JP2020062640A - Processing method and apparatus for organic sludge - Google Patents
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/34—Biological treatment of water, waste water, or sewage characterised by the microorganisms used
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/02—Biological treatment
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/06—Treatment of sludge; Devices therefor by oxidation
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/20—Sludge processing
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- Microbiology (AREA)
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- Biodiversity & Conservation Biology (AREA)
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- Separation Of Suspended Particles By Flocculating Agents (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Abstract
Description
本発明は、有機性汚泥の処理方法及び処理装置に関し、特に難脱水性消化汚泥の処理方法及び処理装置に関する。 The present invention relates to a method and an apparatus for treating organic sludge, and more particularly to a method and an apparatus for treating hardly dehydratable digested sludge.
食品加工残渣、生ごみ、汚泥などの廃棄物系バイオマスを対象としたメタン発酵技術において、設備のコンパクト化やメタンガスのエネルギー回収率向上を目的として、設備への投入原料濃度を高濃度化することで運転動力を削減し、エネルギー回収の効率化を図ることが多い（高濃度消化法）。 In methane fermentation technology for waste-based biomass such as food processing residues, food waste, sludge, etc., to increase the concentration of the raw material input to the equipment in order to make the equipment compact and improve the energy recovery rate of methane gas. It is often the case that the driving power is reduced to improve the efficiency of energy recovery (high-concentration digestion method).
一方、メタン発酵時の汚泥濃度が高濃度化すると、発酵微生物の阻害反応に加えて、汚泥濃度の上昇に伴う移送、混合、撹拌時の設備容量や動力費増大、汚泥の難脱水化などの問題が発生してくる。特に、下水汚泥などの一般的なメタン発酵汚泥のＴＳ濃度（全蒸発残留物：Total solids）は１５〜２０ｇ／Ｌであるのに対して、メタン発酵汚泥のＴＳ濃度が２５ｇ／Ｌ以上となる高濃度消化法では、発酵設備での適切な混合・撹拌技術とともに、難脱水化した発酵汚泥を簡便で安定的に汚泥処理できる技術が必要となっている。さらに、ＴＳ濃度が２５ｇ／Ｌ以上且つＳＳ濃度（懸濁物質：Suspended solids）がＴＳ濃度よりも５ｇ／Ｌ以上少ない性状の汚泥の場合には、汚泥が高粘質化したり、固液分離性が著しく低下したりする傾向が強く、安定した汚泥処理技術が要求されている。 On the other hand, if the sludge concentration during methane fermentation becomes high, in addition to the inhibitory reaction of fermenting microorganisms, increase in equipment capacity and power cost during transfer, mixing, stirring with sludge concentration increase, sludge difficult to dehydrate, etc. The problem arises. In particular, the TS concentration (total evaporation residues: Total solids) of general methane fermentation sludge such as sewage sludge is 15 to 20 g / L, whereas the TS concentration of methane fermentation sludge is 25 g / L or more. In the high-concentration digestion method, it is necessary to have an appropriate mixing / stirring technique in the fermentation equipment and a technique that can easily and stably treat the hardly dehydrated fermented sludge. Furthermore, in the case of a sludge having a TS concentration of 25 g / L or more and an SS concentration (Suspended solids) of 5 g / L or more less than the TS concentration, the sludge becomes highly viscous or has solid-liquid separation property. Stable sludge treatment technology is required because of the strong tendency to significantly reduce the sludge.
メタン発酵汚泥処理では、凝集薬剤を注入して汚泥中の懸濁物質を化学的に凝集処理した後、機械脱水することが多い。その際、ＴＳ濃度が２５ｇ／Ｌ以上の高濃度汚泥では、希釈液などで汚泥を希釈処理してから汚泥脱水処理する方法が採られている（特許文献１）。この高濃度消化汚泥の脱水処理に用いる高分子凝集剤としては、高価なアミジン系高分子凝集剤などが用いられ、適正な凝集フロックを形成させるためには薬注率５ｗｔ％以上（対ＴＳ濃度）の高い添加率で添加する必要があるため、薬品費が著しくコスト高となっていた。下水汚泥を対象とする一般的な嫌気性消化汚泥の脱水処理に用いられる高分子凝集剤が安価な非アミジン系高分子凝集剤で薬注率２ｗｔ％（対ＴＳ濃度）程度であることと比較すると、著しくコスト高であることが明らかであろう。 In the methane fermentation sludge treatment, a flocculating agent is often injected to chemically suspend the suspended matter in the sludge and then mechanically dehydrated. At that time, for high-concentration sludge having a TS concentration of 25 g / L or more, a method of diluting the sludge with a diluting solution and the like and then performing sludge dewatering treatment is adopted (Patent Document 1). As the polymer flocculant used for the dehydration treatment of this high-concentration digested sludge, an expensive amidine-based polymer flocculant is used, and in order to form a proper floc, a chemical injection rate of 5 wt% or more (based on TS concentration ) Is required to be added at a high addition rate, the chemical cost is extremely high. Compared with the fact that the polymer flocculant used for the dehydration treatment of general anaerobic digestion sludge for sewage sludge is an inexpensive non-amidine polymer flocculant and the chemical injection rate is about 2 wt% (vs TS concentration). Then, it will be obvious that the cost is extremely high.
嫌気性消化汚泥の脱水性を改善するために、嫌気性消化処理した消化残物（消化汚泥、又は消化液と消化汚泥との混合スラリー）を酸素含有ガスで曝気したのち機械脱水する方法が提案されている（特許文献２）。特許文献２には、消化残物を十分曝気処理することで、消化残物のアルカリ度およびコロイド成分が微生物の作用によって減少するために、脱水効果が向上することが開示されている。しかし、特許文献２には、曝気条件が何ら明記されておらず、曝気処理の効果が明確ではない。
In order to improve the dehydration property of anaerobic digested sludge, a method of mechanical dehydration after aeration of the digestion residue (digested sludge or a mixed slurry of digested liquid and digested sludge) that has been subjected to anaerobic digestion is proposed. (Patent Document 2).
また、嫌気性消化汚泥（ＳＳ濃度１．５３％＝１５．３ｇ／Ｌ）を曝気処理した後に余剰汚泥を混合し、得られた混合汚泥に金属塩を添加（第１段目の凝集反応）してから、凝集処理（第２段目の凝集反応）及び脱水処理を行う方法が提案されている（特許文献３）。特許文献３には、曝気により汚泥中に溶解している炭酸ガスを脱気し、金属塩を添加した際の発泡による凝集阻害を防止して凝集性を高めることが開示されている。また、余剰汚泥の混合によりアルカリ度を低下させ、金属塩（無機凝集剤）及び有機高分子凝集剤の凝集作用を改善すると記載されている。特許文献３に開示されている曝気条件は５〜１０ｍ３−Ａｉｒ／ｍ３−汚泥・ｈｒ（０．０８３〜０．１６７ｍ３−Ａｉｒ／ｍ３−汚泥・分）の曝気風量にて１〜３時間である。特許文献３には、曝気処理を行った場合に塩化第二鉄の添加時に発泡が殆どなかった（実施例１）と記載されているに過ぎず、溶解している炭酸ガスの脱気効果が確認されているだけである。また、特許文献３には嫌気性消化汚泥のＴＳ濃度は記載されておらず、推定することもできない。
In addition, anaerobic digested sludge (SS concentration 1.53% = 15.3 g / L) is aerated, and then excess sludge is mixed, and a metal salt is added to the obtained mixed sludge (first-stage aggregation reaction). After that, a method of performing aggregation treatment (second-stage aggregation reaction) and dehydration treatment has been proposed (Patent Document 3).
本発明は、低コスト及び高脱水効率を達成できる高濃度消化汚泥の処理方法及び処理装置を提供することを目的とする。 An object of the present invention is to provide a treatment method and a treatment device for high-concentration digested sludge that can achieve low cost and high dehydration efficiency.
本発明者らは、高濃度消化汚泥中に残留する粘着質成分が高濃縮されることによって高濃度消化汚泥が難脱水化するとの知見を得て、高濃度消化汚泥の粘度を低下させることによって、凝集剤の添加量を削減し、脱水効率を向上できることを見いだした。 The present inventors have obtained the finding that high-concentration digested sludge is hardly dehydrated due to high concentration of the sticky component remaining in the high-concentration digested sludge, and by decreasing the viscosity of the high-concentration digested sludge. It was found that the amount of coagulant added can be reduced and the dehydration efficiency can be improved.
