JPH0130554B2 - - Google Patents
Info
- Publication number
- JPH0130554B2 JPH0130554B2 JP59025742A JP2574284A JPH0130554B2 JP H0130554 B2 JPH0130554 B2 JP H0130554B2 JP 59025742 A JP59025742 A JP 59025742A JP 2574284 A JP2574284 A JP 2574284A JP H0130554 B2 JPH0130554 B2 JP H0130554B2
- Authority
- JP
- Japan
- Prior art keywords
- dephosphorization
- water
- fluidized bed
- treated
- liquid
- 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
- 239000003795 chemical substances by application Substances 0.000 claims description 25
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 23
- 239000011574 phosphorus Substances 0.000 claims description 23
- 229910052698 phosphorus Inorganic materials 0.000 claims description 23
- 239000007788 liquid Substances 0.000 claims description 22
- 239000000463 material Substances 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 21
- 229910019142 PO4 Inorganic materials 0.000 claims description 11
- 235000021317 phosphate Nutrition 0.000 claims description 11
- 150000003013 phosphoric acid derivatives Chemical class 0.000 claims description 11
- 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
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims description 2
- 229910001424 calcium ion Inorganic materials 0.000 claims description 2
- 239000002351 wastewater Substances 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 45
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 21
- 230000003197 catalytic effect Effects 0.000 description 18
- 239000011575 calcium Substances 0.000 description 17
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 14
- 229910052791 calcium Inorganic materials 0.000 description 14
- 238000002347 injection Methods 0.000 description 8
- 239000007924 injection Substances 0.000 description 8
- 235000011121 sodium hydroxide Nutrition 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 238000010979 pH adjustment Methods 0.000 description 5
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 4
- 239000001110 calcium chloride Substances 0.000 description 4
- 229910001628 calcium chloride Inorganic materials 0.000 description 4
- 238000002425 crystallisation Methods 0.000 description 4
- 230000008025 crystallization Effects 0.000 description 4
- 239000010802 sludge Substances 0.000 description 4
- 239000003513 alkali Substances 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 238000002203 pretreatment Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 2
- 239000000920 calcium hydroxide Substances 0.000 description 2
- 235000011116 calcium hydroxide Nutrition 0.000 description 2
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 239000010440 gypsum Substances 0.000 description 2
- 229910052602 gypsum Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 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 2
- 239000007787 solid Substances 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 239000010800 human waste Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052816 inorganic phosphate Inorganic materials 0.000 description 1
- 239000008239 natural water Substances 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 229910052585 phosphate mineral Inorganic materials 0.000 description 1
- 239000002367 phosphate rock Substances 0.000 description 1
- 230000005070 ripening Effects 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000010865 sewage Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Landscapes
- Removal Of Specific Substances (AREA)
Description
本発明は、下水、し尿系汚水、工場排水その他
液体中に比較的高濃度で存在するリン酸塩類を流
動化状態にあるリン酸カルシウムを含有する接触
脱リン材を用いて効率良く除去する方法に関する
