JP5164101B2 - Method for removing and collecting phosphorus in wastewater to be treated - Google Patents
Method for removing and collecting phosphorus in wastewater to be treated Download PDFInfo
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- JP5164101B2 JP5164101B2 JP2008089001A JP2008089001A JP5164101B2 JP 5164101 B2 JP5164101 B2 JP 5164101B2 JP 2008089001 A JP2008089001 A JP 2008089001A JP 2008089001 A JP2008089001 A JP 2008089001A JP 5164101 B2 JP5164101 B2 JP 5164101B2
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- 239000011574 phosphorus Substances 0.000 title claims description 49
- 229910052698 phosphorus Inorganic materials 0.000 title claims description 49
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 title claims description 41
- 239000002351 wastewater Substances 0.000 title claims description 30
- 238000000034 method Methods 0.000 title claims description 23
- 239000010440 gypsum Substances 0.000 claims description 15
- 229910052602 gypsum Inorganic materials 0.000 claims description 15
- 238000006243 chemical reaction Methods 0.000 claims description 13
- 238000002425 crystallisation Methods 0.000 claims description 13
- 239000007788 liquid Substances 0.000 claims description 9
- -1 phosphorus compound Chemical class 0.000 claims description 8
- 239000011575 calcium Substances 0.000 claims description 7
- 239000010802 sludge Substances 0.000 claims description 7
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 6
- 239000010842 industrial wastewater Substances 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 6
- 239000010865 sewage Substances 0.000 claims description 6
- 229910052791 calcium Inorganic materials 0.000 claims description 5
- 229910052588 hydroxylapatite Inorganic materials 0.000 claims description 2
- XYJRXVWERLGGKC-UHFFFAOYSA-D pentacalcium;hydroxide;triphosphate Chemical compound [OH-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O XYJRXVWERLGGKC-UHFFFAOYSA-D 0.000 claims description 2
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 claims description 2
- 238000001556 precipitation Methods 0.000 claims 2
- 239000003795 chemical substances by application Substances 0.000 claims 1
- 238000000746 purification Methods 0.000 claims 1
- 238000011084 recovery Methods 0.000 description 10
- 230000029087 digestion Effects 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 230000008025 crystallization Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 238000004065 wastewater treatment Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 238000003795 desorption Methods 0.000 description 2
- 239000002440 industrial waste Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- FUFJGUQYACFECW-UHFFFAOYSA-L calcium hydrogenphosphate Chemical compound [Ca+2].OP([O-])([O-])=O FUFJGUQYACFECW-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000006114 decarboxylation reaction Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000010840 domestic wastewater Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- 239000010800 human waste Substances 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 1
- 244000144972 livestock Species 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 150000003018 phosphorus compounds Chemical class 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000003911 water pollution Methods 0.000 description 1
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Description
本発明は、産業排水又は都市下水等の排水環境中の溶存態リン（ＰＯ4 3- ）を除去回収する方法に係り、詳しくは、排水処理過程で発生する高濃度リン含有中間処理液を被処理排水として石膏と接触させることにより、反応生成した難溶性リン化合物を回収するようにした被処理排水中のリン除去回収方法に関する。なお、排水環境とはリンの発生源から排出した種々の排水をいい、産業排水には工場排水及び農畜業の排水を含み、都市下水等には下水道、し尿処理排水及び生活雑排水を含む。 The present invention relates to a method for removing and recovering dissolved phosphorus (PO 4 3− ) in a wastewater environment such as industrial wastewater or municipal sewage, and more specifically, a high-concentration phosphorus-containing intermediate treatment solution generated during wastewater treatment. The present invention relates to a method for removing and recovering phosphorus in wastewater to be treated so as to recover the hardly soluble phosphorus compound produced by reaction by contacting with gypsum as treated wastewater. The drainage environment refers to various types of wastewater discharged from the source of phosphorus. Industrial wastewater includes industrial wastewater and agricultural and livestock wastewater, and urban sewage includes sewerage, human waste processing wastewater and domestic wastewater. .
従来より、排水からのリン除去技術として、ＰＡＣ（ポリ塩化アルミニウム）や塩化第二鉄による処理が行われているが、凝集汚泥からのリン回収コストが高くなるという難点があり、リン回収方法としては採用されていない。 Conventionally, treatment with PAC (polyaluminum chloride) or ferric chloride has been performed as a technology for removing phosphorus from wastewater. However, there is a problem that the cost of recovering phosphorus from agglomerated sludge is high. Is not adopted.
