JP4591695B2 - Method for treating wastewater containing phosphoric acid and zinc - Google Patents

Method for treating wastewater containing phosphoric acid and zinc Download PDF

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JP4591695B2
JP4591695B2 JP2005203420A JP2005203420A JP4591695B2 JP 4591695 B2 JP4591695 B2 JP 4591695B2 JP 2005203420 A JP2005203420 A JP 2005203420A JP 2005203420 A JP2005203420 A JP 2005203420A JP 4591695 B2 JP4591695 B2 JP 4591695B2
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康之 八木
雅智 渡部
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Hitachi Plant Technologies Ltd
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Description

本発明はリン酸と亜鉛を含有する廃水の処理方法に関する。   The present invention relates to a method for treating wastewater containing phosphoric acid and zinc.

車両製造工場などでは金属材料を塗装する際に、一般に前処理として基材表面の脱脂を行った後に、防錆用の被膜を形成するためにリン酸亜鉛処理を行う。このリン酸亜鉛処理では、基材をリン酸亜鉛含有液が満たされた浴槽に浸漬して基材表面にリン酸亜鉛の被膜を形成させる。次いで、浴槽から引き上げた基材をリンスし、基材表面に付着しているリン酸亜鉛含有液を洗い流す（例えば、特許文献１参照）。   When a metal material is painted at a vehicle manufacturing factory or the like, generally, the base material surface is degreased as a pretreatment, and then a zinc phosphate treatment is performed to form a rust-preventive coating. In this zinc phosphate treatment, the base material is immersed in a bath filled with the zinc phosphate-containing liquid to form a zinc phosphate coating on the base material surface. Next, the base material pulled up from the bathtub is rinsed, and the zinc phosphate-containing liquid adhering to the base material surface is washed away (for example, see Patent Document 1).

したがって、この種の工場ではリン酸亜鉛処理後の基材をリンスした際に、リン酸と亜鉛とを高濃度に含有する洗浄廃水が多量に発生する。従来、このようなリン酸と亜鉛とを高濃度に含有する洗浄廃水を浄化する方法としては、凝集沈殿処理が汎用されている。しかしながら、凝集沈殿処理ではリン酸や亜鉛などを含む沈澱汚泥が多量に発生し、その処理処分に多大なコストを必要とする。   Therefore, in this type of factory, when the base material after the zinc phosphate treatment is rinsed, a large amount of washing waste water containing phosphoric acid and zinc at a high concentration is generated. Conventionally, as a method for purifying cleaning wastewater containing such a high concentration of phosphoric acid and zinc, a coagulation precipitation treatment has been widely used. However, in the coagulation sedimentation treatment, a large amount of sedimentation sludge containing phosphoric acid or zinc is generated, and the disposal of the treatment requires a great deal of cost.

一方、リン含有水からリンを除去する方法としてリン晶析法が知られている（例えば、特許文献２参照）。リン晶析法はリン含有水にカルシウム化合物を添加して種晶の固定床又は流動床に通水することにより、リンをリン酸ヒドロキシアパタイトなどのリン酸カルシウムの結晶として種晶表面に晶析させる方法である。このリン晶析法によれば、得られるリン酸カルシウム結晶は肥料などに有効利用でき資源回収に寄与できる。したがって、上記のようなリン酸と亜鉛とを含有する廃水に対してもリン晶析法を適用すれば資源回収を兼ねた効果的な廃水処理を実現することができる。
特開２００３−１６０８７８号公報 特開２００１−３３４２７４号公報 On the other hand, a phosphorus crystallization method is known as a method for removing phosphorus from phosphorus-containing water (see, for example, Patent Document 2). Phosphorus crystallization is a method of crystallizing phosphorous on the seed crystal surface as calcium phosphate crystals such as hydroxyapatite phosphate by adding a calcium compound to phosphorus-containing water and passing it through a fixed bed or fluidized bed of seed crystals. It is. According to this phosphorus crystallization method, the obtained calcium phosphate crystals can be effectively used as a fertilizer and contribute to resource recovery. Therefore, if wastewater containing phosphoric acid and zinc as described above is applied to the phosphorus crystallization method, effective wastewater treatment that also serves as resource recovery can be realized.
JP 2003-160878 A JP 2001-334274 A