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」、「赤潮」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、その一つとしてさきに本発明者等
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シウム剤を加
え、これを接触脱リン材が流動化する一定の流速
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
る脱リン技術である。
しかしながら今までに述べた従来の流動層式接
触脱リン法には以下のような欠点があつた。
従来法は流入水にアルカリ剤を注入し、PH調整
を行なつた後、流動化状態にある脱リン材と接触
せしめたリンを除去するものであるが、特にリン
濃度が高い場合には、層流入点、即ち層入口附近
の接触脱リン材層と被処理液とが接触する部分で
直ちにPHが急撃に低下してしまうため、それより
上方の大部分の接触脱リン材層のPHは最適PH範囲
から大きく逸脱した状態になつてしまい、その部
分では反応が全く進行しないという状況に、しば
しば陥つた。このため、層内で晶析反応に関与す
る有効な接触脱リン材が極端に少なくなるために
処理が著しく悪化し、流動層式接触脱リン方法に
とつて致命的なものとなつてしまつた。
このような問題点を解決する方法として前段PH
調整槽でアルカリ剤注入量を増加させ、予め流入
PHを高く設定して層内のPHを高める等の運転上の
工夫がなされてきたが、脱リン層前段でPHを高く
設定すると、リン酸凝集反応や被処理液中の有機
物等のコロイド化のみを促進し大量のSSを発生
するばかりでなく、脱リン層本体での晶析反応を
阻害する等の悪影響を生み出す結果となることが
多く根本的な解決策となるものではなかつた。
本発明は、このように従来、流動層式接触脱リ
ン法において問題であつたPH低下によつて脱リン
能力が低下する欠点を解消し、効率良く安定した
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
触脱リン材が流動する条件で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をカルシウム
イオンの存在下において液中のリンを除去する方
法において、脱リン材の流動層内の上部でPHを検
知し、流動層内の下部にアルカリ剤適宜注入して
層内のPHを8.5〜11.0の範囲に望ましくは9.0〜9.5
の範囲に保持しながら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第１図に基づき説
明すればまず被処理液中の粗大固形物その他の爽
雑物を適当な前処理によつて除去する。この様な
前処理操作を経た原水を酸又は苛性ソーダ、消石
灰などのアルカリのPH調整剤でPHを6.0〜11.0望
ましくは6.0〜9.0に調整し、塩化カルシウム、石
膏などのカルシウム剤を加えて脱リン塔４下部へ
導入する。この脱リン塔４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けして一
定の粒径とした接触脱リン材が充填してあり、被
処理液は下部から接触脱リン材が流動化する一定
の通液速度でこれと接触しながら上昇し、処理水
流出管５から塔外へ導出される。
この際、添加される前記カルシウム剤の注入点
は、カルシウム剤がイオン状のまま前記脱リン塔
（流動層）内に流入する如く注意する必要があり、
従つて有効な具体的手段として例えば、流動層に
直接またはその直前において注入するのがよい。
さらに必要に応じ接触脱リン工程では処理水流出
液の一部を流動層に直接循環させるか、あるいは
原水導入管に返流させて流動層に通液するように
することもできる。
かかる脱リン操作においてPHを調整した高濃度
のリンを含む原水が層流入点即ち層入口附近の脱
リン材層Ａと接触すると、直ちにPHが大きく低下
することにより、その上の脱リン材層ＢのPHは最
適PH範囲から逸脱した状態になつてしまうので、
まず、流動層内の上部ＤでPHを検知し、適宜アル
カリ剤を流動層内の下部Ｃから層本体に直接注入
することでPHを全層にわたつて最適な範囲に保持
し、効率良く脱リン反応を行なうことができる。
前記流動層内へのアルカリ剤の注入点およびPHの
検知位置は原水の性状および通液条件に応じて単
数もしくは複数箇所、適宜できる。
以上述べた様に、本発明によれば、流動層内に
アルカリ剤を直接注入して流動層内PH低下を妨止
し、流動層全体にわたつてPHを均一に保持するこ
とにより接触脱リン処理をきわめて効果的にかつ
安定して行なうことが可能となつた。さらに流動
層内にアルカリを直接注入することにより発生し
たSSの脱リン材への晶析固着を促進できSS発生
量即ち汚泥発生量を著しく低減できる。また脱リ
ン材に直接アルカリ剤を接触させることにより脱
リン材の晶析熟成が加速され、脱リン材表面状態
を著しく活性化する効果をも合わせもつことがで
きる。
実施例 １
内径100mm〓、有効深さ2.5ｍの円筒状で底部が
逆円錘型をした脱リン塔にリン鉱石を破砕、篩分
けしたもの（有効径0.40mm、均等係数1.4）を
1000mm厚充填した。粗大固形物を大別分離した工
場廃水を活性汚泥法で処理した２次処理水を被処
理液とし酸性ストリツプ法で炭酸を除去した後、
苛性ソーダを約12mg／添加し、被処理液のPHを
9.0に調整したものを原水とし、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の重
量比が1.0〜15の範囲になるように循環水へ添加
した。原水および原水と同量の循環水を脱リン塔
下部より上方にLV＝30〜40ｍ／Ｈの流速で通水
した。接触脱リン塔の流動層内の上部にPH計を浸
没設置し、この点においてPHが9.5になるよう苛
性ソーダを同じく接触脱リン塔の流動層内の下部
へ約23mg／直接注入し、約２ケ月間の通水実験
を行なつた。この結果を表−１に示す。
The present invention relates to a method for efficiently removing phosphates present in relatively high concentrations in sewage, human waste water, industrial wastewater, and other liquids using a catalytic dephosphorization material containing calcium phosphate in a fluidized state. It is. 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 occurrence of "blue water" and "red tide" in closed or stagnant waters such as lakes, inland seas, and inner bays. Furthermore, when water is used for various purposes, living organisms may be present in equipment and piping. Chemical slime and chemical scale are formed, which is a serious cause of accidents. Therefore, since it is necessary to remove the phosphates present in these liquids, various phosphorus removal methods are being considered. A cylindrical or conical dephosphorization tower is filled with a catalytic dephosphorization material containing calcium phosphate with a certain particle size, and the pH of the liquid to be treated is adjusted to a range of 6 to 