こうした中で、現状のリン回収法では、晶析脱リン法であるＨＡＰ晶析法（例えば、特許文献１、及び図３を参照）、ＭＡＰ晶析法（例えば、特許文献２、及び図４を参照）や汚泥からのリン回収法（例えば、特許文献３を参照）などが知られている。しかしながら、いずれも反応調整装置と多量の薬剤を必要とし、コスト面での問題を有しているため、普及が進んでいないのが実情である。
ところで、植物の必須元素であるリンは、今世紀中にも原料となるリン鉱石の枯渇が懸念されており、資源循環の手法として費用対効果の高いリン回収技術の開発が期待されている。 By the way, phosphorus, which is an essential element of plants, is concerned about the depletion of phosphorus ore as a raw material during this century, and development of cost-effective phosphorus recovery technology is expected as a resource recycling method.
発明が解決しようとする問題点は、産業排水又は都市下水等の排水環境中の溶存態リン（ＰＯ4 3- ）を除去（回収）する際に、複雑な反応調整や多量の薬剤投入を不要とするとともに、処理能力（回収効率）に遜色がなく、簡略手法による低コストの処理技術を確立する点にある。 The problem to be solved by the invention is that no complicated reaction adjustment or a large amount of chemical input is required when removing (recovering) dissolved phosphorus (PO 4 3− ) in the wastewater environment such as industrial wastewater or municipal sewage. In addition, the processing capability (recovery efficiency) is not inferior, and a low-cost processing technology is established by a simplified method.
本発明はこのような事情に鑑みなされたものであって、上記課題を解消し、排水処理過程で発生する高濃度リン含有中間処理液を被処理排水として、石膏を用いることにより簡易な処理操作で反応生成した難溶性リン化合物を回収する被処理排水中のリン除去回収方法を提供するものである。 The present invention has been made in view of the above circumstances, and solves the above-mentioned problems, and a simple treatment operation by using gypsum as a wastewater to be treated as a high-concentration phosphorus-containing intermediate treatment liquid generated in the wastewater treatment process. The present invention provides a method for removing and recovering phosphorus in the wastewater to be treated, which recovers the hardly soluble phosphorus compound produced by the reaction.
課題を解決するために本発明は、産業排水又は都市下水等の排水環境中の溶存態リン（ＰＯ4 3- ）を除去回収する方法において、排水処理過程で発生する高濃度リン含有中間処理液を被処理排水として、該被処理排水と石膏を接触させることにより、反応生成した難溶性リン化合物を回収することを特徴とするものである。 In order to solve the problems, the present invention relates to a high concentration phosphorus-containing intermediate treatment liquid generated during wastewater treatment in a method for removing and recovering dissolved phosphorus (PO 4 3− ) in wastewater environment such as industrial wastewater or municipal sewage. By treating the waste water to be treated with gypsum, the reaction-generated poorly soluble phosphorus compound is recovered.
ここで、リン化合物としては、リン酸水素カルシウム[CaHPO4]、リン酸カルシウム [Ca3(PO4)2]又はヒドロキシアパタイト [Ca5(PO4)3(OH)]が考慮される。 Here, calcium phosphate [CaHPO 4 ], calcium phosphate [Ca 3 (PO 4 ) 2 ] or hydroxyapatite [Ca 5 (PO 4 ) 3 (OH)] is considered as the phosphorus compound.
本発明は、消化脱離液（返流水及び汚泥脱水分離液に包含される）等の高濃度のリンを含む排水（被処理排水に同じ）に対して広く適用可能で、低コストで簡易な処理操作によりリン化合物の形態で効果的に系外回収できる。 The present invention is widely applicable to wastewater containing high-concentration phosphorus (same as wastewater to be treated) such as digestion desorption liquid (included in return water and sludge dewatering separation liquid), and is low-cost and simple. It can be effectively recovered outside the system in the form of a phosphorus compound by the treatment operation.
また、系外回収したリン化合物は、肥料、工業原料等に再利用できるので、資源循環の手法として有益である。石膏（反応に関与するカルシウム源）には、産業廃棄物である廃石膏を用いることができるという利点がある。廃石膏は殆どが埋立処分され、埋立後の硫化水素被害の発生が問題視されており、その解消の方途を指向できるからである。 Moreover, since the phosphorus compounds recovered outside the system can be reused as fertilizers, industrial raw materials, etc., they are useful as a resource recycling technique. Gypsum (a source of calcium involved in the reaction) has the advantage that waste gypsum, which is industrial waste, can be used. This is because most waste gypsum is disposed of in landfills, and the occurrence of hydrogen sulfide damage after landfill is regarded as a problem.
