JPS624198B2 - - Google Patents
Info
- Publication number
- JPS624198B2 JPS624198B2 JP8218879A JP8218879A JPS624198B2 JP S624198 B2 JPS624198 B2 JP S624198B2 JP 8218879 A JP8218879 A JP 8218879A JP 8218879 A JP8218879 A JP 8218879A JP S624198 B2 JPS624198 B2 JP S624198B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid
- decarboxylation
- calcium
- water
- alkalinity
- 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
- 238000000034 method Methods 0.000 claims description 64
- 239000007788 liquid Substances 0.000 claims description 31
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical group [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 24
- 229910019142 PO4 Inorganic materials 0.000 claims description 22
- 235000021317 phosphate Nutrition 0.000 claims description 21
- 150000003013 phosphoric acid derivatives Chemical class 0.000 claims description 21
- 239000011575 calcium Substances 0.000 claims description 19
- 238000006114 decarboxylation reaction Methods 0.000 claims description 18
- 239000002245 particle Substances 0.000 claims description 13
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 12
- 229910052585 phosphate mineral Inorganic materials 0.000 claims description 10
- 239000003795 chemical substances by application Substances 0.000 claims description 7
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 6
- 229910052791 calcium Inorganic materials 0.000 claims description 6
- 239000001506 calcium phosphate Substances 0.000 claims description 6
- 229910000389 calcium phosphate Inorganic materials 0.000 claims description 6
- 235000011010 calcium phosphates Nutrition 0.000 claims description 6
- 229910001748 carbonate mineral Inorganic materials 0.000 claims description 6
- 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 6
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims description 3
- 229910001424 calcium ion Inorganic materials 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 41
- 239000000126 substance Substances 0.000 description 21
- 239000010802 sludge Substances 0.000 description 12
- 239000000243 solution Substances 0.000 description 10
- 239000000463 material Substances 0.000 description 9
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- 238000012545 processing Methods 0.000 description 7
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 5
- 239000000920 calcium hydroxide Substances 0.000 description 5
- 235000011116 calcium hydroxide Nutrition 0.000 description 5
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 5
- 230000003197 catalytic effect Effects 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 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 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
- 238000006243 chemical reaction Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 238000011197 physicochemical method Methods 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- 238000010170 biological method Methods 0.000 description 3
- 239000004576 sand Substances 0.000 description 3
- 238000004062 sedimentation Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 238000005844 autocatalytic reaction Methods 0.000 description 2
- 238000005345 coagulation Methods 0.000 description 2