特許文献２にも記載されているようにリン晶析法では晶析反応を促進させるために被処理水のｐＨをアルカリ側に調整して行うことが通例である。しかしながら、上記のようなリン酸と亜鉛とを含有する廃水にリン晶析法を適用し、被処理水のｐＨをアルカリ側に調整すると被処理水中の亜鉛が水酸化亜鉛として析出し、この水酸化亜鉛がリンの晶析反応を妨害することが判明した。   As described in Patent Document 2, the phosphorus crystallization method is usually performed by adjusting the pH of water to be treated to the alkali side in order to promote the crystallization reaction. However, when the phosphorus crystallization method is applied to waste water containing phosphoric acid and zinc as described above and the pH of the water to be treated is adjusted to the alkali side, zinc in the water to be treated precipitates as zinc hydroxide, and this water It has been found that zinc oxide interferes with the crystallization reaction of phosphorus.

本発明の目的は上記従来技術の問題点を改善し、リン酸と亜鉛とを含有する廃水を処理するに際して、水酸化亜鉛によるリンの晶析反応の妨害を回避しつつ廃水中のリンをリン晶析法によって回収し、凝集沈澱汚泥の発生量を低減することができるリン酸と亜鉛とを含有する廃水の処理方法を提供することにある。   The object of the present invention is to improve the above-mentioned problems of the prior art, and in treating wastewater containing phosphoric acid and zinc, phosphorus in the wastewater is removed while avoiding interference with the crystallization reaction of phosphorus by zinc hydroxide. An object of the present invention is to provide a method for treating wastewater containing phosphoric acid and zinc that can be recovered by crystallization and reduce the amount of coagulated sediment sludge.

上記目的を達成するために、本発明に係るリン酸と亜鉛とを含有する廃水の処理方法は、亜鉛とリン酸を含有する廃水に、当該廃水中のリン酸と反応し晶析するために必要な反応当量の１〜１．３倍の量の塩化カルシウムや水酸化カルシウムなどのカルシウム化合物を添加するとともにｐＨを４〜６に調整する第１工程と、次いで当該廃水を種晶が充填されたリン晶析槽に通水して晶析処理する第２工程と、第２工程の処理水を凝集沈澱処理する第３工程とを含むことを特徴とする。 In order to achieve the above object, a method for treating wastewater containing phosphoric acid and zinc according to the present invention is to react and crystallize wastewater containing zinc and phosphoric acid with phosphoric acid in the wastewater. The first step of adding a calcium compound such as calcium chloride or calcium hydroxide in an amount 1 to 1.3 times the required reaction equivalent and adjusting the pH to 4-6, and then the waste water is filled with seed crystals And a third step of flocculating and precipitating the treated water in the second step.

また、本発明は前記リン晶析槽が流動床式のリン晶析槽であり、前記廃水の量に対して１０〜３０倍の循環水を用いて前記廃水を槽内に上向流で通水させ、その上向流によって槽内に充填した種晶の流動床を形成するようにしたことを特徴とする。
Further, in the present invention, the phosphorus crystallization tank is a fluidized bed type phosphorus crystallization tank, and the waste water is passed through the tank in an upward flow using 10 to 30 times as much circulating water as the amount of the waste water. It is characterized by forming a fluidized bed of seed crystals filled in the tank by the upward flow of water .

本発明のリン酸と亜鉛を含有する廃水の処理方法によれば、廃水中に含まれるリン酸の大部分が第２工程における晶析反応によって、種晶の表面にリン酸ヒドロキシアパタイトとして晶析する。このため、第２工程の処理水に含まれるリン酸が低減する。その結果、第３工程において凝集分離される沈澱汚泥の発生量をその分、削減することができる。また、第２工程で種晶表面に晶析したリン酸ヒドロキシアパタイトは種晶ごと回収して肥料や工業原料として有効利用することができる。したがって、リン酸と亜鉛とを含有する廃水に対して資源回収を兼ねた効果的な廃水処理を実現することができる。   According to the method for treating wastewater containing phosphoric acid and zinc of the present invention, most of phosphoric acid contained in the wastewater is crystallized as phosphate hydroxyapatite on the surface of the seed crystal by the crystallization reaction in the second step. To do. For this reason, the phosphoric acid contained in the treated water of a 2nd process reduces. As a result, the generation amount of the precipitated sludge that is coagulated and separated in the third step can be reduced accordingly. Further, the hydroxyapatite phosphate crystallized on the seed crystal surface in the second step can be recovered together with the seed crystal and effectively used as a fertilizer or an industrial raw material. Therefore, it is possible to realize an effective wastewater treatment that also serves as resource recovery for the wastewater containing phosphoric acid and zinc.

