナトリウム水溶液、５％塩化カルシウム水溶液を順に通水させることによって官能基をカルシウム型に置換した。その後、不織布を直径２５ｍｍ、厚さ１．８ｍｍとしたものに対し、水道水を市販の中空糸膜を通過させて濁質成分を除去した後に鉛を１５０ｐｐｂ加えｐＨ＝７とした供給液をＳＶ＝５００［ｈ−１］で透過した。不織布を通過した液を５０ｍｌずつ分画した結果、１２分画においても透過液の中の鉛濃度は３ｐｐｂ以下であった。ゆえに、中空糸膜の後段にキレート不織布を配置すれば実用上十分な鉛除去能を有する浄水器が得られることがわかる。
【００１５】
【比較例１】
実施例１と同一のキレート不織布を用い、これを中空糸膜の前段に組み入れ、鉛を加えた水道水を供給液として用いて透過試験を行った結果、１分画では鉛除去率が８８％であったが、６分画では７９％に低下した。これは水道水中の濁質成分が予め中空糸膜によって除去されなかったために、中空糸膜の前段に配置されたキレート不織布が濁質除去機能を担い、結果として鉛除去機能が低下したためと考えられる。よって、本発明のキレート不織布を鉛除去用浄水器に組み入れる場合には、中空糸膜の後段に配置する必要であることがわかった。
【００１６】
【比較例２】
実施例１と同一のキレート不織布を用い、これを中空糸膜の後段に組み入れ、これに２％水酸化ナトリウム水溶液、５％塩化カルシウム水溶液を順に通水するという前処理を施さない場合には、透過液中の鉛濃度が通水初期にも高くなり、吸着能がはなはだ低かった。また透過液のｐＨも供給液のそれに比べて著しく低下し、飲料水としては不適切なものとなった。よって、キレート不織布を中空糸膜の後段に配置した場合であっても、２％水酸化ナトリウム水溶液、５％塩化カルシウム水溶液による前処理が必要であることがわかった。
【００１７】
【発明の効果】
本発明により、中空糸膜とイミノジ酢酸基を有した機能性不織布との組み合わせによって、従来存在し得なかったハイレベルの鉛除去機能を有した浄水器を開発するめどを立てることができた。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a water purifier incorporating a nonwoven fabric for removing heavy metals, which will be a next-generation water purifier. In particular, the present invention relates to a water purifier incorporating a nonwoven fabric having a function of removing heavy metals and a porous hollow fiber membrane.
[0002]
[Prior art]
In recent years, the deterioration of tap water quality has become a problem, and the sales of household water purifiers have been increasing accordingly. Those recognized as contaminants include musty odor, smelt odor, iron rust, etc., but at present, lead is not much of a problem. By the way, the problem concerning lead is caused by a lead pipe which has been conventionally laid as a water supply pipe, but at present, a new lead pipe is not laid.
[0003]
However, of the 40 million homes nationwide, about 10 million homes (25%) still use water that has passed through lead pipes as water supply. Lead is not an essential element, and is set to 10 μg / l or less as a desirable level for drinking water in the guidelines for drinking water quality by WHO. Even if drinking water exceeding this guideline value is not immediately affected by health, it has been pointed out that it may lead to intellectual disability and the like, especially when the intake of children increases.
[0004]
Japan's water quality standards were revised in December 1993, and it has been declared that lead, which had been less than 100 μg / l, has been strengthened to 50 μg / l, and that it will be 10 μg / l 10 years later.
[0005]
As described above, the problem of lead in clean water has been recognized, and measures are being taken to replace laid lead pipes with PVC pipes. However, it is enormous labor and cost to replace all quarters of lead pipes nationwide immediately. Cost. Therefore, one of the measures that the general public should take for now is to install a water purifier and remove lead eluted from the lead pipe.
[0006]
[Problems to be solved by the invention]
However, none of the water purifiers currently used have a function of sufficiently removing lead even if iron rust and various germs are removed. Although some purported to remove lead components in water purifiers, even if the initial removal capacity is high, the capacity is insufficient, and the removal capacity immediately decreases, as a result of detailed examination reveals became. The water purifier had a structure in which a lead removal mechanism was installed downstream (downstream) of activated carbon, and a hollow fiber membrane was installed further downstream. However, even if the initial removal ability is close to 90%, the water immediately drops to 80% or less as water flows, and there is a problem that the life is extremely short.
[0007]
In addition, considering the specifications of the water purifier for removing lead, the performance of sufficiently removing lead has a long service life, but the function provided conventionally must not be impaired. For example, it is a function to be provided that a sufficient processing flow rate can be ensured and that a pressure loss can be reduced as much as possible.