- 230000015271 coagulation Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000000911 decarboxylating effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000005189 flocculation Methods 0.000 description 2
- 230000016615 flocculation Effects 0.000 description 2
- 239000003112 inhibitor Substances 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- 239000002562 thickening agent Substances 0.000 description 2
- 239000002351 wastewater Substances 0.000 description 2
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 1
- 235000014653 Carica parviflora Nutrition 0.000 description 1
- 241000243321 Cnidaria Species 0.000 description 1
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 1
- 229910052586 apatite Inorganic materials 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010800 human waste Substances 0.000 description 1
- 239000008235 industrial water Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910052816 inorganic phosphate Inorganic materials 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000004579 marble Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000008239 natural water Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910017464 nitrogen compound Inorganic materials 0.000 description 1
- 150000002830 nitrogen compounds Chemical class 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
- 239000002367 phosphate rock Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000003643 water by type Substances 0.000 description 1
Landscapes
- Removal Of Specific Substances (AREA)
- Water Treatment By Sorption (AREA)
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
れており、その代表的なものとして、生物学的処
理法、イオン交換樹脂法、化学的凝集沈澱法など
があげられるが、このうち、化学的凝集沈澱法は
現時点で一応完成された処理技術として評価さ
れ、すでにかなりのところで実際処理規模の処理
装置が稼動している。
この化学的凝集処理法によるリン酸塩類の除去
は、液中に存在するリン酸塩類を、特定の凝集剤
を添加することによつて不溶性リン酸塩として除
去する方法であり、凝集剤としては、通常、消石
灰〔Ca（OH）3〕、硫酸アルミニウム〔Al2
（SO4）3〕、塩化第２鉄〔FeCl3〕などが用いられ
る。ところが、化学的凝集沈澱法の最大の欠点
は、使用する凝集剤の種類にあまり関係なく、
一般に大量の凝集剤を必要とし、処理コスト
が高いこと。
大なる薬注量に比例的に大量の汚泥が発生
し、この汚泥の沈降性、凝縮性が極めて悪いこ
と（石灰汚泥は例外）。
さらにこの汚泥は脱水性が劣ること（石灰汚
泥は例外）。
であり、大なる汚泥処理施設と処理費用を必要と
するため、現用技術であるにもかかわらず、実用
上多くの問題をかかえている。
また、本発明者等によつて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
を含有するリン酸塩鉱物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、充填されているリ
ン酸塩鉱物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も提案されるに至つた。
この場合、リン酸塩鉱物表面での代表的な化学
反応は次の通りである。
5Ca2+＋70H-＋3H2PO4 -
＝Ca5（OH）（PO4）3＋6H2O …(1)式
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リン
酸塩鉱物の分離、脱水が極めて容易であり、従来
の化学的凝集沈澱法によるいわゆる凝集汚泥と比
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
いだけではなく、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
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+＋HCO3 -＋OH-→CaCO3＋H2O …(2)式
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リン酸塩鉱物の表面に固
着成長する。その結果、リン酸塩鉱物の表面活性
が劣化し、脱リン機能は低減し、当初ほどの脱リ
ン効果は期待できなくなる。
また液中に存在する色度成分などの有機物も長
期間のうちに除去され、リン酸塩鉱物表面に付着
し、脱リン性能が低下する。
このように接触脱リン法は、液中にアルカリ度
成分などの阻害物質が多量に含まれ、かつ溶解性
リン酸塩類も含まれている液についてはその適用
に限界があるが、何らかの方法でアルカリ度成分
などの阻害物質を除去すれば、接触脱リン法の適
用範囲は拡大される。
そして従来液中のＭ―アルカリ度成分を除去す
る方法、すなわち軟化の方法には生物学的な方法
〔生物学的硝化法または生物学的硝化、脱窒素
法、（但し液中に窒素成分を含む場合のみ適用さ
れる）〕と化学的または物理化学的な方法とがあ
り、生物学的な方法は効果的な脱Ｍ―アルカリ度
成分が可能であるが、大なる処理施設を必要と
し、また運転管理が必ずしも容易ではない。一方
化学的または物理化学的な方法はＭ―アルカリ度
成分を除去するための薬剤が必要であり、また方
法によつては大量の汚泥が発生するが、簡単な処
理施設と簡単な方法で容易にＭ―アルカリ度成分
を除去することがきるので水処理技術として一般
的に採用されている。
生物学的な方法の最大の難点は、処理すべき排
水中に窒素化合物（好ましくはNH4―Ｎ）が含ま
れていない限り適用はできないが、これに反して
化学的または物理化学的な方法はいかなる排につ
いても適用が可能であり、Ｍ―アルカリ度成分の