図１は本発明に係る処理方法の実施形態を示す系統図である。本方法を実施するための処理装置は主に原水調整槽１０と循環槽１２と晶析槽１４と凝集沈澱処理装置１６とによって構成される。第１工程ではリン酸と亜鉛とを含有する原水１８が原水調整槽１０に供給される。   FIG. 1 is a system diagram showing an embodiment of a processing method according to the present invention. The processing apparatus for carrying out this method is mainly composed of the raw water adjusting tank 10, the circulation tank 12, the crystallization tank 14, and the coagulation / precipitation processing apparatus 16. In the first step, raw water 18 containing phosphoric acid and zinc is supplied to the raw water adjustment tank 10.

原水調整槽１０には塩化カルシウムや水酸化カルシウムなどのカルシウム化合物２０が添加される。カルシウム化合物２０の添加量は添加したカルシウムが原水中のリンと反応して分子式がＣａ５(ＰＯ４)３ＯＨで表わされるリン酸ヒドロキシアパタイトを生成するために必要十分な量とし、通常はリンとの反応当量の１〜１．３倍とする。添加量が反応当量に対して１未満である場合には後述の第２工程でカルシウムが不足し、晶析反応が十分に進行しない。添加量が反応当量に対して１．３倍を超えると第２工程を経た処理水中に残存するカルシウム量が増大し、後述の第３工程で発生する沈澱汚泥の増大を招く。 A calcium compound 20 such as calcium chloride or calcium hydroxide is added to the raw water adjustment tank 10. The calcium compound 20 is added in an amount sufficient to react with the phosphorus in the raw water to produce phosphate hydroxyapatite whose molecular formula is represented by Ca 5 (PO 4 ) 3 OH. 1 to 1.3 times the reaction equivalent of When the addition amount is less than 1 with respect to the reaction equivalent, calcium is insufficient in the second step described later, and the crystallization reaction does not proceed sufficiently. If the amount added exceeds 1.3 times the reaction equivalent, the amount of calcium remaining in the treated water that has passed through the second step will increase, leading to an increase in the amount of precipitated sludge generated in the third step described later.

また、原水調整槽１０にはｐＨ調整剤２２を添加し、流入した原水のｐＨを４〜６となるように調整する。原水調整槽１０には攪拌機２４が装備され、上記添加したカルシウム化合物２０及びｐＨ調整剤２２を原水１８に対して均一に混合する。なお、この第１工程に係る原水調整槽１０を二つに分割し、前段のｐＨ調整槽、後段のカルシウム量調整槽で構成してもよい。   Moreover, the pH adjuster 22 is added to the raw | natural water adjustment tank 10, and the pH of the raw | natural water which flowed in is adjusted so that it may become 4-6. The raw water adjustment tank 10 is equipped with a stirrer 24 and uniformly mixes the added calcium compound 20 and the pH adjuster 22 with the raw water 18. In addition, you may divide | segment the raw | natural water adjustment tank 10 which concerns on this 1st process into two, and you may comprise by the pH adjustment tank of a front | former stage, and the calcium amount adjustment tank of a back | latter stage.

第１工程でカルシウム量とｐＨが調整された原水１８Ａは第２工程である循環槽１２と晶析槽１４に送られる。循環槽１２には晶析槽１４を循環する循環水２６が流入し、原水１８Ａと循環水２６が合流・混合される。この合流・混合水２８が晶析槽１４の底部から晶析槽１４に供給される。晶析槽１４は流動床式であり、内部に粒径が１ｍｍ程度の種晶が充填されている。種晶としてはリン酸カルシウムを主体とするリン鉱石が好ましく用いられる。ただし、種晶はこれに限らず、例えば骨炭や珪酸カルシウムを用いることもできる。   The raw water 18A whose calcium amount and pH are adjusted in the first step is sent to the circulation tank 12 and the crystallization tank 14 which are the second process. Circulating water 26 circulating in the crystallization tank 14 flows into the circulating tank 12, and the raw water 18A and the circulating water 26 are merged and mixed. The combined / mixed water 28 is supplied to the crystallization tank 14 from the bottom of the crystallization tank 14. The crystallization tank 14 is a fluidized bed type and is filled with a seed crystal having a particle size of about 1 mm. As the seed crystal, a phosphate ore mainly composed of calcium phosphate is preferably used. However, the seed crystal is not limited to this, and for example, bone charcoal or calcium silicate can be used.

