JPS6230835B2 - - Google Patents
Info
- Publication number
- JPS6230835B2 JPS6230835B2 JP9398681A JP9398681A JPS6230835B2 JP S6230835 B2 JPS6230835 B2 JP S6230835B2 JP 9398681 A JP9398681 A JP 9398681A JP 9398681 A JP9398681 A JP 9398681A JP S6230835 B2 JPS6230835 B2 JP S6230835B2
- Authority
- JP
- Japan
- Prior art keywords
- catalytic
- dephosphorization
- acid
- treated
- 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
Links
- 239000000463 material Substances 0.000 claims description 57
- 230000003197 catalytic effect Effects 0.000 claims description 56
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 34
- 239000002253 acid Substances 0.000 claims description 25
- 239000007788 liquid Substances 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 21
- 239000007864 aqueous solution Substances 0.000 claims description 18
- 229910019142 PO4 Inorganic materials 0.000 claims description 13
- 235000021317 phosphate Nutrition 0.000 claims description 13
- 150000003013 phosphoric acid derivatives Chemical class 0.000 claims description 12
- 238000005406 washing Methods 0.000 claims description 8
- 239000001506 calcium phosphate Substances 0.000 claims description 5
- 229910000389 calcium phosphate Inorganic materials 0.000 claims description 5
- 235000011010 calcium phosphates Nutrition 0.000 claims description 5
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 claims description 5
- 239000002245 particle Substances 0.000 claims description 4
- 229910052585 phosphate mineral Inorganic materials 0.000 claims description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 2
- 239000011707 mineral Substances 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 20
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 20
- 239000011574 phosphorus Substances 0.000 description 19
- 229910052698 phosphorus Inorganic materials 0.000 description 19
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 15
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 14
- 239000011575 calcium Substances 0.000 description 10
- 238000006243 chemical reaction Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- 239000008399 tap water Substances 0.000 description 9
- 235000020679 tap water Nutrition 0.000 description 9
- 229910000019 calcium carbonate Inorganic materials 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 6
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 5
- 238000010306 acid treatment Methods 0.000 description 5
- 229910052791 calcium Inorganic materials 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 5
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 150000007524 organic acids Chemical class 0.000 description 4
- XYJRXVWERLGGKC-UHFFFAOYSA-D pentacalcium;hydroxide;triphosphate Chemical compound [OH-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O XYJRXVWERLGGKC-UHFFFAOYSA-D 0.000 description 4
- 239000010865 sewage Substances 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 239000010802 sludge Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000002351 wastewater Substances 0.000 description 3
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000001110 calcium chloride Substances 0.000 description 2