当然のことながら、リン含有排水等に起因する水質汚濁負荷の軽減、及び廃棄物の埋立処分量の低減、並びにリン資源の再生（循環）に寄与するものであることから、循環型社会を標榜する行政ニーズに即応できる処理技術として普及が期待できる。 As a matter of course, it contributes to reducing the water pollution load caused by phosphorus-containing wastewater, etc., reducing the amount of waste landfilled, and regenerating (recycling) phosphorus resources. It can be expected to spread as a processing technology that can respond to administrative needs.
本発明を実施するための最良の形態は、上記リン除去回収方法において、必要な石膏の量は、石膏中のカルシウムと被処理排水中の溶存態リンのモル比が同量以上となるように添加すると効率的である。 The best mode for carrying out the present invention is that in the above phosphorus removal and recovery method, the amount of gypsum required is such that the molar ratio of calcium in gypsum and dissolved phosphorus in the wastewater to be treated is equal to or greater than the same. It is efficient when added.
さらに、石膏には、産業廃棄物である廃石膏を用いることができる。なお、被処理排水を反応槽に導入して石膏と接触させるのが便宜である。 Furthermore, waste gypsum which is industrial waste can be used for gypsum. In addition, it is convenient to introduce the wastewater to be treated into the reaction tank and contact with gypsum.
著効を期待できる被処理排水（高濃度リン含有中間処理液）は、嫌気処理後の処理排水であり、汚泥処理後の汚泥脱水分離液（特に消化処理後の汚泥脱水工程で発生する消化脱離液）であり、汚泥処理後のリン除去を行っていない返流水である。 Wastewater to be treated (intermediate treatment solution containing high-concentration phosphorus) that can be expected to be highly effective is treated wastewater after anaerobic treatment. This is the return water that has not undergone phosphorus removal after sludge treatment.
なお、この種の被処理排水についてさらに至適な条件を望むとすれば、前処理として懸濁物質（ＳＳ分）をある程度除去することである。 If more optimal conditions are desired for this type of wastewater to be treated, the suspended matter (SS content) is removed to some extent as pretreatment.
本発明の一実施例（以下、実施例方法）について添付図面を参照して以下説明する。 An embodiment of the present invention (hereinafter, an embodiment method) will be described below with reference to the accompanying drawings.
図１は実施例方法の処理フロー説明図である。 FIG. 1 is an explanatory diagram of the processing flow of the embodiment method.
図示するように、汚泥の消化設備を有する処理施設において、消化処理後の汚泥脱水工程で発生する消化脱離液を本発明方法を実施するための反応槽に導入する。反応槽で消化脱離液と石膏を接触させ、反応生成したリン化合物を回収する。なお、処理後の流出水は常法どおり返流水として処理前段に返送する。 As shown in the figure, in a treatment facility having a sludge digestion facility, a digestion and desorption liquid generated in the sludge dehydration step after the digestion treatment is introduced into a reaction tank for carrying out the method of the present invention. The digestion detachment liquid and gypsum are brought into contact with each other in the reaction tank, and the phosphorus compound produced by the reaction is recovered. The treated effluent is returned to the pre-treatment stage as return water as usual.
リン回収能力を実験的事実により検証したので以下に説明する。 The phosphorus recovery ability was verified by experimental facts and will be described below.
＜実験方法及び結果＞
直径15mmのカラムに粉砕した石膏10g(粒径2-5mm)を充填し、カラム内へ公共下水処理場の消化脱離液を導入（流入）し、滞留時間を変化させてリン除去量からリン回収率を算出した。消化脱離液の性状はpH7.8、130mg-P/l であった。
<Experimental method and results>
Fill a column with a diameter of 15 mm with 10 g of crushed gypsum (particle size 2-5 mm), introduce (inflow) the digestion and effluent from a public sewage treatment plant into the column, change the residence time, and remove phosphorus from the phosphorus removal amount. The recovery rate was calculated. The properties of the digestion detachment solution were pH 7.8 and 130 mg-P / l.
図２にリン回収率（％）vs滞留時間（日）のデータプロットを示す。実験結果から理解されるように、リン回収率は最大97％であることが認められた。しかも、１時間程度で90％を超えるものであり短時間処理が期待できるものである。 FIG. 2 shows a data plot of phosphorus recovery rate (%) vs residence time (days). As can be seen from the experimental results, the phosphorus recovery was found to be up to 97%. Moreover, it is over 90% in about 1 hour, and a short time treatment can be expected.
参考までに、化学的プロセスを利用した従来技術である晶析脱リン法におけるＨＡＰ晶析法及びＭＡＰ晶析法について、それらのプロセス概要図をそれぞれ図３及び図４に示す。 For reference, FIGS. 3 and 4 show schematic diagrams of the HAP crystallization method and the MAP crystallization method in the crystallization dephosphorization method, which is a conventional technique using a chemical process, respectively.
ＨＡＰ晶析法（図３を参照）は、被処理排水に酸を加えて。低pH条件下で脱炭酸後、晶析槽でカルシウムと水酸化ナトリウムを加えた高pH条件下でリンを結晶化し回収するものである。 In the HAP crystallization method (see FIG. 3), acid is added to the wastewater to be treated. After decarboxylation under low pH conditions, phosphorus is crystallized and recovered under high pH conditions in which calcium and sodium hydroxide are added in a crystallization tank.
ＭＡＰ晶析法（図４を参照）は、高濃度のアンモニアを含む被処理排水に、晶析槽でマグネシウムと水酸化ナトリウムを加えた高pH条件下でリンを結晶化し回収するものである。 In the MAP crystallization method (see FIG. 4), phosphorus is crystallized and recovered under a high pH condition in which magnesium and sodium hydroxide are added to a wastewater to be treated containing high-concentration ammonia in a crystallization tank.
いずれも回収リンの純度は良いといえるが、上述したとおりpH調整を含む反応調整に要する管理コストや設備コストが無視できないし、本発明手法の有用性が肯認されるであろう。 In any case, the purity of the recovered phosphorus can be said to be good. However, as described above, the management cost and equipment cost required for reaction adjustment including pH adjustment cannot be ignored, and the usefulness of the method of the present invention will be confirmed.
本発明は、簡略手法ながら高いリン回収率を実現可能であり、既設の設備系にも容易に組み込むことができる等、斯界への貢献が期待でき、産業上極めて有益である。 The present invention can realize a high phosphorus recovery rate in a simple manner, and can be easily incorporated into an existing equipment system, and thus can contribute to the field.
Claims (1)
前記有機性排水の浄化処理過程で発生する汚泥処理後の消化脱離液からなるリン含有中間処理液を被処理排水として、該被処理排水と所定量の石膏を接触させ、難溶性リン化合物を沈殿回収する被処理排水中のリン除去回収方法であって、
反応槽に導入した前記中間処理液中の溶存態リン（ＰＯ4 3- −Ｐ）の存在量に対してカルシウムのモル比が同等以上となるような量比で石膏を投入することにより、リン酸水素カルシウム[CaHPO 4 ]、リン酸カルシウム [Ca 3 (PO 4 ) 2 ]又はヒドロキシアパタイト [Ca 5 (PO 4 ) 3 (OH)]からなる難溶性リン化合物の沈殿生成反応を進行させることを特徴とする被処理排水中のリン除去回収方法。 In order to remove and recover dissolved phosphorus (PO 4 3- -P) in organic wastewater such as industrial wastewater or municipal sewage, a calcium supply source as a reaction treatment agent is added, and it does not depend on the crystallization method. In the method of removing and recovering phosphorus in the wastewater to be treated, which is dephosphorized by reacting and generating a phosphorus compound in
Using the phosphorus-containing intermediate treatment liquid consisting of the digested and desorbed liquid after the sludge treatment generated in the purification process of the organic wastewater as the wastewater to be treated, bringing the wastewater to be treated into contact with a predetermined amount of gypsum, A method for removing and collecting phosphorus in the wastewater to be collected for precipitation,
By placing the gypsum in a quantity ratio such that the molar ratio of calcium is equal to or higher relative abundance of Dissolved phosphorus of the intermediate processing liquid introduced into the reaction vessel (PO 4 3- -P), phosphorus It is characterized by causing a precipitation reaction of a sparingly soluble phosphorus compound comprising calcium oxyhydrogen [CaHPO 4 ], calcium phosphate [Ca 3 (PO 4 ) 2 ] or hydroxyapatite [Ca 5 (PO 4 ) 3 (OH)] To remove and recover phosphorus in treated wastewater.
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| JP3480904B2 (en) * | 1998-11-11 | 2003-12-22 | 三菱マテリアル株式会社 | Method and apparatus for recovering phosphorus from sludge |
| JP2003088880A (en) * | 2001-07-10 | 2003-03-25 | Mie Prefecture | Method for removing water-soluble phosphorus by using calcium sulfate |
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