晶析槽１４の底部から流入させた合流・混合水２８を晶析槽１４内に上向流で通水させることによって、充填された種晶が流動し晶析槽１４内に種晶の流動床３０が形成される。合流・混合水２８がこの流動床３０を通過し種晶と接触する過程で、種晶の表面にリン酸ヒドロキシアパタイトなどが晶析して、水中の大部分のリンが回収される。流動床３０を通過した合流・混合水２８の大部分は槽上部に配置された集水手段３２によって集水され、循環水２６として循環槽１２に戻される。また、原水１８Ａの流量に見合う量の処理水３４が晶析槽１４の上部から排出され、次の第３工程に送られる。   The merged / mixed water 28 that has flowed in from the bottom of the crystallization tank 14 is caused to flow upward into the crystallization tank 14, whereby the filled seed crystals flow and the seed crystals flow into the crystallization tank 14. A floor 30 is formed. In the process in which the combined / mixed water 28 passes through the fluidized bed 30 and contacts the seed crystals, hydroxyapatite phosphate crystallizes on the surface of the seed crystals, and most of the phosphorus in the water is recovered. Most of the combined / mixed water 28 that has passed through the fluidized bed 30 is collected by the water collecting means 32 disposed in the upper part of the tank, and returned to the circulation tank 12 as the circulating water 26. In addition, an amount of treated water 34 corresponding to the flow rate of the raw water 18A is discharged from the upper part of the crystallization tank 14 and sent to the next third step.

循環水２６の量は原水１８Ａの量に対して通常１０〜３０倍に設定する。この循環水２６の上向流によって種晶の流動床３０が適正に形成される。また、循環水２６は原水１８Ａを希釈するので、原水１８Ａの水質変動が大きい場合でも、その悪影響を緩和する役割を果たす。図１では循環水２６を循環槽１２に戻す場合を図示したが、循環槽１２を省略して循環水２６を原水調整槽１０に直接戻すようにしてもよい。   The amount of the circulating water 26 is usually set to 10 to 30 times the amount of the raw water 18A. Due to the upward flow of the circulating water 26, the seed crystal fluidized bed 30 is appropriately formed. In addition, since the circulating water 26 dilutes the raw water 18A, even if the water quality fluctuation of the raw water 18A is large, it plays a role in mitigating the adverse effects. Although FIG. 1 illustrates the case where the circulating water 26 is returned to the circulating tank 12, the circulating tank 12 may be omitted and the circulating water 26 may be directly returned to the raw water adjustment tank 10.

なお、晶析槽１４では長期間の運転によって種晶表面での晶析が継続すると、種晶は晶析したリン酸ヒドロキシアパタイトなどによって肥大化し流動性が低下する。したがって、適当なタイミングで肥大化した種晶をリン晶析槽１４から抜き出して、新規の種晶に更新する。回収した肥大化種晶は肥料などに有効利用する。又は肥大化種晶を破砕やその他の手段を用いて一定の粒径に粒度調整し、種晶として再利用することもできる。   In the crystallization tank 14, if crystallization on the surface of the seed crystal is continued by a long-term operation, the seed crystal is enlarged by the crystallized hydroxyapatite phosphate and the fluidity is lowered. Therefore, the seed crystal enlarged at an appropriate timing is extracted from the phosphorus crystallization tank 14 and updated to a new seed crystal. The recovered enlarged seed crystals are used effectively as fertilizers. Alternatively, the enlarged seed crystals can be adjusted to a certain particle size by crushing or other means and reused as seed crystals.

第３工程の凝集沈澱処理装置１６では流入した第２工程の処理水３４に対して適量の凝集剤３６及びｐＨ調整剤３８を添加し、処理水３４中に残存している亜鉛、リン酸などを凝集沈澱処理する。前記第２工程で過剰に添加したカルシウム化合物もこの凝集沈澱処理によって例えばリン酸カルシウムとして沈澱分離される。凝集沈澱処理によって清澄化した処理水４０は系外に排出され、また、分離した沈澱汚泥４２は適当な方法で処理処分する。   In the flocculation / precipitation treatment apparatus 16 in the third step, appropriate amounts of the flocculating agent 36 and the pH adjuster 38 are added to the treated water 34 in the second step, and zinc, phosphoric acid, etc. remaining in the treated water 34. The material is coagulated and precipitated. The calcium compound added excessively in the second step is also precipitated and separated, for example, as calcium phosphate by this aggregation precipitation treatment. The treated water 40 clarified by the coagulation precipitation treatment is discharged out of the system, and the separated precipitation sludge 42 is treated and disposed by an appropriate method.