- 229910001628 calcium chloride Inorganic materials 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000007654 immersion Methods 0.000 description 2
- 150000007522 mineralic acids Chemical class 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000011975 tartaric acid Substances 0.000 description 2
- 235000002906 tartaric acid Nutrition 0.000 description 2
- 235000014653 Carica parviflora Nutrition 0.000 description 1
- 241000243321 Cnidaria Species 0.000 description 1
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 229910052586 apatite Inorganic materials 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 235000011116 calcium hydroxide Nutrition 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000010800 human waste Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000008235 industrial water Substances 0.000 description 1
- 229910052816 inorganic phosphate Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000008239 natural water Substances 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- VSIIXMUUUJUKCM-UHFFFAOYSA-D pentacalcium;fluoride;triphosphate Chemical compound [F-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O VSIIXMUUUJUKCM-UHFFFAOYSA-D 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000002367 phosphate rock Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 230000008685 targeting Effects 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Description
本発明は、上水、下水、し尿系汚水、工業用
水、工場排水、ボイラー用水、その他あらゆる液
体中に存在するリン酸塩類を除去する方法、詳し
くは接触脱リン材を用いて溶解性リン酸塩類を除
去する際に使用する接触脱リン材の能力を向上さ
せて処理する方法に関するものである。
一般に自然水系に排出される上記の各種液体中
には、無機性のリン酸塩としてオルトリン酸塩や
各種の縮合リン酸塩さらに有機性リン酸塩などが
様々な状態で存在しており、これらのリン酸塩類
の存在が湖沼、内海、内湾などの閉鎖水域乃至は
停滞水域の「あおこ」、「赤湖」発生の誘起因子と
なり、さらに各種の用水として使用する場合に装
置、配管内に生物学的なスライムが発生し、また
化学的なスケールが形成されて、事故発生の重大
な原因となつている。
したがつて、これら液中に存在するリン酸塩を
除去する必要から、各種のリン除去方法が検討さ
れているが、その一つとして本発明者等は、従来
にない新規な処理方法として一定の粒径をもつリ
ン酸カルシウムを含有する接触脱リン材を筒状あ
るいは錐状の脱リン塔に充填し、被処理液のPHを
６〜11の範囲に調整し、さらに被処理液中に含ま
れている溶解性リン酸塩類の濃度に対応して塩化
カルシウムなどのカルシウム剤を加え、これを一
定の流速条件で通過接触せしめることにより、充
填されている接触脱リン材の表面にカルシウムハ
イドロキシアパタイトの結晶を晶出、固着せしめ
て溶解性リン酸塩類を除去する方法を提案した。
この方法における接触脱リン材表面での代表的な
化学反応は次の通りである。
5Ca2+＋7OH-＋3H2PO4 -
＝Ca5（OH）（PO4）3＋6H2O …(1)
このような新規な脱リン方法を適用すれば、カ
ルシウムハイドロキシアパタイトが固着した接触
脱リン材の分離、脱水が極めて容易であり、従来
の化学的凝集沈殿法によるいわゆる凝沈汚泥と比
較すると、濃縮装置、脱水機、乾燥装置などの既
成概念による汚泥処理施設をまつたく必要としな
いだけでなく、資源としてのリンを回収すること
ができる優れた脱リン技術である。
しかしながら、この新しい接触脱リン法では、
液中に含まれている溶解性リン酸塩類をカルシウ
ムハイドロキシアパタイト〔Ca5（OH）
（PO4）3〕の結晶として固定するために、適当なPH
条件下でカルシウム剤としてCaCl2、Ca
（OH）2、CaSO4などが添加されるが、被処理液中
にアルカリ度成分が含まれていると次に示すよう
な反応式にしたがつて炭酸カルシウムが生成され
る。
Ca2+＋HCO− ３＋OH-→CaCO3＋H2O …(2)
この炭酸カルシウムは、液のPHがカルシウムハ
イドロキシアパタイトが生成されるに適したPH範
囲にあるか、あるいは調整されていれば、アパタ
イトの生成速度のほうが炭酸カルシウムの生成速
度よりも大きいために生成されないが、現実の実
際処理装置では完全なPHコントロールは難しく、
またアルカリ度成分が濃厚な場合には、カルシウ
ム剤を添加した瞬間に前記(2)式の反応がある程度
進行することは避けられない。
このような条件下で生成される炭酸カルシウム
の結晶は極めて少量であるが、長期間中に徐々に
炭酸カルシウムの結晶が接触脱リン材の表面に固
着成長する。その結果、接触脱リン材の表面活性
が劣下し、脱リン機能は低減し、当初ほどの脱リ
ン果は期待できなくなる。本発明は、このように
接触脱リン法において脱リン機能の低下した接触
脱リン材の脱リン能力を向上させて効率よくリン
除去ができる方法を提供することを目的とするも
のである。
即ち、本発明は、リン酸カルシウムを含有する
接触脱リン材に被処理液を通液することにより、
液中に存在するリン酸塩類を除去する方法におい
て、前記接触脱リン材を酸水溶液と接触して、該
接触脱リン材の脱リン能力を向上せしめて処理す
ることを特徴とするものである。
以下に本発明の一実施態様をいわゆる下水の二
次処理水を対象として、図面に基づき説明すれ
ば、まずこの二次処理水中に多量の浮遊物質が存
在する場合には、この浮遊物質を沈殿槽又は過
槽などを通してあらかじめ除去する。
このように前処理操作により、予め浮遊物質を
