JP5550459B2 - Recovery phosphorus and recovery method - Google Patents
Recovery phosphorus and recovery method Download PDFInfo
- Publication number
- JP5550459B2 JP5550459B2 JP2010133806A JP2010133806A JP5550459B2 JP 5550459 B2 JP5550459 B2 JP 5550459B2 JP 2010133806 A JP2010133806 A JP 2010133806A JP 2010133806 A JP2010133806 A JP 2010133806A JP 5550459 B2 JP5550459 B2 JP 5550459B2
- Authority
- JP
- Japan
- Prior art keywords
- phosphorus
- aqueous solution
- recovered
- water
- adsorbent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Removal Of Specific Substances (AREA)
- Water Treatment By Sorption (AREA)
Description
本発明は、下水、し尿、工場排水等の排水、それら排水の処理水、さらに自然水等に含有されるリンを、工業原料としても利用可能な不純物含有率が低いリン化合物として回収する技術に関する。 The present invention relates to a technique for recovering phosphorus contained in wastewater such as sewage, human waste, factory wastewater, treated water of these wastewater, natural water, etc., as a phosphorus compound having a low impurity content that can be used as an industrial raw material. .
リンは生物にとって必須の元素であるが、その資源枯渇が世界的に懸念されるようになってきている。一方、リンは下水や工場排水等に含有されて自然界に多量に放出されており、これらのリンは閉鎖性水域の湖沼、港湾等で富栄養化を進行させ、水質汚濁、悪臭、生態系崩壊等の水環境悪化の原因になっている。 Phosphorus is an essential element for living organisms, but its resource depletion has become a global concern. On the other hand, phosphorus is contained in sewage and industrial effluents and released in large quantities to the natural world. These phosphorus promote eutrophication in closed lakes, harbors, etc., resulting in water pollution, bad odor, and ecosystem collapse. It causes the deterioration of the water environment.
そこで、下水や工場排水、あるいはその処理水等からリンを除去し、かつ除去したリンを回収してリン資源として有効利用するための技術が求められている。下水や工場排水中に含有されるリンを不純物含有率が低いリン化合物として回収する技術としては、特許文献１および２に開示された技術が提案されている。 Therefore, there is a need for a technique for removing phosphorus from sewage, industrial wastewater, treated water, etc., and recovering the removed phosphorus for effective use as a phosphorus resource. As a technique for recovering phosphorus contained in sewage or industrial wastewater as a phosphorus compound having a low impurity content, techniques disclosed in Patent Documents 1 and 2 have been proposed.
現在、下水や排水等から回収された回収リンの有効利用法としては、肥料や肥料の配合原料といった農業用途で利用する方法が主流になっている。農業用途で利用する場合は、不純物含有に対する制限が比較的緩やかなためである。一方、回収したリンを工業用途、例えばリン酸原料用リン鉱石代替品として利用する場合には、不純物の含有に対する制限が厳しくなり、特に、マグネシウム、アルミニウム、ケイ素、鉄、塩素等の特定の不純物含有率が一定の基準以下であることが求められる。特許文献１および２に開示された技術を利用して得られた回収リンは、特にこのような工業用途で利用するという観点からは、不純物含有率が充分に低減されているとはいえない。 At present, as an effective utilization method of recovered phosphorus collected from sewage or drainage, a method for use in agricultural applications such as fertilizer and fertilizer compounding raw materials has become mainstream. This is because when used for agricultural purposes, the restriction on impurity content is relatively loose. On the other hand, when the recovered phosphorus is used as an industrial application, for example, as a substitute for phosphate ore for phosphoric acid raw materials, there are strict restrictions on the inclusion of impurities, especially certain impurities such as magnesium, aluminum, silicon, iron and chlorine. The content is required to be below a certain standard. The recovered phosphorus obtained by using the techniques disclosed in Patent Documents 1 and 2 cannot be said to have a sufficiently reduced impurity content, particularly from the viewpoint of use in such industrial applications.
本発明は、このような事情に鑑みなされたもので、下水、し尿、工場排水等の排水、これら排水の処理水、湖沼水、海水、河川水等の自然水といった、リン以外の雑多な成分を多く含む水中からも、リンを、工業用途、特にリン酸原料用リン鉱石代替品等にも利用可能な不純物含有率が低いリン化合物として回収する技術を提供することを目的とする。 The present invention has been made in view of such circumstances, and various components other than phosphorus, such as sewage, human waste, waste water such as factory waste water, treated water of these waste water, natural water such as lake water, sea water, and river water. It is an object of the present invention to provide a technique for recovering phosphorus from water containing a large amount of phosphorus as a phosphorus compound having a low impurity content that can be used for industrial applications, in particular, phosphate ore substitutes for phosphoric acid raw materials.
本発明者は、上記課題を達成するために鋭意研究を重ねた結果、金属酸化物系吸着剤で水中からリンを吸着除去し、この吸着除去したリンに対して特定量のカルシウム化合物を添加してリンを析出し、析出リンを回収し、特定のｐＨ下中和することで、リンを不純物含有率が低いリン化合物として回収できることを見出し、本発明を完成するに至った。 As a result of intensive research to achieve the above-mentioned problems, the present inventor adsorbed and removed phosphorus from water with a metal oxide adsorbent, and added a specific amount of calcium compound to the adsorbed and removed phosphorus. As a result, it was found that phosphorus can be recovered as a phosphorus compound having a low impurity content by recovering the precipitated phosphorus, recovering the precipitated phosphorus, and neutralizing at a specific pH, thereby completing the present invention.
すなわち、本発明は以下の回収リンの回収方法及び回収リンに関する。
［１］
以下の工程（１）〜（５）：
（１）リン含有水溶液中のリンを、金属酸化物系吸着剤に吸着させる吸着工程；
（２）前記吸着剤にアルカリ水溶液を接触させて、吸着工程（１）で吸着したリンを脱着させる脱着工程；
（３）脱着工程（２）で脱着させたリンを含有するアルカリ水溶液中に、カルシウム化合物をＣａ／Ｐモル比が０．６〜１．８になる量添加し、アルカリ水溶液中のリンをリン酸カルシウムとして析出させる析出工程；
（４）析出工程（３）で析出させたリンをアルカリ水溶液から分離し回収する分離回収工程；および
（５）分離回収工程（４）で回収したリンをｐＨ４．５〜１２．５に中和する中和工程
を含む、リン含有水溶液からの回収リンの回収方法。
［２］
前記吸着工程（１）における金属酸化物系吸着剤が、活性アルミナ、水和酸化鉄、水和酸化チタン、水和酸化ジルコニウム、水和酸化スズ、水和酸化セリウム、水和酸化ランタンおよび水和酸化イットリウムからなる群から選ばれる一種以上の酸化物をイオン吸着体として含有する吸着剤である、［１］に記載の回収リンの回収方法。
［３］
前記工程（１）におけるリン含有水溶液が、リン濃度に対してマグネシウム、アルミニウム、珪素および鉄の濃度の和が０．５〜１０００倍のリン含有水溶液である、［１］または［２］に記載の回収リンの回収方法。
［４］
前記中和工程（５）が、塩素を含有しない酸を用いて行われる、［１］〜［３］のいずれかに記載の回収リンの回収方法。
［５］
［１］〜［４］のいずれかに記載の回収方法を用いて回収される、リン含有率が１２重量％以上であり、かつマグネシウム、アルミニウム、珪素および鉄の含有率の合計が２．０重量％以下である回収リン。
［６］
排水、排水処理水、自然水またはこれらの２種以上の混合水であるリン含有水溶液中から除去したリンを回収して得られるリン酸カルシウムを主成分とする回収リンであって、リン含有率が１２重量％以上であり、かつマグネシウム、アルミニウム、珪素および鉄の含有率の合計が２．０重量％以下である回収リン。
［７］
マグネシウム、アルミニウム、珪素および鉄の各含有率がいずれも０．５重量％以下である、［６］に記載の回収リン。
That is, the present invention relates to the following recovered phosphorus recovery method and recovered phosphorus.