[0008]
[Means for Solving the Problems]
The present invention has been studied in detail for the purpose of solving the above problems, and the following results have been obtained. That is, in the water purifier of the present invention, the nonwoven fabric is located downstream of the water channel of the porous hollow fiber membrane, and the nonwoven fabric has an iminodiacetic acid functional group having a heavy metal removing function introduced by a radiation graft polymerization method. In order to provide water quality suitable for drinking water, a functional group is replaced with a calcium type by sequentially passing a 2% aqueous sodium hydroxide solution and a 5% aqueous calcium chloride solution.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
In the present invention, a lead component is completely removed by a water purifier in which a nonwoven fabric having a function having a sufficient lead-removing ability is arranged at the subsequent stage of the hollow fiber membrane. As a result of intensive studies by the present inventors, when a nonwoven fabric having a lead removing function is incorporated into a water purifier, the initial performance is close to 90% at the upstream (upstream) stage of the hollow fiber membrane, but the performance immediately deteriorates. This was equivalent to the characteristics of the currently used lead removal water purifier described above.
[0010]
However, in the case where the nonwoven fabric was disposed after the hollow fiber membrane in the present invention, the lead removal rate was 97% or more over a long period of time. On the other hand, the lead removal rate was 10% or less in the case where only the hollow fiber membrane was provided, and the lead removal rate was 88% in the initial stage when only the nonwoven fabric was provided. Was unsuitable for use as a lead removal water purifier. Therefore, a configuration composed of a combination of the hollow fiber membrane and the nonwoven fabric of the present invention is indispensable.
[0011]
In addition, when the nonwoven fabric of the present invention is used by incorporating it into a water purifier, it is necessary to prepare water having an appropriate pH range for the purpose of preparing drinking water. For this purpose, a nonwoven fabric having only an iminodiacetic acid group is not suitable, and it is necessary to replace a functional group with a calcium type by passing a 2% aqueous sodium hydroxide solution and a 5% aqueous calcium chloride solution sequentially as a pretreatment. However, it was found that if this was neglected, the pH of the permeate passed through the nonwoven fabric was significantly lowered, and the permeate became unsuitable as drinking water.
[0012]
Hereinafter, the configuration and effects of the present invention will be specifically described with reference to Examples, but none of them will limit the present invention.
[0013]
Embodiment 1
After irradiating 200 kGy to a polypropylene non-woven fabric (30 g / m 2 in basis weight and 1.8 μm in fiber diameter) under a nitrogen atmosphere using an electron accelerator (acceleration voltage: 2 MeV, electron beam current: 1 mA), glycidyl methacrylate was applied under reduced pressure. The nonwoven fabric was brought into contact and a graft polymerization reaction was carried out to obtain a nonwoven fabric having a mass increase (graft ratio) of 361%. The graft membrane was immersed in an aqueous solution of iminodiacetic acid containing 50% of dimethyl sulfoxide and reacted at 80 ° C. for 24 hours to obtain a chelated nonwoven fabric having a chelate-forming group with an imidinoacetic acid group content of 2.0 mmol per 1 g of the base material.
[0014]
This chelate nonwoven fabric was incorporated into the latter stage (downstream) of the hollow fiber membrane, and a water permeability test was performed. First, as a pretreatment, a 2% aqueous sodium hydroxide solution and a 5% aqueous calcium chloride solution were sequentially passed through to replace the functional group with a calcium type. After that, tap water was passed through a commercially available hollow fiber membrane to remove turbid components, and then 150 ppb of lead was added to the non-woven fabric having a diameter of 1.8 mm and a thickness of 1.8 mm. = 500 [h -1 ]. As a result of fractionating 50 ml of the liquid passed through the nonwoven fabric, the lead concentration in the permeated liquid was 3 ppb or less even in the 12 fractions. Therefore, it can be seen that a water purifier having a practically sufficient lead removing ability can be obtained by disposing the chelating nonwoven fabric at the subsequent stage of the hollow fiber membrane.
[0015]
[Comparative Example 1]
The same chelated nonwoven fabric as in Example 1 was incorporated into the front stage of the hollow fiber membrane, and a permeation test was conducted using tap water to which lead was added as a feed solution. As a result, the lead removal rate was 88% in one fraction. However, it decreased to 79% in the 6 fractions. This is probably because the turbid components in the tap water were not removed by the hollow fiber membrane in advance, so that the chelate nonwoven fabric placed in front of the hollow fiber membrane took on the turbidity removing function, and as a result, the lead removing function was reduced. . Therefore, when incorporating the chelated nonwoven fabric of the present invention into a lead-removing water purifier, it was found that it was necessary to arrange the nonwoven fabric after the hollow fiber membrane.