11. A calcium agent such as calcium chloride is added in accordance with the concentration of soluble phosphates contained, and the catalytic dephosphorization material is passed through the contact at a constant flow rate to fluidize it. We proposed a method to remove soluble phosphates by crystallizing and fixing calcium hydroxyapatite crystals on the surface of the dephosphorizing material. A typical chemical reaction on the surface of the catalytic dephosphorization 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 this dephosphorization method is applied, the catalytic dephosphorization material to which calcium hydroxyapatite is fixed can be removed. Separation and dewatering are extremely easy, and compared to so-called flocculated sludge made using conventional chemical flocculation and sedimentation methods, it not only does not require preconceived sludge treatment facilities such as thickening equipment, dewatering equipment, and drying equipment. , is a dephosphorization technology that can recover phosphorus as a resource. However, the conventional fluidized bed catalytic dephosphorization method described so far has the following drawbacks. The conventional method involves injecting an alkaline agent into the inflow water, adjusting the pH, and then removing the phosphorus that has come into contact with the fluidized dephosphorization material, but when the phosphorus concentration is particularly high, At the bed inflow point, that is, the area where the catalytic dephosphorization material layer near the bed inlet and the liquid to be treated come into contact, the PH immediately drops rapidly, so the PH of most of the catalytic dephosphorization material layer above it drops. often fell into a situation where the pH value of the reactor deviated significantly from the optimum pH range, and the reaction did not proceed at all in that region. As a result, the amount of effective catalytic dephosphorization material involved in the crystallization reaction in the bed is extremely reduced, resulting in a significant deterioration of the process, which is fatal to the fluidized bed catalytic dephosphorization method. . As a way to solve such problems, the first stage PH
Increase the amount of alkaline agent injected in the adjustment tank and pre-inflow
Operational measures have been taken to increase the PH in the layer by setting the PH high, but setting the PH high before the dephosphorization layer causes phosphoric acid aggregation reactions and colloidization of organic matter in the liquid to be treated. This was not a fundamental solution, as it not only promoted the dephosphorization and generated a large amount of SS, but also resulted in negative effects such as inhibiting the crystallization reaction in the dephosphorization layer itself. The object of the present invention is to provide a method that can remove phosphorus efficiently and stably by solving the problem of the dephosphorization ability decreasing due to a decrease in pH, which has been a problem in the conventional fluidized bed catalytic dephosphorization method. The purpose is to That is, the present invention provides a method for removing phosphorus present in the liquid in the presence of calcium ions by passing the liquid to be treated under conditions in which a catalytic dephosphorizing material containing calcium phosphate flows. , the PH is detected at the upper part of the fluidized bed of the dephosphorizing material, and an alkaline agent is appropriately injected into the lower part of the fluidized bed to bring the PH in the bed to a range of 8.5 to 11.0, preferably 9.0 to 9.5.