除去された原水は、必要に応じて原水中の溶解性
リン酸塩濃度に対応してカルシウム剤が添加され
た後、酸又はアルカリのPH調整剤でPHを6.0〜
11.0に調整し、原水流入管１から脱リン塔２の上
部へ導入する。この脱リン塔２内には、リン酸カ
ルシウムを含有するリン酸塩鉱物を破砕し篩分し
て一定の粒径（0.42〜1.0mm）としたものを接触
脱リン材３として充填してあり、原水はこの接触
脱リン材３と接触しながら下降し、処理水流出管
４から塔外へ導出される。
前記接触脱リン材３としてリン酸塩鉱物に代え
て、骨炭、サンゴ砂、砂などの表面にリン酸カル
シウムを担持させるもの等でも利用できる。
かかる脱リン操作において接触脱リン材３上に
は、炭酸カルシウムが生成することおよび原水中
の不純物が付着すること等により、接触脱リン材
３の表面活性が劣化し、脱リン機能は低下するの
で、まず、脱リン塔２への原水の通水と同時に又
は一定期間経過後、塔内の接触脱リン材３は、連
続的又は間欠的に取出管５から反応槽６に送り込
まれ、該接触脱リン材は反応槽６において、酸水
溶液をタンク１４からポンプ７で給入され酸水溶
液と撹拌機８で時々撹拌機されて接触処理され
る。接触処理が終了した酸水溶液は排水管９より
排出される。
接触処理において使用する酸は、鉱酸でも有機
酸でもよく、酸の濃度は0.5〜20％が適当であ
る。接触反応は短時間で終了するので接触時間は
30〜60分で十分である。
次に反応槽６に洗浄水として水道水導入管１０
より水道水が導入され、該接触脱リン材３は洗浄
廃水のPHが低下しなくなるまで洗浄された後ポン
プ１１で脱リン塔２へ戻され洗浄廃水は排水管９
より排出される。但し、この洗浄工程は脱リン処
理する原水の種類によつて省略することも可能で
ある。
また、接触脱リン材３を塔外へ導出することな
く、脱リン塔２内で、前記塔外の接触処理におけ
る反応槽６と同様の操作を行なうことにより接触
脱リン材３の脱リン能力を高めることもできる。
この場合における接触処理に用いる酸水溶液は脱
リン塔２を流入管１２から流出管１３へと上向流
に通水させ、接触脱リン材３が膨張し、流動化す
るような条件で接触させると更に効果的である。
なお、接触脱リン材を酸水溶液と接触処理する
のは、被処理液の通水により接触脱リン材の脱リ
ン効果が低下した場合においてのみでなく、被処
理液の通水前に接触脱リン材を調整処理する場合
にも用いることができる。即ち、前記のように、
接触脱リン材には種々のものがあり、その種類に
よつてはその表面に炭酸カルシウムが沈積してい
るもの又は有機物が付着しているものがあり、こ
のようなものについては脱リン塔に被処理液を通
水する以前に、予め酸水溶液と接触処理すること
で、当初から脱リン能力を良好な状態に維持でき
る。
以上述べたように本発明法によれば、脱リン操
作中に接触脱リン材を必要に応じて、酸水溶液と
接触処理することにより、接触脱リン材の脱リン
効果を長期間良好な状態に維持することができ、
安定した脱リン処理が可能となつた。
次に本発明法の実施例を示す。
実施例 １
直径0.5ｍ、有効深さ25ｍの円筒状の脱リン塔
にリン鉱石を破砕、篩分し、粒径0.42〜0.54mmの
ものを充填した。
粗大固形物を大別分離した下水を従来技術とし
ての活性汚泥法で処理した二次処理水を被処理液
とし苛性ソーダ（消石灰でも同等の効果が得られ
た）により被処理液のPHを9.0付近に調整し、ま
た、カルシウム剤として塩化カルシウムを使用
し、被処理液中の溶解性リン酸塩類の濃度に対応
して、Ca／PO4のモル重量比が1.0〜15の範囲と
なるように添加した、この被処理液を前記脱リン
塔に導き上方より下向にLV＝2.5ｍ／Ｈの流速で
通水した。
接触脱リン材は１ケ月に１回全量を取り出し、
0.2％の塩酸溶液１m3中に約１時間浸漬して接触
処理した。
塩酸と接触処理した接触脱リン材を水道水で洗
浄したのち、上記脱リン塔にもどす操作を定期的
に行ないながら約12ケ月の通水実験を行なつた。
この結果を表―１に示す。
The present invention provides a method for removing phosphates present in tap water, sewage, human waste water, industrial water, factory wastewater, boiler water, and all other liquids. The present invention relates to a method for improving the ability of a catalytic dephosphorizing material used to remove salts. Generally, in the various liquids mentioned above that are discharged into natural water systems, inorganic phosphates such as orthophosphates, various condensed phosphates, and organic phosphates exist in various states. The presence of phosphates is a factor that induces the formation of "blue water" and "red lake" in closed or stagnant waters such as lakes, inland seas, and inner bays. Biological slime is generated and chemical scale is formed, which is a major cause of accidents. Therefore, various phosphorus removal methods are being considered in order to remove the phosphates present in these liquids. A cylindrical or conical dephosphorization tower is filled with catalytic dephosphorization material containing calcium phosphate with a particle size of By adding a calcium agent such as calcium chloride according to the concentration of soluble phosphates and bringing it into contact with the catalytic dephosphorizer at a constant flow rate, calcium hydroxyapatite is added to the surface of the filled catalytic dephosphorization material. We proposed a method to remove soluble phosphates by crystallizing and fixing them.