本発明によれば、下記の有機性汚泥の処理方法及び処理装置が提供される。
［１］嫌気性処理後の有機性汚泥を処理する方法であって、当該有機性汚泥は、２５ｇ／Ｌ以上のＴＳ濃度と、当該ＴＳ濃度よりも５ｇ／Ｌ以上少ないＳＳ濃度と、を有する難脱水性消化汚泥であり、当該消化汚泥を脱水処理する前に、当該難脱水性消化汚泥に対して酸素含有気体を通気して曝気処理を行ない、当該難脱水性消化汚泥の粘度を低減させることを特徴とする有機性汚泥の処理方法。
［２］前記曝気処理は、曝気処理後の難脱水性消化汚泥の粘度が、下水試験方法に定められたＢ型回転粘度計による３０℃での測定で２００ｍＰａ・ｓ以下に低下するまで行うことを特徴とする［１］に記載の有機性汚泥の処理方法。
［３］前記曝気処理は、０．１ｍ３／（ｍ３・分）以上の曝気強度にて４時間以上４８時間以下の曝気時間で行うことを特徴とする［１］又は［２］に記載の有機性汚泥の処理方法。
［４］前記曝気強度は０．２ｍ３／（ｍ３・分）以上であることを特徴とする［３］に記載の有機性汚泥の処理方法。
［５］前記曝気処理に用いる酸素含有気体は、空気、又は処理対象となる有機性汚泥が形成される処理施設内で発生する臭気成分を含む空気であることを特徴とする［１］〜［４］のいずれか１に記載の有機性汚泥の処理方法。
［６］前記曝気処理を行う前に、難脱水性消化汚泥に、好気性微生物群を含む汚泥を添加することを特徴とする［１］〜［５］のいずれか１項に記載の有機性汚泥の処理方法。
［７］前記曝気処理は、前記難脱水性消化汚泥中の溶存酸素濃度を１．０ｍｇ／Ｌ以下に維持して行うことを特徴とする［１］〜［６］のいずれか１に記載の有機性汚泥の処理方法。
［８］前記曝気処理後の消化汚泥に、６．０ｇ／Ｌ以下のＴＳ濃度を有する希釈液を添加して希釈した後、脱水処理することを特徴とする［１］〜［７］のいずれか１項に記載の有機性汚泥の処理方法。
［９］前記曝気処理後の消化汚泥に凝集剤を添加して凝集汚泥を形成し、当該凝集汚泥を脱水処理し、脱水処理により発生する脱水分離水を前記希釈液として用いることを特徴とする［８］に記載の有機性汚泥の処理方法。
［１０］前記凝集剤としてポリ硫酸第二鉄、塩化第二鉄、ＰＡＣ（ポリ塩化アルミニウム）又は硫酸バンドを用いることを特徴とする［８］に記載の有機性汚泥の処理方法。
［１１］２５ｇ／Ｌ以上のＴＳ濃度と、当該ＴＳ濃度よりも５ｇ／Ｌ以上少ないＳＳ濃度と、を有する難脱水性消化汚泥を形成する嫌気性処理槽と、
当該難脱水性消化汚泥に酸素含有気体を曝気させる曝気槽と、
曝気処理後の消化汚泥に凝集剤を添加して凝集汚泥を形成する凝集槽と、
当該嫌気性処理槽又は当該凝集槽の撹拌装置の撹拌抵抗に応じて当該曝気槽に供給する酸素含有気体の曝気速度を調整する制御装置と、
当該凝集汚泥を脱水する脱水装置と、
を具備することを特徴とする、有機性汚泥の処理装置。
［１２］前記脱水装置からの脱水分離水を硝化脱窒素する硝化脱窒素槽と、
当該硝化脱窒素槽からの処理水を前記曝気処理後の消化汚泥に添加する希釈液供給配管をさらに具備することを特徴とする、［１１］に記載の有機性汚泥の処理装置。
［１３］前記硝化脱窒素槽からの好気性微生物群含有汚泥を前記曝気槽又は前記曝気槽に流入する前の難脱水性消化汚泥に添加する好気性微生物群含有汚泥供給配管をさらに具備することを特徴とする、［１２］に記載の有機性汚泥の処理装置。
According to the present invention, the following method and apparatus for treating organic sludge are provided.
[1] A method for treating organic sludge after anaerobic treatment, wherein the organic sludge has a TS concentration of 25 g / L or more and an SS concentration of 5 g / L or more less than the TS concentration. It is a hardly dehydratable digested sludge, and before dehydration treatment of the digested sludge, an oxygen-containing gas is passed through the aeration treatment to the hardly dehydrated digested sludge to reduce the viscosity of the hardly dehydrated digested sludge. A method for treating organic sludge, which is characterized in that
[2] The aeration treatment should be performed until the viscosity of the hardly dehydratable digested sludge after the aeration treatment decreases to 200 mPa · s or less when measured at 30 ° C. by a B-type rotary viscometer specified in the sewage test method. The method for treating organic sludge according to [1], characterized in that
[3] The aeration treatment is performed with an aeration intensity of 0.1 m 3 / (m 3 · min) or more and an aeration time of 4 hours or more and 48 hours or less, [1] or [2] Method of treating organic sludge.
[4] The method for treating organic sludge according to [3], wherein the aeration strength is 0.2 m 3 / (m 3 · min) or more.
[5] The oxygen-containing gas used for the aeration treatment is air or air containing an odorous component generated in a treatment facility where an organic sludge to be treated is formed [1] to [[1]. [4] The method for treating organic sludge according to any one of [4].
[6] The organic substance according to any one of [1] to [5], wherein sludge containing aerobic microorganisms is added to the hardly dehydrated digested sludge before the aeration treatment. Sludge treatment method.
[7] The aeration process is performed while maintaining the dissolved oxygen concentration in the hardly dehydratable digested sludge at 1.0 mg / L or less, [1] to [6] Treatment method of organic sludge.
[8] Any one of [1] to [7], wherein the digested sludge after the aeration treatment is diluted by adding a diluent having a TS concentration of 6.0 g / L or less and then dehydrated. The method for treating organic sludge according to
[9] A coagulant is added to the digested sludge after the aeration process to form a coagulated sludge, the coagulated sludge is dehydrated, and dehydrated separated water generated by the dehydration process is used as the diluent. The method for treating organic sludge according to [8].
[10] The method for treating organic sludge according to [8], wherein a polyferric sulfate, ferric chloride, PAC (polyaluminum chloride) or sulfuric acid band is used as the coagulant.
[11] An anaerobic treatment tank for forming a hardly dehydratable digested sludge having a TS concentration of 25 g / L or more and an SS concentration of 5 g / L or more lower than the TS concentration,
An aeration tank for aerating an oxygen-containing gas to the hardly dehydratable digested sludge,
A coagulation tank that forms a coagulated sludge by adding a coagulant to the digested sludge after aeration treatment,
A controller for adjusting the aeration rate of the oxygen-containing gas supplied to the aeration tank according to the stirring resistance of the stirring device of the anaerobic treatment tank or the aggregating tank,
A dehydrator for dehydrating the coagulated sludge,
An apparatus for treating organic sludge, comprising:
[12] A nitrification and denitrification tank for nitrifying and denitrifying the dewatered separated water from the dewatering device,
The treatment apparatus for organic sludge according to [11], further comprising a diluting liquid supply pipe for adding treated water from the nitrification / denitrification tank to the digested sludge after the aeration treatment.
[13] Further comprising an aerobic microbial group-containing sludge supply pipe for adding the aerobic microbial group-containing sludge from the nitrification denitrification tank to the aeration tank or to the hardly dehydrated digestive sludge before flowing into the aeration tank [12] The apparatus for treating organic sludge according to [12].
本発明によれば、嫌気性処理により発生するメタン発酵汚泥などのＴＳ濃度２５〜５０ｇ／Ｌ、ＳＳ濃度１８〜４５ｇ／Ｌ、好ましくは２０〜４０ｇ／Ｌの高濃度で高粘度の難脱水性消化汚泥を低コストで効率的に脱水処理することができる。 According to the present invention, TS concentration of methane fermentation sludge or the like generated by anaerobic treatment is 25 to 50 g / L, SS concentration is 18 to 45 g / L, preferably 20 to 40 g / L. The digested sludge can be efficiently dehydrated at low cost.
本発明の有機性汚泥の処理方法によれば、難脱水性消化汚泥を曝気処理することによって、当該汚泥の粘度が低下し、凝集剤による凝集作用と脱水効率が向上し、薬品コスト及び脱水コストを大幅に低減することができる。汚泥粘度の低減は、曝気処理による粘着質成分の低減によるものと考えられる。 According to the method for treating organic sludge of the present invention, by aeration-treating the hardly dehydratable digested sludge, the viscosity of the sludge is reduced, the coagulant action by the coagulant and the dehydration efficiency are improved, and the chemical cost and the dehydration cost are increased. Can be significantly reduced. The reduction of sludge viscosity is considered to be due to the reduction of sticky components by aeration treatment.
従来は、高粘度の難脱水性消化汚泥を凝集及び脱水処理する際には、希釈により粘度を低下させることが必要であったが、本発明の方法によれば、凝集及び脱水処理の際の希釈が不要となるか、あるいは低希釈率で十分となる。よって、希釈液のコストを削減でき、脱水分離水の浄化のために行われる生物処理工程での分離膜濾過コスト及び下水道放流コストも削減することができる。 Conventionally, when coagulating and dehydrating a highly viscous hardly dehydratable digested sludge, it was necessary to reduce the viscosity by dilution, but according to the method of the present invention, the coagulation and dehydrating treatment is performed. Dilution is unnecessary, or a low dilution rate is sufficient. Therefore, the cost of the diluting liquid can be reduced, and the separation membrane filtration cost and the sewer discharge cost in the biological treatment process performed to purify the dehydrated separated water can also be reduced.
また、従来の高濃度消化汚泥処理において、凝集剤としてポリ硫酸第二鉄などの鉄系無機凝集剤を用いる場合に問題となっていた脱炭酸反応に基づく発泡も著しく低減することができ、凝集槽における発泡制御も可能となる。 Further, in the conventional high-concentration digested sludge treatment, the foaming due to the decarboxylation reaction, which was a problem when using an iron-based inorganic coagulant such as ferric polysulfate as the coagulant, can be significantly reduced. It is also possible to control foaming in the tank.