It is characterized by processing while maintaining the range of . One embodiment of the present invention will be described below with reference to FIG. 1. First, coarse solids and other impurities in the liquid to be treated are removed by an appropriate pretreatment. The raw water that has undergone such pretreatment is adjusted to a pH of 6.0 to 11.0, preferably 6.0 to 9.0, using an acid or an alkaline pH regulator such as caustic soda or slaked lime, and then dephosphorized by adding calcium agents such as calcium chloride or gypsum. Introduced into the lower part of tower 4. This dephosphorization tower 4 is filled with a catalytic dephosphorizing material that crushes and sieves phosphate minerals containing calcium phosphate to a certain particle size, and the catalytic dephosphorizing material is poured into the treated liquid from the bottom. The treated water rises while coming into contact with it at a constant flow rate to fluidize it, and is led out of the tower from the treated water outflow pipe 5. At this time, care must be taken regarding the injection point of the calcium agent to be added so that the calcium agent flows into the dephosphorization tower (fluidized bed) in an ionic state.
Therefore, an effective specific method is, for example, to inject it directly into the fluidized bed or immediately before it.
Furthermore, if necessary, in the catalytic dephosphorization step, a part of the treated water effluent may be directly circulated to the fluidized bed, or may be returned to the raw water introduction pipe and passed through the fluidized bed. In such a dephosphorization operation, when the raw water containing highly concentrated phosphorus whose pH has been adjusted comes into contact with the dephosphorization material layer A near the layer inflow point, that is, the layer entrance, the PH immediately decreases greatly, causing the dephosphorization material layer above it to drop. Since the PH of B will deviate from the optimal PH range,
First, the PH is detected at the upper part D of the fluidized bed, and an appropriate alkaline agent is directly injected into the bed body from the lower part C of the fluidized bed to maintain the PH within the optimum range throughout the bed and efficiently desorb the fluid. A phosphorus reaction can be carried out.
The injection point of the alkali agent into the fluidized bed and the PH detection position can be set at one or more locations as appropriate depending on the properties of the raw water and the conditions for flowing the fluid. As described above, according to the present invention, an alkaline agent is directly injected into the fluidized bed to prevent the pH from decreasing in the fluidized bed, and the PH is maintained uniformly throughout the fluidized bed, thereby achieving catalytic dephosphorization. It has become possible to carry out the treatment extremely effectively and stably. Furthermore, by directly injecting alkali into the fluidized bed, the crystallization and fixation of generated SS to the dephosphorization material can be promoted, and the amount of SS generated, that is, the amount of sludge generated, can be significantly reduced. Furthermore, by bringing the alkaline agent into direct contact with the dephosphorizing material, the crystallization and ripening of the dephosphorizing material can be accelerated, and it can also have the effect of significantly activating the surface condition of the dephosphorizing material. Example 1 The crushed and sieved phosphate rock (effective diameter 0.40 mm, uniformity factor 1.4) was placed in a cylindrical dephosphorization tower with an inner diameter of 100 mm and an effective depth of 2.5 m and an inverted conical bottom.
Filled with a thickness of 1000mm. Factory wastewater from which coarse solids have been roughly separated is treated using the activated sludge method. The secondary treated water is used as the liquid to be treated, and carbon dioxide is removed using the acid strip method.
Add about 12 mg of caustic soda to adjust the pH of the liquid to be treated.