[1]
The following steps (1) to (5):
(1) An adsorption process for adsorbing phosphorus in a phosphorus-containing aqueous solution to a metal oxide adsorbent;
(2) A desorption step of bringing the aqueous solution into contact with the adsorbent and desorbing the phosphorus adsorbed in the adsorption step (1);
(3) In the alkaline aqueous solution containing phosphorus desorbed in the desorption step (2), a calcium compound is added in an amount such that the Ca / P molar ratio is 0.6 to 1.8, and phosphorus in the alkaline aqueous solution is calcium phosphate. A precipitation step to precipitate as;
(4) Separation and recovery step of separating and recovering phosphorus precipitated in the precipitation step (3) from the alkaline aqueous solution; and (5) Neutralizing phosphorus recovered in the separation and recovery step (4) to pH 4.5 to 12.5 A method for recovering recovered phosphorus from a phosphorus-containing aqueous solution, comprising a neutralization step.
[2]
The metal oxide adsorbent in the adsorption step (1) is activated alumina, hydrated iron oxide, hydrated titanium oxide, hydrated zirconium oxide, hydrated tin oxide, hydrated cerium oxide, hydrated lanthanum oxide, and hydrated. The method for recovering recovered phosphorus according to [1], which is an adsorbent containing one or more oxides selected from the group consisting of yttrium oxide as an ion adsorbent.
[3]
[1] or [2], wherein the phosphorus-containing aqueous solution in the step (1) is a phosphorus-containing aqueous solution in which the sum of the concentrations of magnesium, aluminum, silicon, and iron is 0.5 to 1000 times the phosphorus concentration. Recovery method of recovered phosphorus.
[4]
The method for recovering recovered phosphorus according to any one of [1] to [3], wherein the neutralization step (5) is performed using an acid not containing chlorine.
[5]
The phosphorus content recovered using the recovery method according to any one of [1] to [4] is 12% by weight or more, and the total content of magnesium, aluminum, silicon and iron is 2.0. Recovered phosphorus that is less than or equal to weight percent.
[6]
A recovered phosphorus mainly composed of calcium phosphate obtained by recovering phosphorus removed from a phosphorus-containing aqueous solution, which is wastewater, wastewater treated water, natural water or a mixture of two or more of these, and has a phosphorus content of 12 Recovered phosphorus that is not less than wt% and the total content of magnesium, aluminum, silicon and iron is not more than 2.0 wt%.
[7]
The recovered phosphorus according to [6], wherein each content of magnesium, aluminum, silicon, and iron is 0.5% by weight or less.
本発明によれば、下水や工場排水等に含まれて自然界に流出し、閉鎖性水域等で富栄養化を進行させ水環境悪化の原因になっているリンを、下水や工業排水等から除去できることに加え、除去したリンを工業用途にも利用可能な不純物含有率が低いリン化合物として回収することができる。したがって閉鎖性水域の水環境悪化を抑制するとともに、リン資源枯渇問題の解決に対して大きな効果を有する。 According to the present invention, phosphorus, which is contained in sewage and industrial wastewater, flows out to the natural world, advances eutrophication in closed water areas and causes deterioration of the water environment, is removed from sewage and industrial wastewater. In addition to being able to be removed, the removed phosphorus can be recovered as a phosphorus compound having a low impurity content that can be used for industrial purposes. Therefore, it has a great effect on the solution of the phosphorus resource depletion problem while suppressing the deterioration of the water environment in closed water areas.
以下、本発明を実施するための形態（以下、「本実施の形態」という。）について、具体的に説明する。なお、本発明は、以下の本実施の形態に限定されるものではなく、その要旨の範囲内で種々変形して実施することができる。 Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be specifically described. The present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of the gist.
本実施の形態は、リン含有水溶液からの不純物含有率が低いリンの回収方法および回収された回収リンに関する。ここで、リン含有水溶液は、リンを含有する限り特に限定されず、以下に説明する排水、排水処理水および自然水等が例示される。 The present embodiment relates to a method for recovering phosphorus with a low impurity content from a phosphorus-containing aqueous solution and recovered recovered phosphorus. Here, the phosphorus-containing aqueous solution is not particularly limited as long as it contains phosphorus, and examples thereof include waste water, waste water treated water, and natural water described below.
本実施の形態において、排水とは、下水、し尿、各種工場排水等、人間や動物の活動により発生する汚水である。 In the present embodiment, the waste water is sewage generated by human or animal activities, such as sewage, human waste, various factory waste water.
本実施の形態において、排水処理水とは、排水を公共水域等に放流する前に行う処理の過程で発生するプロセス水および処理後の処理水である。排水処理水について下水の場合の例を挙げれば、下水処理過程の最初の沈殿処理後の水や生物反応処理後の水（二次処理水）、下水汚泥脱水濾液、下水処理後の放流水等である。すなわち、下水処理場で採水可能な水は全て排水処理水に含まれる。また、下水汚泥焼却灰から酸、アルカリを用いてリンを抽出した際の抽出液も排水処理水に含まれる。排水がし尿、各種工場排水の場合の排水処理水についても同様である。 In the present embodiment, the waste water treated water is process water generated in the course of treatment performed before the waste water is discharged into public water areas and the treated water after treatment. Examples of wastewater treated water include sewage treatment water after the first precipitation treatment in the sewage treatment process, water after biological reaction treatment (secondary treatment water), sewage sludge dehydrated filtrate, effluent after sewage treatment, etc. It is. That is, all the water that can be collected at the sewage treatment plant is included in the wastewater treatment water. Moreover, the extracted liquid at the time of extracting phosphorus from an sewage sludge incineration ash using an acid and an alkali is also contained in drainage treated water. The same applies to wastewater treated wastewater in the case of wastewater excreta and various factory wastewater.
本実施の形態において、自然水とは、自然界に存在する水で、河川水、湖沼水、海水、雨水等を例示できる。 In the present embodiment, natural water is water existing in the natural world, and can be exemplified by river water, lake water, seawater, rainwater, and the like.
本実施の形態のリンの回収方法は、特に、リン以外の不純物を高濃度に含むリン含有水溶液からであっても、不純物含有率が低い回収リンを回収することができる。例えば、リン濃度に対するマグネシウム、アルミニウム、珪素および鉄の濃度の和が、０．５倍〜１０００倍であるような、不純物を多く含む水からであっても、これら不純物の含有率の和が２重量％以下で、かつリン含有率が１２重量％以上の回収リンを回収することができる。 The phosphorus recovery method of the present embodiment can recover recovered phosphorus having a low impurity content even from a phosphorus-containing aqueous solution containing impurities other than phosphorus in a high concentration. For example, even if the concentration of magnesium, aluminum, silicon, and iron with respect to the phosphorus concentration is 0.5 to 1000 times, and the water contains a large amount of impurities, the sum of the contents of these impurities is 2 Recovered phosphorus having a weight percentage of 12% or less and a phosphorus content of 12% or more can be recovered.
本実施の形態の回収リンは、リン含有率が１２重量％以上であり、１３重量％以上であることが好ましく、１３．５重量％以上であることが特に好ましい。１２重量％以上であることでリン酸原料用リン鉱石代替品等の工業用途で経済的に利用することができる。リン含有率は回収リンを工業用途で経済的に利用するにあたって重要である。 The recovered phosphorus of the present embodiment has a phosphorus content of 12% by weight or more, preferably 13% by weight or more, and particularly preferably 13.5% by weight or more. When it is 12% by weight or more, it can be economically used in industrial applications such as a phosphate ore substitute for phosphoric acid raw materials. Phosphorus content is important in using recovered phosphorus economically for industrial applications.