除去効果が確実である利点がある。
この化学的または物理化学的方法の主たるもの
は、液酸性下におけるストリツピング法と、Ca
（OH）2添加による軟化法（一種の凝集沈殿処理）
とがある。前者の液酸性下におけるストリツピン
グ法は、処理すべき液に酸を加え、除去すべきＭ
―アルカリ度成分の程度に対応して液のPHを３〜
６の範囲に設定し、次に酸性となつた液をストリ
ツピング装置に導入してＭ―アルカリ度成分を大
気中に放散させる方法である。また後者のCa
（OH）2添加による軟化法は、液中のＭ―アルカリ
度成分に対応するCa（OH）2を液に添加し、Ｍ―
アルカリ度成分をCaCO3の沈殿物として除去す
る方法で、CaCO3の沈殿物はシツクナーで濃縮
したのち処理系外に取り出されるものである。
これらの２つのＭ―アルカリ度成分除去方法の
うち、酸性ストリツピング法はコスト的な制約が
なければ充分に実用性はあるが、Ca（OH）2添加
によるアルカリ軟化法は前記凝集沈殿法の欠点が
そのまま継承され、実用化は可能であるにして
も、汚泥の処理が極めて厄介である。
本発明は、接触脱リン法の利点をそのままいか
し、リン酸塩類を含みかつＭ―アルカリ度成分な
どの阻害物質を含む液からリン酸塩類を長期間に
わたり効率よく、しかも安定して除去する有効な
方法を提供することを目的とするものである。
また本発明の他の目的は、従来法の諸欠点を解
消し、極めて簡単な操作で質的に著しく良質な処
理水が経済的に得られ、さらに処理設備、処理費
用の節減をも大巾にはかることができる有用な方
法とすることにある。
本発明は、一定の粒径をもつ炭酸カルシウムを
含有する炭酸塩鉱物、例えば大理石、泥炭岩、苦
灰岩、サンゴ砂などを充填した充填塔に一定の通
水条件で被処理液を通水して液中のＭ―アルカリ
度成分を可及的に除去したのち、この脱炭酸工程
流出液をさらに一定の粒径をもつリン酸カルシウ
ムを主成分とするリン酸塩鉱物、例えばヨルダン
産、フロリダ産、メキシコ産、カナダ産、神奈川
県玄倉産、栃木県足尾銅山産、与論島産、福岡県
長垂産、北海道大玖鉱山産などのリン鉱石を特殊
加工した脱リン材を充填した充填塔に通液させる
ことで接触させることを特徴とし、液中のＭ―ア
ルカリ度成分などの阻害物質による接触脱リン効
果の減退を防止するものである。
本発明の一実施態様を図面を参照しつつ説明す
れば、例えば、BOD15mg／、SS10mg／、
COD（Mn）15mg／、COD（Cr）25mg／、
PO4 3-8mg／、PH7.10、Ｍ―アルカリ度120mg／
の都市下水の２次処理水の砂過水を対象原水
とし、消石灰注入装置１から消石灰を注入し、対
象原水のPHを8.0〜11.0の範囲に調整する。しか
るのち、PH調整した砂過水を導水管２を経由し
て脱炭酸工程が行なわれる脱炭酸塔３に導入す
る。この脱炭酸工程は炭酸カルシウムを主成分と
する炭酸塩鉱物を破砕し、篩分して一定の粒径
0.1〜100mm好ましくは0.3〜30mm粒径必要に応じ
ては100mm以上の粒径としたものを充填した充填
塔が中核であり、この充填塔に一定の通水条件
（固定層方式ではSVとして0.1〜１m3／m3hr、流
動層方式では１〜10m3／m3hr）で通水して、ある
一定レベルまで脱炭酸処理する。この脱炭酸用の
充填塔を通し脱炭酸材と接触させることにより、
液中に溶存しているＭ―アルカリ度成分は炭酸カ
ルシウムを主成分とする炭酸塩鉱物の表面に自触
媒反応的に炭酸カルシウムとして晶出、成長して
くるために脱炭酸材（炭酸カルシウムを主成分と
する炭酸塩鉱物）は半永久的に脱炭酸機能が維持
される。またこの過程で液中に含まれる色度成分
等の有機物も除去され、後段の脱リン塔における
材の汚染を防止できる。またこの脱炭酸方式で
は従来の凝集沈殿法のように所謂処理しにくい凝
集汚泥が全く発生せず、かつ、液中の溶存Ｍ―ア
ルカリ度成分を効率よく除去し、操作も簡単で安
定した処理が可能である。
そして脱炭酸工程における脱炭酸塔３を経由
し、Ｍ―アルカリ度成分を部分的に除去された対
象原水はさらに導水管５で脱リン塔６に導入され
る過程で塩化カルシウム注入装置４から塩化カル
シウム剤が注入される。前記脱炭酸工程でＭ―ア
ルカリ度成分の全量あるいは一部を除去され、か
つCa2+を注入された脱炭酸工程流出液（２次処
理水）は脱リン工程をする脱リン塔６に導入さ
れ、質的に良質な処理水として流出管７より導出
し得られる。この脱リン工程には、リン酸カルシ
ウムを含有するリン酸塩鉱物を特殊加工して製造
した脱リン材を破砕、篩分して一定の粒径例えば
0.1〜100mm好ましくは0.4〜4.0mm必要に応じて100
mm以上の粒径としたものが充填されている脱リン
塔６があり、２次処理水（脱炭酸された２次処理
水）がこの脱リン塔６を一定の通水条件、PH条件
で通水することにより、液中に溶存する各種のリ
ン酸塩は、前記(1)式に示すような反応式にしたが
つて脱リン材の表面にカルシウムハイドロキシア
パタイトの結晶として晶出し、半永久的に除去さ
れる。該脱リン塔６での通水方法は流動層方式、
固定層方式のいずれでもよく、また固定層方式で
は上向流、下向流のいずれでもよいが、この通水
条件は流動層方式では一般にSVとして10〜100
m3／m3hr、固定層方式ではSVとして１〜10m3／
m3hrの範囲が適当である。さらに通水液のPHは普
通8.0〜10.0の範囲に設定され、カルシウムイオ
ンの注入率は液中に溶存する各種リン酸塩類の濃
度によつて異なるが通常Ca／PO4として0.5〜20
好ましくは1.0〜5.0の範囲で添加される。
図中２′は導水管、４′はカルシウム注入装置、
５′は導水管、７′は流出管で前記実施態様の固定
層方式に代わり流動層方式として通液する場合に
用いられ、独立的な配管系としたり、切換弁を含
めて切替方式のバイパス配管系に構成することも
選んでできる。
以上述べたように本発明は、炭酸カルシウムを
主成分とする脱炭酸材によつて液中に溶存してい
るＭ―アルカリ度成分を効率的、かつ経済的に除
去すると共に液中に溶存する色度成分等の有機物
も除去し、さらにリン酸カルシウムを主成分とす
る脱リン材によつて長期間に渡り安定かつ効率的
に液中のリン酸塩類を除去することができるとと
もに、脱炭酸材、脱リン材の表面における自触媒
反応によつて、従来の化学的凝集沈殿法の欠点を
全て解消し、液中のリン酸塩類を効率よく除去
し、操作も簡単で安定した処理が可能であり、大
量処理に適し、敷地や装置据付面積も減少し、さ
らに処理設備、処理費用の節減を適確にはかるこ
とができるものである。
次に本発明方法の一実施例を示す。
団地下水の活性汚泥法による２次処理水をさら
に砂過により処理したものに適量の消石灰を添
加してPHを９〜10の範囲となるように調整し、し
かるのち一定粒度の炭酸カルシウムを主成分とす
る脱炭酸材を充填した脱炭酸塔にSV0.5m3／m3hr
の通水条件で通水して液中に溶存しているＭ―ア
ルカリ度成分を部分的に除去する。処理の１例を
第１表に示したが、対象原水（２次処理水を砂
過したもの）のＭ―アルカリ度126mg／のもの
を前記の条件で通水し、さらに脱リン処理した最
終流水のＭ―アルカリ度は20〜24mg／の範囲と
なり、ほぼ80％のＭ―アルカリ度が除去された。
またこの過程で対象原水中とCOD（Cr）も37.5
％除去された。次いで、脱炭酸処理水にCa／PO4
＝５となるように塩化カルシウムを加え、リン酸
カルシウムを主成分とするリン鉱石を特殊加工し
た脱リン材を破砕、篩分して粒径0.42〜0.54mmの
ものを充填した脱リン塔（固定層、下向流式）に
SV5m3／m3hrの条件で通水した。前記の条件で実