The raw water was adjusted to 9.0, and calcium chloride was used as a calcium agent, so that the Ca/PO 4 weight ratio was in the range of 1.0 to 15, depending on the concentration of soluble phosphates in the liquid to be treated. was added to the circulating water. Raw water and circulating water in the same amount as the raw water were passed above the lower part of the dephosphorization tower at a flow rate of LV = 30 to 40 m/H. A PH meter was submerged in the upper part of the fluidized bed of the catalytic dephosphorization tower, and about 23 mg of caustic soda was directly injected into the lower part of the fluidized bed of the catalytic dephosphorization tower so that the pH at this point was 9.5. A water flow experiment was conducted for several months. The results are shown in Table-1.
【表】
表−１から明らかなように流動層内のPHを調整
しながら通水した結果、リン除去率70％以上、リ
ン濃度３mg／asP以下の処理水が安定して得ら
れた。一方、比較例として層内のPH調整は行なわ
ず、他は全て同条件で２ケ月間通水した場合の結
果は同じく表−１の比較例１に示す通りであるが
処理水PHが8.5と低下し、リン除去率は40％、処
理水リン濃度6.0mg／asP程度の水質しか得られ
なかつた。また比較例の方法において苛性ソーダ
注入率を増加させ原水のPHを高めた場合の結果も
同じく表−１の比較例２に示したが、前記本発明
方法と同程度の苛性ソーダを注入しているのにも
かかわらず、リン除去率は70％未満でかつSS発
生量が増大する結果となつた。
実施例 ２
実施例１と同一の実験装置、被処理液を用い、
前処理段階での苛性ソーダ注入による被処理液の
PH調整は行なわず、脱リン塔内においてのみ苛性
ソーダを注入してPHを9.0〜9.5に調整し、他の前
処理方法、カルシウム剤添加方法、通水方法等は
全く実施例１と同一にして、約２ケ月間通水実験
を行なつた。結果を表−２に示す。[Table] As is clear from Table 1, as a result of flowing water while adjusting the pH in the fluidized bed, treated water with a phosphorus removal rate of 70% or more and a phosphorus concentration of 3 mg/asP or less was stably obtained. On the other hand, as a comparative example, when water was passed for two months under the same conditions without adjusting the pH in the layer, the results are as shown in Comparative Example 1 in Table 1, but the pH of the treated water was 8.5. The phosphorus removal rate was 40%, and the phosphorus concentration in the treated water was only about 6.0 mg/asP. In addition, the results when the pH of the raw water was raised by increasing the caustic soda injection rate in the method of the comparative example are also shown in Comparative Example 2 in Table 1. Despite this, the phosphorus removal rate was less than 70% and the amount of SS generated increased. Example 2 Using the same experimental equipment and liquid to be treated as in Example 1,
of the liquid to be treated by injection of caustic soda in the pre-treatment stage.
No pH adjustment was performed, and the pH was adjusted to 9.0 to 9.5 by injecting caustic soda only in the dephosphorization tower, and the other pretreatment methods, calcium agent addition method, water flow method, etc. were completely the same as in Example 1. We conducted water flow experiments for about two months. The results are shown in Table-2.
【表】
表−２から明らかなように、原水のPH調整を行
なわず、流動層内においてのみPH調整しながら運
転しても、リン除去率65％以上、リン濃度4.0
mg／asP以下の水質が安定して得られた。一
方、比較例として原水のPH調整のみを行ない、層
内でのPH調整は行なわず他は全て同条件で２ケ月
間通水した場合の結果は同じく表−２に示す通り
であるが、リン除去率38％、リン濃度6.0mg／
を超える処理水しか得られなかつた。以上の結果
から層内で直接PH調整する方が効果的であること
が確認できた。
実施例 ３
実施例１において層内のPHがリン除去性能にど
のように影響するかを調べた。使用した装置、被
処理液および被処理液の前処理方法、通水条件等
は全く実施例１と同一で行なつた。表−３に結果
を示す。[Table] As is clear from Table 2, even if the operation is performed while adjusting the pH of the raw water only in the fluidized bed, the phosphorus removal rate is 65% or more, and the phosphorus concentration is 4.0.