また、本実施の形態の回収リンは、不純物であるマグネシウム、アルミニウム、珪素および鉄の含有率の合計が２．０重量％以下、好ましくは１．５重量％以下、さらに好ましくは１．０重量％以下である。これらの含有率の合計を２．０重量％以下にすることでリン酸原料用リン鉱石代替品等の工業用途で容易に利用することができる。 The recovered phosphorus of the present embodiment has a total content of impurities magnesium, aluminum, silicon and iron of 2.0% by weight or less, preferably 1.5% by weight or less, more preferably 1.0% by weight. % Or less. By making the total of these content rates 2.0% by weight or less, it can be easily used in industrial applications such as a phosphate ore substitute for phosphoric acid raw materials.
さらに、本実施の形態の回収リンは、マグネシウム、アルミニウム、珪素および鉄の各含有率がいずれも０．５重量％以下であることが好ましい。不純物はその成分毎に悪影響をおよぼす機構が異なる場合があるため、これら不純物の含有率が全て一定値以下であることで、工業用途での利用がより容易になる。 Further, the recovered phosphorus of the present embodiment preferably has a magnesium, aluminum, silicon and iron content of 0.5% by weight or less. Impurities may have different adverse effects depending on their components, so that the content of these impurities is all equal to or less than a certain value, which makes it easier to use in industrial applications.
また、本実施の形態の回収リンは、塩素含有率が０．０８重量％以下であることが好ましく、０．０５重量％以下であることがさらに好ましく、０．０２重量％以下であることが特に好ましい。塩素含有率を０．０８重量％以下にすることで、上述と同様の理由によりリン酸原料用リン鉱石代替品等の工業用途での利用が容易になる。 The recovered phosphorus of the present embodiment preferably has a chlorine content of 0.08% by weight or less, more preferably 0.05% by weight or less, and 0.02% by weight or less. Particularly preferred. By making a chlorine content rate into 0.08 weight% or less, the utilization for industrial uses, such as a phosphate ore substitute for phosphoric acid raw materials, becomes easy for the same reason as the above-mentioned.
次に、本実施の形態の回収リンの回収方法を説明する。
回収方法は：（１）リン含有水溶液中のリンを、金属酸化物系吸着剤に吸着させる吸着工程；（２）前記吸着剤にアルカリ水溶液を接触させて、吸着工程（１）で吸着したリンを脱着させる脱着工程；（３）脱着工程（２）で脱着させたリンを含有するアルカリ水溶液中に、カルシウム化合物をＣａ／Ｐモル比が０．６〜１．８になる量添加し、アルカリ水溶液中のリンをリン酸カルシウムとして析出させる析出工程；（４）析出工程（３）で析出させたリンをアルカリ水溶液から分離し回収する分離回収工程；および（５）分離回収工程（４）で回収したリンをｐＨ４．５〜１２．５に中和する中和工程を少なくとも含む。
Next, a recovery phosphorus recovery method according to the present embodiment will be described.
The recovery methods are: (1) an adsorption step in which phosphorus in a phosphorus-containing aqueous solution is adsorbed on a metal oxide-based adsorbent; (2) phosphorus adsorbed in an adsorption step (1) by contacting the adsorbent with an alkaline aqueous solution (3) A calcium compound is added in an alkaline aqueous solution containing phosphorus desorbed in the desorption step (2) so that the Ca / P molar ratio is 0.6 to 1.8. A precipitation step of precipitating phosphorus in the aqueous solution as calcium phosphate; (4) a separation and recovery step of separating and collecting the phosphorus precipitated in the precipitation step (3); and (5) a recovery step of the separation and recovery step (4). At least a neutralization step for neutralizing phosphorus to pH 4.5 to 12.5 is included.
吸着工程（１）では、排水、排水処理水、自然水等のリン含有水溶液と金属酸化物系吸着剤を接触させて、リン含有水溶液中に含有されるリンを吸着剤に吸着させる。吸着工程（１）に供するリン含有水溶液は、浮遊物質（ＳＳ）濃度が１０ｍｇ／Ｌ以下であることが好ましい。ＳＳ濃度を１０ｍｇ／Ｌに低減するために、吸着工程（１）に先立って、砂濾過、膜濾過等の濾過処理を行ってもよい。リン含有水溶液と金属酸化物系吸着剤を接触させる方法については特に制限はなく、吸着剤に水中に含有される成分を吸着させる方法として従来公知の方法を何れも使用することができる。好ましい方法としては、カラム内に充填した吸着剤に対して上向流または下向流でリン含有水溶液を通水する方式を例示できる。この際、吸着剤は、固定床方式にしてもよいし、流動床方式にしてもよい。また、吸着剤を入れた容器内にリン含有水溶液を一定量入れ、容器内の水を攪拌して、接触させてリンを吸着剤に吸着させてもよい。 In the adsorption step (1), a phosphorus-containing aqueous solution such as waste water, wastewater-treated water, natural water, and the like are brought into contact with the metal oxide-based adsorbent to adsorb phosphorus contained in the phosphorus-containing aqueous solution to the adsorbent. The phosphorus-containing aqueous solution used for the adsorption step (1) preferably has a suspended matter (SS) concentration of 10 mg / L or less. In order to reduce the SS concentration to 10 mg / L, filtration treatment such as sand filtration and membrane filtration may be performed prior to the adsorption step (1). The method for bringing the phosphorus-containing aqueous solution into contact with the metal oxide-based adsorbent is not particularly limited, and any conventionally known method can be used as a method for adsorbing the components contained in water to the adsorbent. As a preferable method, a method of passing an aqueous solution containing phosphorus in an upward flow or a downward flow with respect to the adsorbent packed in the column can be exemplified. At this time, the adsorbent may be a fixed bed system or a fluidized bed system. Alternatively, a certain amount of a phosphorus-containing aqueous solution may be placed in a container containing an adsorbent, and the water in the container may be stirred and contacted to adsorb phosphorus to the adsorbent.
吸着工程（１）で用いる金属酸化物系吸着剤は、水中のリン酸イオンを吸着することができる、金属酸化物や水和金属酸化物（金属水酸化物）をイオン吸着体として含有する吸着剤であれば特に限定されない。活性アルミナ、水和酸化鉄、水和酸化チタン、水和酸化ジルコニウム、水和酸化スズ、水和酸化セリウム、水和酸化ランタンおよび水和酸化イットリウムからなる群から選ばれる一種または二種以上の酸化物をイオン吸着体として含有している吸着剤が、リンの吸着性能が高いという点で好ましい。例えば、後述の実施例等に記載の酸化セリウム系吸着剤、特許文献１に記載されるようなジルコニウムフェライト系吸着剤等を使用することができる。 The metal oxide adsorbent used in the adsorption step (1) can adsorb phosphate ions in water and contains metal oxide or hydrated metal oxide (metal hydroxide) as an ion adsorbent. If it is an agent, it will not specifically limit. One or more oxidations selected from the group consisting of activated alumina, hydrated iron oxide, hydrated titanium oxide, hydrated zirconium oxide, hydrated tin oxide, hydrated cerium oxide, hydrated lanthanum oxide, and hydrated yttrium oxide. An adsorbent containing an object as an ion adsorbent is preferable in that the adsorption performance of phosphorus is high. For example, a cerium oxide-based adsorbent described in Examples and the like described later, a zirconium ferrite-based adsorbent as described in Patent Document 1, and the like can be used.
脱着工程（２）では、吸着工程（１）でリン酸イオンを吸着した吸着剤にアルカリ水溶液を接触させて、吸着したリン酸イオンを脱着させる。なお、脱着工程（２）に先立って、吸着剤に逆洗処理等を行い、吸着剤に付着しているＳＳや、吸着剤層内に巻き込まれているＳＳを除去することが、より不純物含有率の低い回収リンを回収するために好ましい。 In the desorption step (2), an alkaline aqueous solution is brought into contact with the adsorbent that has adsorbed the phosphate ions in the adsorption step (1) to desorb the adsorbed phosphate ions. Prior to the desorption process (2), the adsorbent is subjected to a backwash process or the like to remove the SS adhering to the adsorbent or the SS entrained in the adsorbent layer. It is preferable for recovering recovered phosphorus having a low rate.