A typical chemical reaction on the surface of the catalytic dephosphorizing material in this method is as follows. 5Ca 2+ +7OH - +3H 2 PO 4 - = Ca 5 (OH) (PO 4 ) 3 +6H 2 O...(1) If such a new dephosphorization method is applied, catalytic dephosphorization with fixed calcium hydroxyapatite can be achieved. It is extremely easy to separate and dewater the material, and compared to so-called flocculated sludge made using conventional chemical coagulation and sedimentation methods, it does not require preconceived sludge treatment facilities such as thickeners, dehydrators, and dryers. It is an excellent dephosphorization technology that can recover phosphorus as a resource. However, in this new catalytic dephosphorization method,
The soluble phosphates contained in the liquid are converted to calcium hydroxyapatite [Ca 5 (OH)
(PO 4 ) 3 ] at an appropriate pH to fix it as a crystal.
CaCl 2 , Ca as a calcium agent under conditions
(OH) 2 , CaSO 4 , etc. are added, but if the liquid to be treated contains alkalinity components, calcium carbonate is produced according to the reaction formula shown below. Ca 2+ +HCO − 3 +OH − →CaCO 3 +H 2 O…(2) This calcium carbonate can be used if the pH of the liquid is in the pH range suitable for producing calcium hydroxyapatite or if it has been adjusted. Apatite is not produced because the production rate is higher than that of calcium carbonate, but complete PH control is difficult in actual processing equipment.
Furthermore, if the alkalinity component is concentrated, it is inevitable that the reaction of formula (2) will proceed to some extent the moment the calcium agent is added. Although the amount of calcium carbonate crystals produced under such conditions is extremely small, the calcium carbonate crystals gradually grow fixedly on the surface of the catalytic dephosphorizing material over a long period of time. As a result, the surface activity of the catalytic dephosphorization material deteriorates, the dephosphorization function decreases, and the dephosphorization effect cannot be expected to be as high as initially. An object of the present invention is to provide a method that can efficiently remove phosphorus by improving the dephosphorizing ability of a catalytic dephosphorizing material whose dephosphorizing function has deteriorated in the catalytic dephosphorizing method. That is, in the present invention, by passing a liquid to be treated through a catalytic dephosphorization material containing calcium phosphate,
The method for removing phosphates present in a liquid is characterized in that the catalytic dephosphorizing material is brought into contact with an acid aqueous solution to improve the dephosphorizing ability of the catalytic dephosphorizing material. . An embodiment of the present invention will be described below with reference to the drawings, targeting so-called secondary treated sewage water. First, if there is a large amount of suspended solids in this secondary treated water, the suspended solids will be precipitated. Remove it in advance by passing it through a tank or overtank. The raw water from which suspended solids have been removed in advance through pretreatment operations is treated with a calcium agent depending on the concentration of soluble phosphate in the raw water as necessary, and then an acidic or alkaline PH adjuster. PH at 6.0~
11.0 and introduce it into the upper part of the dephosphorization tower 2 from the raw water inlet pipe 1. This dephosphorization tower 2 is filled with catalytic dephosphorization material 3 containing crushed and sieved phosphate minerals containing calcium phosphate to a certain particle size (0.42 to 1.0 mm). descends while contacting this catalytic dephosphorization material 3, and is led out of the tower from the treated water outflow pipe 4. Instead of phosphate minerals as the catalytic dephosphorization material 3, materials such as bone char, coral sand, sand, etc., which have calcium phosphate supported on their surfaces, can also be used. In such a dephosphorization operation, the surface activity of the catalytic dephosphorizing material 3 deteriorates due to the formation of calcium carbonate and the adhesion of impurities in the raw water on the catalytic dephosphorizing material 3, resulting in a decrease in the dephosphorizing function. Therefore, first, simultaneously with the passage of raw water to the dephosphorization tower 2 or after a certain period of time, the catalytic dephosphorization material 3 in the tower is continuously or intermittently fed into the reaction tank 6 from the extraction pipe 5. The catalytic dephosphorizing material is brought into contact with the acid aqueous solution in the reaction tank 6 by supplying the acid aqueous solution from the tank 14 with the pump 7 and occasionally stirring the acid aqueous solution with the agitator 8. The acid aqueous solution that has undergone the contact treatment is discharged from the drain pipe 9. The acid used in the contact treatment may be a mineral acid or an organic acid, and the appropriate acid concentration is 0.5 to 20%. The contact reaction completes in a short time, so the contact time is
30-60 minutes is sufficient. Next, a pipe 10 introducing tap water into the reaction tank 6 as washing water.