さらに、本発明の処理方法によって得られる脱水ケーキは、従来の高濃度消化汚泥の脱水ケーキと比較して、含水率を低下させるだけではなく、汚泥の粘着性が低減されることから、脱水ケーキの搬送機器への汚泥付着に伴う移送効率低下、汚泥乾燥設備での乾燥部位への汚泥付着に伴う乾燥効率低下、などの後処理工程で生じていた不具合を解消することもできる。 Further, the dehydrated cake obtained by the treatment method of the present invention, as compared with the dehydrated cake of conventional high-concentration digested sludge, not only lowers the water content, but also reduces the stickiness of the sludge, so that the dehydrated cake It is also possible to eliminate the problems that have occurred in the post-treatment process, such as a decrease in transfer efficiency due to the adhesion of sludge to the transport device and a decrease in drying efficiency due to the adhesion of sludge to the drying site in the sludge drying equipment.
以下、添付図面を参照しながら本発明を詳細に説明するが、本発明はこれらに限定されるものではない。
本発明の有機性汚泥の処理方法は、嫌気性処理後の有機性汚泥を処理する方法であって、当該有機性汚泥は、２５ｇ／Ｌ以上のＴＳ濃度と、当該ＴＳ濃度よりも５ｇ／Ｌ以上少ないＳＳ濃度と、を有する難脱水性消化汚泥であり、当該消化汚泥を脱水処理する前に、酸素含有気体による曝気処理を行ない、当該難脱水性消化汚泥の粘度を低減させることを特徴とする。
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited thereto.
The method for treating organic sludge of the present invention is a method for treating organic sludge after anaerobic treatment, wherein the organic sludge has a TS concentration of 25 g / L or more and 5 g / L higher than the TS concentration. It is a hardly dehydratable digested sludge having a low SS concentration as described above, and is characterized by performing aeration treatment with an oxygen-containing gas before dehydrating the digested sludge to reduce the viscosity of the hardly dehydratable digested sludge. To do.
（１）難脱水性消化汚泥
本発明による処理対象は、２５ｇ／Ｌ以上、好ましくは２５〜６０ｇ／ＬのＴＳ濃度と、当該ＴＳ濃度よりも５ｇ／Ｌ以上少ないＳＳ濃度と、を有する難脱水性消化汚泥である。より好ましくは、ＴＳ濃度２５〜５０ｇ／Ｌ、さらに好ましくは３５〜４５ｇ／Ｌ、ＳＳ濃度１８〜４５ｇ／Ｌ、さらに好ましくは２０〜４０ｇ／Ｌの高濃度で高粘度の難脱水性消化汚泥である。汚泥性状としては、ｐＨ６．５〜８．０、下水試験方法に定められたＢ型回転粘度計で測定した３０℃での汚泥粘度４００〜２０００ｍＰａ・ｓ、好ましくは４００〜１５００ｍＰａ・ｓ、ＳＳに対する粗浮遊物含有率３〜２０ｗｔ％であることが多い。難脱水性消化汚泥は、食品製造残渣、生ごみ、汚泥などの有機性物質を嫌気性処理（メタン発酵処理）する工程から発生する。一般には処理温度３０〜６０℃の中温発酵領域及び高温発酵領域にて、滞留日数（ＨＲＴ）１２〜４０日の条件で運転される完全混合型メタン発酵槽や乾式メタン発酵槽などから排出される汚泥である。
(1) Difficult to dehydrate digested sludge The target to be treated according to the present invention has a TS concentration of 25 g / L or more, preferably 25 to 60 g / L, and an SS concentration of 5 g / L or more less than the TS concentration. It is sexually digested sludge. More preferably, the TS concentration is 25 to 50 g / L, more preferably 35 to 45 g / L, the SS concentration is 18 to 45 g / L, and further preferably 20 to 40 g / L, which is a highly concentrated and highly viscous hardly dehydrated digestive sludge. is there. The sludge properties are pH 6.5 to 8.0, sludge viscosity at 30 ° C. measured by a B-type rotational viscometer specified in the sewage test method is 400 to 2000 mPa · s, preferably 400 to 1500 mPa · s, with respect to SS. Coarse suspended matter content is often 3 to 20 wt%. Hardly dehydrated digested sludge is generated from the process of anaerobic treatment (methane fermentation treatment) of organic substances such as food production residues, food waste, and sludge. Generally, in a medium temperature fermentation region and a high temperature fermentation region of a treatment temperature of 30 to 60 ° C., the exhaust gas is discharged from a completely mixed methane fermentation tank or a dry methane fermentation tank operated under the condition of a residence time (HRT) of 12 to 40 days. It is sludge.
（２）曝気処理
酸素を含む気体で難脱水性消化汚泥を曝気処理して、当該汚泥中に残留する粘着質成分を生物的反応とともに化学的反応で分解させて汚泥粘度を低下させる。硝化脱窒素処理後の余剰汚泥や生物脱臭処理後の汚泥などには、種々の好気性微生物群が高分子成分の分解活性は高くないが多数生存している。これらの好気性微生物群は、嫌気性処理工程において汚泥中に残留する粘着質成分を生育源として摂取し分解することが可能であるため、曝気処理によって部分的に好気性雰囲気とすることによって高分子成分の分解活性を高めることが重要である。曝気処理では、汚泥中に溶解している炭酸ガスの脱炭酸反応が進行するのみでなく、汚泥中の残留有機物と無機物とが架橋作用で結合して生じた粘着物、有機物同士が会合して生じた粘着物、高分子系粘着物が曝気処理による生物的反応及び化学的反応で低減される。特に、消化汚泥中に残留する分子量１００万〜２００万以上の高分子物質が低分子化されることで汚泥粘度が低減する。曝気処理時の温度は１０〜５０℃、ｐＨは７〜９、曝気強度は０．１〜０．３ｍ３／（ｍ３・分）、曝気時間は４〜４８時間が好ましい。曝気強度や処理時間が過大となると、汚泥中の粘着質成分ばかりでなく、汚泥自体の分解が進行して汚泥性状が更に変化して、後段の凝集処理や脱水処理に悪影響を及ぼす。曝気強度が０．１ｍ３／（ｍ３・分）未満では、汚泥粘度が高いため汚泥全体に曝気することが困難である。
(2) Aeration treatment Aeration treatment is applied to the hardly dehydratable digested sludge with a gas containing oxygen, and the sticky component remaining in the sludge is decomposed by a chemical reaction as well as a biological reaction to reduce the sludge viscosity. In surplus sludge after nitrification denitrification treatment and sludge after biological deodorization treatment, various aerobic microbial groups survive, although the decomposition activity of polymer components is not high. These aerobic microorganisms can ingest and decompose the sticky components remaining in the sludge in the anaerobic treatment process as a growth source, so that they can be highly aerated by partially aerobic atmosphere by aeration treatment. It is important to increase the decomposition activity of molecular components. In the aeration process, not only the decarboxylation reaction of carbon dioxide gas dissolved in the sludge progresses, but also the sticky substances and organic substances formed by the residual organic substances and inorganic substances in the sludge bonded by the cross-linking action. The generated sticky substances and polymer-based sticky substances are reduced by biological reactions and chemical reactions due to aeration treatment. In particular, the sludge viscosity is reduced by lowering the molecular weight of the polymer substance having a molecular weight of 1 to 2,000,000 or more remaining in the digested sludge. Aeration temperature during treatment is 10 to 50 ° C., pH is 7-9, aeration intensity is 0.1~0.3m 3 / (m 3 · min), the aeration time is preferably 4 to 48 hours. If the aeration strength and the treatment time are too long, not only the sticky components in the sludge but also the sludge itself will be decomposed and the sludge properties will be further changed, which will adversely affect the coagulation treatment and the dehydration treatment in the subsequent stage. When the aeration strength is less than 0.1 m 3 / (m 3 · min), it is difficult to aerate the whole sludge because the sludge viscosity is high.
曝気に用いる酸素含有気体としては、酸素ガスを含む気体であれば問題なく、難脱水性消化汚泥が形成される処理施設内のごみ受入ピットやごみ選別設備などから発生する悪臭成分を含む低濃度系および高濃度系の臭気ガス、汚水の活性汚泥処理設備から発生する曝気排ガスなどを用いることができる。曝気処理時の汚泥中の溶存酸素（ＤＯ）濃度は１．０ｍｇ／Ｌ以下に維持する。汚泥の酸化還元電位（ＯＲＰ）は多くの場合−４００〜＋１００ｍＶ程度である。本発明において、曝気処理は、汚泥ｐＨ７．５〜９．５、下水試験方法に定められたＢ型回転粘度計による３０℃での測定で汚泥粘度２００ｍＰａ・ｓ以下となるまで行うことが好ましい。 As the oxygen-containing gas used for aeration, there is no problem if it is a gas containing oxygen gas, and a low concentration containing a foul-smelling component generated from the waste receiving pit or the waste sorting facility in the treatment facility where the hardly dehydratable digested sludge is formed. System and high-concentration odor gas, aeration exhaust gas generated from the activated sludge treatment facility of sewage, and the like can be used. The dissolved oxygen (DO) concentration in sludge during aeration treatment is maintained at 1.0 mg / L or less. In many cases, the redox potential (ORP) of sludge is about -400 to +100 mV. In the present invention, the aeration treatment is preferably carried out until the sludge viscosity becomes 200 mPa · s or less when measured at 30 ° C. with a sludge pH of 7.5 to 9.5 and a type B rotational viscometer specified in the sewage test method.