験を６ケ月間継続し、長期間通水した場合の脱リ
ン材の性能劣化をチエツクするために、運転開始
後１ケ月後と４ケ月後に最終処理水のPO３− ４を側
定比較したところ、第１表に示してあるようにそ
れぞれのPO３− ４は0.37mg／、0.31mg／であり、
液中に溶存しているＭ―アルカリ度成分及び色度
成分等の有機物による脱リン材の性能劣化は全く
認められなかつた。
The present invention relates to a method for removing phosphates present in tap water, sewage, human waste water, industrial water, factory wastewater, boiler water, and all other liquids. 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, biological substances may be present in equipment and piping. Chemical slime is generated and chemical scale is formed, which is a serious cause of accidents. Therefore, various phosphorus removal methods are being considered in order to remove the phosphates present in these liquids, and the representative ones include biological treatment, ion exchange resin method, and chemical treatment. Among these methods, the chemical coagulation-sedimentation method is currently regarded as a completed treatment technology, and treatment equipment on an actual scale is already in operation in many places. The removal of phosphates by this chemical flocculation treatment is a method in which phosphates present in the liquid are removed as insoluble phosphates by adding a specific flocculant. , usually slaked lime [Ca(OH) 3 ], aluminum sulfate [Al 2
(SO 4 ) 3 ], ferric chloride [FeCl 3 ], etc. are used. However, the biggest disadvantage of chemical flocculation and precipitation is that it generally requires a large amount of flocculant and is expensive, regardless of the type of flocculant used. A large amount of sludge is generated in proportion to the large amount of chemical injection, and the settling and condensation properties of this sludge are extremely poor (with the exception of lime sludge). Furthermore, this sludge has poor dewatering properties (lime sludge is an exception). However, it requires a large sludge treatment facility and processing costs, so although it is a current technology, it has many practical problems. In addition, the present inventors have developed a novel treatment method that involves filling a cylindrical or cone-shaped dephosphorization tower with phosphate minerals containing calcium phosphate having a certain particle size. is adjusted to a range of 6 to 11, and a calcium agent such as calcium chloride is added in accordance with the concentration of soluble phosphates contained in the liquid to be treated, and this is passed through and brought into contact at a constant flow rate. As a result, a method has been proposed for removing soluble phosphates by crystallizing and fixing calcium hydroxyapatite crystals on the surface of the filled phosphate mineral. In this case, typical chemical reactions on the phosphate mineral surface are as follows. 5Ca 2+ +70H - +3H 2 PO 4 - =Ca 5 (OH) (PO 4 ) 3 +6H 2 O...Equation (1) If this new dephosphorization method is applied, phosphoric acid to which calcium hydroxyapatite is fixed Separation and dewatering of salt minerals is extremely easy, and compared to so-called flocculated sludge produced by conventional chemical coagulation and sedimentation methods, it does not require preconceived sludge treatment facilities such as thickeners, dehydrators, and dryers. Instead, 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(OH) 2 as a calcium agent under conditions