Tap water is then introduced, and the catalytic dephosphorization material 3 is washed until the pH of the washing wastewater no longer decreases, and then returned to the dephosphorization tower 2 by the pump 11, and the washing wastewater is sent to the drain pipe 9.
more excreted. However, this washing step may be omitted depending on the type of raw water to be dephosphorized. In addition, the dephosphorization capacity of the catalytic dephosphorizing material 3 can be increased by performing the same operation as in the reaction tank 6 in the contact treatment outside the tower in the dephosphorizing tower 2 without leading the catalytic dephosphorizing material 3 outside the tower. It is also possible to increase
In this case, the acid aqueous solution used for the contact treatment is made to flow upward through the dephosphorization tower 2 from the inflow pipe 12 to the outflow pipe 13, and is brought into contact with the catalytic dephosphorization material 3 under conditions such that it expands and becomes fluidized. It is even more effective. The catalytic dephosphorization material is contacted with an acid aqueous solution not only when the dephosphorizing effect of the catalytic dephosphorization material decreases due to the passage of the liquid to be treated; It can also be used when adjusting phosphor materials. That is, as mentioned above,
There are various types of catalytic dephosphorization materials, and depending on the type, some have calcium carbonate deposited on their surface or organic matter attached to them. By contacting the liquid with an acid aqueous solution in advance before passing the liquid through it, the dephosphorization ability can be maintained in a good state from the beginning. As described above, according to the method of the present invention, the dephosphorizing effect of the catalytic dephosphorizing material can be maintained in a good state for a long period of time by contacting the catalytic dephosphorizing material with an acid aqueous solution as necessary during the dephosphorizing operation. can be maintained,
Stable dephosphorization treatment is now possible. Next, examples of the method of the present invention will be shown. Example 1 A cylindrical dephosphorization tower with a diameter of 0.5 m and an effective depth of 25 m was filled with crushed and sieved phosphate rock having a particle size of 0.42 to 0.54 mm. Secondary treatment water, which is obtained by treating sewage from which coarse solids have been roughly separated using the conventional activated sludge method, is used as the treatment liquid, and the pH of the treatment liquid is brought to around 9.0 with caustic soda (the same effect was obtained with slaked lime). In addition, calcium chloride was used as the calcium agent, and the molar weight ratio of Ca/PO 4 was adjusted to be in the range of 1.0 to 15, depending on the concentration of soluble phosphates in the liquid to be treated. The added liquid to be treated was introduced into the dephosphorization tower, and water was passed from the top to the bottom at a flow rate of LV=2.5 m/H. The entire amount of contact dephosphorization material is taken out once a month.
Contact treatment was carried out by immersing it in 1 m 3 of 0.2% hydrochloric acid solution for about 1 hour. After washing the catalytic dephosphorization material that had been contacted with hydrochloric acid with tap water, water flow experiments were conducted for approximately 12 months while periodically returning the material to the dephosphorization tower. The results are shown in Table-1.
【表】
表―１より明らかなように、充填した接触脱リ
ン材を１ケ月に１回全量を取り出して酸処理しな
がら通水した処理水の濃度は、12ケ月経過しても
約0.3mg／を維持することができ、脱リン効果
の低減は全く認められなかつた。
一方比較例として、接触脱リン材の酸処理を行
なわず他はすべて同一条件で12ケ月間処理を継続
した場合の結果は同じく表―１に示す通りで、通
水当初の脱リン効果は顕著であつても通水開始12
ケ月後の処理水のリン濃度は約1.2mg／とな
り、脱リン効果は著しく悪化した。
実施例 ２
実施例１と同一条件で調整した下水二次処理水
を12ケ月通水し、リン除去性能の低下した接触脱
リン材を脱リン塔より抜き出し、濃度約２％の塩
酸、硫酸、硝酸、リン酸の各水溶液に１時間浸漬
して無機性の酸水溶液と接触処理した。
一方、濃度10％の酢酸、くえん酸、酒石酸の各
水溶液に上記接触脱リン材を一時間浸漬して有機
性の酸水溶液と接触処理した。この場合、接触脱
リン材は500ｇずつ用い酸水溶液は１使用し
た。
酸処理した接触脱リン材は水道水で洗浄後内径
25mmの脱リン塔に充填し、実施例１と同一の条件
でLV＝25（ｍ／Ｈ）で約１ケ月通水しリン除去
性能を比較した。
結果を表―２に示す。[Table] As is clear from Table 1, the concentration of the treated water in which the filled catalytic dephosphorization material was taken out once a month and passed through it while being treated with acid was approximately 0.3 mg even after 12 months had passed. / could be maintained, and no reduction in the dephosphorization effect was observed at all. On the other hand, as a comparative example, when the catalytic dephosphorization material was not acid-treated and the treatment was continued for 12 months under the same conditions, the results are also shown in Table 1, and the dephosphorization effect at the beginning of water flow was remarkable. Water starts flowing even at 12
After several months, the phosphorus concentration in the treated water was approximately 1.2mg/, and the dephosphorization effect deteriorated significantly. Example 2 Secondary treated sewage water prepared under the same conditions as in Example 1 was passed through the water for 12 months, and the catalytic dephosphorization material with reduced phosphorus removal performance was extracted from the dephosphorization tower and treated with hydrochloric acid, sulfuric acid, and sulfuric acid with a concentration of approximately 2%. It was immersed in each aqueous solution of nitric acid and phosphoric acid for 1 hour, and was subjected to contact treatment with an inorganic acid aqueous solution. On the other hand, the above-mentioned catalytic dephosphorization material was immersed in each aqueous solution of acetic acid, citric acid, and tartaric acid at a concentration of 10% for one hour to be brought into contact with the organic acid aqueous solution. In this case, 500 g of catalytic dephosphorization material was used and one acid aqueous solution was used. The inner diameter of the acid-treated catalytic dephosphorization material was washed with tap water.
It was packed in a 25 mm dephosphorization tower, and water was passed through it for about 1 month at LV=25 (m/H) under the same conditions as in Example 1, and the phosphorus removal performance was compared. The results are shown in Table-2.
【表】
表―２より明らかなように接触脱リン材の酸処
理に使用する酸は無機性の酸（塩酸、硫酸、硝
酸、リン酸）でも有機性の酸（酢酸、くえん酸、
酒石酸）でもリン除去性能は殆んど変らず、いず
れの酸でも使用可能であることを確認することが
できた。
実施例 ３
実施例２と同様に12ケ月脱リン材処理に使用し
てリン除去性能が低下した接触脱リン材各500ｇ
を、濃度0.2％、５％、10％の塩酸水溶液中にそ
れぞれ１時間浸漬して接触処理した。一方、濃度
５％、10％、20％、の酢酸溶液に前記接触脱リン
材を１時間浸漬して接触処理した。
酸処理した各接触脱リン材は水道水で洗浄した
後、内径25mmの脱リン塔にそれぞれ充填し、実施
例１と同一条件でLV＝2.5（ｍ／Ｈ）で約１ケ月
通水し、リン除去性能を比較した結果を表―３に
示す。[Table] As is clear from Table 2, the acids used for acid treatment of catalytic dephosphorization materials include inorganic acids (hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid) and organic acids (acetic acid, citric acid,
Even with tartaric acid), the phosphorus removal performance remained almost unchanged, confirming that any acid could be used. Example 3 500g each of catalytic dephosphorization materials whose phosphorus removal performance decreased after 12 months of dephosphorization treatment as in Example 2
were immersed in aqueous hydrochloric acid solutions with concentrations of 0.2%, 5%, and 10% for 1 hour, respectively, for contact treatment. On the other hand, the catalytic dephosphorization material was immersed in an acetic acid solution having a concentration of 5%, 10%, and 20% for 1 hour for contact treatment. After washing each acid-treated catalytic dephosphorization material with tap water, it was packed into a dephosphorization tower with an inner diameter of 25 mm, and water was passed through it for about 1 month at LV = 2.5 (m/H) under the same conditions as in Example 1. Table 3 shows the results of comparing the phosphorus removal performance.