脱着工程（２）で用いるアルカリ水溶液の種類に特に制限はなく、従来公知の水酸化リチウム水溶液、水酸化ナトリウム水溶液、水酸化カリウム水溶液、水酸化アンモニウム水溶液、水酸化カルシウム水溶液等を使用することができる。２重量％〜１０重量％、好ましくは５重量％〜８重量％の範囲の水酸化ナトリウム水溶液または水酸化カリウム水溶液を用いることが、高い脱着率を効率的に達成するためには好ましい。 There is no restriction | limiting in particular in the kind of aqueous alkali solution used at a desorption process (2), Conventionally well-known lithium hydroxide aqueous solution, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, ammonium hydroxide aqueous solution, calcium hydroxide aqueous solution, etc. can be used. it can. In order to efficiently achieve a high desorption rate, it is preferable to use an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution in the range of 2 wt% to 10 wt%, preferably 5 wt% to 8 wt%.
脱着工程（２）で、吸着剤とアルカリ水溶液を接触させる方法についても特に制限はなく、従来公知の方法を何れも使用することができる。 In the desorption step (2), the method of bringing the adsorbent into contact with the alkaline aqueous solution is not particularly limited, and any conventionally known method can be used.
吸着剤とアルカリ水溶液の接触時間は、アルカリ水溶液の種類や濃度によって脱着速度が変化するために一概に決定できないが、１〜８時間の範囲であることが効率的に高脱着率を達成する上で好ましい。 The contact time between the adsorbent and the aqueous alkali solution cannot be determined unconditionally because the desorption rate varies depending on the type and concentration of the aqueous alkali solution, but the range of 1 to 8 hours can efficiently achieve a high desorption rate. Is preferable.
なお、カラム内に充填した吸着剤に対してアルカリ水溶液を上向流または下降流で通液して脱着する場合の通液速度は、通常ＳＶ（Space Velocity、１時間あたりの通液量／吸着剤の体積）が０．５〜１５（ｈｒ−1）の範囲にすることが効率的に高脱着率を達成する上で好ましい。 In addition, when the alkaline aqueous solution is passed upward or downward with respect to the adsorbent packed in the column and then desorbed, the liquid passing speed is usually SV (Space Velocity, liquid passing amount per hour / adsorption). The volume of the agent is preferably in the range of 0.5 to 15 (hr −1 ) in order to efficiently achieve a high desorption rate.
析出工程（３）では、脱着させたリンを含有しているアルカリ水溶液を吸着剤と分離した後、該アルカリ水溶液中に水酸化カルシウムや塩化カルシウム等のカルシウム化合物を添加して、リンとカルシウムを反応させてリンをリン酸カルシウムとして析出させる。回収リンの塩素含有率を高めないという観点からは、上記カルシウム化合物は塩素を含有しないものであることが好ましい。 In the precipitation step (3), after separating the alkaline aqueous solution containing the desorbed phosphorus from the adsorbent, a calcium compound such as calcium hydroxide or calcium chloride is added to the alkaline aqueous solution, and phosphorus and calcium are added. React to precipitate phosphorus as calcium phosphate. From the viewpoint of not increasing the chlorine content of the recovered phosphorus, it is preferable that the calcium compound does not contain chlorine.
析出工程（３）におけるカルシウム化合物の添加量は、アルカリ水溶液中のＣａ／Ｐモル比が０．６〜１．８になる量であり、好ましくは０．７〜１．６、さらに好ましくは０．８〜１．４、特に好ましくは０．９〜１．３である。添加量を上記の範囲にすることで、カルシウム化合物から持ち込まれる不純物を低減することができ、アルカリ水溶液中のリンを効率的に、不純物含有率の低いリン酸カルシウムとして析出させることが可能になる。Ｃａ／Ｐモル比が０．６よりも小さい場合には、不純物含有率の低い回収リンは得られるが、リンの析出率が低く、リンの回収率が低くなる。 The amount of calcium compound added in the precipitation step (3) is such that the Ca / P molar ratio in the alkaline aqueous solution is 0.6 to 1.8, preferably 0.7 to 1.6, more preferably 0. .8 to 1.4, particularly preferably 0.9 to 1.3. By making the addition amount in the above range, impurities brought in from the calcium compound can be reduced, and phosphorus in the alkaline aqueous solution can be efficiently precipitated as calcium phosphate having a low impurity content. When the Ca / P molar ratio is less than 0.6, recovered phosphorus with a low impurity content is obtained, but the phosphorus precipitation rate is low and the phosphorus recovery rate is low.
本実施の形態におけるＣａ／Ｐモル比の算出方法を以下に示す。
まずカルシウム化合物添加前のアルカリ水溶液のリン濃度を測定する。アルカリ水溶液を０．４５μｍフィルターで濾過後、硫酸でｐＨ１〜１０の範囲に中和し、必要に応じて純水で希釈後、モリブドバナジン酸塩法で測定することで、リン濃度を測定することができる。
得られたリン濃度とアルカリ水溶液の体積からアルカリ水溶液中のリンの合計量を算出し、以下の式（１）を用いてＣａ／Ｐモル比を算出する。
First, the phosphorus concentration of the alkaline aqueous solution before adding the calcium compound is measured. It is possible to measure the phosphorus concentration by filtering the alkaline aqueous solution with a 0.45 μm filter, neutralizing with sulfuric acid to a pH of 1 to 10 and diluting with pure water as necessary, and then measuring by the molybdovanadate method. it can.
The total amount of phosphorus in the alkaline aqueous solution is calculated from the obtained phosphorus concentration and the volume of the alkaline aqueous solution, and the Ca / P molar ratio is calculated using the following formula (1).
カルシウム化合物の添加方法は、特に制限はなく粉末状のものを添加してもよいし、水分散スラリーや水溶液として添加してもよい。また所定量を一気に添加してもよいし、少量ずつ時間をかけて添加してもよい。 The method for adding the calcium compound is not particularly limited, and a powdery one may be added, or may be added as an aqueous dispersion slurry or an aqueous solution. Further, a predetermined amount may be added all at once, or may be added little by little over time.
析出工程（３）は、リンとカルシウムとの反応速度を高めるという観点から、アルカリ水溶液を攪拌しながら行うことが好ましく、カルシウム化合物添加開始時から析出工程終了時まで継続して攪拌することがさらに好ましい。攪拌方法に特に制限はなく、従来公知のスラリー等の攪拌方法を何れも使用することができる。 From the viewpoint of increasing the reaction rate between phosphorus and calcium, the precipitation step (3) is preferably performed while stirring the alkaline aqueous solution, and the stirring is further continued from the start of the calcium compound addition until the end of the precipitation step. preferable. There is no restriction | limiting in particular in the stirring method, Any stirring methods, such as a conventionally well-known slurry, can be used.
また、効率的に不純物含有率の低いリン酸カルシウムを析出させるという観点から、カルシウム化合物の添加終了後、攪拌を、好ましくは５〜１２０分間、より好ましくは１０〜６０分間継続する。 Further, from the viewpoint of efficiently depositing calcium phosphate having a low impurity content, stirring is preferably continued for 5 to 120 minutes, more preferably for 10 to 60 minutes after the addition of the calcium compound.