However, if the liquid to be treated contains an alkalinity component, calcium carbonate is produced according to the reaction equation shown below. Ca 2+ +HCO 3 - +OH - →CaCO 3 +H 2 O...Equation (2) This calcium carbonate can be used as long as the pH of the liquid is within 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 the moment the calcium agent is added. Although the amount of calcium carbonate crystals produced under such conditions is extremely small, over a long period of time, the calcium carbonate crystals gradually grow fixedly on the surface of the phosphate mineral. As a result, the surface activity of the phosphate mineral deteriorates, the dephosphorization function decreases, and the dephosphorization effect can no longer be expected to be as high as it was initially. Furthermore, organic substances such as chromaticity components present in the liquid are also removed over a long period of time and adhere to the surface of phosphate minerals, resulting in a decrease in dephosphorization performance. In this way, the catalytic dephosphorization method has limitations in its applicability to liquids that contain large amounts of inhibitory substances such as alkalinity components and also contain soluble phosphates, but some methods can be used. The scope of application of catalytic dephosphorization can be expanded by removing inhibitors such as alkalinity components. Conventional methods for removing M-alkalinity components in the solution, that is, methods for softening, include biological methods [biological nitrification method, biological nitrification, denitrification method (however, nitrogen components are removed from the solution). (applicable only when the alkalinity component is present)] and chemical or physicochemical methods.Biological methods can effectively remove M-alkalinity components, but require large treatment facilities; Moreover, operation management is not always easy. On the other hand, chemical or physicochemical methods require chemicals to remove M-alkalinity components, and some methods generate large amounts of sludge, but they are easy to use with simple treatment facilities and simple methods. It is generally used as a water treatment technology because it can remove M-alkalinity components. The biggest drawback of biological methods is that they cannot be applied unless the wastewater to be treated contains nitrogen compounds (preferably NH 4 -N), whereas chemical or physicochemical methods This method can be applied to any type of waste, and has the advantage that the removal effect of M-alkalinity components is reliable. The main chemical or physicochemical methods are the stripping method under liquid acidity and the Ca stripping method.
Softening method by adding (OH) 2 (a type of coagulation precipitation treatment)
There is. The former method of stripping under acidic conditions involves adding acid to the liquid to be treated and stripping the M to be removed.
- Adjust the pH of the liquid from 3 to 3 depending on the level of alkalinity component.
6, and then introduces the acidified liquid into a stripping device to diffuse the M-alkalinity component into the atmosphere. Also, the latter Ca
In the softening method by adding (OH) 2 , Ca(OH) 2 corresponding to the M-alkalinity component in the solution is added to the solution.
This method removes alkalinity components as CaCO 3 precipitates, and the CaCO 3 precipitates are concentrated in a thickener and then taken out of the treatment system. Of these two methods for removing M-alkalinity components, the acid stripping method is fully practical if there are no cost constraints, but the alkaline softening method by adding Ca(OH) 2 has the disadvantages of the coagulation-precipitation method. Even if it is possible to put it into practical use because it has been inherited as it is, the treatment of sludge is extremely troublesome. The present invention utilizes the advantages of the catalytic dephosphorization method and is effective in efficiently and stably removing phosphates over a long period of time from a solution containing phosphates and inhibitors such as M-alkalinity components. The purpose is to provide a method for Another object of the present invention is to eliminate various drawbacks of conventional methods, to economically obtain treated water of extremely high quality with extremely simple operations, and to significantly reduce treatment equipment and treatment costs. The aim is to provide a useful method that can be used to measure In the present invention, water is passed through a packed tower filled with carbonate minerals containing calcium carbonate having a certain particle size, such as marble, peatstone, dolostone, coral sand, etc., under certain water flow conditions. After removing as much of the M-alkalinity component in the solution as possible, the decarboxylation process effluent is further treated with phosphate minerals whose main component is calcium phosphate with a certain particle size, such as those produced in Jordan and Florida. , from Mexico, Canada, Kurokura in Kanagawa Prefecture, Ashio Copper Mine in Tochigi Prefecture, Yoron Island, Nagatari in Fukuoka Prefecture, Daiku Mine in Hokkaido, etc. are used in a packed tower filled with a specially processed dephosphorizing material. It is characterized by contacting by passing a liquid through it, and prevents the catalytic dephosphorization effect from decreasing due to inhibitory substances such as M-alkalinity components in the liquid. If one embodiment of the present invention is explained with reference to the drawings, for example, BOD15mg/, SS10mg/,
COD (Mn) 15 mg/, COD (Cr) 25 mg/,
PO 4 3- 8mg/, PH7.10, M-alkalinity 120mg/
The target raw water is sand filtered water of secondary treated urban sewage, and slaked lime is injected from the slaked lime injection device 1 to adjust the pH of the target raw water to a range of 8.0 to 11.0. Thereafter, the pH-adjusted sand-filtered water is introduced via a water conduit 2 into a decarbonation tower 3 where a decarbonation process is performed. In this decarboxylation process, carbonate minerals whose main component is calcium carbonate are crushed and sieved to obtain particles of a certain size.
The core is a packed tower filled with particles with a particle size of 0.1 to 100 mm, preferably 0.3 to 30 mm, if necessary, with a particle size of 100 mm or more. Water is passed at a rate of ~1 m 3 /m 3 hr (1 to 10 m 3 /m 3 hr in the fluidized bed method) to decarboxylate to a certain level. By passing through this packed tower for decarboxylation and bringing it into contact with the decarboxylating agent,
The M-alkalinity component dissolved in the liquid crystallizes and grows as calcium carbonate in an autocatalytic reaction on the surface of carbonate minerals whose main component is calcium carbonate. The decarboxylation function of carbonate minerals (the main component) is maintained semi-permanently. In addition, in this process, organic substances such as chromaticity components contained in the liquid are also removed, and contamination of materials in the subsequent dephosphorization tower can be prevented. In addition, this decarboxylation method does not generate the so-called flocculated sludge that is difficult to treat, unlike the conventional coagulation-sedimentation method, and efficiently removes dissolved M-alkalinity components in the liquid, making it easy to operate and a stable process. is possible. Then, the target raw water from which the M-alkalinity component has been partially removed via the decarboxylation tower 3 in the decarboxylation process is further introduced into the dephosphorization tower 6 through the water conduit 5, where it is chlorinated from the calcium chloride injection device 4. Calcium tablets are injected. The decarboxylation process effluent (secondary treated water) from which all or part of the M-alkalinity component has been removed in the decarboxylation process and Ca 2+ has been injected is introduced into the dephosphorization tower 6 where the dephosphorization process is performed. The treated water is then discharged from the outflow pipe 7 as high-quality treated water. In this dephosphorization process, a dephosphorization material made by specially processing phosphate minerals containing calcium phosphate is crushed and sieved to a certain particle size, e.g.
0.1~100mm preferably 0.4~4.0mm 100 as required
There is a dephosphorization tower 6 filled with particles with a particle size of mm or more, and the secondary treated water (decarbonated secondary treated water) passes through this dephosphorization tower 6 under certain water flow conditions and PH conditions. By passing water through the solution, various phosphates dissolved in the solution crystallize as calcium hydroxyapatite crystals on the surface of the dephosphorizing material according to the reaction formula shown in equation (1) above, resulting in a semi-permanent state. will be removed. The water flow method in the dephosphorization tower 6 is a fluidized bed method,
Either fixed bed method may be used, and in the fixed bed method, either upward flow or downward flow may be used, but in the fluidized bed method, the water flow conditions are generally SV of 10 to 100.
m 3 /m 3 hr, SV of fixed bed method is 1 to 10 m 3 /
A range of m 3 hr is appropriate. Furthermore, the pH of the water flowing solution is normally set in the range of 8.0 to 10.0, and the injection rate of calcium ions varies depending on the concentration of various phosphates dissolved in the solution, but is usually 0.5 to 20 as Ca/ PO4 .
It is preferably added in a range of 1.0 to 5.0. In the figure, 2' is a water pipe, 4' is a calcium injection device,
5' is a water conduit pipe, and 7' is an outflow pipe, which is used when liquid is passed in a fluidized bed system instead of the fixed bed system in the previous embodiment, and can be used as an independent piping system or as a switching system bypass including a switching valve. You can also choose to configure it as a piping system. As described above, the present invention efficiently and economically removes the M-alkalinity component dissolved in the liquid by using a decarboxylating agent mainly composed of calcium carbonate, and also removes the M-alkalinity component dissolved in the liquid. It also removes organic substances such as chromaticity components, and the dephosphorizing agent whose main component is calcium phosphate can stably and efficiently remove phosphates from the liquid over a long period of time. The autocatalytic reaction on the surface of the dephosphorizing material eliminates all the shortcomings of the conventional chemical coagulation-precipitation method, efficiently removes phosphates from the liquid, and enables simple and stable processing. It is suitable for large-scale processing, requires less land and equipment installation space, and can appropriately reduce processing equipment and processing costs. Next, an example of the method of the present invention will be described. The secondary treated water from the activated sludge method for underground water was further treated by sand filter, and an appropriate amount of slaked lime was added to adjust the pH to a range of 9 to 10. SV0.5m 3 /m 3 hr in a decarboxylation tower filled with decarboxylation material as a component
The M-alkalinity component dissolved in the liquid is partially removed by passing water under the following conditions. An example of the treatment is shown in Table 1. The target raw water (secondary treated water is sand-filtered) with an M-alkalinity of 126mg/ is passed through under the above conditions, and the final treated water is dephosphorized. The M-alkalinity of the flowing water ranged from 20 to 24 mg/alkalinity, and almost 80% of the M-alkalinity was removed.
In addition, during this process, the target raw water and COD (Cr) were reduced to 37.5
% removed. Next, Ca/PO 4 was added to the decarboxylated water.
A dephosphorization tower (fixed bed) in which calcium chloride is added so that the dephosphorization material is specially processed from phosphate rock whose main component is calcium phosphate is crushed, sieved, and packed with particles with a particle size of 0.42 to 0.54 mm. , downflow type)
Water was passed under the condition of SV5m 3 /m 3 hr. The experiment was continued for 6 months under the above conditions, and in order to check the performance deterioration of the dephosphorizing material when water was passed for a long period of time, the final treated water was treated with PO 3-4 after 1 month and 4 months after the start of operation. After comparing the measurements, as shown in Table 1 , each PO3-4 was 0.37mg/, 0.31mg/,
No deterioration in the performance of the dephosphorizing material was observed at all due to organic substances such as M-alkalinity components and chromaticity components dissolved in the liquid.
【表】【table】
図面は本発明方法の実施態様の系統説明図であ
る。
１…消石灰注入装置、２，５…導水管、３…脱
炭酸塔、４…塩化カルシウム注入装置、６…脱リ
ン塔。
The drawing is a system explanatory diagram of an embodiment of the method of the present invention. 1... Slaked lime injection device, 2, 5... Water pipe, 3... Decarbonation tower, 4... Calcium chloride injection device, 6... Dephosphorization tower.
Claims (1)
を添加して液中のPHを8.0〜11.0の範囲に設定し
た後炭酸カルシウムを主成分とする炭酸塩鉱物を
充填した固定層方式或いは流動層方式の脱炭酸塔
に通液して液中のＭ―アルカリ度成分を可及的に
除去する脱炭酸工程を経たのち、脱炭酸工程流出
液をカルシウムイオンの存在下で、リン酸カルシ
ウムを主成分とするリン酸塩鉱物と接触せしめて
処理することを特徴とする液中のリン酸塩類の除
去方法。 ２ 前記脱炭酸工程が、炭酸カルシウムを主成分
とする炭酸塩鉱物の粒径を0.1〜100mmに設定した
脱炭酸塔へ固定層方式あるいは流動層方式として
通液するものである特許請求の範囲第１項記載の
リン酸塩類の除去方法。 ３ 前記脱リン工程が、脱リン塔に供給する脱炭
酸工程流出液にCa／PO4として0.5〜20の範囲の
カルシウムイオンを注入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項記載のリン酸塩
類の除去方法。[Claims] 1. A fixed bed filled with a carbonate mineral whose main component is calcium carbonate after adding an alkaline agent containing calcium to the liquid to be treated and setting the pH of the liquid in the range of 8.0 to 11.0. After passing through a decarboxylation process in which the liquid is passed through a decarboxylation tower using either a decarboxylation method or a fluidized bed method to remove as much of the M-alkalinity component in the liquid as possible, the effluent from the decarboxylation process is converted into calcium phosphate in the presence of calcium ions. A method for removing phosphates from a liquid, the method comprising contacting with a phosphate mineral whose main component is phosphate mineral. 2. The decarboxylation step involves passing carbonate minerals mainly composed of calcium carbonate through a decarboxylation tower in which the particle size is set to 0.1 to 100 mm in a fixed bed system or a fluidized bed system. The method for removing phosphates according to item 1. 3. Claim 1 or 3, wherein the dephosphorization step is performed by injecting calcium ions in the range of 0.5 to 20 as Ca/PO 4 into the decarboxylation step effluent supplied to the dephosphorization tower. The method for removing phosphates according to item 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8218879A JPS567678A (en) | 1979-06-29 | 1979-06-29 | Removing method for phosphates in liquid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8218879A JPS567678A (en) | 1979-06-29 | 1979-06-29 | Removing method for phosphates in liquid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS567678A JPS567678A (en) | 1981-01-26 |
| JPS624198B2 true JPS624198B2 (en) | 1987-01-29 |
Family
ID=13767455
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8218879A Granted JPS567678A (en) | 1979-06-29 | 1979-06-29 | Removing method for phosphates in liquid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS567678A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57204287A (en) * | 1981-06-10 | 1982-12-14 | Ebara Infilco Co Ltd | Fractional separation of thin ion contained in solution |
| JP2004237170A (en) * | 2003-02-04 | 2004-08-26 | Nippon Steel Chem Co Ltd | Method and apparatus for treating nitrate nitrogen and phosphorus-containing water |
-
1979
- 1979-06-29 JP JP8218879A patent/JPS567678A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS567678A (en) | 1981-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Giesen | Crystallisation process enables environmental friendly phosphate removal at low costs | |
| Bourgeois et al. | Treatment of drinking water residuals: comparing sedimentation and dissolved air flotation performance with optimal cation ratios | |
| Joko | Phosphorus removal from wastewater by the crystallization method | |
| EP0159178B1 (en) | Water treatment | |
| Balmér et al. | Control of phosphorus discharges: present situation and trends | |
| US4882069A (en) | Method for the treatment of sewage and other impure water | |
| JPS6242677B2 (en) | ||
| Arora et al. | Evaluation of dissolved air flotation process for water clarification and sludge thickening | |
| JPS624198B2 (en) | ||
| KR100441405B1 (en) | A method for anion removal by forming chemical precipitation under an electric field and a continuous process for anion removal | |
| CA1334543C (en) | Method for the treatment of sewage and other impure water | |
| JP2023117544A (en) | Phosphorus recovery method and phosphorus recovery apparatus | |
| JPS5857995B2 (en) | How to remove phosphates from liquid | |
| JPH0130554B2 (en) | ||
| JP2002177966A (en) | Dephosphorizing agent and dephosphorization method as well as dewatering treatment method for sludge | |
| JPS6231632B2 (en) | ||
| JPH0127913Y2 (en) | ||
| US4228003A (en) | Method of removing phosphates from waste water | |
| JPS6044996B2 (en) | How to remove phosphates from liquid | |
| Antes et al. | Digestate treatment: phosphorus removal. | |
| Liberti et al. | Field demonstrations of the RIM-NUT process for nutrients recovery from municipal wastewater | |
| JPS58143884A (en) | Purification of filthy water | |
| SU695971A1 (en) | Method of purifying waste water | |
| JPS598439B2 (en) | How to treat organic wastewater | |
| JPH03207489A (en) | Method for removing phosphorus in liquid |