【表】
表―３より明らかなように塩酸で処理した接触脱
リン材の30日後の処理水のリン濃度はいずれもほ
とんど同じで塩酸の濃度の差によるリン除去性能
の有位差は認められず、0.2％の稀薄な濃度でも
高濃度と同じ酸処理が可能であることを確認でき
た。
従つて酸処理する場合の塩酸の濃度は0.2〜５
％の範囲で適当に稀釈すればよい。
一方有機性の酸である酢酸の場合は塩酸と異な
り、30日通水した処理水のリン濃度は10％の濃度
で処理した場合が最低であるところから濃度条件
がリン除去性能に有位差をあたえることが明らか
となり酢酸で接触処理する場合の濃度は約10％が
最適条件でありこの条件を守ることにより効率よ
く酸処理することができる。
実施例 ４
実施例２〜３と同様に12ケ月脱リン処理に使用
してリン除去性能が低下した接触脱リン材各500
ｇを２％の塩酸の水溶液１中にそれぞれ30分、
60分、120分浸漬して接触処理した。
酸処理が終了した接触脱リン材を酸と分離し、
水道水で洗浄した後、内径25mmの脱リン塔に充填
し、実施例１と同一条件でLV＝2.5（ｍ／Ｈ）で
約１ケ月通水しリン除去性能を比較した。結果を
表―４に示す。[Table] As is clear from Table 3, the phosphorus concentration of the treated water after 30 days from the catalytic dephosphorization materials treated with hydrochloric acid is almost the same, and there is no difference in the phosphorus removal performance due to the difference in the concentration of hydrochloric acid. First, we were able to confirm that acid treatment at a dilute concentration of 0.2% can be performed in the same manner as at a high concentration. Therefore, the concentration of hydrochloric acid in acid treatment is 0.2 to 5.
It may be diluted appropriately within the range of %. On the other hand, in the case of acetic acid, which is an organic acid, unlike hydrochloric acid, the phosphorus concentration of treated water that has been passed for 30 days is the lowest when treated at a concentration of 10%, so the concentration conditions have a significant difference in phosphorus removal performance. It has become clear that the optimum concentration for contact treatment with acetic acid is about 10%, and by maintaining this condition, the acid treatment can be carried out efficiently. Example 4 500 each of catalytic dephosphorization materials whose phosphorus removal performance decreased after being used for 12 months of dephosphorization treatment as in Examples 2 and 3.
g in 1 aqueous solution of 2% hydrochloric acid for 30 minutes each.
Contact treatment was performed by immersing for 60 minutes and 120 minutes. After acid treatment, the catalytic dephosphorization material is separated from the acid,
After washing with tap water, it was packed into a dephosphorization tower with an inner diameter of 25 mm, and water was passed through it for about 1 month at LV = 2.5 (m/H) under the same conditions as in Example 1, and the phosphorus removal performance was compared. The results are shown in Table 4.
【表】
表―４より明らかなように処理水のリン濃度は
浸漬時間が30分でも120分でも変らず、従つて30
分浸漬すれば十分であることがわかつた。
実施例 ５
実施例２と同様に12ケ月脱リン処理に使用して
リン除去性能が低下した接触脱リン材500ｇを純
水を満した２のビーカにとり、この液に炭酸ガ
スを１分間に５の割合で約１時間吹き込んで接
触処理した。
炭酸で処理した接触脱リン材は水道水で洗浄し
た後内径25mmの脱リン塔に充填し、実施例１と同
一条件でLV＝25（ｍ／Ｈ）で約１ケ月通水しリ
ン除去性を比較した。この結果を表―５に示す。[Table] As is clear from Table 4, the phosphorus concentration of the treated water does not change whether the immersion time is 30 minutes or 120 minutes.
It was found that immersion for a minute was sufficient. Example 5 As in Example 2, 500 g of catalytic dephosphorization material whose phosphorus removal performance had deteriorated after being used for 12 months of dephosphorization treatment was placed in a beaker 2 filled with pure water, and carbon dioxide gas was added to this liquid at 50% per minute. Contact treatment was carried out by blowing at a rate of about 1 hour. The catalytic dephosphorization material treated with carbonic acid was washed with tap water, then packed into a dephosphorization tower with an inner diameter of 25 mm, and water was passed through it at LV = 25 (m/H) for about 1 month under the same conditions as in Example 1 to improve phosphorus removal properties. compared. The results are shown in Table-5.