本実施形態のリン酸と亜鉛を含有する廃水の処理方法によれば、原水１８中に含まれるリン酸の大部分が第２工程における晶析反応によって、種晶表面にリン酸ヒドロキシアパタイトとして晶析する。このため、第２工程の処理水３４に含まれるリン酸が低減する。その結果、第３工程において分離される沈澱汚泥４２の発生量をその分、削減することができる。また、第２工程で種晶表面に晶析したリン酸ヒドロキシアパタイトは種晶ごと回収して肥料や工業原料として有効利用することができる。   According to the method for treating wastewater containing phosphoric acid and zinc according to the present embodiment, most of phosphoric acid contained in the raw water 18 is crystallized as hydroxyapatite phosphate on the seed crystal surface by the crystallization reaction in the second step. Analyze. For this reason, phosphoric acid contained in the treated water 34 in the second step is reduced. As a result, the generation amount of the precipitated sludge 42 separated in the third step can be reduced correspondingly. Further, the hydroxyapatite phosphate crystallized on the seed crystal surface in the second step can be recovered together with the seed crystal and effectively used as a fertilizer or an industrial raw material.

以下に、第１工程において廃水のｐＨを４〜６に調整する意義について説明する。図２はリン酸カルシウムと亜鉛の溶解度曲線を示したグラフであり、横軸はｐＨ、縦軸はリン又は亜鉛の濃度を示す。図中、曲線ａはリン酸カルシウムの溶解度曲線、曲線ｂは亜鉛の溶解度曲線である。リン酸カルシウムは溶解度曲線ａを境として、その左側が安定域、右側が準安定域になる。安定域では水中のリンとカルシウムは解離してイオンの状態で安定に存在する。準安定域では水中のリンとカルシウムは核となる種晶が存在すると、晶析反応によって種晶の表面にリン酸ヒドロキシアパタイトとして析出する。一方、亜鉛は溶解度曲線ｂを境として、その左側が安定域、右側が不安定域になる。安定域では水中の亜鉛は解離してイオンの状態で安定に存在する。不安定域では水中の亜鉛は水酸化亜鉛として析出する。   Below, the significance of adjusting the pH of wastewater to 4-6 in the first step will be described. FIG. 2 is a graph showing solubility curves of calcium phosphate and zinc. The horizontal axis represents pH, and the vertical axis represents phosphorus or zinc concentration. In the figure, curve a is a calcium phosphate solubility curve and curve b is a zinc solubility curve. Calcium phosphate has a solubility curve a as a boundary and the left side is a stable region and the right side is a metastable region. In the stable region, phosphorus and calcium in the water dissociate and exist stably in an ionic state. In the metastable region, when phosphorus and calcium in water have a seed crystal serving as a nucleus, they are precipitated as hydroxyapatite phosphate on the surface of the seed crystal by a crystallization reaction. On the other hand, with the solubility curve b as the boundary, zinc has a stable region on the left side and an unstable region on the right side. In the stable region, zinc in water dissociates and exists stably in an ionic state. In the unstable region, zinc in water precipitates as zinc hydroxide.