分離回収工程（４）では、析出工程（３）で析出させたリンを、固液分離処理によりアルカリ水溶液から分離してリンを回収する。分離回収方法は、析出させたリンを分離回収できる方法であれば特に限定されないが、ベルトプレス脱水機、遠心分離脱水機、スクリュープレス脱水機、フィルタープレス機等を用いた回収方法を例示できる。 In the separation and recovery step (4), phosphorus precipitated in the precipitation step (3) is separated from the alkaline aqueous solution by solid-liquid separation treatment, and phosphorus is recovered. The separation and recovery method is not particularly limited as long as the precipitated phosphorus can be separated and recovered, and examples thereof include a recovery method using a belt press dehydrator, a centrifugal dehydrator, a screw press dehydrator, a filter press, and the like.
中和工程（５）では、強アルカリ性の回収リンを、酸を用いて中和する。中和後の回収リンのｐＨがｐＨ４．５〜１２．５、好ましくはｐＨ５．０〜１１．０、さらに好ましくはｐＨ５．０〜１０．０、特に好ましくはｐＨ５．０〜９．５の範囲になるように中和することで、回収リンからのリンの溶出を抑制しながら、不純物を溶出させ、不純物含有率を低減することができる。 In the neutralization step (5), the strongly alkaline recovered phosphorus is neutralized using an acid. The pH of the recovered phosphorus after neutralization is in the range of pH 4.5 to 12.5, preferably pH 5.0 to 11.0, more preferably pH 5.0 to 10.0, particularly preferably pH 5.0 to 9.5. By neutralizing so as to become, impurities can be eluted while suppressing the elution of phosphorus from the recovered phosphorus, and the impurity content can be reduced.
中和方法は特に限定されないが、回収リンを水中に分散させて攪拌しながら酸を添加し、水のｐＨが上述の範囲内に安定するまで攪拌を継続する方法や、フィルタープレス機で回収した回収リンをその濾室内に充填したままの状態で濾室内に酸でｐＨ調整した水を通水し、濾室からの流出水のｐＨが上述の範囲内になるまで通水を継続する方法等を例示できる。前者の方法で中和した場合は、再度回収リンを水中から取出すために固液分離が必要になるが、後者の方法で中和した場合は固液分離を省略できる。 The neutralization method is not particularly limited, but the recovered phosphorus is dispersed in water and the acid is added while stirring, and the stirring is continued until the pH of the water is stabilized within the above range, or the filter is recovered with a filter press. A method in which water adjusted to pH with acid is passed through the filter chamber while the recovered phosphorus is still packed in the filter chamber, and the water flow is continued until the pH of the effluent from the filter chamber falls within the above range. Can be illustrated. When neutralization is performed by the former method, solid-liquid separation is necessary to take out recovered phosphorus from water again. However, when neutralization is performed by the latter method, solid-liquid separation can be omitted.
中和に用いる酸は、回収リンの塩素含有率を高めないという観点から、硫酸等の塩素を含有しない酸を用いることが好ましい。塩酸等の塩素を含有する酸を中和に用いた場合は、中和後に回収リンを水洗することが好ましい。塩素を含有しない硫酸、硝酸等で中和した場合も、必要に応じて中和後に水洗をすることが回収リンのリン含有率を高めるという観点から好ましい。 The acid used for neutralization is preferably an acid containing no chlorine such as sulfuric acid from the viewpoint of not increasing the chlorine content of the recovered phosphorus. When an acid containing chlorine such as hydrochloric acid is used for neutralization, the recovered phosphorus is preferably washed with water after neutralization. Even when neutralized with sulfuric acid, nitric acid, or the like that does not contain chlorine, it is preferable to wash with water after neutralization from the viewpoint of increasing the phosphorus content of the recovered phosphorus.
水洗方法は特に限定されないが、回収リンを水中に分散させて一定時間攪拌後、固液分離により回収リンを水中から取出す方法や、フィルタープレスの濾室内に回収リンを充填した状態でその濾室内に水を通水する方法等が例示される。 Although the washing method is not particularly limited, the recovered phosphorus is dispersed in water and stirred for a certain period of time, and then the recovered phosphorus is taken out of the water by solid-liquid separation, or the filter chamber is filled with the recovered phosphorus in the filter chamber. A method of passing water through is exemplified.
次に、実施例、比較例および製造例（以下、「実施例等」という。）によって本実施の形態をさらに詳細に説明するが、本発明の範囲はこれらにより何ら限定されるものではない。 Next, the present embodiment will be described in more detail with reference to Examples, Comparative Examples, and Production Examples (hereinafter referred to as “Examples”), but the scope of the present invention is not limited thereto.
なお、実施例等中に示した測定は、以下の方法で行った。
リン含有水溶液のマグネシウム、アルミニウム、珪素または鉄の濃度の測定：０．４５μｍフィルターで濾過した後、必要に応じて純水で希釈し、エスアイアイ・ナノテクノロジー（株）製ＩＣＰ発光分析装置ＳＰＳ６１００を用いて測定した。
リン含有水溶液の塩素濃度の測定：０．４５μｍフィルターで濾過後、必要に応じて純水で希釈し、東ソー（株）イオンクロマト装置ＩＣ−２００１を用いて測定した。
リン含有水溶液のリン濃度の測定：０．４５μｍフィルターで濾過後、必要に応じて硫酸、水酸化ナトリウムを用いてｐＨ１〜１０に調整し、さらに必要に応じて純水で希釈して、モリブドバナジン酸塩法で測定した。
回収リンのマグネシウム、アルミニウム、珪素または鉄の含有率：１００℃で乾燥した回収リンを王水で溶解し純水で希釈した後、エスアイアイ・ナノテクノロジー（株）製ＩＣＰ発光分析装置ＳＰＳ６１００を用いて測定した。
回収リンの塩素含有率：肥料分析法（１９９２年版 農林水産省農業技術研究所編）に記載の硝酸銀による重量法で測定した。
回収リンのリン含有率：回収リンを１００℃で乾燥し、王水で溶解し純水で希釈した後、モリブドバナジン酸塩法で測定した。
In addition, the measurement shown in the Example etc. was performed with the following method.
Measurement of the concentration of magnesium, aluminum, silicon or iron in the phosphorus-containing aqueous solution: After filtering with a 0.45 μm filter, it is diluted with pure water as necessary, and the ICP emission analyzer SPS6100 manufactured by SII NanoTechnology Co., Ltd. is used. And measured.
Measurement of chlorine concentration in phosphorus-containing aqueous solution: After filtration with a 0.45 μm filter, the solution was diluted with pure water as necessary, and measured using Tosoh Corporation ion chromatograph IC-2001.
Measurement of phosphorus concentration of phosphorus-containing aqueous solution: After filtration with a 0.45 μm filter, the pH is adjusted to 1 to 10 with sulfuric acid and sodium hydroxide as necessary, and further diluted with pure water as necessary to obtain molybdovanadic acid. Measured by the salt method.
Magnesium, aluminum, silicon or iron content of recovered phosphorus: After recovering recovered phosphorus dried at 100 ° C. with aqua regia and diluting with pure water, ICP emission analyzer SPS6100 manufactured by SII NanoTechnology Co., Ltd. was used. Measured.
Chlorine content of recovered phosphorus: Measured by gravimetric method using silver nitrate as described in Fertilizer Analysis (1992 Edition, Agriculture Technology Laboratory, Ministry of Agriculture, Forestry and Fisheries).
Phosphorus content of recovered phosphorus: The recovered phosphorus was dried at 100 ° C., dissolved in aqua regia and diluted with pure water, and then measured by the molybdovanadate method.
〔製造例〕
ポリビニルピロリドン（ＰＶＰ、ＢＡＳＦジャパン（株）、Ｌｕｖｉｔｅｃ Ｋ３０ Ｐｏｗｄｅｒ（商品名））３７５ｇを、ジメチルスルホキシド（ＤＭＳＯ、関東化学（株））４１２５ｇ中に溶解して均一な溶液を得た。該溶液４５００ｇに対し、平均粒径３０μｍの水和酸化セリウム粉末（包頭華美稀土高科公司）２２５０ｇを加えて、直径１ｍｍのジルコニアボールを充填したビーズミル（ＳＣ１００、三井鉱山（株））を用いて、３０分間粉砕・混合処理を行い黄色のスラリーを得た。さらに、このスラリーにエチレンビニルアルコール共重合体（ＥＶＯＨ、日本合成化学工業（株）、ソアノールＥ３８０３（商品名））３７５ｇを、溶解槽中にて、６０℃に加温して撹拌羽根を用いて撹拌・溶解し、均一なスラリー溶液を得た。
得られたポリマースラリーを４０℃に加温し、側面に直径５ｍｍのノズルを開けた円筒状回転容器の内部に供給し、この容器を回転させ、遠心力（１５Ｇ）によりノズルから液滴を形成し、６０℃の水からなる凝固浴槽中に吐出させ、ポリマースラリーを凝固させた。さらに、洗浄、分級を行い、平均粒径６００μｍの球状成形体として吸着剤を得た。
[Production example]
375 g of polyvinylpyrrolidone (PVP, BASF Japan K.K., Luvitec K30 Powder (trade name)) was dissolved in 4125 g of dimethyl sulfoxide (DMSO, Kanto Chemical Co., Inc.) to obtain a uniform solution. A bead mill (SC100, Mitsui Mining Co., Ltd.) filled with zirconia balls having a diameter of 1 mm was added to 4500 g of this solution, 2250 g of hydrated cerium oxide powder (Hakka Hanami Rare Earth High School Corporation) having an average particle size of 30 μm, The mixture was pulverized and mixed for 30 minutes to obtain a yellow slurry. Further, 375 g of an ethylene vinyl alcohol copolymer (EVOH, Nippon Synthetic Chemical Industry Co., Ltd., Soarnol E3803 (trade name)) was heated to 60 ° C. in a dissolving tank, and a stirring blade was used. The mixture was stirred and dissolved to obtain a uniform slurry solution.
The obtained polymer slurry is heated to 40 ° C., supplied to the inside of a cylindrical rotating container with a nozzle having a diameter of 5 mm on the side, and this container is rotated to form droplets from the nozzle by centrifugal force (15 G). And it was made to discharge in the coagulation bath which consists of 60 degreeC water, and the polymer slurry was solidified. Furthermore, washing | cleaning and classification were performed and the adsorbent was obtained as a spherical molded object with an average particle diameter of 600 micrometers.
〔実施例１〕
製造例で作製した酸化セリウム系吸着剤を１０Ｌ充填したカラム内に、標準活性汚泥法で処理した下水二次処理水１５ｍ３（マグネシウム濃度６．７ｍｇ／Ｌ、アルミニウム濃度０．０２ｍｇ／Ｌ、ケイ素濃度２３ｍｇ／Ｌ、鉄濃度０．０３ｍｇ／Ｌ、塩素濃度４８ｍｇ／Ｌ、リン濃度０．３１ｍｇ／Ｌ）を通水速度ＳＶ２０（ｈ−１）の下向流で通水して、処理水中のリンを吸着剤に吸着させた。
次に５重量％ＮａＯＨ水溶液１２０Ｌを通液速度ＳＶ３（ｈ−１）の下向流でカラムに通液し、続いて１０Ｌの水を通水速度ＳＶ３（ｈ−１）の下向流で通水して、吸着剤に吸着したリンを脱着させた。
カラムから流失したアルカリ水溶液中のリン濃度をモリブデン黄法で測定し、その濃度とアルカリ水溶液の液量からアルカリ水溶液中に含有されるリンの合計量を算出したところ１６．２ｇであった。
このアルカリ水溶液をスリーワンモーター式攪拌機で攪拌しながら、水溶液中のＣａ／Ｐモル比が１．１になる量の水酸化カルシウムをスラリーで添加し、スラリー添加が終了後２０分間攪拌を継続してアルカリ水溶液中にリンをリン酸カルシウムとして析出させた。
次に、フィルタープレス機を用いて、アルカリ水溶液から析出したリンを回収した。回収したリンをフィルタープレス機の濾室内に充填したまま、濾室内にｐＨ５．０の硫酸酸性水を、濾室からの流出水のｐＨが９．０になるまで通水した。その後、１Ｌの水を濾室内に通水して、回収リンを水洗した。
濾室から取出した回収リンの分析結果を表１に示した。
[Example 1]
In a column packed with 10 L of the cerium oxide adsorbent prepared in the production example, 15 m 3 of sewage secondary treated water treated by the standard activated sludge method (magnesium concentration 6.7 mg / L, aluminum concentration 0.02 mg / L, silicon concentration 23 mg / L, iron concentration 0.03 mg / L, and it passed through in downward flow of chlorine concentration 48 mg / L, phosphorus concentration 0.31 mg / L) of the water flow rate SV20 (h -1), the treated water Phosphorus was adsorbed on the adsorbent.
Next, 120 L of 5 wt% NaOH aqueous solution is passed through the column at a downward flow rate of SV3 (h −1 ), and then 10 L of water is passed through the downstream flow rate of SV3 (h −1 ). Water was used to desorb phosphorus adsorbed on the adsorbent.
The phosphorus concentration in the alkaline aqueous solution washed away from the column was measured by the molybdenum yellow method, and the total amount of phosphorus contained in the alkaline aqueous solution was calculated from the concentration and the amount of the alkaline aqueous solution to be 16.2 g.
While stirring this alkaline aqueous solution with a three-one motor type stirrer, calcium hydroxide in an amount such that the Ca / P molar ratio in the aqueous solution becomes 1.1 is added to the slurry, and stirring is continued for 20 minutes after the slurry addition is completed. Phosphorus was precipitated as calcium phosphate in the alkaline aqueous solution.
Next, phosphorus precipitated from the aqueous alkaline solution was collected using a filter press. While the collected phosphorus was filled in the filter chamber of the filter press, sulfuric acid acidic water having a pH of 5.0 was passed through the filter chamber until the pH of the effluent water from the filter chamber reached 9.0. Thereafter, 1 L of water was passed through the filter chamber, and the recovered phosphorus was washed with water.
Table 1 shows the analysis results of the recovered phosphorus taken out from the filter chamber.
〔実施例２〕
回収したリンをフィルタープレス機の濾室内に充填したまま、濾室内にｐＨ４．０の塩酸酸性水を、濾室からの流出水のｐＨが５．５になるまで通水したこと以外は、実施例１と同様の方法で回収リンを得た。
得られた回収リンの分析結果を表１に示した。
[Example 2]
Except that the pH of 4.0 acidified hydrochloric acid was passed through the filter chamber while the recovered phosphorus was packed in the filter chamber of the filter press until the pH of the effluent from the filter chamber reached 5.5. Recovered phosphorus was obtained in the same manner as in Example 1.
The analysis results of the obtained recovered phosphorus are shown in Table 1.