【表】
表―５より明らかなように接触脱リン材のリン
除去能力は未使用と比較してはるかに改善されて
おり、通常の酸溶液による酸処理のみならず、炭
酸ガスを酸処理法として適用することが可能であ
ることを確認できた。[Table] As is clear from Table 5, the phosphorus removal ability of the catalytic dephosphorization material is much improved compared to unused material. It was confirmed that it can be applied as
図面は、本発明方法の一実施例のフローシート
である。
１…原水流入管、２…脱リン塔、３…接触脱リ
ン材、４…処理水流出管、５…取出管、６…反応
槽、７…ポンプ、８…撹拌機、９…排水管、１０
…水道水導入管、１１…ポンプ、１２…流入管、
１３…流出管、１４…タンク。
The drawing is a flow sheet of one embodiment of the method of the present invention. 1... Raw water inflow pipe, 2... Dephosphorization tower, 3... Catalytic dephosphorization material, 4... Treated water outflow pipe, 5... Takeout pipe, 6... Reaction tank, 7... Pump, 8... Stirrer, 9... Drain pipe, 10
...Tap water introduction pipe, 11...Pump, 12...Inflow pipe,
13... Outflow pipe, 14... Tank.
Claims (1)
被処理液を通液することにより、液中に存在する
リン酸塩類を除去する方法において、前記接触脱
リン材を酸水溶液と接触処理し、該接触脱リン材
の脱リン能力を向上せしめることを特徴とする接
触脱リン法。 ２ 前記接触脱リン材と酸水溶液を接触する際
に、使用する酸水溶液の濃度を0.5〜20％として
処理する特許請求の範囲第１項記載の方法。 ３ 前記被処理液中に存在するリン酸塩類を除去
する際に、該液を酸又はアルカリのPH調整剤でPH
を6.0〜11.0に調整して処理するものである特許
請求の範囲第１項又は第２項記載の方法。 ４ 前記接触脱リン材が、リン酸塩鉱物を破砕し
た粒径0.4〜1.0mmのものを用いてこれに被処理液
を接触処理させるものである特許請求の範囲第１
項、第２項又は第３項記載の方法。 ５ 前記接触脱リン材が、鉱酸で処理され、洗浄
水で洗浄してから用いられるものである特許請求
の範囲第２項、第３項又は第４項記載の方法。[Scope of Claims] 1. A method for removing phosphates present in a liquid by passing a liquid to be treated through a catalytic dephosphorizing material containing calcium phosphate, wherein the catalytic dephosphorizing material is brought into contact with an acid aqueous solution. A catalytic dephosphorization method characterized by improving the dephosphorization ability of the catalytic dephosphorization material. 2. The method according to claim 1, wherein the concentration of the acid aqueous solution used is 0.5 to 20% when the catalytic dephosphorization material and the acid aqueous solution are brought into contact with each other. 3. When removing phosphates present in the liquid to be treated, the liquid is PH adjusted with an acid or alkaline PH adjuster.
3. The method according to claim 1 or 2, wherein the treatment is performed by adjusting the amount of water to 6.0 to 11.0. 4. Claim 1, wherein the catalytic dephosphorizing material is a crushed phosphate mineral with a particle size of 0.4 to 1.0 mm, and the liquid to be treated is contacted with the catalytic dephosphorizing material.
2. The method described in Section 2, Section 2, or Section 3. 5. The method according to claim 2, 3 or 4, wherein the catalytic dephosphorization material is treated with a mineral acid and washed with washing water before use.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9398681A JPS57209681A (en) | 1981-06-19 | 1981-06-19 | Catalytic dephosphorization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9398681A JPS57209681A (en) | 1981-06-19 | 1981-06-19 | Catalytic dephosphorization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57209681A JPS57209681A (en) | 1982-12-23 |
| JPS6230835B2 true JPS6230835B2 (en) | 1987-07-04 |
Family
ID=14097715
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9398681A Granted JPS57209681A (en) | 1981-06-19 | 1981-06-19 | Catalytic dephosphorization |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57209681A (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53103973A (en) * | 1977-02-23 | 1978-09-09 | Ebara Infilco Co Ltd | Removing method for phosphoric acid salts in liquid |
-
1981
- 1981-06-19 JP JP9398681A patent/JPS57209681A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57209681A (en) | 1982-12-23 |
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