Water quality below mg/asP was stably obtained. On the other hand, as a comparative example, only the PH adjustment of the raw water was performed, but no PH adjustment was performed within the layer, and water was passed for two months under the same conditions.The results are also shown in Table 2, but the phosphorus Removal rate 38%, phosphorus concentration 6.0mg/
However, only treated water exceeding From the above results, it was confirmed that direct pH adjustment within the layer is more effective. Example 3 In Example 1, it was investigated how the pH within the layer affected the phosphorus removal performance. The equipment used, the liquid to be treated, the pretreatment method for the liquid to be treated, the water flow conditions, etc. were exactly the same as in Example 1. The results are shown in Table-3.
【表】
表−３から明らかな様に、層内PHが高くなるほ
ど、リン除去性能が良くなる傾向があり、PH8.5
以上にするとリン除去率が50％以上となつた。し
かし、層内PHの上昇は一方ではSS発生量を高め
る傾向があり、PH12になるとSSが67mg／と極
端に増加した。
実施例 ４
実施例１の実験において、カルシウム剤の検討
をするため、塩化カルシウムの他に石膏および消
石灰をそれぞれ使用し、性能を比較した。実施例
１と同一の装置、被処理液を用い、被処理液を同
様な方法で前処理したものを原水とした。カルシ
ウム剤は原水中の溶解性リン酸塩類の濃度に対応
してCa／PO4の重量比が２〜３の範囲になるよ
うに循環水に添加し、原水と循環水の流量比が１
になるようにして脱リン塔下部から上方へLV＝
30〜40ｍ／Ｈの流速で通水した。層内のPHを9.5
になるように苛性ソーダを注入して調整しながら
前記３種のカルシウム剤を代えて各約１ケ月間通
水した。結果を表−４に示す。[Table] As is clear from Table 3, the higher the PH in the layer, the better the phosphorus removal performance.
When the above amount was used, the phosphorus removal rate was over 50%. However, an increase in the intralayer PH tends to increase the amount of SS generated, and when the pH reached 12, the SS increased dramatically to 67 mg/. Example 4 In the experiment of Example 1, in order to examine calcium agents, gypsum and slaked lime were used in addition to calcium chloride, and their performances were compared. Using the same equipment and liquid to be treated as in Example 1, the liquid to be treated was pretreated in the same manner as raw water. The calcium agent is added to the circulating water so that the Ca/PO 4 weight ratio is in the range of 2 to 3, depending on the concentration of soluble phosphates in the raw water, and the flow rate ratio of the raw water and circulating water is 1.
From the bottom of the dephosphorization tower upwards, LV=
Water was passed through at a flow rate of 30 to 40 m/H. PH in layer 9.5
The three types of calcium agents were changed and water was passed through the tube for about one month each, while adjusting the amount of caustic soda injected so as to give the following conditions. The results are shown in Table 4.
【表】
表４から明らかなように前記３種のどのカルシ
ウム剤を使用しても原水中の70％以上リンが除去
されることがわかり、本方式のカルシウム剤とし
て使用できることを確認した。[Table] As is clear from Table 4, it was found that 70% or more of phosphorus in raw water was removed no matter which of the three types of calcium agents were used, confirming that they can be used as calcium agents in this method.
第１図は本発明の一実施態様を示す系統説明図
である。
１……PH調整槽、２……原水流入管、２′……
原水ポンプ、３……循環水導入管、３′……循環
水ポンプ、４……脱リン塔、５……処理水流出
管、６……アルカリ剤貯槽、７，８……アルカリ
剤注入管、７′，８′……アルカリ剤注入ポンプ、
９……カルシウム剤注入管、９′……カルシウム
剤注入ポンプ、１０……カルシウム剤貯槽、１１
……撹拌器、１２……PH計。
FIG. 1 is a system explanatory diagram showing one embodiment of the present invention. 1...PH adjustment tank, 2...Raw water inflow pipe, 2'...