また、曝気処理による生物的反応を促進する上では、曝気処理を行う前に、難脱水性消化汚泥に、好気性微生物群を含む汚泥（以下「好気性微生物群含有汚泥」という）を添加することが好ましく、粘着質成分を積極的に分解させ汚泥粘度を低下させることが可能である。添加することができる汚泥としては、硝化脱窒素工程から得られる活性汚泥の余剰濃縮汚泥、あるいは堆肥化汚泥、生物脱臭の汚泥などの好気性微生物群含有汚泥が好ましい。好気性微生物群含有汚泥の添加量は、その汚泥濃度にもよるが、曝気槽での汚泥滞留時間等を考慮して嫌気性消化汚泥量の５〜２０％、好ましくは５〜１０％程度が好ましい。好気性微生物群含有汚泥の添加量が２０％を大きく上回ると、曝気槽での汚泥滞留時間が短くなるために、粘着質成分の分解反応が進行しにくくなり、併せて、難脱水性の余剰汚泥率が高くなり、脱水性能が低下する。したがって、好気性微生物群含有汚泥の添加量は、微生物が粘着質成分の分解に寄与できる範囲にすることが好ましい。 In addition, in order to accelerate the biological reaction by aeration treatment, sludge containing aerobic microbial groups (hereinafter referred to as "aerobic microbial group-containing sludge") is added to the hardly dehydratable digested sludge before the aeration treatment. It is preferable that the viscous component be positively decomposed to reduce the viscosity of sludge. As the sludge that can be added, excess concentrated sludge of activated sludge obtained from the nitrification and denitrification step, or aerobic microbial group-containing sludge such as composted sludge and biological deodorant sludge is preferable. The addition amount of the aerobic microbial group-containing sludge depends on the sludge concentration, but is 5 to 20%, preferably about 5 to 10% of the amount of the anaerobic digested sludge in consideration of the sludge retention time in the aeration tank. preferable. If the amount of sludge containing aerobic microorganisms significantly exceeds 20%, the sludge retention time in the aeration tank will be shortened and the decomposition reaction of the sticky components will not proceed easily. The sludge rate increases and the dewatering performance decreases. Therefore, the addition amount of the aerobic microbial group-containing sludge is preferably within the range in which the microorganisms can contribute to the decomposition of the sticky component.
（３）凝集処理
曝気処理した消化汚泥に凝集剤を添加して凝集フロックを形成させ、凝集フロックを脱水処理する。
(3) Coagulation treatment A flocculant is added to the aerated digested sludge to form floc, and the floc is dehydrated.
凝集剤としては、特に限定されないが、高分子凝集剤が用いられる。また、ポリ硫酸第二鉄または硫酸バンド、ＰＡＣ等の無機系凝集助剤と高分子凝集剤の併用も分離液の清澄度を高めるために有効な場合がある。高分子凝集剤としては、カチオン系、アニオン系、両性系、等が挙げられ、例えば、アミジン系凝集剤、アクリルアミド系凝集剤、アクリル酸系凝集剤等が挙げられる。また、比較的安価なカチオンポリマー系凝集剤、例えば、アクリル酸エステル系、メタアクリル酸エステル系、アニオン度よりもカチオン度が高い両性系等を用いることができる。アクリル酸エステル系凝集剤としては、分子量が３００万〜６００万程度が好ましい。汚泥凝集時の高分子凝集剤の添加率は、汚泥のＴＳ濃度に対して２〜７ｗｔ％が好ましく、２〜５ｗｔ％程度が更に好ましい。本凝集処理によって、直径、すなわちフロック径が数ミリ程度であり、沈降分離性が高い凝集フロックを形成することができる。 The aggregating agent is not particularly limited, but a polymer aggregating agent is used. Further, the combined use of an inorganic flocculant such as polyferric sulfate or a sulfuric acid band, PAC and the like and a polymer flocculant may be effective for increasing the clarity of the separated liquid. Examples of the polymer flocculant include cation type, anion type, amphoteric type, and the like. Examples thereof include amidine type coagulant, acrylamide type coagulant, acrylic acid type coagulant and the like. Further, a relatively inexpensive cationic polymer-based coagulant, such as an acrylic acid ester-based agent, a methacrylic acid ester-based agent, an amphoteric system having a higher cation degree than the anion degree, or the like can be used. The acrylic acid ester-based coagulant preferably has a molecular weight of about 3,000,000 to 6,000,000. The addition rate of the polymer flocculant at the time of coagulating sludge is preferably 2 to 7 wt% and more preferably about 2 to 5 wt% with respect to the TS concentration of sludge. By this coagulation treatment, it is possible to form coagulated flocs having a diameter, that is, a floc diameter of about several millimeters and having high sedimentation and separability.
凝集処理の前に、曝気処理した消化汚泥を希釈してもよく、凝集剤注入率を低減することができる。希釈された消化汚泥のＭアルカリ度は、４０００ｍｇ／Ｌ以下が好ましく、２５００ｍｇ／Ｌ以下が更に好ましい。希釈された消化汚泥の電気伝導度は１２００ｍＳ／ｍ以下に調整することが好ましく、７５０ｍＳ／ｍ以下に調整することが更に好ましい。希釈液としては、通常の飲用水等の他、凝集作用及び脱水作用に影響を与えない性状、たとえば溶解性成分濃度が低いプロセス水、あるいは脱水処理後にさらに生物処理を行う高次処理施設においては生物処理に影響しない性状、たとえばｐＨ５〜９、ＮＨ４−Ｎ１０００ｍｇ／Ｌ以下、ヘキサン抽出物質５００ｍｇ／Ｌ以下であれば、処理プラント内のプロセス水を用いることができる。具体的には、活性汚泥処理水、生物脱臭装置廃液などの生物処理水、汚泥脱水処理により排出される脱水分離水、ボイラ排水、場内洗浄排水、コンポスト化凝縮排水、雑排水などを使用することができる。
The aerated digested sludge may be diluted before the coagulation treatment, and the coagulant injection rate can be reduced. The M alkalinity of the diluted digested sludge is preferably 4000 mg / L or less, more preferably 2500 mg / L or less. The electric conductivity of the diluted digested sludge is preferably adjusted to 1200 mS / m or less, more preferably 750 mS / m or less. As the diluting liquid, in addition to ordinary drinking water, properties that do not affect the aggregating action and the dehydrating action, such as process water having a low concentration of soluble components, or high-level treatment facilities that further perform biological treatment after dehydration treatment, are used. Process water in the treatment plant can be used as long as it does not affect biological treatment, such as
（４）濃縮処理
凝集処理により形成された凝集フロックを脱水処理前に固液分離して消化汚泥濃縮物としてから脱水処理してもよい。
(4) Concentration treatment The flocculation flocs formed by the coagulation treatment may be subjected to solid-liquid separation before the dehydration treatment to obtain a digested sludge concentrate, and then the dehydration treatment.
濃縮処理により、凝集フロックは汚泥濃縮物と分離液とに固液分離される。ＴＳ濃度８〜１２ｗｔ％に濃縮された汚泥は、より効率的に脱水処理することができる。
（５）脱水処理
凝集処理、又は凝集処理及び濃縮処理された消化汚泥の凝集フロックを脱水ケーキと分離水とに固液分離する。
The flocculation flocs are solid-liquid separated into a sludge concentrate and a separation liquid by the concentration treatment. The sludge concentrated to a TS concentration of 8 to 12 wt% can be dehydrated more efficiently.
(5) Dehydration treatment Aggregated flocs of digested sludge that have been subjected to coagulation treatment or coagulation treatment and concentration treatment are subjected to solid-liquid separation into dehydrated cake and separated water.
本発明の処理方法により得られる脱水ケーキの含水率は７８〜８２％以下と低含水率であるため、コンポスト化、炭化、燃料化などの再資源化が可能である。分離水は、ＳＳ濃度１００〜２０００ｍｇ／Ｌ、Ｍアルカリ度１０００〜２０００ｍｇ／Ｌ、電気伝導度２００〜５００ｍＳ／ｍとなるため、消化汚泥の希釈液として用いることができる。 Since the water content of the dehydrated cake obtained by the treatment method of the present invention is as low as 78 to 82% or less, it can be recycled as compost, carbonized, or fueled. The separated water has an SS concentration of 100 to 2000 mg / L, an M alkalinity of 1000 to 2000 mg / L, and an electric conductivity of 200 to 500 mS / m, and thus can be used as a diluting solution of digested sludge.
本発明の有機性汚泥の処理装置は、２５ｇ／Ｌ以上のＴＳ濃度と、当該ＴＳ濃度よりも５ｇ／Ｌ以上少ないＳＳ濃度と、を有する難脱水性消化汚泥を形成する嫌気性処理槽と、当該難脱水性消化汚泥に酸素含有気体を曝気させる曝気槽と、曝気処理後の消化汚泥に凝集剤を添加して凝集汚泥を形成する凝集槽と、当該嫌気性処理槽又は当該凝集槽の撹拌装置の撹拌抵抗に応じて当該曝気槽に供給する酸素含有気体の曝気速度を調整する制御装置と、当該凝集汚泥を脱水する脱水装置と、を具備することを特徴とする。図４を参照しながら、各構成要素について説明する。 The organic sludge treatment device of the present invention is an anaerobic treatment tank for forming a hardly dehydratable digested sludge having a TS concentration of 25 g / L or more and an SS concentration of 5 g / L or more lower than the TS concentration, An aeration tank for aerating an oxygen-containing gas to the hardly dehydratable digested sludge, a coagulation tank for forming a coagulated sludge by adding a coagulant to the digested sludge after aeration treatment, and stirring of the anaerobic treatment tank or the coagulation tank It is characterized by comprising a control device for adjusting the aeration rate of the oxygen-containing gas supplied to the aeration tank according to the stirring resistance of the device, and a dewatering device for dewatering the coagulated sludge. Each component will be described with reference to FIG.