したがって、リンとカルシウムと亜鉛が共存する原水をリン晶析槽に通水させた場合、図中、Ａで示した領域では水中のリン、カルシウム、亜鉛はすべて解離してイオンの状態で安定に存在し、リン晶析槽では格別の反応は起きない。Ｂで示した領域では水中の亜鉛はイオンの状態で安定に存在するとともに、リンとカルシウムは種晶の表面にリン酸ヒドロキシアパタイトとして晶析する。Ｃで示した領域では亜鉛が水酸化亜鉛として析出し、この水酸化亜鉛が種晶表面に付着するとリンの晶析反応を妨害する。また、回収した肥大化種晶の中に異物としての水酸化亜鉛が混入し肥料や工業原料としての付加価値を低下させる。このため、本発明では廃水中のリンと亜鉛の共存関係が図２の領域Ｂで示した範囲に属するように、第１工程において廃水のｐＨを４〜６に調整する。   Therefore, when raw water in which phosphorus, calcium and zinc coexist is passed through the phosphorus crystallization tank, phosphorus, calcium and zinc in the water are all dissociated and stabilized in the ionic state in the region indicated by A in the figure. It exists and no special reaction occurs in the phosphorus crystallization tank. In the region indicated by B, zinc in water is stably present in an ionic state, and phosphorus and calcium are crystallized as hydroxyapatite phosphate on the surface of the seed crystal. In the region indicated by C, zinc precipitates as zinc hydroxide, and if this zinc hydroxide adheres to the seed crystal surface, the crystallization reaction of phosphorus is hindered. In addition, zinc hydroxide as a foreign substance is mixed in the recovered enlarged seed crystals, and the added value as a fertilizer or industrial raw material is reduced. For this reason, in the present invention, the pH of the wastewater is adjusted to 4 to 6 in the first step so that the coexistence relationship between phosphorus and zinc in the wastewater belongs to the range indicated by the region B in FIG.

実験例
リン酸と亜鉛を含有する廃水に対して処理実験を実施した。この廃水のリン濃度は８０ｍｇ／Ｌ、亜鉛濃度は１００ｍｇ／Ｌであった。この廃水に塩化カルシウムをカルシウム濃度として２００ｍｇ／Ｌ添加した。この添加量は当該カルシウムが廃水中のリン酸と反応し晶析するために必要な反応当量の約１．２倍に相当する。この塩化カルシウムを添加した廃水に塩酸又は水酸化ナトリウムを添加して、ｐＨを３〜８の範囲で変化させた複数の試料を調整した。ビーカー内の各試料に種晶として粒径が１ｍｍリン鉱石を投入し、スターラーによって１時間、攪拌する回分式の晶析実験を行った。実験後の各試料中のリン濃度と懸濁物質濃度を計測して、リン晶析率と析出ＳＳ濃度を求めた。 Experimental Example A treatment experiment was performed on wastewater containing phosphoric acid and zinc. The wastewater had a phosphorus concentration of 80 mg / L and a zinc concentration of 100 mg / L. 200 mg / L of calcium chloride was added to the wastewater as the calcium concentration. This amount of addition corresponds to about 1.2 times the reaction equivalent required for the calcium to react with phosphoric acid in the wastewater and crystallize. A plurality of samples whose pH was changed in the range of 3 to 8 was prepared by adding hydrochloric acid or sodium hydroxide to the wastewater to which calcium chloride was added. A batch-type crystallization experiment was performed in which phosphorous ore having a particle diameter of 1 mm was introduced as a seed crystal into each sample in the beaker and stirred for 1 hour by a stirrer. The phosphorus concentration and suspended substance concentration in each sample after the experiment were measured to determine the phosphorus crystallization rate and the precipitated SS concentration.

図３は実験結果を示すグラフであり、横軸は各試料のｐＨである。この実験結果から、試料のｐＨが４〜６の範囲でリン晶析率が高く、特にｐＨ５の時に最大のリン晶析率が得られることが判る。また、ｐＨを高くするに従って析出ＳＳ濃度が高くなり、リン晶析率が低下することが判る。   FIG. 3 is a graph showing the experimental results, and the horizontal axis represents the pH of each sample. From this experimental result, it can be seen that the phosphorus crystallization rate is high when the pH of the sample is in the range of 4 to 6, and that the maximum phosphorus crystallization rate is obtained particularly when the pH is 5. It can also be seen that as the pH is increased, the concentration of precipitated SS increases and the phosphorus crystallization rate decreases.

本発明に係る処理方法の実施形態を示す系統図である。It is a systematic diagram which shows embodiment of the processing method which concerns on this invention. リン酸カルシウムと亜鉛の溶解度曲線を示したグラフである。It is the graph which showed the solubility curve of calcium phosphate and zinc. 実験結果を示すグラフである。It is a graph which shows an experimental result.