Raw water pump, 3... Circulating water introduction pipe, 3'... Circulating water pump, 4... Dephosphorization tower, 5... Treated water outflow pipe, 6... Alkali agent storage tank, 7, 8... Alkaline agent injection pipe , 7', 8'...alkaline agent injection pump,
9...Calcium agent injection pipe, 9'...Calcium agent injection pump, 10...Calcium agent storage tank, 11
... Stirrer, 12 ... PH meter.
Claims (1)
化せしめた層にリン含有排水を通液して、カルシ
ウムイオンの存在下で液中のリンを除去する方法
において、脱リン材の流動層内の上部でPHを検知
し、流動層内の下部にアルカリ剤を注入して層内
のPHを8.5〜11.0の範囲に保持するように調整し
ながら処理することを特徴とする液中のリン酸塩
の除去方法。 ２ 前記流動層内のPHを9.0〜9.5の範囲に保持す
るように調整しながら処理する特許請求の範囲第
１項記載の液中のリン酸塩の除去方法。[Claims] 1. A method for removing phosphorus from the liquid in the presence of calcium ions by passing phosphorus-containing wastewater through a layer in which a dephosphorizing material containing calcium phosphate is fluidized. In a liquid, the pH is detected in the upper part of the fluidized bed, and an alkaline agent is injected into the lower part of the fluidized bed to adjust the pH in the bed to maintain it in the range of 8.5 to 11.0. How to remove phosphates. 2. The method for removing phosphates from a liquid according to claim 1, wherein the treatment is performed while adjusting the pH in the fluidized bed to be maintained in the range of 9.0 to 9.5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2574284A JPS60168587A (en) | 1984-02-14 | 1984-02-14 | Fluidized bed type catalytic dephosphorization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2574284A JPS60168587A (en) | 1984-02-14 | 1984-02-14 | Fluidized bed type catalytic dephosphorization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60168587A JPS60168587A (en) | 1985-09-02 |
| JPH0130554B2 true JPH0130554B2 (en) | 1989-06-20 |
Family
ID=12174273
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2574284A Granted JPS60168587A (en) | 1984-02-14 | 1984-02-14 | Fluidized bed type catalytic dephosphorization |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60168587A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002273456A (en) * | 2001-03-23 | 2002-09-24 | Kurita Water Ind Ltd | Dephosphorizing method and device therefor |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4385560B2 (en) * | 2001-12-25 | 2009-12-16 | 栗田工業株式会社 | Crystallization dephosphorization method and crystallization dephosphorization apparatus |
| JP4519485B2 (en) * | 2004-03-04 | 2010-08-04 | 荏原エンジニアリングサービス株式会社 | Phosphorus recovery method and apparatus |
| JP4892212B2 (en) * | 2004-09-28 | 2012-03-07 | 三菱マテリアル株式会社 | Reaction crystallizer |
| JP7301105B2 (en) * | 2018-05-24 | 2023-06-30 | 水ｉｎｇ株式会社 | Method for treating liquid to be treated and apparatus for treating liquid to be treated |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5640485A (en) * | 1979-09-10 | 1981-04-16 | Ataka Kogyo Kk | Treatment of waste water |
| JPS58223479A (en) * | 1982-06-21 | 1983-12-26 | Kurita Water Ind Ltd | Device for treating water containing phosphate |
-
1984
- 1984-02-14 JP JP2574284A patent/JPS60168587A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5640485A (en) * | 1979-09-10 | 1981-04-16 | Ataka Kogyo Kk | Treatment of waste water |
| JPS58223479A (en) * | 1982-06-21 | 1983-12-26 | Kurita Water Ind Ltd | Device for treating water containing phosphate |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002273456A (en) * | 2001-03-23 | 2002-09-24 | Kurita Water Ind Ltd | Dephosphorizing method and device therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60168587A (en) | 1985-09-02 |
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