（Ａ）嫌気性処理槽
廃棄物系バイオマス処理設備や下水処理施設などで一般に用いられる完全混合型メタン発酵槽や乾式メタン発酵槽など、公知の嫌気性処理槽を制限なく用いることができる。
(A) Anaerobic treatment tank A known anaerobic treatment tank, such as a completely mixed methane fermentation tank or a dry methane fermentation tank, which is generally used in a waste-based biomass treatment facility or a sewage treatment facility, can be used without limitation.
通常、嫌気性処理槽は、槽内液の均質化や温度分布の均一化とともに、スカムの発生を防止するために撹拌手段を具備している。本発明では機械撹拌方式が最も効率的であるが、設備環境や処理条件に応じてポンプ撹拌方式やガス撹拌方式を使用してもよい。さらに、これらの要件を備えた水密かつ気密な構造の発酵処理槽であれば鉄筋コンクリート製または鋼板製のいずれでもよい。また、嫌気性処理槽は、対象バイオマスを可溶化および酸発酵処理する可溶化・酸発酵処理槽と、該槽での処理物を発酵処理する嫌気性処理槽と、を含む構成としてもよい。 Usually, the anaerobic treatment tank is equipped with a stirring means for preventing the generation of scum as well as the homogenization of the liquid in the tank and the homogenization of the temperature distribution. In the present invention, the mechanical stirring method is the most efficient, but a pump stirring method or a gas stirring method may be used depending on the facility environment and processing conditions. Further, any fermented concrete or steel plate may be used as long as it is a watertight and airtight fermentation treatment tank having these requirements. In addition, the anaerobic treatment tank may be configured to include a solubilization / acid fermentation treatment tank for solubilizing and acid-fermenting the target biomass, and an anaerobic treatment tank for fermenting the processed product in the tank.
（Ｂ）曝気槽
水処理施設などで一般に用いられる曝気槽を制限なく用いることができ、難脱水性消化汚泥（メタン発酵汚泥など）を導入する手段、酸素含有気体を消化汚泥中に導入するためのブロワなどの曝気手段又は散気手段、曝気汚泥の引き抜き手段を備え、運転管理する計測機器としてｐＨ計、ＤＯ計、ＯＲＰ計、粘度計を備えることが好ましい。曝気手段は、曝気槽底部から曝気槽内の難脱水性消化汚泥中に気泡を導入できるように設けることが好ましい。
(B) Aeration tank An aeration tank that is commonly used in water treatment facilities can be used without limitation, means for introducing hardly dehydratable digestive sludge (methane fermentation sludge, etc.), and for introducing oxygen-containing gas into digestive sludge. It is preferable to provide an aeration means or an air diffusion means such as a blower, and an aeration sludge extraction means, and to provide a pH meter, a DO meter, an ORP meter, and a viscometer as measuring instruments for operation management. The aeration means is preferably provided so that air bubbles can be introduced from the bottom of the aeration tank into the hardly dehydratable digested sludge in the aeration tank.
さらに、曝気槽の前段に、高速分散機などの汚泥分散装置を設けてもよい。この場合には、難脱水性消化汚泥を均質に分散したスラリー状態を保持することができ、曝気槽容量を小型化することができる。 Further, a sludge dispersing device such as a high speed dispersing machine may be provided in the preceding stage of the aeration tank. In this case, the slurry state in which the hardly dehydratable digested sludge is uniformly dispersed can be maintained, and the aeration tank capacity can be reduced.
（Ｄ）制御装置
嫌気性処理槽または凝集槽及び曝気槽には、消化汚泥の粘度に応じて酸素含有気体の曝気速度を調整する制御装置が電気的に連結されている。通常、消化汚泥の粘度の計測は、試料を採取して回転粘度計で計測するため、自動連続計測を行うことができない。本発明では、嫌気性処理槽または凝集槽の撹拌装置の撹拌抵抗に基づいて、嫌気性処理槽または凝集槽内の消化汚泥の粘度を推測し、曝気処理中の消化汚泥の粘度を推測して、曝気速度を調整する。具体的には、たとえば、嫌気性処理槽または凝集槽の撹拌装置に電流検出部を設け、検出された電流値から撹拌抵抗を求め、曝気槽内の難脱水性消化汚泥の粘度変動を推定して、所定の曝気速度に調整する。
(D) Control Device A control device that adjusts the aeration rate of the oxygen-containing gas according to the viscosity of the digested sludge is electrically connected to the anaerobic treatment tank or the coagulation tank and the aeration tank. Normally, in measuring the viscosity of digested sludge, a continuous viscometer cannot be used because a sample is taken and measured with a rotary viscometer. In the present invention, based on the stirring resistance of the stirring device of the anaerobic treatment tank or the flocculation tank, the viscosity of the digested sludge in the anaerobic treatment tank or the flocculation tank is estimated, and the viscosity of the digested sludge during aeration treatment is estimated. , Adjust the aeration rate. Specifically, for example, a current detector is provided in the stirring device of the anaerobic treatment tank or the flocculation tank, the stirring resistance is calculated from the detected current value, and the viscosity fluctuation of the hardly dehydratable digested sludge in the aeration tank is estimated. And adjust to a predetermined aeration rate.
（Ｅ）凝集槽
水処理施設などで一般に用いられる凝集槽を制限なく用いることができる。凝集槽には、曝気槽にて曝気処理した後の消化汚泥を供給する曝気処理後汚泥供給配管、当該汚泥に対して凝集剤を添加する凝集剤供給配管、凝集処理により形成される凝集フロックを含む凝集汚泥を濃縮槽に送る凝集汚泥配管が連結されている。
(E) Coagulation tank A coagulation tank generally used in water treatment facilities can be used without limitation. The coagulation tank is equipped with an aeration-treated sludge supply pipe for supplying digested sludge after aeration treatment in the aeration tank, a coagulant supply pipe for adding a coagulant to the sludge, and a floc floc formed by the coagulation treatment. The coagulated sludge pipe for sending the coagulated sludge containing it to the concentration tank is connected.
（Ｆ）濃縮槽
凝集槽にて形成された凝集フロックを固液分離して濃縮凝集フロックを形成する固液分離装置を備える。固液分離装置としては、特に限定されず、重力濃縮法が適用される単なる槽、遠心濃縮法が適用される遠心分離機、浮上濃縮法が適用される分離機、スクリーンを用いた分離機等が挙げられる。中でも、液体成分を通過させる多数のスリットを形成したスリット板と、スリット板上に周面を突出せしめた多数の円板と、を備えるスリット型濃縮機が好ましい。スリット型濃縮機は、例えば、スリット板で受け止められた処理物は、処理物排出方向に偏心回転するスリット板上の多数の円板によってスリット板上を排出側に送られ、この過程でスリットと円板との隙間から液体成分が落下して濾過され、処理物中の固体成分は分離捕集される。さらに、スリット板の上面に近接して処理物の排出方向に回転し、スリット板上の捕集物を圧搾して濃縮する背圧板を上記スリット板上に設けた機械構造も好ましく用いることができる。
(F) Concentration tank A solid-liquid separation device is provided which solid-liquid separates the flocculation flocs formed in the flocculation tank to form concentrated flocculation flocs. The solid-liquid separation device is not particularly limited, a simple tank to which the gravity concentration method is applied, a centrifugal separator to which the centrifugal concentration method is applied, a separator to which the flotation concentration method is applied, a separator using a screen, etc. Is mentioned. Above all, a slit-type concentrator provided with a slit plate having a large number of slits for allowing liquid components to pass therethrough and a large number of discs having a circumferential surface projected on the slit plate is preferable. The slit type concentrator, for example, the processed product received by the slit plate is sent to the discharge side on the slit plate by a large number of discs on the slit plate that are eccentrically rotated in the discharged direction of the processed product, and in this process, The liquid component drops from the gap between the disc and the disc, and is filtered, and the solid component in the treated product is separated and collected. Furthermore, a mechanical structure in which a back pressure plate that rotates in the discharge direction of the processed object close to the upper surface of the slit plate and squeezes and concentrates the collected substances on the slit plate is provided on the slit plate can also be preferably used. .
（Ｇ）脱水装置
凝集槽からの凝集フロック、又は濃縮槽からの濃縮凝集フロックを受け入れ、脱水する脱水装置を備える。脱水装置としては特に限定されず、凝集フロック又は濃縮凝集フロックへ応力を付与する手段と、分離液を透過し、消化汚泥凝集物を保持するろ過手段を具備することが好ましい。応力を付与する手段としては、プレス、遠心等が挙げられる。ろ過手段としては、開孔径が０．１〜２．５ｍｍのスクリ−ン等が挙げられる。
(G) Dehydration Device A dehydration device that receives and dehydrates the flocculation flocs from the flocculation tank or the concentrated flocculation flocs from the concentration tank is provided. The dewatering device is not particularly limited, and it is preferable to provide a means for applying a stress to the flocculation flocs or concentrated flocculation flocs and a filtration means for permeating the separated liquid and holding the digested sludge flocculates. Examples of means for applying stress include pressing and centrifugation. Examples of the filtering means include a screen having an opening diameter of 0.1 to 2.5 mm.
（Ｈ）硝化脱窒素槽
脱水装置からの脱水分離水を硝化脱窒素する硝化脱窒素槽を備えていてもよい。水処理施設などで一般に用いられる循環式硝化脱窒素槽、高負荷脱窒素槽、膜分離式高負荷硝化脱窒素槽を制限なく用いることができる。循環式硝化脱窒素槽の場合、嫌気的環境の脱窒槽、及び曝気等による好気的環境の硝酸化槽の２槽を設けてもよい。たとえば、硝酸化槽において好気性微生物反応で生成された硝酸塩を脱窒槽に戻して、嫌気性又は通性嫌気性微生物反応で脱窒素する方式で、循環法による硝化・脱窒を行うことができる。膜分離高負荷脱窒素槽の場合、硝化脱窒素槽は嫌気部と好気部に分割され、生物浮遊法を採用し、活性汚泥や凝集汚泥の固液分離を限外ろ過膜で処理を行うことができる。
(H) Nitrification and denitrification tank A nitrification and denitrification tank for nitrifying and denitrifying the dehydrated separated water from the dehydrator may be provided. A circulating type nitrification denitrification tank, a high load denitrification tank, and a membrane separation type high load nitrification denitrification tank that are generally used in water treatment facilities can be used without limitation. In the case of the circulation type nitrification denitrification tank, two tanks may be provided, a denitrification tank in an anaerobic environment and a nitrification tank in an aerobic environment by aeration or the like. For example, it is possible to carry out nitrification / denitrification by a circulation method by returning nitrates generated by aerobic microbial reaction in a nitrification tank to the denitrification tank and denitrifying by anaerobic or facultative anaerobic microbial reaction. . In the case of a membrane separation high load denitrification tank, the nitrification denitrification tank is divided into an anaerobic part and an aerobic part, and the biofloating method is adopted to perform solid-liquid separation of activated sludge and coagulated sludge with an ultrafiltration membrane. be able to.
（Ｉ）希釈液供給配管
硝化脱窒素槽からの処理水を曝気処理後の消化汚泥に添加する希釈液供給配管を備えていてもよい。希釈液供給配管は、曝気槽と凝集槽とを連結する配管に連結されていることが好ましい。希釈液供給配管には、脱水槽からの脱水分離水を送液する配管が連結されていてもよい。
(I) Diluting liquid supply pipe A diluting liquid supply pipe may be provided for adding the treated water from the nitrification denitrification tank to the digested sludge after the aeration treatment. The diluent supply pipe is preferably connected to a pipe connecting the aeration tank and the aggregation tank. A pipe for sending the dehydrated separated water from the dehydration tank may be connected to the diluent supply pipe.
（Ｊ）好気性微生物群含有汚泥供給配管
硝化脱窒素槽からの好気性微生物群含有汚泥を汚泥引き抜きポンプで引き抜いて、曝気槽又は曝気槽に流入する前の難脱水性消化汚泥に添加する好気性微生物群含有汚泥供給配管を備えていてもよい。好気性微生物群含有汚泥供給配管は、嫌気性処理槽と曝気槽とを連結する配管に連結されていることが好ましい。
(J) Pipe for supplying aerobic microbial group-containing sludge It is preferable that the aerobic microbial group-containing sludge from the nitrification denitrification tank be drawn by a sludge drawing pump and added to the aeration tank or the hardly dehydrated digested sludge before flowing into the aeration tank. An aerobic microorganisms-containing sludge supply pipe may be provided. The aerobic microbial group-containing sludge supply pipe is preferably connected to a pipe connecting the anaerobic treatment tank and the aeration tank.
次に、実施例及び比較例により、本発明を具体的に説明する。
［実施例１］
表１に示すメタン発酵汚泥（難脱水性消化汚泥）を用いて、表２に示す８通りの処理試験を行って曝気処理による脱水性改善効果を確認した。曝気処理では、２０リットルタンクにメタン発酵汚泥１２リットルを投入し、温度３０℃、曝気強度０．２５ｍ３／（ｍ３・分）で連続曝気した。汚泥中のＤＯ濃度は１．０ｍｇ／Ｌ以下であった。試験４では、活性汚泥の余剰濃縮汚泥（ｐＨ７．６、ＳＳ １３，７００ｍｇ／Ｌ、ＮＨ４−Ｎ １．４ｍｇ／Ｌ）１.０リットルを投入して連続曝気した。比較のため、熱処理、水酸化ナトリウムによるアルカリ処理、及び硫酸による酸処理での脱水性改善効果も確認した。
Next, the present invention will be specifically described with reference to Examples and Comparative Examples.
[Example 1]
Using the methane fermented sludge shown in Table 1 (difficult to dehydrate digested sludge), eight treatment tests shown in Table 2 were conducted to confirm the effect of improving the dehydration by aeration treatment. In the aeration process, 12 liters of methane fermentation sludge was put into a 20 liter tank and continuously aerated at a temperature of 30 ° C. and an aeration strength of 0.25 m 3 / (m 3 · min). The DO concentration in the sludge was 1.0 mg / L or less. In
熱処理は、１リットル三角フラスコにメタン発酵汚泥５００ｍＬを投入し、ウォーターバス（温度５０℃又は８０℃）で２時間、熱処理した（比較試験１及び２）。
酸処理は、１リットル三角フラスコにメタン発酵汚泥５００ｍＬを投入し、５％濃度の硫酸溶液でｐＨ６に調整後、室温で６時間静置した（比較試験３）。
Regarding the heat treatment, 500 mL of methane fermentation sludge was put into a 1 liter Erlenmeyer flask and heat treated in a water bath (
For the acid treatment, 500 mL of methane fermentation sludge was placed in a 1-liter Erlenmeyer flask, pH was adjusted to 6 with a 5% sulfuric acid solution, and the mixture was allowed to stand at room temperature for 6 hours (Comparative Test 3).
アルカリ処理は、酸処理と同様、１リットル三角フラスコにメタン発酵汚泥５００ｍＬを投入し、１０％濃度の水酸化ナトリウム水溶液でｐＨ９に調整後、室温で６時間静置した（比較試験４）。
In the alkali treatment, like the acid treatment, 500 mL of methane fermentation sludge was placed in a 1-liter Erlenmeyer flask, adjusted to
各分析項目は以下の分析方法に拠った。
・ＴＳ（Total solids、全蒸発残留物）；105℃蒸発残留物重量（JIS K 0102）
・ＶＳ（Volatile total solids、強熱減量）；600℃強熱減量（JIS K 0102）
・ＳＳ（Suspended solids、懸濁物質）；遠心分離機による回転数3,000rpm,10分間での沈殿物重量（JIS K 0102）
・ＶＳＳ（Volatile suspended solids、揮発性懸濁物質）；懸濁物質の600℃強熱減量（JIS K 0102）
・Ｍアルカリ度；遠心分離機による回転数3,000rpm,3分間での上澄液を0.1mol/Lの塩酸溶液でpH4.8まで滴定（下水試験方法）
・コロイド荷電量；汚泥の表面荷電量、コロイド滴定法により当量を測定（下水試験方法）
・粗浮遊物含有量；呼び寸法７４μｍふるいでの残留物の強熱減量分析（下水試験方法）
・汚泥粘度；Ｂ型回転粘度計を用いて３０℃で測定（下水試験方法）
・脱水試験；カチオン性高分子凝集剤エバグロースCS-374Dを用いた。脱水試験はベルトプレス式脱水機を用いた（ろ布緊張力４．９ｋＮ／ｍ、ろ布スピード１．０ｍ／分）。
・粘り感；脱水汚泥を掌で触った際の汚泥粘着性（粘り感）を３段階評価（なし：さらさらで粘り感なし、弱：粘り感ややあり、強：掌に付着する強い粘り感あり）
Each analysis item was based on the following analysis method.
・ TS (Total solids): 105 ℃ evaporation residue weight (JIS K 0102)
・ VS (Volatile total solids): 600 ℃ ignition loss (JIS K 0102)
・ SS (Suspended solids); Weight of sediment by centrifuge at 3,000 rpm for 10 minutes (JIS K 0102)
・ VSS (Volatile suspended solids); 600 ℃ ignition loss of suspended matter (JIS K 0102)
・ M alkalinity; Titrate the supernatant with a centrifuge at 3,000 rpm for 3 minutes to pH 4.8 with 0.1 mol / L hydrochloric acid solution (sewage test method)
・ Collage charge amount: Surface charge amount of sludge, equivalent amount is measured by colloid titration method (sewage test method)
・ Rough suspended matter content; Ignition weight loss analysis of residue on nominal size 74μm sieve (sewage test method)
・ Sludge viscosity; measured at 30 ° C using B-type rotational viscometer (sewage test method)
Dehydration test: Cationic polymer flocculant Ebagrose CS-374D was used. For the dehydration test, a belt press type dehydrator was used (filter cloth tension force 4.9 kN / m, filter cloth speed 1.0 m / min).
-Thickness: Sludge adhesion (stickiness) when touching dehydrated sludge with the palm is evaluated in 3 levels (None: smooth and non-sticky, weak: slightly sticky, strong: strong stickiness on the palm) )
［実施例２］
表１に示すメタン発酵汚泥を用いて、曝気強度０．１ｍ３／（ｍ３・分）、０．２ｍ３／（ｍ３・分）、０．３ｍ３／（ｍ３・分）の３系列で連続曝気処理し、汚泥粘度の経時的変化を調べた。曝気処理時の汚泥温度は２２〜２７℃、ＤＯ濃度は１．０ｍｇ／Ｌ以下であった。
試験結果を表４及び図５に示す。曝気強度に比例して、また、処理時間と共に汚泥粘度は低下することが分かった。
[Example 2]
Using the methane fermentation sludge shown in Table 1, aeration strength of 0.1 m 3 / (m 3 · min), 0.2 m 3 / (m 3 · min), 0.3 m 3 / (m 3 · min) 3 Continuous aeration treatment was carried out in series to examine the change with time of the sludge viscosity. The sludge temperature during the aeration process was 22 to 27 ° C, and the DO concentration was 1.0 mg / L or less.
The test results are shown in Table 4 and FIG. It was found that the sludge viscosity decreased in proportion to the aeration strength and with the treatment time.
実施例１および実施例２の試験結果より、メタン発酵汚泥を曝気処理することで汚泥粘度は低下し、脱水性が改善されると言える。特に、曝気強度０．３ｍ３／（ｍ３・分）の場合には、わずか４時間で汚泥粘度（３０℃）が２００ｍＰａ・ｓ未満となり、１８時間で１００ｍＰａ・ｓ未満となる。一方、曝気時間が長くなると再び汚泥粘度が上昇する傾向が見られるため、曝気時間は４時間〜８０時間、好ましくは４時間〜４８時間、より好ましくは１８時間〜４８時間程度、特に好ましくは２０時間〜３０時間である。曝気強度が０．２ｍ３／（ｍ３・分）の場合にも同様の傾向が認められ、汚泥粘度が２００ｍＰａ・ｓ未満を達成する曝気時間は１５時間〜８０時間であり、曝気時間としては１８時間〜５０時間がより好ましい。曝気強度が０．１ｍ３／（ｍ３・分）の場合には、汚泥粘度２００ｍＰａ・ｓ未満を達成するまでに１９時間程度が必要となり、曝気時間は長くなる傾向が認められ、４８時間程度で汚泥粘度１００ｍＰａ・ｓ以下となる。いずれの曝気強度においても曝気時間を３０時間より長期化しても汚泥粘度低下効果はほぼ一定となる。したがって、本実施例によれば、曝気強度０．２ｍ３／（ｍ３・分）〜０．３ｍ３／（ｍ３・分）、曝気時間４〜４８時間、好ましくは１０〜４０時間程度が、難脱水性消化汚泥の粘度低下に極めて効果的であるといえる。
From the test results of Example 1 and Example 2, it can be said that the aeration treatment of the methane fermentation sludge lowers the sludge viscosity and improves the dehydration property. In particular, when the aeration strength is 0.3 m 3 / (m 3 · min), the sludge viscosity (30 ° C.) is less than 200 mPa · s in just 4 hours and less than 100 mPa · s in 18 hours. On the other hand, when the aeration time becomes longer, the sludge viscosity tends to increase again, so the aeration time is 4 hours to 80 hours, preferably 4 hours to 48 hours, more preferably about 18 hours to 48 hours, and particularly preferably 20 hours. Hours to 30 hours. The same tendency is observed when the aeration strength is 0.2 m 3 / (m 3 · min), and the aeration time for achieving a sludge viscosity of less than 200 mPa · s is 15 to 80 hours. More preferably 18 hours to 50 hours. When the aeration strength is 0.1 m 3 / (m 3 · min), it takes about 19 hours to reach a sludge viscosity of less than 200 mPa · s, and the aeration time tends to be longer, about 48 hours. The sludge viscosity becomes 100 mPa · s or less. At any aeration intensity, the sludge viscosity reducing effect is almost constant even if the aeration time is made longer than 30 hours. Therefore, according to this embodiment, the aeration intensity 0.2m 3 / (m 3 · min) ~0.3m 3 / (m 3 · min),
［実施例３］
（ａ）ＴＳ濃度３０ｇ／Ｌ、ＳＳ濃度１８ｇ／Ｌ、（ｂ）ＴＳ濃度３８ｇ／Ｌ、ＳＳ濃度１９ｇ／Ｌ、（ｃ）ＴＳ濃度４４ｇ／Ｌ、ＳＳ濃度３０ｇ／Ｌの３種類の高濃度消化（メタン発酵）汚泥を用いて、曝気強度０．２４ｍ３／（ｍ３・分）の条件で連続曝気処理し、汚泥粘度（３０℃）の経時的変化を調べた。ＤＯ濃度は１．０ｍｇ／Ｌ以下であった。試験結果を表５及び図６に示す。メタン発酵汚泥のＴＳ濃度４４ｇ／Ｌ、汚泥粘度１６００ｍＰａ・ｓの高濃度汚泥でも、２４時間の曝気処理によって２００ｍＰａ・ｓにまで汚泥粘度が低下することが分かった。
[Example 3]
(A) TS concentration 30 g / L, SS concentration 18 g / L, (b) TS concentration 38 g / L, SS concentration 19 g / L, (c) TS concentration 44 g / L, SS concentration 30 g / L, three types of high concentration Using digested (methane fermentation) sludge, continuous aeration treatment was performed under the condition of aeration strength of 0.24 m 3 / (m 3 · min), and the change with time of sludge viscosity (30 ° C.) was examined. The DO concentration was 1.0 mg / L or less. The test results are shown in Table 5 and FIG. It was found that even with a high-concentration sludge having a TS concentration of 44 g / L and a sludge viscosity of 1600 mPa · s, the sludge viscosity decreased to 200 mPa · s by the aeration treatment for 24 hours.
汚泥（ａ）の曝気時間０（ｈ）、６（ｈ）及び１２（ｈ）の各試料について、ＧＰＣ（ゲルパーミエーションクロマトグラフ）による分子量分布測定を行った。汚泥試料を１０倍希釈後、０．４５μｍフィルターでろ過したろ液試料を分離カラム（東ソー製ＴＳＫｇｅｌ ＧＭＰＷＸＬ）に導入し、ＲＩ検出器（示差屈折率検出）でＧＰＣ分析を行った。高分子物質の標準物質としてプルラン（平均分子量２３５万、１０．７万、０．６万の３種類）を用いた。分析条件を下記表５に示す。 The molecular weight distribution measurement by GPC (gel permeation chromatograph) was performed for each sample of aeration time 0 (h), 6 (h) and 12 (h) of the sludge (a). After diluting the sludge sample by 10 times, the filtrate sample filtered with a 0.45 μm filter was introduced into a separation column (TSKgel GMPWXL manufactured by Tosoh Corporation), and GPC analysis was performed with an RI detector (differential refractive index detection). Pullulan (three kinds having an average molecular weight of 2,350,000, 107,000, and 60,000) was used as a standard substance of the polymer substance. The analysis conditions are shown in Table 5 below.
分析結果のクロマトグラフを図７に示す。図中、（１）は曝気０時間（ｈｒ）の試料、（２）は曝気６時間（ｈｒ）の試料、（３）は曝気１２時間（ｈｒ）の試料である。なお、図７はすべての結果を比較するために便宜的に並べて示しており、曝気１２時間（ｈｒ）の試料が最も高い位置にあるが測定値が高いことを示すものではない。保持時間（Retention time）５分〜１０分のＲＩ強度（RI Intensity)をベースラインとした場合のＲＩ強度差でピーク強度の高低を認定した。
The chromatograph of the analysis result is shown in FIG. In the figure, (1) is a sample with
分析結果では、保持時間（Retention time）約１３分〜１４分における高分子画分ピークは、曝気時間が長くなるほどＲＩ強度が低くなることから、曝気処理によって高分子物質が分解されていることがわかる。また、いずれの汚泥試料においても、保持時間（Retention time）約１８〜１９分に大きなピークが認められる中、曝気０時間（ｈｒ）試料、曝気６時間（ｈｒ）試料では分子量２３５万付近（プルラン換算）の物質が多く存在するのに対して、曝気１２時間（ｈｒ）試料では分子量１００万付近（プルラン換算）の物質が多く存在しており、曝気処理によって高分子物質が低分子化されていると言える。そして、曝気１２時間（ｈｒ）試料の保持時間（Retention time）約１９分のピークは、曝気０時間（ｈｒ）試料や６時間（ｈｒ）試料よりも鋭利となっていることから、曝気０時間（ｈｒ）試料や曝気６時間（ｈｒ）試料中の高分子物質の分解が進行していることが分かる。
According to the analysis results, the polymer fraction peak at a retention time of about 13 minutes to 14 minutes shows that the RI intensity decreases as the aeration time becomes longer, so that the polymer substance is decomposed by the aeration treatment. Recognize. In addition, in all sludge samples, a large peak was observed at a retention time (Retention time) of about 18 to 19 minutes, while the
表６に曝気処理時間と消化汚泥の粘度との関係、表７に曝気処理時間と分子量との関係を示す。 Table 6 shows the relationship between the aeration treatment time and the viscosity of the digested sludge, and Table 7 shows the relationship between the aeration treatment time and the molecular weight.
［実施例４］
図２のフローシートに基づいて、表８に示す条件にて、種々の食品製造廃棄物を混合してメタン発酵処理を行った。曝気用気体として、原料受入ホッパ、破砕機、選別機、可溶化槽、堆肥化発酵槽などの処理設備からの高濃度臭気含有空気を吸引して使用し、曝気槽底部の散気装置から導入した。
[Example 4]
Based on the flow sheet of FIG. 2, various food manufacturing wastes were mixed under the conditions shown in Table 8 to perform methane fermentation treatment. As aeration gas, high-concentration odor-containing air from processing equipment such as raw material receiving hopper, crusher, sorter, solubilization tank, composting fermentation tank is sucked and used, and introduced from the air diffuser at the bottom of the aeration tank. did.
曝気槽ブロワ運転は、図４に示す制御装置系統図に基づいて、メタン発酵槽の汚泥粘度７２０ｍＰａ・ｓ、曝気槽の汚泥粘度１０５ｍＰａ・ｓでの初期設定時を基準とし、メタン発酵槽撹拌機の初期電流設定の５％以上が検出された際にブロワ強度を３％ずつ段階的に増大させて曝気速度の調整を行う自動制御とした。メタン発酵汚泥及び曝気処理後の汚泥の性状を表９に示す。 The aeration tank blower operation is based on the controller system diagram shown in FIG. 4, and is based on the initial settings of the methane fermentation tank sludge viscosity of 720 mPa · s and the aeration tank sludge viscosity of 105 mPa · s. When 5% or more of the initial current setting was detected, the blower strength was increased stepwise by 3% to adjust the aeration rate automatically. Table 9 shows the properties of the methane fermentation sludge and the sludge after the aeration treatment.
次に、曝気処理後の消化汚泥に凝集剤を添加した後、脱水処理した。脱水処理（１）ではカチオン系高分子凝集剤（水ｉｎｇ（株）エバグロースCS-374D）と無機凝集剤（ポリ鉄）を併用し、脱水処理（２）及び（３）では高分子凝集剤のみ添加した。脱水処理（３）は比較試験で、曝気処理をしなかった難脱水性消化汚泥での脱水試験結果である。脱水処理（１）〜（３）における凝集剤添加率及び脱水処理後の脱水ケーキ性状及び時間当たりの固形物処理量を表１０に示す。 Next, a coagulant was added to the digested sludge after the aeration treatment, and then the dehydration treatment was performed. In the dehydration treatment (1), a cationic polymer flocculant (water ing Co., Ltd. Eggrose CS-374D) and an inorganic flocculant (polyiron) are used together, and in the dehydration treatments (2) and (3), only the polymer flocculant is used. Was added. Dehydration treatment (3) is a comparative test, and is the result of the dehydration test on the hardly dehydratable digested sludge that was not subjected to aeration treatment. Table 10 shows the coagulant addition rate in the dehydration treatments (1) to (3), the properties of the dehydrated cake after the dehydration treatment, and the amount of solid matter treated per hour.
［実施例５］
図３のフローシートに基づいて、硝化脱窒素工程から得られる活性汚泥の余剰濃縮汚泥（好気性微生物群含有汚泥）を曝気槽に導入した点を除いて実施例４と同様に処理を行った。結果を表１１及び１２に示す。
[Example 5]
Based on the flow sheet of FIG. 3, treatment was performed in the same manner as in Example 4 except that excess concentrated sludge (aerobic microbial group-containing sludge) of activated sludge obtained from the nitrification and denitrification step was introduced into the aeration tank. . The results are shown in Tables 11 and 12.
以上のように、本発明によれば、有機性廃棄物を高濃度でメタン発酵処理した難脱水性消化汚泥に対して、脱水処理の前に曝気処理を施すことで汚泥の粘度を大幅に低下させることができ、凝集性能及び脱水効率を向上させることができる。本発明の処理方法によれば、凝集剤の添加量を低減でき（低薬注率）、安定的に短時間で高濃度消化汚泥の脱水処理が可能となる。本発明によって得られた含水率８２％以下の脱水ケーキは、従来の脱水ケーキと比較して低含水率で、粘着性がなく、特殊な不快臭もないことから、コンポスト、炭化、燃料化などの再資源化にも好適である。 As described above, according to the present invention, the viscosity of sludge is significantly reduced by subjecting the hardly-dehydrated digested sludge obtained by subjecting organic waste to high-concentration methane fermentation treatment to aeration treatment before dehydration treatment. It is possible to improve the aggregation performance and dehydration efficiency. According to the treatment method of the present invention, the amount of the flocculant added can be reduced (low chemical injection rate), and the dehydration treatment of highly concentrated digested sludge can be stably performed in a short time. The dehydrated cake having a water content of 82% or less obtained by the present invention has a lower water content than conventional dehydrated cakes, is not sticky, and has no special unpleasant odor. It is also suitable for recycling.
Claims (13)
当該有機性汚泥は、２５ｇ／Ｌ以上のＴＳ濃度と、当該ＴＳ濃度よりも５ｇ／Ｌ以上少ないＳＳ濃度と、を有する難脱水性消化汚泥であり、
当該消化汚泥を脱水処理する前に、当該難脱水性消化汚泥に対して酸素含有気体を通気して曝気処理を行ない、当該難脱水性消化汚泥の粘度を低減させることを特徴とする有機性汚泥の処理方法。 A method for treating organic sludge after anaerobic treatment, comprising:
The organic sludge is a hardly dehydratable digested sludge having a TS concentration of 25 g / L or more and an SS concentration of 5 g / L or more lower than the TS concentration,
Prior to dehydration treatment of the digested sludge, an aeration treatment is performed by aerating an oxygen-containing gas to the hardly dehydrated digested sludge to reduce the viscosity of the hardly dehydrated digested sludge. Processing method.
当該難脱水性消化汚泥に酸素含有気体を曝気させる曝気槽と、
曝気処理後の消化汚泥に凝集剤を添加して凝集汚泥を形成する凝集槽と、
当該嫌気性処理槽又は当該凝集槽の撹拌装置の撹拌抵抗に応じて当該曝気槽に供給する酸素含有気体の曝気速度を調整する制御装置と、
当該凝集汚泥を脱水する脱水装置と、
を具備することを特徴とする、有機性汚泥の処理装置。 An anaerobic treatment tank for forming a hardly dehydratable digested sludge having a TS concentration of 25 g / L or more and an SS concentration of 5 g / L or more lower than the TS concentration,
An aeration tank for aerating an oxygen-containing gas to the hardly dehydratable digested sludge,
A coagulation tank that forms a coagulated sludge by adding a coagulant to the digested sludge after aeration treatment,
A controller for adjusting the aeration rate of the oxygen-containing gas supplied to the aeration tank according to the stirring resistance of the stirring device of the anaerobic treatment tank or the aggregating tank,
A dehydrator for dehydrating the coagulated sludge,
An apparatus for treating organic sludge, comprising:
当該硝化脱窒素槽からの処理水を前記曝気処理後の消化汚泥に添加する希釈液供給配管をさらに具備することを特徴とする、請求項１１に記載の有機性汚泥の処理装置。 A nitrifying and denitrifying tank for nitrifying and denitrifying the dehydrated separated water from the dehydrator,
The apparatus for treating organic sludge according to claim 11, further comprising a diluent supply pipe for adding treated water from the nitrification / denitrification tank to the digested sludge after the aeration treatment.
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| JP2003305498A (en) * | 2002-04-11 | 2003-10-28 | Kurita Water Ind Ltd | Sludge treatment apparatus |
| JP2005199258A (en) * | 2003-12-16 | 2005-07-28 | Kurita Water Ind Ltd | Anaerobic digestion treatment apparatus of organic waste solution |
| WO2012077778A1 (en) * | 2010-12-10 | 2012-06-14 | 水ｉｎｇ株式会社 | Anaerobic processing method and device |
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| JPS56115695A (en) * | 1980-02-20 | 1981-09-10 | Hitachi Ltd | Chemical dosage control unit in sludge treatment process |
| JPS56121696A (en) * | 1980-03-03 | 1981-09-24 | Toshiba Corp | Dust disposer |
| JPS6038099A (en) * | 1983-08-08 | 1985-02-27 | Ebara Infilco Co Ltd | Treatment of organic waste material |
| JP3906323B2 (en) * | 1998-09-07 | 2007-04-18 | 株式会社荏原製作所 | Treatment method for highly concentrated waste liquid |
| JP5061551B2 (en) * | 2006-09-21 | 2012-10-31 | 栗田工業株式会社 | Biological treatment equipment for organic waste liquid |
| JP5628963B2 (en) * | 2013-05-01 | 2014-11-19 | 水ｉｎｇ株式会社 | Organic sludge treatment method and treatment equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6094200A (en) * | 1983-10-28 | 1985-05-27 | Hitachi Plant Eng & Constr Co Ltd | Treatment before dehydration of organic sludge |
| JPS61209100A (en) * | 1985-03-13 | 1986-09-17 | Kawasaki Steel Corp | Dehydration pretreatment of sludge |
| JPH08206699A (en) * | 1995-02-06 | 1996-08-13 | Kurita Water Ind Ltd | Dehydrating method for anaerobic digestion sludge |
| JP2003305498A (en) * | 2002-04-11 | 2003-10-28 | Kurita Water Ind Ltd | Sludge treatment apparatus |
| JP2005199258A (en) * | 2003-12-16 | 2005-07-28 | Kurita Water Ind Ltd | Anaerobic digestion treatment apparatus of organic waste solution |
| WO2012077778A1 (en) * | 2010-12-10 | 2012-06-14 | 水ｉｎｇ株式会社 | Anaerobic processing method and device |
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| JP6679503B2 (en) | 2020-04-15 |
| JPWO2016111324A1 (en) | 2017-10-12 |
| JP6868679B2 (en) | 2021-05-12 |
| WO2016111324A1 (en) | 2016-07-14 |
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