[0016]
[Comparative Example 2]
In the case where the same chelated nonwoven fabric as in Example 1 was used and incorporated into the latter stage of the hollow fiber membrane, and a pretreatment of passing a 2% aqueous sodium hydroxide solution and a 5% aqueous calcium chloride solution in this order was not performed, The lead concentration in the permeate was high even at the beginning of the water flow, and the adsorption capacity was extremely low. Also, the pH of the permeate was significantly lower than that of the feed, making it unsuitable for drinking water. Therefore, it was found that pretreatment with a 2% aqueous sodium hydroxide solution and a 5% aqueous calcium chloride solution was necessary even when the chelated nonwoven fabric was disposed downstream of the hollow fiber membrane.
[0017]
【The invention's effect】
The present invention, by a combination of the functional nonwoven fabric having a hollow fiber membrane and iminodiacetic acid groups, it was possible to make a prospect for developing a water purifier having a lead removal function of a high level which could not have existed before.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06763796A JP3602640B2 (en) | 1996-03-25 | 1996-03-25 | New water purifier combining hollow fiber membrane and non-woven fabric |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06763796A JP3602640B2 (en) | 1996-03-25 | 1996-03-25 | New water purifier combining hollow fiber membrane and non-woven fabric |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09253646A JPH09253646A (en) | 1997-09-30 |
| JP3602640B2 true JP3602640B2 (en) | 2004-12-15 |
Family
ID=13350719
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06763796A Expired - Fee Related JP3602640B2 (en) | 1996-03-25 | 1996-03-25 | New water purifier combining hollow fiber membrane and non-woven fabric |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3602640B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4683820B2 (en) * | 2001-01-31 | 2011-05-18 | 中部キレスト株式会社 | Method for treating metal and / or metal-containing solution |
-
1996
- 1996-03-25 JP JP06763796A patent/JP3602640B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09253646A (en) | 1997-09-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8506807B2 (en) | Spiral wound type filter cartridge | |
| Ando et al. | Removal of musty-odorous compounds in water and retained in algal cells through water purification processes | |
| Lyko et al. | Estrogenic trace contaminants in wastewater—possibilities of membrane bioreactor technology | |
| JP3602640B2 (en) | New water purifier combining hollow fiber membrane and non-woven fabric | |
| CA2871513C (en) | Mitigating leaching of arsenic and antimony from activated carbon | |
| KR101970499B1 (en) | An odor removing apparatus for removing odor, a method for manufacturing the same, and an odor removing apparatus using the manufactured adsorption deodorizer | |
| JP3915597B2 (en) | Water purification cartridge | |
| JPS63178804A (en) | Method for separating phenol reduced water and water rich in phenol from phenolic aqueous solution | |
| CN114425238B (en) | Stain-resistant chlorine-resistant dual-functional polyamide composite reverse osmosis membrane and preparation method thereof | |
| JPH09248570A (en) | Production of novel hollow fiber membrane for water purifier and hollow fiber membrane by the same | |
| JPS6312315A (en) | Filter for gas cleaning apparatus | |
| ATE195704T1 (en) | METHOD AND PLANT FOR THE TREATMENT OF WATER POISONED BY CAMPUS | |
| Sethi et al. | Microfiltration of primary effluent for clarification and microbial removal | |
| Chaminda et al. | Heavy metal (Zn and Cu) complexation and molecular size distribution in wastewater treatment plant effluent | |
| KR20100089556A (en) | Multi-step water purification system including filtering step using dna on solid support catalyst | |
| US20190076765A1 (en) | Pre-filter for removal of cesium and method of manufacturing same | |
| EP1945331A1 (en) | Process for eliminating hydrogen sulphide and odours from wastewater systems | |
| CN115321679B (en) | Anaerobic ammonia oxidation treatment process for degrading landfill leachate | |
| KR830002326B1 (en) | Wastewater Treatment Method | |
| KR20190081489A (en) | Manufacturing method of membrane filter for cesium removal | |
| JP3893754B2 (en) | Water purifier | |
| JP2009112928A (en) | Method of modifying separation membrane, separation membrane modified thereby, modifier and apparatus for this modification | |
| CN108283941B (en) | Nonlinear photocatalytic film for total nitrogen treatment in tail water of sewage treatment plant and application thereof | |
| Vik | Effects on wastewater due to new active pharmaceutical ingredients and products | |
| Lee et al. | Evaluation of removal efficiencies of micropollutants in wastewater treatment plants |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20040521 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20040604 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20040727 |
|
| 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: 20040827 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040924 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313115 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081001 Year of fee payment: 4 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091001 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091001 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101001 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111001 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131001 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |