JP4519986B2

JP4519986B2 - Crystallization reactor and crystallization dephosphorization method using the same

Info

Publication number: JP4519986B2
Application number: JP2000108839A
Authority: JP
Inventors: 俊明中沢
Original assignee: Mitsubishi Kakoki Kaisha Ltd
Current assignee: Mitsubishi Kakoki Kaisha Ltd
Priority date: 2000-04-11
Filing date: 2000-04-11
Publication date: 2010-08-04
Anticipated expiration: 2020-04-11
Also published as: JP2001286701A

Description

【０００１】
【発明の属する技術分野】
本発明は、種結晶と接触させて水中の結晶化成分を種結晶の表面に析出させる晶析反応装置と該装置を用いて燐化合物を含有する排水中の燐を燐酸マグネシウム化合物結晶として種結晶の表面に析出させて分離する晶析脱燐方法に関する。
【０００２】
【従来の技術】
従来、化学工業分野や水処理分野などでは、結晶化成分含有水を種結晶と接触させて水中の結晶化成分を種結晶の表面に析出させて回収又は除去する晶析反応装置が使用されており、従来の晶析反応装置としては、析出した結晶や外部から添加した結晶を種結晶して晶析反応槽内に充填し、曝気装置、機械攪拌装置又はポンプ循環などにより攪拌しながら水中の結晶化成分を種結晶の表面に析出させる流動床式晶析反応装置が多く用いられている。
【０００３】
また、し尿、下水、食品排水又は厨房排水などの燐化合物を含有する排水中の燐を除去する方法として、嫌気性処理と好気性処理を組合せて燐を微生物汚泥に取り込んで除去する生物脱燐方法や硫酸アルミニウム、ポリ塩化アルミニウムなどの凝集剤を用いてＳＳやコロイドなどと共に凝集させて沈降分離する凝集沈殿法が一般的に用いられているが、生物脱燐方法にあっては、生物学的処理であるため、運転管理が煩雑であり、また高度な技術を必要とし、更に、処理時間がかかるため装置が過大となる問題があり、また、凝集沈殿法では、凝集剤自体とＳＳやコロイドなどが凝集分離するため、発生スラッジ量が多くなり、スラッジの処理に多額な費用や過大な設備が必要となる問題があるため、できるだけスラッジ量などを少なくすると共に資源の有効活用が図れる処理方法として、前記の流動床式晶析反応装置を用いて、消石灰や生石灰などのカルシウム塩を添加し、ヒドロキシアパタイト結晶を析出させて分離するＣａ塩晶析脱燐方法や塩化マグネシウム、水酸化マグネシウムなどのマグネシウム塩を添加し、排水中のアンモニアを利用してマグネシウムアンモニア燐酸（ＭＡＰ）などの結晶を析出させて分離するＭＡＰ法晶析脱燐方法などが開発されている。
【０００４】
【発明が解決しようとする課題】
前記流動床式晶析反応装置では、結晶造粒物の比重が重いため、流動化させるための動力が大きくなり、動力費が嵩む問題があり、特に、流動床式晶析反応装置を晶析脱燐方法に用いる場合には、晶析脱燐における析出結晶は、比重が１．５〜２．０と重いため、流動動力費が嵩む問題と、カルシウム塩による晶析脱燐では、スケールが発生しやすいため、流動不完全により晶析反応槽内の底部に沈降し、沈降した結晶により晶析反応槽内にスケール付着や配管の閉塞などを惹起しやすい問題がある。また、ＭＡＰ法晶析脱燐では、微細なフロックが流出しやすく、脱燐効率が低い問題などがある。
【０００５】
本発明は、前記従来の流動床式晶析反応装置やその装置を用いる晶析脱燐方法の問題点に鑑みて成されたものであり、設備面積が狭くすみ、設備費が低廉であり、また、動力費などの運転経費も低廉となる晶析反応装置及びその装置を用いて、脱燐効果を安定して高く維持でき、析出結晶も容易に分離でき、また、分離回収した結晶も不純物が少なくマグネシウムや燐酸及びアンモニアを多量に含んでいるため、肥料や土壌改良材として還元することができる晶析脱燐方法を提供する目的で成されたものである。
【０００６】
【課題を解決するための手段】
前記目的を達成するための本発明の要旨は、請求項１に記載した発明においては、結晶化成分含有水を種結晶と接触させて水中の結晶化成分を種結晶の表面に析出させる晶析反応装置において、晶析反応装置が、処理液排出口を具備する処理液槽と、該処理液槽内に内設され、内部に種結晶が充填された周部に多数の通液孔が設けられた円筒形のスクリ−ンとからなり、該スクリ−ンは、円周面が上下方向となるよう横架され、処理液槽内の処理液中に下方の適宜深さまで浸漬され、回転駆動装置に接続して回転可能に支持されて設けられており、スクリ−ンの内周面に、軸線と平行する長尺掻揚げ板が、スクリ−ンの内周方向に一定間隔で複数装着され、スクリ−ンの軸線部には、中空軸が両端面を貫通して横設され、該中空軸は、軸線方向に排水供給部と結晶排出部とに区画され、排水供給部にはスクリ−ン内と連通する排水供給口が設けられ、結晶排出部には結晶排出口と、上面の軸線方向に穿設された長孔と、長孔の対向する両長辺部から長尺矩形板が夫々突設され、内部にはスクリュウ部材が挿通されて設けられていることを特徴とする晶析反応装置である。前記の構成とすることにより、設備面積が狭くすみ、設備費が低廉であり、また、動力費などの運転経費も低廉となる。
【０００７】
また、請求項２に記載した発明においては、請求項１記載の晶析反応装置において、長尺矩形板が先端側になるに従い外側に傾斜して夫々突設され、長尺掻揚げ板がスクリ−ンの回転方向に傾斜して装着されたことを特徴とする晶析反応装置である。前記の構成とすることにより、請求項１に記載した発明の効果と共に、結晶を効率よく掬い上げることができ、より効率的に結晶を排出することができる。
【０００８】
また、請求項３に記載した発明においては、排水中にマグネシウム塩溶液を排水に含有される燐の１〜３倍モル比となるように添加すると共にアルカリ溶液を添加してｐＨを、７．５〜１０に調整する溶液混合工程と、溶液混合工程でｐＨ調整された排水を燐酸マグネシウム化合物の種結晶と接触させて排水中の燐を種結晶の表面に析出させる晶析反応工程を設けた晶析脱燐方法において、晶析反応工程に、処理液排出口を具備する処理液槽と、該処理液槽内に内設され、内部に種結晶が充填された周部に多数の通液孔が設けられた円筒形のスクリ−ンとからなり、該スクリ−ンは、円周面が上下方向となるよう横架され、処理液槽内の処理液中に下方の適宜深さまで浸漬され、回転駆動装置に接続して回転可能に支持されて設けられており、スクリ−ンの内周面に、軸線と平行する長尺掻揚げ板が、スクリ−ンの内周方向に一定間隔で複数装着され、スクリ−ンの軸線部には、中空軸が両端面を貫通して横設され、該中空軸は、軸線方向に排水供給部と結晶排出部とに区画され、排水供給部にはスクリ−ン内と連通する排水供給口が設けられ、結晶排出部には結晶排出口と、上面の軸線方向に穿設された長孔と、該長孔の対向する両長辺部から長尺矩形板が夫々突設され、内部にはスクリュウ部材が挿通されて設けられた晶析反応装置を用い、種結晶として燐酸マグネシウム化合物の結晶を充填し、排水を中空軸の排水供給口からスクリ−ン内に供給し、スクリ−ンを回転しながら晶析反応させ、液分はスクリ−ンの通液孔で結晶を分離して処理液槽の処理液排出口から排出し、結晶は長尺掻揚げ板で掻揚げて長孔上で落下させ、長尺矩形板で誘導して長孔内に導入し、内部に挿通されたスクリュウ部材により結晶排出口に移送してスクリ−ン外に排出することを特徴とする晶析脱燐方法である。前記の構成とすることにより、設備面積が狭くすみ、設備費が低廉であり、また、動力費などの運転経費も低廉となり、更に、脱燐効果が安定して高く維持でき、析出結晶も容易に分離でき、また、分離回収した結晶も不純物が少なくマグネシウムや燐酸及びアンモニアを多量に含んでいるため、肥料や土壌改良材として還元することができる。
【０００９】
【発明の実施の形態】
以下に本発明の実施の形態について図面に基づいて説明する。図１は本発明の一実施の形態である晶析反応装置の概略縦断面図、図２は図１のＡ−Ａ矢視図であり、また、図３は本発明の一実施の形態である晶析脱燐装置全体の系統図である。なお、全図において、同一の作用を有する部材については同一の番号を付与した。
【００１０】
図１において、１は処理液排出口１５を具備する処理液槽１ａと、処理液槽１ａ内に内設される周部に多数の通液孔が設けられた円筒形のスクリ−ン２とからなる晶析反応装置であり、処理液槽１ａは、実施例では上部が開放された矩形体の槽であるが、適宜形状の蓋体で覆蓋した密閉構造の槽としてもよく、また、内設するスクリ−ン形状に合わせた円弧状底部の槽であってもよい。また、スクリ−ン２は、多数の通液孔が設けられたスクリ−ンの周部を形成するスクリ−ン部材３として、金網、多孔板、スリット板などを用い、円筒形に形成したスクリ−ン部材３の両端を適宜な係着手段により平板部材で覆蓋し、内部に種結晶ａを充填している。
【００１１】
またスクリ−ン２は、円周面が上下方向となるよう処理液槽１ａ内に横架され、処理液槽１ａ内の処理液中に下方の適宜深さまで浸漬されて設けられ、回転駆動装置８に接続して回転可能に支持されて設けられている。回転駆動装置８の接続は、スクリ−ン２を後記の中空軸４に軸支する適宜な軸受手段１３ａ、１３ｂの一方の軸受手段１３ａに嵌合させたプ−リ１６ａと、回転駆動装置８のプ−リ１６ｂとをベルト１７で連結するのが好ましいが、ギア構造でもよく、また、スクリ−ン２に直接プ−リを付設した構造であってもよい。更に、スクリ−ン２の内周面には、軸線と平行する長尺掻揚げ板６が、スクリ−ン２の内周方向に一定間隔で複数装着され、また、スクリ−ン２の軸線部には、中空軸４が両端面を貫通して横設されている。なお、スクリ−ン２の処理液中への浸漬深さは、中空軸４よりも下方の位置に設定される。
【００１２】
前記中空軸４は、軸線方向に排水供給部１０と結晶排出部１１とに区画され、排水供給部１０にはスクリ−ン２内と連通する排水供給口１２が設けられ、結晶排出部１１には結晶排出口１４と、上面の軸線方向に穿設された長孔９と、長孔９の対向する両長辺部から長尺矩形板５ａ、５ｂが夫々突設され、内部にはスクリュウ部材７が挿通されて設けられている。なお、長尺矩形板５ａ、５ｂは先端側になるに従い外側に傾斜して夫々突設されるのが好ましい。
【００１３】
図３において、２０は、排水を導入する原水導入管ｂ、マグネシウム溶液を供給するマグネシウム供給管ｆ及びアルカリ溶液を供給するアルカリ供給管ｇが接続され、原水導入管ｂから導入された排水に、マグネシウム供給管ｆから供給された塩化マグネシウムなどのマグネシウム溶液を添加すると共に、アルカリ供給管ｇから供給された水酸化ナトリウムなどのアルカリ溶液でｐＨ調整する溶液混合工程に用いる原水調整槽であり、内部には攪拌手段２１が付設されている。なお、攪拌手段２１としては、攪拌羽根で攪拌する機械式攪拌機が好ましいが、空気攪拌手段又はポンプ循環などであってもよい。１は前記図１で説明した晶析反応装置と略同一構成の装置であり、排水中の燐とマグネシウムを反応させて燐酸マグネシウム化合物の結晶を種結晶の表面に析出させる晶析反応工程の晶析反応装置である。
【００１４】
次に、前記図３の構成の晶析脱燐装置により排水中の燐を除去する方法について以下詳述する。排水を排水供給ポンプ２４により原水導入管ｂから原水調整槽２０に導入し、マグネシウム塩溶液貯槽２２からマグネシウム塩溶液供給ポンプ２５によりマグネシウム供給管ｆを経てマグネシウム溶液を添加すると共に、アルカリ溶液貯槽２３からアルカリ溶液供給ポンプ２６によりアルカリ供給管ｇを経てアルカリ溶液を供給し、攪拌手段２１により攪拌混合してｐＨ調整する。
【００１５】
なお、マグネシウム溶液の添加量は、マグネシウムが排水に含有される燐の１〜３倍モル比となるように添加するのが好ましく、更に好ましくは、１．５〜２倍モル比である。前記において、マグネシウムが燐の１倍モル比以下では燐の除去率が低くなり、３倍モル比以上では、残存マグネシウム量が多くなり、薬品費が嵩むと共に、スケールが発生する恐れがある。また、調整ｐＨは、７．５〜１０が好ましく、更に好ましくは、８〜８．５であり、ｐＨが７．５以下であると燐酸マグネシウム化合物の生成効率が低下し、ｐＨが１０以上では薬品費が嵩むと共に、スケールが発生する恐れがある。
【００１６】
原水調整槽２０で調整された混合液は、混合液導入管ｃから中空軸４の排水供給口１２を経てスクリ−ン２内に供給され、スクリ−ン２を回転駆動装置８により回転させながら排水中の燐とマグネシウムを反応させて燐酸マグネシウム化合物とし、種結晶として充填された燐酸マグネシウム結晶の表面に結晶として析出させる。液分は、スクリ−ン部材３の通液孔により結晶が分離され処理液槽１ａの処理液排出口１５から処理液排出管ｄを経て排出され、結晶は、長尺掻揚げ板６で掻揚げて長孔９上で落下させ、長尺矩形板５ａ、５ｂで誘導して長孔９内に導入し、中空軸４の内部に挿通されたスクリュウ部材７により結晶排出口１４に移送して結晶排出口１４から排出管ｅを経て図示しない結晶貯留槽などに貯留される。
【００１７】
【発明の効果】
本発明は、設備面積が狭くすみ、設備費が低廉であり、また、動力費などの運転経費も低廉となる晶析反応装置及びその装置を用いて、脱燐効果が安定して高く維持でき、析出結晶も容易に分離でき、また、分離回収した結晶も不純物が少なくマグネシウムや燐酸及びアンモニアを多量に含んでいるため、肥料や土壌改良材として還元することができる晶析脱燐方法である。
【図面の簡単な説明】
【図１】本発明の一実施の形態である晶析反応装置の概略縦断面図
【図２】図１のＡ−Ａ矢視図
【図３】本発明の一実施の形態である晶析脱燐装置全体の系統図
【符号の説明】
１：晶析反応装置
１ａ：処理液槽
２：スクリ−ン
３：スクリ−ン部材
４：中空軸
５ａ、５ｂ：長尺矩形板
６：長尺掻揚げ板
７：スクリュウ部材
８：回転駆動装置
９：長孔
１０：排水供給部
１１：結晶排出部
２０：原水調整槽
２１：攪拌手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a crystallization reaction apparatus for bringing a crystallized component in water onto the surface of a seed crystal by contacting with the seed crystal, and using the apparatus, phosphorus in waste water containing a phosphorus compound as a magnesium phosphate compound crystal as a seed crystal The present invention relates to a crystallization dephosphorization method that precipitates on the surface of the steel and separates it.
[0002]
[Prior art]
Conventionally, in the chemical industry field, the water treatment field, etc., a crystallization reaction apparatus has been used in which water containing a crystallization component is brought into contact with a seed crystal to precipitate or recover the crystallization component in water on the surface of the seed crystal. As a conventional crystallization reaction apparatus, the precipitated crystals or externally added crystals are seeded and filled in the crystallization reaction tank, and are stirred in water by stirring with an aeration apparatus, a mechanical stirring apparatus or a pump circulation. Many fluidized bed crystallization reactors that deposit crystallization components on the surface of seed crystals are used.
[0003]
In addition, as a method for removing phosphorus in wastewater containing phosphorus compounds such as human waste, sewage, food wastewater or kitchen wastewater, biological dephosphorization that combines anaerobic treatment and aerobic treatment to remove and remove phosphorus into microbial sludge. In general, a coagulation-precipitation method in which a coagulation agent such as aluminum sulfate or polyaluminum chloride is used to coagulate with SS or colloid and precipitate is separated. Therefore, there is a problem that operation management is complicated, advanced technology is required, and processing time is long, resulting in an excessively large apparatus. In the coagulation precipitation method, the coagulant itself and SS and Since colloids and the like are agglomerated and separated, the amount of generated sludge increases, and there is a problem that a large amount of cost and excessive equipment are required for sludge treatment, so reduce the amount of sludge as much as possible As a treatment method that enables effective utilization of resources, a calcium salt crystallization dephosphorization is performed by adding calcium salts such as slaked lime and quick lime to precipitate hydroxyapatite crystals and separating them using the fluidized bed crystallization reaction apparatus. MAP method crystallization dephosphorization method has been developed, in which magnesium salts such as magnesium chloride and magnesium hydroxide are added, and ammonia in the waste water is used to precipitate and separate crystals such as magnesium ammonia phosphate (MAP). ing.
[0004]
[Problems to be solved by the invention]
In the fluidized bed crystallization reactor, the specific gravity of the crystal granulated material is heavy, so there is a problem that the power for fluidization becomes large and the power cost increases, and in particular, the fluidized bed crystallization reactor is crystallized. When used in the dephosphorization method, the crystals precipitated in the crystallization dephosphorization have a heavy specific gravity of 1.5 to 2.0. Since it tends to occur, there is a problem that it settles at the bottom of the crystallization reaction tank due to incomplete flow, and the precipitated crystals tend to cause scale adhesion or piping blockage in the crystallization reaction tank. In addition, the MAP method crystallization dephosphorization has a problem that fine flocs easily flow out and the dephosphorization efficiency is low.
[0005]
The present invention has been made in view of the problems of the conventional fluidized bed type crystallization reaction apparatus and the crystallization dephosphorization method using the apparatus, the equipment area is reduced, and the equipment cost is low. In addition, by using a crystallization reaction apparatus and its apparatus that can reduce operating costs such as power costs, the dephosphorization effect can be maintained stably and high, the precipitated crystals can be easily separated, and the separated and recovered crystals are also impurities. The purpose of the present invention is to provide a crystallization dephosphorization method that can be reduced as a fertilizer or a soil conditioner because it contains a small amount of magnesium, phosphoric acid and ammonia.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the gist of the present invention is that in the invention described in claim 1, the crystallization component containing water is brought into contact with the seed crystal to precipitate the crystallized component in water on the surface of the seed crystal. In the reaction apparatus, the crystallization reaction apparatus is provided with a processing liquid tank having a processing liquid discharge port, and a large number of liquid passage holes are provided in the processing liquid tank and filled with seed crystals inside. The screen is horizontally mounted so that the circumferential surface is in the vertical direction, and is immersed in the processing liquid in the processing liquid tank to a suitable depth below, and is rotationally driven. Connected to the device, it is rotatably supported, and a plurality of long lifting plates parallel to the axis are mounted on the inner peripheral surface of the screen at regular intervals in the inner peripheral direction of the screen. A hollow shaft is provided in the axial portion of the screen so as to pass through both end faces. The drainage supply part is provided with a drainage supply port communicating with the inside of the screen, and the crystal discharge part is drilled in the axial direction of the upper surface of the crystal. The crystallization reaction apparatus is characterized in that a long rectangular plate protrudes from each of the long holes and the long side portions of the long holes facing each other, and a screw member is inserted therein. By adopting the above-described configuration, the facility area is reduced, the facility cost is low, and the operation cost such as the power cost is also low.
[0007]
Further, in the invention described in claim 2, in the crystallization reaction apparatus described in claim 1, the long rectangular plate is inclined and protruded outwardly as it becomes the tip side, and the long lifting plate is The crystallization reaction apparatus is mounted with an inclination in the rotation direction. With the above-described configuration, the effect of the invention described in claim 1 can be used to efficiently scoop up the crystal, and the crystal can be discharged more efficiently.
[0008]
Further, in the invention described in claim 3, the magnesium salt solution is added to the waste water so as to have a molar ratio of 1 to 3 times that of phosphorus contained in the waste water, and the alkaline solution is added to adjust the pH to 7. A solution mixing step of adjusting to 5 to 10 and a crystallization reaction step of bringing the wastewater adjusted to pH in the solution mixing step into contact with the seed crystal of the magnesium phosphate compound to precipitate phosphorus in the waste water on the surface of the seed crystal are provided. In the crystallization dephosphorization method, in the crystallization reaction step, a treatment liquid tank having a treatment liquid discharge port, and a large number of liquid passing through a peripheral portion provided in the treatment liquid tank and filled with seed crystals therein. It is composed of a cylindrical screen provided with holes, and the screen is laid horizontally so that the circumferential surface is in the vertical direction, and is immersed in the processing liquid in the processing liquid tank to an appropriate depth below. Connected to the rotation drive device, is provided rotatably supported On the inner peripheral surface of the screen, a plurality of long lifting plates parallel to the axis are mounted at regular intervals in the inner peripheral direction of the screen, and the hollow shaft has both end surfaces on the axial portion of the screen. The hollow shaft is divided into a drainage supply part and a crystal discharge part in the axial direction, and the drainage supply part is provided with a drainage supply port communicating with the inside of the screen. Each has a crystal discharge port, a long hole drilled in the axial direction of the upper surface, and a long rectangular plate projecting from both long sides facing the long hole, and a screw member is inserted inside. Using the obtained crystallization reaction apparatus, the crystal of the magnesium phosphate compound is filled as a seed crystal, the waste water is supplied into the screen from the waste water supply port of the hollow shaft, and the crystallization reaction is performed while rotating the screen. The liquid is separated from the crystal through the through-hole of the screen and discharged from the processing liquid outlet of the processing liquid tank. The crystal is lifted by a long lifting plate, dropped on the long hole, guided by a long rectangular plate, introduced into the long hole, transferred to the crystal outlet by a screw member inserted inside, and screened. The crystallization dephosphorization method is characterized in that the crystallization dephosphorization method is characterized in that it is discharged outside the tank. By adopting the above-described configuration, the equipment area is reduced, the equipment cost is low, the operating cost such as the power cost is low, the dephosphorization effect can be stably maintained high, and the precipitated crystals are easy. Moreover, since the separated and recovered crystals have few impurities and contain a large amount of magnesium, phosphoric acid and ammonia, they can be reduced as fertilizers and soil conditioners.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of a crystallization reaction apparatus according to an embodiment of the present invention, FIG. 2 is a view taken along the line AA of FIG. 1, and FIG. 3 is an embodiment of the present invention. It is a systematic diagram of a certain crystallization dephosphorization apparatus. In all the drawings, members having the same action are given the same numbers.
[0010]
In FIG. 1, reference numeral 1 denotes a processing liquid tank 1 a having a processing liquid discharge port 15, and a cylindrical screen 2 provided with a large number of liquid passage holes in a peripheral portion provided in the processing liquid tank 1 a. In this embodiment, the treatment liquid tank 1a is a rectangular tank whose upper part is opened, but may be a tank having a sealed structure covered with a lid having an appropriate shape. It may be a tank with an arcuate bottom that matches the shape of the screen to be provided. The screen 2 is a screen formed in a cylindrical shape by using a wire net, a perforated plate, a slit plate, etc. as the screen member 3 that forms the periphery of the screen provided with a large number of liquid passage holes. The both ends of the lead member 3 are covered with a flat plate member by appropriate engaging means, and the inside is filled with the seed crystal a.
[0011]
The screen 2 is installed in the processing liquid tank 1a so that its circumferential surface is in the vertical direction, and is immersed in the processing liquid in the processing liquid tank 1a to an appropriate depth below. 8 is provided so as to be connected to and rotatable. The rotation drive device 8 is connected to a pulley 16a fitted to one bearing means 13a of appropriate bearing means 13a and 13b for supporting the screen 2 on the hollow shaft 4 described later, and the rotation drive device 8. The pulley 16b is preferably connected to the belt 17 by a belt 17. However, a gear structure may be used, or a structure in which the pulley is directly attached to the screen 2 may be used. Further, a plurality of long lifting plates 6 parallel to the axis are mounted on the inner peripheral surface of the screen 2 at regular intervals in the inner peripheral direction of the screen 2, and the axis portion of the screen 2 The hollow shaft 4 is horizontally provided through both end faces. The immersion depth of the screen 2 in the processing liquid is set at a position below the hollow shaft 4.
[0012]
The hollow shaft 4 is divided into a drainage supply unit 10 and a crystal discharge unit 11 in the axial direction. The drainage supply unit 10 is provided with a drainage supply port 12 communicating with the inside of the screen 2. The crystal discharge port 14, the long hole 9 drilled in the axial direction of the upper surface, and the long rectangular plates 5a and 5b project from the opposite long side portions of the long hole 9, respectively, and a screw member is provided inside. 7 is inserted and provided. In addition, it is preferable that the long rectangular plates 5a and 5b are respectively provided so as to incline outward toward the tip side.
[0013]
In FIG. 3, reference numeral 20 denotes a raw water introduction pipe b for introducing waste water, a magnesium supply pipe f for supplying magnesium solution, and an alkali supply pipe g for supplying alkaline solution, and the waste water introduced from the raw water introduction pipe b is connected to A raw water adjusting tank used for a solution mixing step of adding a magnesium solution such as magnesium chloride supplied from a magnesium supply pipe f and adjusting pH with an alkali solution such as sodium hydroxide supplied from an alkali supply pipe g. The agitation means 21 is attached to this. The stirring means 21 is preferably a mechanical stirrer that stirs with stirring blades, but may be an air stirring means or a pump circulation. 1 is an apparatus having substantially the same configuration as the crystallization reaction apparatus described in FIG. 1, and is a crystal in the crystallization reaction process in which phosphorus and magnesium in waste water are reacted to precipitate crystals of a magnesium phosphate compound on the surface of the seed crystal. It is an analysis reactor.
[0014]
Next, a method for removing phosphorus in the wastewater by the crystallization dephosphorization apparatus having the structure shown in FIG. 3 will be described in detail. Drainage is introduced into the raw water adjustment tank 20 from the raw water introduction pipe b by the drainage supply pump 24, the magnesium solution is added from the magnesium salt solution storage tank 22 through the magnesium supply pipe f by the magnesium salt solution supply pump 25, and the alkaline solution storage tank 23. Then, the alkali solution is supplied by the alkali solution supply pump 26 through the alkali supply pipe g, and the pH is adjusted by stirring and mixing by the stirring means 21.
[0015]
In addition, it is preferable to add so that the addition amount of a magnesium solution may become 1-3 times molar ratio of the phosphorus contained in a waste_water | drain, More preferably, it is 1.5-2 times molar ratio. In the above, if the magnesium is less than 1 molar ratio of phosphorus, the removal rate of phosphorus is low, and if it is 3 molar ratio or more, the amount of residual magnesium increases, the chemical cost increases, and scale may be generated. The adjusted pH is preferably 7.5 to 10, more preferably 8 to 8.5, and if the pH is 7.5 or less, the production efficiency of the magnesium phosphate compound is lowered. There is a risk that scale increases due to an increase in chemical costs.
[0016]
The mixed liquid adjusted in the raw water adjusting tank 20 is supplied into the screen 2 from the mixed liquid introduction pipe c through the drainage supply port 12 of the hollow shaft 4, and the screen 2 is rotated by the rotary drive device 8. Phosphorus and magnesium in the waste water are reacted to form a magnesium phosphate compound, which is precipitated as a crystal on the surface of the magnesium phosphate crystal filled as a seed crystal. The liquid is separated from the crystal through the liquid passage hole of the screen member 3 and discharged from the treatment liquid discharge port 15 of the treatment liquid tank 1a through the treatment liquid discharge pipe d. It is lifted and dropped on the long hole 9, guided by the long rectangular plates 5 a and 5 b, introduced into the long hole 9, and transferred to the crystal discharge port 14 by the screw member 7 inserted into the hollow shaft 4. It is stored in a crystal storage tank or the like (not shown) from the crystal discharge port 14 through the discharge pipe e.
[0017]
【The invention's effect】
According to the present invention, the dephosphorization effect can be stably maintained at a high level by using a crystallization reaction apparatus and its apparatus, which requires only a small equipment area, low equipment costs, and low operating costs such as power costs. This is a crystallization dephosphorization method that can easily separate the precipitated crystals, and the separated and recovered crystals contain few impurities, and contain a large amount of magnesium, phosphoric acid and ammonia, so that they can be reduced as fertilizers and soil conditioners. .
[Brief description of the drawings]
1 is a schematic longitudinal sectional view of a crystallization reaction apparatus according to an embodiment of the present invention. FIG. 2 is a view taken along the line AA in FIG. 1. FIG. 3 is a crystallization according to an embodiment of the present invention. System diagram of the entire dephosphorization system [Explanation of symbols]
1: Crystallization reaction apparatus 1a: Treatment liquid tank 2: Screen 3: Screen member 4: Hollow shaft 5a, 5b: Long rectangular plate 6: Long lifting plate 7: Screw member 8: Rotation drive device 9: Long hole 10: Drain supply part 11: Crystal discharge part 20: Raw water adjustment tank 21: Stirring means

Claims

結晶化成分含有水を種結晶と接触させて水中の結晶化成分を種結晶の表面に析出させる晶析反応装置において、晶析反応装置が、処理液排出口を具備する処理液槽と、該処理液槽内に内設され、内部に種結晶が充填された周部に多数の通液孔が設けられた円筒形のスクリ−ンとからなり、該スクリ−ンは、円周面が上下方向となるよう横架され、処理液槽内の処理液中に下方の適宜深さまで浸漬され、回転駆動装置に接続して回転可能に支持されて設けられており、スクリ−ンの内周面に、軸線と平行する長尺掻揚げ板が、スクリ−ンの内周方向に一定間隔で複数装着され、スクリ−ンの軸線部には、中空軸が両端面を貫通して横設され、該中空軸は、軸線方向に排水供給部と結晶排出部とに区画され、排水供給部にはスクリ−ン内と連通する排水供給口が設けられ、結晶排出部には結晶排出口と、上面の軸線方向に穿設された長孔と、長孔の対向する両長辺部から長尺矩形板が夫々突設され、内部にはスクリュウ部材が挿通されて設けられていることを特徴とする晶析反応装置。In a crystallization reaction apparatus in which water containing a crystallization component is brought into contact with a seed crystal to precipitate a crystallization component in water on the surface of the seed crystal, the crystallization reaction apparatus includes a treatment liquid tank having a treatment liquid discharge port, It consists of a cylindrical screen that is installed in the processing liquid tank and has a large number of liquid passage holes in the periphery filled with seed crystals. The inner peripheral surface of the screen is horizontally mounted so that it is immersed in an appropriate depth below in the processing liquid in the processing liquid tank, and is rotatably supported by being connected to a rotation driving device. In addition, a plurality of long lifting plates parallel to the axis are mounted at a constant interval in the inner circumferential direction of the screen, and a hollow shaft is provided horizontally across the both end surfaces in the screen axis portion, The hollow shaft is partitioned in the axial direction into a drainage supply unit and a crystal discharge unit, and the drainage supply unit communicates with the inside of the screen. A drainage supply port is provided, and the crystal discharge port is provided with a crystal discharge port, a long hole drilled in the axial direction of the upper surface, and a long rectangular plate projecting from both long sides facing the long hole, A crystallization reaction apparatus characterized in that a screw member is inserted inside.

長尺矩形板が先端側になるに従い外側に傾斜して夫々突設され、長尺掻揚げ板がスクリ−ンの回転方向に傾斜して装着されたことを特徴とする請求項１記載の晶析反応装置。2. The crystal according to claim 1, wherein the long rectangular plate is inclined and protruded outwardly as it becomes the tip side, and the long rake plate is mounted inclined with respect to the rotational direction of the screen. Analysis reaction equipment.

排水中にマグネシウム塩溶液を排水に含有される燐の１〜３倍モル比となるように添加すると共にアルカリ溶液を添加してｐＨを、７．５〜１０に調整する溶液混合工程と、溶液混合工程でｐＨ調整された排水を燐酸マグネシウム化合物の種結晶と接触させて排水中の燐を種結晶の表面に析出させる晶析反応工程を設けた晶析脱燐方法において、晶析反応工程に、処理液排出口を具備する処理液槽と、該処理液槽内に内設され、内部に種結晶が充填された周部に多数の通液孔が設けられた円筒形のスクリ−ンとからなり、該スクリ−ンは、円周面が上下方向となるよう横架され、処理液槽内の処理液中に下方の適宜深さまで浸漬され、回転駆動装置に接続して回転可能に支持されて設けられており、スクリ−ンの内周面に、軸線と平行する長尺掻揚げ板が、スクリ−ンの内周方向に一定間隔で複数装着され、スクリ−ンの軸線部には、中空軸が両端面を貫通して横設され、該中空軸は、軸線方向に排水供給部と結晶排出部とに区画され、排水供給部にはスクリ−ン内と連通する排水供給口が設けられ、結晶排出部には結晶排出口と、上面の軸線方向に穿設された長孔と、該長孔の対向する両長辺部から長尺矩形板が夫々突設され、内部にはスクリュウ部材が挿通されて設けられた晶析反応装置を用い、種結晶として燐酸マグネシウム化合物の結晶を充填し、排水を中空軸の排水供給口からスクリ−ン内に供給し、スクリ−ンを回転しながら晶析反応させ、液分はスクリ−ンの通液孔で結晶を分離して処理液槽の処理液排出口から排出し、結晶は長尺掻揚げ板で掻揚げて長孔上で落下させ、長尺矩形板で誘導して長孔内に導入し、内部に挿通されたスクリュウ部材により結晶排出口に移送してスクリ−ン外に排出することを特徴とする晶析脱燐方法。A solution mixing step of adding a magnesium salt solution in the waste water so as to have a molar ratio of 1 to 3 times that of phosphorus contained in the waste water, and adjusting the pH to 7.5 to 10 by adding an alkaline solution; In a crystallization dephosphorization method in which a crystallization reaction step is provided in which the wastewater adjusted in pH in the mixing step is brought into contact with a seed crystal of a magnesium phosphate compound to deposit phosphorus in the wastewater on the surface of the seed crystal. A treatment liquid tank having a treatment liquid discharge port, and a cylindrical screen provided in the treatment liquid tank and provided with a large number of liquid passage holes in the periphery filled with seed crystals. The screen is horizontally mounted so that the circumferential surface is in the vertical direction, immersed in the processing liquid in the processing liquid tank to an appropriate depth below, and connected to a rotary drive device to be rotatably supported. The length of the inner peripheral surface of the screen is parallel to the axis. A plurality of scraping plates are mounted at regular intervals in the inner circumferential direction of the screen, and a hollow shaft is horizontally provided through the both end surfaces in the axial portion of the screen, and the hollow shaft extends in the axial direction. The drainage supply unit is divided into a drainage supply unit and a crystal discharge unit. The drainage supply unit is provided with a drainage supply port communicating with the inside of the screen. The crystal discharge unit is drilled in the crystal discharge port and in the axial direction of the upper surface. Magnesium phosphate compound as a seed crystal using a crystallization reaction apparatus in which a long rectangular plate protrudes from a long hole and from both long sides facing the long hole, and a screw member is inserted inside The waste water is fed into the screen through the drainage outlet of the hollow shaft, and the crystallization reaction is carried out while rotating the screen. The liquid is separated from the crystal through the through-hole of the screen. The crystal is discharged from the treatment liquid discharge port of the treatment liquid tank, and the crystals are lifted by a long rake plate and dropped on the long hole. So, to induce a long rectangular plate is introduced into the elongated hole, subscriptions and transferred to the crystal outlet by inserting therein has been screw member - crystal phosphorus removal method characterized by discharged out emissions.