〔実施例３〕
下水汚泥脱水濾液をＭＦ膜濾過し、ＳＳ（浮遊物質）を除去した。
このＳＳ除去後の濾液１０ｍ３（マグネシウム濃度１２ｍｇ／Ｌ、アルミニウム濃度０．０２ｍｇ／Ｌ、ケイ素濃度１８ｍｇ／Ｌ、鉄濃度０．１０ｍｇ／Ｌ、塩素濃度５６ｍｇ／Ｌ、リン濃度１９ｍｇ／Ｌ）を、製造例で作製した酸化セリウム系吸着剤を１０Ｌ充填したカラム内に通水速度ＳＶ１５（ｈ−１）の下向流で通水して、水中のリンを吸着剤に吸着させた。
次に８重量％ＮａＯＨ水溶液１２０Ｌを通液速度ＳＶ３（ｈ−１）の下向流でカラムに通液し、続いて１０Ｌの水を通水速度ＳＶ３（ｈ−１）の下向流で通水して、吸着剤に吸着したリンを脱着させた。
カラムから流失したアルカリ水溶液中のリン濃度をモリブデン黄法で測定し、その濃度とアルカリ水溶液の液量からアルカリ水溶液中に含有されるリンの合計量を算出したところ１８．０ｇだった。
このアルカリ水溶液をスリーワンモーター式攪拌機で攪拌しながら、水溶液中のＣａ／Ｐモル比が１．０になる量の水酸化カルシウムをスラリーで添加し、スラリー添加が終了後３０分間攪拌を継続してアルカリ水溶液中にリンをリン酸カルシウムとして析出させた。
次に、フィルタープレス機を用いて、アルカリ水溶液から析出したリンを回収した。回収したリンをフィルタープレス機の濾室内に充填したまま、濾室内にｐＨ４．０の硫酸酸性水を、濾室からの流出水のｐＨが８．５になるまで通水した。その後、１Ｌの水を濾室内に通水して、回収リンを水洗した。
濾室から取出した回収リンの分析結果を表１に示した。
Example 3
The sewage sludge dehydrated filtrate was subjected to MF membrane filtration to remove SS (floating matter).
The filtrate after removal of SS was 10 m 3 (magnesium concentration 12 mg / L, aluminum concentration 0.02 mg / L, silicon concentration 18 mg / L, iron concentration 0.10 mg / L, chlorine concentration 56 mg / L, phosphorus concentration 19 mg / L). Then, water was passed through the column filled with 10 L of the cerium oxide-based adsorbent prepared in the production example at a water flow rate of SV15 (h −1 ) to adsorb phosphorus in the water to the adsorbent.
Next, 120 L of 8 wt% NaOH aqueous solution is passed through the column at a downward flow rate of SV3 (h −1 ), and then 10 L of water is passed through the downstream flow rate of SV3 (h −1 ). Water was used to desorb phosphorus adsorbed on the adsorbent.
The phosphorus concentration in the alkaline aqueous solution washed away from the column was measured by the molybdenum yellow method, and the total amount of phosphorus contained in the alkaline aqueous solution was calculated from the concentration and the amount of the alkaline aqueous solution to find 18.0 g.
While stirring this alkaline aqueous solution with a three-one motor type stirrer, calcium hydroxide in an amount such that the Ca / P molar ratio in the aqueous solution becomes 1.0 is added as a slurry, and stirring is continued for 30 minutes after the slurry addition is completed. Phosphorus was precipitated as calcium phosphate in the alkaline aqueous solution.
Next, phosphorus precipitated from the aqueous alkaline solution was collected using a filter press. While the collected phosphorus was filled in the filter chamber of the filter press, sulfuric acid acidic water having a pH of 4.0 was passed through the filter chamber until the pH of the effluent water from the filter chamber reached 8.5. Thereafter, 1 L of water was passed through the filter chamber, and the recovered phosphorus was washed with water.
Table 1 shows the analysis results of the recovered phosphorus taken out from the filter chamber.
〔実施例４〕
１重量％硫酸中に下水汚泥焼却灰をいれ、３時間攪拌して焼却灰からリンを抽出した。抽出後、濾過により抽出液を焼却灰と分離した。得られた抽出液のｐＨは２．２であった。
この抽出液２ｍ３（マグネシウム濃度７２０ｍｇ／Ｌ、アルミニウム濃度２４００ｍｇ／Ｌ、ケイ素濃度１００ｍｇ／Ｌ未満、鉄濃度５００ｍｇ／Ｌ、塩素濃度１００ｍｇ/Ｌ未満、リン濃度４７００ｍｇ／Ｌ）を、製造例で作製した酸化セリウム系吸着剤を１０Ｌ充填したカラム内に通水速度ＳＶ１０（ｈ−１）の下向流で通水して、水中のリンを吸着剤に吸着させた。
次に５重量％ＮａＯＨ水溶液１２０Ｌを通液速度ＳＶ３（ｈ−１）の下向流でカラムに通液し、続いて１０Ｌの水を通水速度ＳＶ３（ｈ−１）の下向流で通水して、吸着剤に吸着したリンを脱着させた。
カラムから流失したアルカリ水溶液中のリン濃度をモリブデン黄法で測定し、その濃度とアルカリ水溶液の液量からアルカリ水溶液中に含有されるリンの合計量を算出したところ２６．４ｇだった。
このアルカリ水溶液をスリーワンモーター式攪拌機で攪拌しながら、水溶液中のＣａ／Ｐモル比が１．２になる量の水酸化カルシウムをスラリーで添加し、スラリー添加が終了後１５分間攪拌を継続してアルカリ水溶液中にリンを析出させた。
次に、フィルタープレス機を用いて、アルカリ水溶液から析出したリンを回収した。回収したリンをフィルタープレス機の濾室内に充填したまま、濾室内にｐＨ５．５の硫酸酸性水を、濾室からの流出水のｐＨが９．５になるまで通水した。その後、１Ｌの水を濾室内に通水して、回収リンを水洗した。
濾室から取出した回収リンの分析結果を表１に示した。
Example 4
Sewage sludge incineration ash was placed in 1% by weight sulfuric acid and stirred for 3 hours to extract phosphorus from the incineration ash. After extraction, the extract was separated from the incinerated ash by filtration. The pH of the obtained extract was 2.2.
This extract 2m 3 (magnesium concentration 720 mg / L, aluminum concentration 2400 mg / L, silicon concentration less than 100 mg / L, iron concentration 500 mg / L, chlorine concentration less than 100 mg / L, phosphorus concentration 4700 mg / L) was produced in the production example The column was packed with 10 L of the cerium oxide-based adsorbent, and water was passed in a downward flow of the water flow rate SV10 (h −1 ) to adsorb phosphorus in the water to the adsorbent.
Next, 120 L of 5 wt% NaOH aqueous solution is passed through the column at a downward flow rate of SV3 (h −1 ), and then 10 L of water is passed through the downstream flow rate of SV3 (h −1 ). Water was used to desorb phosphorus adsorbed on the adsorbent.
The phosphorus concentration in the alkaline aqueous solution washed away from the column was measured by the molybdenum yellow method, and the total amount of phosphorus contained in the alkaline aqueous solution was calculated from the concentration and the amount of the alkaline aqueous solution to be 26.4 g.
While stirring this alkaline aqueous solution with a three-one motor type stirrer, calcium hydroxide in an amount such that the Ca / P molar ratio in the aqueous solution becomes 1.2 is added as a slurry, and stirring is continued for 15 minutes after the slurry addition is completed. Phosphorus was precipitated in the alkaline aqueous solution.
Next, phosphorus precipitated from the aqueous alkaline solution was collected using a filter press. With the recovered phosphorus filled in the filter chamber of the filter press machine, sulfuric acid acidic water having a pH of 5.5 was passed through the filter chamber until the pH of the effluent water from the filter chamber reached 9.5. Thereafter, 1 L of water was passed through the filter chamber, and the recovered phosphorus was washed with water.
Table 1 shows the analysis results of the recovered phosphorus taken out from the filter chamber.
〔比較例１〕
水酸化カルシウム添加量がＣａ／Ｐモル比２．０であること以外は実施例１と同様の方法で回収リンを得た。
得られた回収リンの分析結果を表１に示した。
[Comparative Example 1]
Recovered phosphorus was obtained in the same manner as in Example 1 except that the amount of calcium hydroxide added was a Ca / P molar ratio of 2.0.
The analysis results of the obtained recovered phosphorus are shown in Table 1.
〔比較例２〕
フィルタープレス機の濾室からの流出水のｐＨが１３．０になるまで濾室内にｐＨ５．０の硫酸酸性水を通水したこと以外は、実施例１と同様の方法で回収リンを得た。
得られた回収リンの分析結果を表１に示した。
Recovered phosphorus was obtained in the same manner as in Example 1 except that pH 5.0 sulfuric acid acidic water was passed through the filter chamber until the pH of the effluent from the filter chamber of the filter press machine reached 13.0. .