符号の説明Explanation of symbols

１０………原水調整槽、１２………循環槽、１４………リン晶析槽、１６………凝集沈澱処理装置、１８，１８Ａ………原水、２０………カルシウム化合物、２２………ｐＨ調整剤、２４………攪拌機、２６………循環水、２８………合流・混合水、３０………流動床、３２………集水手段、３４………（第２工程の）処理水、３６………凝集剤、３８………ｐＨ調整剤、４０………処理水、４２………沈澱汚泥。   DESCRIPTION OF SYMBOLS 10 ......... Raw water adjustment tank, 12 ......... Circulation tank, 14 ...... Phosphorus crystallization tank, 16 ......... Coagulation sedimentation processing apparatus, 18, 18A ......... Raw water, 20 ......... Calcium compound, 22 ... ...... pH adjuster, 24 ......... Stirrer, 26 ......... Circulating water, 28 ...... Merging / mixing water, 30 ......... Fluidized bed, 32 ......... Water collecting means, 34 ......... (Second Processed water, 36 ......... flocculant, 38 ......... pH adjuster, 40 ......... treated water, 42 ......... settling sludge.

Claims (2)

亜鉛とリン酸を含有する廃水に、当該廃水中のリン酸と反応し晶析するために必要な反応当量の１〜１．３倍の量の塩化カルシウムや水酸化カルシウムなどのカルシウム化合物を添加するとともにｐＨを４〜６に調整する第１工程と、次いで当該廃水を種晶が充填されたリン晶析槽に通水して晶析処理する第２工程と、第２工程の処理水を凝集沈澱処理する第３工程とを含むことを特徴とするリン酸と亜鉛を含有する廃水の処理方法。 Adds calcium compounds such as calcium chloride and calcium hydroxide to waste water containing zinc and phosphoric acid in an amount 1 to 1.3 times the reaction equivalent necessary to react and crystallize with phosphoric acid in the waste water. In addition, the first step of adjusting the pH to 4 to 6, the second step of passing the waste water through a phosphorus crystallization tank filled with seed crystals, and the crystallization treatment, and the treated water of the second step A method for treating waste water containing phosphoric acid and zinc, comprising a third step of coagulating and precipitating. 前記リン晶析槽が流動床式のリン晶析槽であり、前記廃水の量に対して１０〜３０倍の循環水を用いて前記廃水を槽内に上向流で通水させ、その上向流によって槽内に充填した種晶の流動床を形成するようにしたことを特徴とする請求項１に記載のリン酸と亜鉛を含有する廃水の処理方法。   The phosphorus crystallization tank is a fluidized bed type phosphorus crystallization tank, and the waste water is passed through the tank in an upward flow using 10 to 30 times the amount of the waste water. The method for treating wastewater containing phosphoric acid and zinc according to claim 1, wherein a fluidized bed of seed crystals filled in the tank is formed by counterflow.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103011371A (en) * 2012-12-07 2013-04-03 常州大学 Method for removing germanium in sewage

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6484782B2 (en) * 2014-03-19 2019-03-20 富士シリシア化学株式会社 Wastewater treatment method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51149874A (en) * 1975-06-19 1976-12-23 Toray Ind Inc A process for fractional recovery of divalent heavy metal ions and pho sphate ions
JPS5640484A (en) * 1979-09-10 1981-04-16 Ataka Kogyo Kk Removal of phosphoric acid ion in water
JPH01284390A (en) * 1988-05-09 1989-11-15 Kawasaki Steel Corp Treatment of phosphate-containing water
JPH057879A (en) * 1991-07-04 1993-01-19 Kurita Water Ind Ltd Treatment of waste water containing heavy metal
JP2001337274A (en) * 2000-01-28 2001-12-07 Asahi Optical Co Ltd Zoom lens system
JP2003126868A (en) * 2001-10-24 2003-05-07 Kurita Water Ind Ltd Treating method of fluorine-containing water containing phosphoric acid ion and treating equipment

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51149874A (en) * 1975-06-19 1976-12-23 Toray Ind Inc A process for fractional recovery of divalent heavy metal ions and pho sphate ions
JPS5640484A (en) * 1979-09-10 1981-04-16 Ataka Kogyo Kk Removal of phosphoric acid ion in water
JPH01284390A (en) * 1988-05-09 1989-11-15 Kawasaki Steel Corp Treatment of phosphate-containing water
JPH057879A (en) * 1991-07-04 1993-01-19 Kurita Water Ind Ltd Treatment of waste water containing heavy metal
JP2001337274A (en) * 2000-01-28 2001-12-07 Asahi Optical Co Ltd Zoom lens system
JP2003126868A (en) * 2001-10-24 2003-05-07 Kurita Water Ind Ltd Treating method of fluorine-containing water containing phosphoric acid ion and treating equipment

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103011371A (en) * 2012-12-07 2013-04-03 常州大学 Method for removing germanium in sewage

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