The analysis results of the obtained recovered phosphorus are shown in Table 1.
本発明によれば、下水や工場排水等に含まれて自然界に流出し、閉鎖性水域等で富栄養化を進行させ水環境悪化の原因になっているリンを、下水や工業排水等から除去できることに加え、除去したリンを工業用途にも利用可能な不純物含有率の低いリン化合物として回収することができる。したがって閉鎖性水域の水環境の悪化を抑制するとともに、リン資源枯渇問題の解決に寄与するという産業上の利用可能性を有する。 According to the present invention, phosphorus, which is contained in sewage and industrial wastewater, flows out to the natural world, advances eutrophication in closed water areas and causes deterioration of the water environment, is removed from sewage and industrial wastewater. In addition to being able to be removed, the removed phosphorus can be recovered as a phosphorus compound having a low impurity content that can be used for industrial purposes. Therefore, it has industrial applicability to suppress the deterioration of the water environment in closed water areas and contribute to solving the phosphorus resource depletion problem.
Claims (5)
（１）リン含有水溶液中のリンを、金属酸化物系吸着剤に吸着させる吸着工程；
（２）前記吸着剤にアルカリ水溶液を接触させて、吸着工程（１）で吸着したリンを脱着させる脱着工程；
（３）脱着工程（２）で脱着させたリンを含有するアルカリ水溶液中に、カルシウム化合物をＣａ／Ｐモル比が０．６〜１．８になる量添加し、アルカリ水溶液中のリンをリン酸カルシウムとして析出させる析出工程；
（４）析出工程（３）で析出させたリンをアルカリ水溶液から分離し回収する分離回収工程；および
（５）分離回収工程（４）で回収したリンをｐＨ４．５〜１２．５に中和する中和工程を含む、リン含有水溶液からの回収リンの回収方法。 The following steps (1) to (5):
(1) An adsorption process for adsorbing phosphorus in a phosphorus-containing aqueous solution to a metal oxide adsorbent;
(2) A desorption step of bringing the aqueous solution into contact with the adsorbent and desorbing the phosphorus adsorbed in the adsorption step (1);
(3) In the alkaline aqueous solution containing phosphorus desorbed in the desorption step (2), a calcium compound is added in an amount such that the Ca / P molar ratio is 0.6 to 1.8, and phosphorus in the alkaline aqueous solution is calcium phosphate. A precipitation step to precipitate as;
(4) Separation and recovery step of separating and recovering phosphorus precipitated in the precipitation step (3) from the alkaline aqueous solution; and (5) Neutralizing phosphorus recovered in the separation and recovery step (4) to pH 4.5 to 12.5 A method for recovering recovered phosphorus from a phosphorus-containing aqueous solution, comprising a neutralization step.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010133806A JP5550459B2 (en) | 2010-06-11 | 2010-06-11 | Recovery phosphorus and recovery method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010133806A JP5550459B2 (en) | 2010-06-11 | 2010-06-11 | Recovery phosphorus and recovery method |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2014092370A Division JP2014177399A (en) | 2014-04-28 | 2014-04-28 | Recovery phosphorus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2011255341A JP2011255341A (en) | 2011-12-22 |
| JP5550459B2 true JP5550459B2 (en) | 2014-07-16 |
Family
ID=45472128
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2010133806A Expired - Fee Related JP5550459B2 (en) | 2010-06-11 | 2010-06-11 | Recovery phosphorus and recovery method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5550459B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014079688A (en) * | 2012-10-16 | 2014-05-08 | Asahi Kasei Chemicals Corp | Phosphorus recovery system and phosphorus recovery method |
| CN103253727B (en) * | 2013-04-28 | 2015-09-16 | 重庆科技学院 | A kind of method of high-phosphorus iron ore mine tailing deep purifying Removal of Phosphorus in Wastewater |
| JP2015123434A (en) * | 2013-12-27 | 2015-07-06 | 旭化成ケミカルズ株式会社 | Ion processing apparatus, and ion processing method |
| JP2015211941A (en) * | 2014-05-02 | 2015-11-26 | 旭化成ケミカルズ株式会社 | Phosphorous recovery system and phosphorous recovery method |
| WO2018230489A1 (en) | 2017-06-16 | 2018-12-20 | 高橋金属株式会社 | Adsorption method |
| CN113493274A (en) * | 2020-04-08 | 2021-10-12 | 大渊环境技术（厦门）有限公司 | Deep and efficient purification method for water body |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59136190A (en) * | 1983-01-27 | 1984-08-04 | Hitachi Plant Eng & Constr Co Ltd | Treatment of waste water containing phosphate |
| JP4444457B2 (en) * | 2000-07-04 | 2010-03-31 | 月島機械株式会社 | Phosphorus recovery method |
| JP4072091B2 (en) * | 2003-04-25 | 2008-04-02 | アタカ大機株式会社 | Phosphorus resource recovery method |
| JP2007260561A (en) * | 2006-03-28 | 2007-10-11 | Asahi Kasei Chemicals Corp | Ion treatment apparatus and method |
| JP2010069413A (en) * | 2008-09-18 | 2010-04-02 | Cosmo Oil Co Ltd | Organic waste water treatment method |
-
2010
- 2010-06-11 JP JP2010133806A patent/JP5550459B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2011255341A (en) | 2011-12-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jadhav et al. | Arsenic and fluoride contaminated groundwaters: a review of current technologies for contaminants removal | |
| Singh et al. | Fluoride ions vs removal technologies: A study | |
| JP5550459B2 (en) | Recovery phosphorus and recovery method | |
| EP2866915A1 (en) | Aluminized silicious sorbent and water purification device incorporating the same | |
| WO2011016038A1 (en) | Method for removal of selenium contaminants from aqueous fluids | |
| JP2014177399A (en) | Recovery phosphorus | |
| Altaf et al. | Electroanalytical techniques for the remediation of heavy metals from wastewater | |
| Özcan et al. | Removal of heavy metals from simulated water by using eggshell powder | |
| Long et al. | Comparison of arsenic (V) removal with different lead-containing substances and process optimization in aqueous chloride solution | |
| Itankar et al. | Assessing physicochemical technologies for removing hexavalent chromium from contaminated waters—An overview and future research directions | |
| CN109382004A (en) | A method of mixture-metal is separated and recovered using Calcium alginate film | |
| JP4936453B2 (en) | Adsorbent for water treatment having a pH of less than 4 and containing iron ions and ions containing arsenic and method for purifying the water | |
| CA3066212C (en) | Method of adsorbing an anion of interest from an aqueous solution | |
| Kaprara et al. | Evaluation of current treatment technologies for Cr (VI) removal from water sources at sub-ppb levels | |
| JP5484702B2 (en) | Water purification material and water purification method using the same | |
| JP4808093B2 (en) | Recycling method of iron powder for arsenic removal | |
| JP2018122273A (en) | Method for treating boron-containing water | |
| RU2689576C1 (en) | Method of purifying high-arsenic-containing waste water | |
| JP7008456B2 (en) | Treatment method and treatment equipment for the liquid to be treated | |
| JP6949621B2 (en) | How to treat selenium-containing soil and rocks | |
| JP2015211941A (en) | Phosphorous recovery system and phosphorous recovery method | |
| JP6304622B2 (en) | Method for removing anionic species in solution | |
| PL235943B1 (en) | Method for removing metals from wastes from wet-flue gas desulfurization systems | |
| Jampang et al. | Chitosan Beads as Eco-Friendly Biosorbent for the Biosorption of Au (III) and Cu (II) from Aqueous Solutions | |
| Junuzovic et al. | Precipitation and separation cations from binary aqueous systems using waste sludge from the solway process |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20130610 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20140306 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20140310 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20140428 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20140516 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20140520 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5550459 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |