JP7462527B2 - Sewage sludge treatment device and sewage sludge treatment method - Google Patents
Sewage sludge treatment device and sewage sludge treatment method Download PDFInfo
- Publication number
- JP7462527B2 JP7462527B2 JP2020168812A JP2020168812A JP7462527B2 JP 7462527 B2 JP7462527 B2 JP 7462527B2 JP 2020168812 A JP2020168812 A JP 2020168812A JP 2020168812 A JP2020168812 A JP 2020168812A JP 7462527 B2 JP7462527 B2 JP 7462527B2
- Authority
- JP
- Japan
- Prior art keywords
- sludge
- acid
- treatment tank
- ozone
- tank
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000010801 sewage sludge Substances 0.000 title claims description 35
- 238000000034 method Methods 0.000 title claims description 16
- 239000010802 sludge Substances 0.000 claims description 124
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 119
- 238000010306 acid treatment Methods 0.000 claims description 48
- 239000002253 acid Substances 0.000 claims description 43
- 150000007522 mineralic acids Chemical class 0.000 claims description 36
- 239000007788 liquid Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 238000005192 partition Methods 0.000 claims description 7
- 230000029087 digestion Effects 0.000 claims description 5
- 238000002407 reforming Methods 0.000 claims description 2
- 230000004044 response Effects 0.000 claims description 2
- 238000010586 diagram Methods 0.000 description 12
- 238000003756 stirring Methods 0.000 description 10
- 244000005700 microbiome Species 0.000 description 7
- 230000003068 static effect Effects 0.000 description 7
- 230000008719 thickening Effects 0.000 description 6
- 230000005611 electricity Effects 0.000 description 5
- 239000010865 sewage Substances 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000005416 organic matter Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Treatment Of Sludge (AREA)
- Sewage (AREA)
Description
本願は、下水汚泥処理装置および下水汚泥処理方法に関するものである。 This application relates to a sewage sludge treatment device and a sewage sludge treatment method.
下水処理場では、流入した下水排水を処理して河川、海に放流している。放流は処理水中の無機系または有機系の浮遊物および溶解性の有機物を基準レベルまで除去する必要があり、除去方法として活性汚泥法が用いられる。この活性汚泥法に使用する微生物は、溶解性有機物を分解することでエネルギーを得て増殖する。曝気槽の微生物濃度が増加すると、沈殿によって微生物を処理水と分離することが困難になる。これを防ぐため増殖した微生物を余剰汚泥として引き抜いている。大量の余剰汚泥を効率的に改質するためにオゾンガスを利用しているが、このオゾンガス発生には多くの電力が必要となり、従来からオゾンガス使用量の削減化に注力されている。例えば、生物処理系において生成する余剰汚泥をオゾン処理槽においてオゾン処理した後、嫌気性処理装置で生物処理する方法にあって、余剰汚泥に硫酸などの無機酸を加えてＰＨを５以下に調整した後、オゾン処理する技術が開示されている（例えば、特許文献１参照）。 In sewage treatment plants, sewage discharged from the plant is treated and discharged into rivers and the sea. Before discharge, inorganic or organic suspended matter and soluble organic matter in the treated water must be removed to a standard level, and activated sludge is used as a removal method. The microorganisms used in the activated sludge method obtain energy by decomposing soluble organic matter and grow. If the concentration of microorganisms in the aeration tank increases, it becomes difficult to separate the microorganisms from the treated water by precipitation. To prevent this, the grown microorganisms are extracted as excess sludge. Ozone gas is used to efficiently reform large amounts of excess sludge, but a lot of electricity is required to generate this ozone gas, and efforts have been focused on reducing the amount of ozone gas used. For example, a method in which excess sludge generated in a biological treatment system is ozone-treated in an ozone treatment tank and then biologically treated in an anaerobic treatment device has been disclosed in which an inorganic acid such as sulfuric acid is added to the excess sludge to adjust the pH to 5 or less, and then the ozone treatment is performed (see, for example, Patent Document 1).
しかしながら、上記特許文献１に示された技術は、以下のような問題点がある。余剰汚泥に無機酸を添加してオゾン処理を行う場合、オゾンガス使用量を削減するには、余剰汚泥全体に無機酸を均等に分布させることが必要である。その理由として、余剰汚泥は微生物の集合体である数十ミクロンから１ｍｍ程度の大きさのフロックが多数浮遊した形状を持っているオゾン処理において、前記フロックとオゾンガスとの反応が生じるため、フロックの表面を無機酸と接触させて、フロックの表面を無機酸で改質する必要がある。この状態を生成するには、添加した無機酸がフロック間に侵入させる必要があるが、上記特許文献１には余剰汚泥に添加した無機酸を分散させる点に関する記載は示されていない。一方、従来よりオゾン処理槽内で攪拌機を用いて、余剰汚泥と無機酸を混合させるものが知られているが、攪拌機の運転およびオゾン発生器の運転に伴う使用電力量の低減ならびにオゾンガス使用量の低減に関する技術は開示されていないという問題点がある。 However, the technology disclosed in the above-mentioned Patent Document 1 has the following problems. When performing ozone treatment by adding inorganic acid to excess sludge, it is necessary to distribute the inorganic acid evenly throughout the excess sludge in order to reduce the amount of ozone gas used. The reason for this is that excess sludge has a shape in which many flocs, which are aggregates of microorganisms and have sizes ranging from several tens of microns to about 1 mm, are suspended in the ozone treatment. In order to cause a reaction between the flocs and ozone gas, it is necessary to bring the surface of the flocs into contact with the inorganic acid and modify the surface of the flocs with the inorganic acid. To create this state, the added inorganic acid needs to penetrate between the flocs, but the above-mentioned Patent Document 1 does not disclose any description of dispersing the inorganic acid added to the excess sludge. On the other hand, there is a problem that no technology is disclosed regarding the reduction of the amount of electricity used in the operation of the agitator and the ozone generator and the reduction of the amount of ozone gas used.
本願は、上記のような課題を解決するための技術を開示するものであり、使用電力量とオゾンガス使用量を低減した下水汚泥処理装置および下水汚泥処理方法を提供することを目的とする。 This application discloses technology to solve the problems described above, and aims to provide a sewage sludge treatment device and a sewage sludge treatment method that reduce the amount of electricity and ozone gas used.
本開示の下水汚泥処理装置は、生物処理を行う生物処理槽と、前記生物処理槽の後段で、処理水と活性汚泥とに分離する沈殿槽と、前記沈殿槽の後段で、前記活性汚泥の一部の余剰汚泥に無機酸を添加する酸添加装置と攪拌機が設けられた酸処理槽と、前記酸処理槽の後段で、酸処理汚泥を貯留するとともに、前記酸処理汚泥を、オゾン発生器から送出されるオゾンガスで改質するオゾン処理槽とを備え、
前記酸処理槽には、仕切板で多段に分離された部屋が設けられ、前記部屋毎に前記攪拌機で前記酸処理汚泥を撹拌し、前記酸処理汚泥を前記仕切板の貫通穴を介して、下段の部屋から上段の部屋に流動させ、
前記酸処理槽と前記オゾン処理槽を接続する循環配管にはポンプが設けられ、前記ポンプによって前記オゾン処理槽からオゾン処理汚泥を引き抜き、前記酸処理槽に投入するものである。
また、本開示の下水汚泥処理方法は、上記記載の下水汚泥処理装置を用いて処理を行うものである。
The sewage sludge treatment device of the present disclosure includes a biological treatment tank for performing biological treatment, a settling tank downstream of the biological treatment tank for separating treated water and activated sludge, an acid treatment tank downstream of the settling tank and provided with an acid addition device and an agitator for adding inorganic acid to excess sludge that is a part of the activated sludge, and an ozone treatment tank downstream of the acid treatment tank for storing acid treated sludge and reforming the acid treated sludge with ozone gas delivered from an ozone generator ,
The acid treatment tank is provided with chambers separated into multiple stages by partition plates, and the acid treated sludge is stirred by the agitator in each of the chambers, and the acid treated sludge is caused to flow from the lower chamber to the upper chamber through the through holes in the partition plates,
A pump is provided in the circulation pipe connecting the acid treatment tank and the ozone treatment tank, and the pump extracts ozone-treated sludge from the ozone treatment tank and feeds it into the acid treatment tank.
Further, the sewage sludge treatment method of the present disclosure performs treatment using the above-described sewage sludge treatment apparatus.
本願に開示される下水汚泥処理装置は、上記のような構成を採用しているので、使用電力量とオゾン使用量を低減した下水汚泥処理装置を提供できるという効果があり、また下水汚泥処理方法も同様の効果がある。 The sewage sludge treatment device disclosed in this application employs the above-mentioned configuration, and therefore has the effect of providing a sewage sludge treatment device that uses less power and ozone, and the sewage sludge treatment method also has the same effect.
実施の形態１．
実施の形態１を図に基づいて説明する。図１は、実施の形態１による下水汚泥処理装置１００を示すブロック図である。図１において、下水は生物処理槽１によって溶解性有機物が分解され、沈殿槽２において処理水と、微生物を含む活性汚泥３とに分離される。活性汚泥３の一部は、余剰汚泥４として生物処理槽１に戻さずに引き抜かれる。この引き抜き量は、下水処理の状況に対応した量である。余剰汚泥４は投入配管２０を介して無機酸を添加する酸処理槽６に投入される。使用する無機酸は、例えば塩酸、硫酸、硝酸などである。酸処理槽６には、無機酸を添加する酸添加装置７と、余剰汚泥４を撹拌する羽根１４を取り付けた攪拌機８、ＰＨ計９が設置されている。この酸処理槽６の後段には、汚泥配管１０を介してオゾン処理槽５が設けられている。このオゾン処理槽５には、オゾン発生器１１で発生したオゾンガスを注入するオゾン配管１２と、オゾンガスによって改質したオゾン処理汚泥を引き抜くオゾン処理汚泥配管１３と液面計１６とオゾン排出管３２とが設けられている。また、上記各構成要素の出力を入力し、演算、運転制御する制御部５０が設けられている。
Embodiment 1.
The first embodiment will be described with reference to the drawings. FIG. 1 is a block diagram showing a sewage sludge treatment device 100 according to the first embodiment. In FIG. 1, soluble organic matter in sewage is decomposed in a biological treatment tank 1, and the sewage is separated into treated water and activated sludge 3 containing microorganisms in a settling tank 2. A part of the activated sludge 3 is withdrawn as excess sludge 4 without being returned to the biological treatment tank 1. The amount withdrawn corresponds to the state of sewage treatment. The excess sludge 4 is fed through an input pipe 20 into an acid treatment tank 6 to which an inorganic acid is added. The inorganic acid used is, for example, hydrochloric acid, sulfuric acid, or nitric acid. The acid treatment tank 6 is provided with an acid addition device 7 for adding an inorganic acid, an agitator 8 equipped with blades 14 for agitating the excess sludge 4, and a pH meter 9. An ozone treatment tank 5 is provided downstream of the acid treatment tank 6 through a sludge pipe 10. The ozone treatment tank 5 is provided with an ozone pipe 12 for injecting ozone gas generated in an ozone generator 11, an ozone treatment sludge pipe 13 for drawing out ozone-treated sludge reformed by the ozone gas, a liquid level gauge 16, and an ozone exhaust pipe 32. Also provided is a control unit 50 for inputting the outputs of the above-mentioned components and for performing calculations and operation control.
図１を用い、余剰汚泥４をオゾンガスによって改質する手順を説明する。沈殿槽２から生物処理槽１に戻す活性汚泥３の一部が引き抜かれた余剰汚泥４は、投入配管２０を介して酸処理槽６に投入されるとともに、攪拌機８の羽根１４によって撹拌される。酸添加装置７から注入配管２１を介して酸処理槽６に注入される無機酸は、余剰汚泥４の内部に分散される。前記無機酸は、余剰汚泥４中に含まれる微生物の集合体であるフロックの表面全体に付着することにより、フロックの表面が改質されて余剰汚泥４の粘度が低下した酸処理汚泥が生成され、汚泥配管１０を介しオゾン処理槽５に送出される。 The procedure for modifying excess sludge 4 with ozone gas will be described using Figure 1. The excess sludge 4, which is a part of the activated sludge 3 returned from the settling tank 2 to the biological treatment tank 1, is fed into the acid treatment tank 6 via the input pipe 20 and stirred by the blades 14 of the agitator 8. The inorganic acid injected into the acid treatment tank 6 from the acid adding device 7 via the injection pipe 21 is dispersed inside the excess sludge 4. The inorganic acid adheres to the entire surface of the flocs, which are an aggregate of microorganisms contained in the excess sludge 4, thereby modifying the surface of the flocs and generating acid-treated sludge with a reduced viscosity of the excess sludge 4, which is then sent to the ozone treatment tank 5 via the sludge pipe 10.
酸処理汚泥のＰＨはＰＨ計９によって測定され、その出力は制御部５０に送信される。制御部５０はＰＨ計９の出力に対応して酸添加装置７からの無機酸の注入量を制御する。この制御はＰＨ計９の値が予め設定されたしきい値、例えばＰＨ＝３～６の値となるようになされるものであり、ＰＨ計９の出力が高い場合は、酸添加装置７から注入する無機酸の量を増やし、前記しきい値より低くなった場合には、酸添加装置７からの無機酸の添加を停止する。尚、前記しきい値は、汚泥の状態によって変化させるものである。 The pH of the acid-treated sludge is measured by a pH meter 9, and the output is sent to the control unit 50. The control unit 50 controls the amount of inorganic acid injected from the acid addition device 7 in response to the output of the pH meter 9. This control is performed so that the value of the pH meter 9 becomes a preset threshold value, for example, pH = 3 to 6. If the output of the pH meter 9 is high, the amount of inorganic acid injected from the acid addition device 7 is increased, and if the output falls below the threshold value, the addition of inorganic acid from the acid addition device 7 is stopped. The threshold value is changed depending on the condition of the sludge.
酸処理槽６に添加した無機酸は、濃度が不均一に分布する。羽根１４によって撹拌されることにより、測定されるＰＨ値は時間的に変動する。この場合、ＰＨ値が設定しきい値より±０．５以上変動する場合、制御部５０の信号に基づき、攪拌機８の回転数を制御することで酸処理汚泥内部における無機酸の分布を均等とする。このように、酸処理槽６における酸処理汚泥の処理は、ＰＨ計９の時間変動が±０．３以下となるよう制御される。 The inorganic acid added to the acid treatment tank 6 is distributed in an uneven concentration. The measured pH value fluctuates over time as a result of stirring by the blades 14. In this case, if the pH value fluctuates by ±0.5 or more from the set threshold value, the rotation speed of the agitator 8 is controlled based on a signal from the control unit 50 to ensure an even distribution of the inorganic acid within the acid treatment sludge. In this way, the treatment of the acid treatment sludge in the acid treatment tank 6 is controlled so that the time fluctuation of the pH meter 9 is within ±0.3.
酸処理槽６で処理された酸処理汚泥は、汚泥配管１０を介してオゾン処理槽５に流入される。このオゾン処理槽５には、オゾン発生器１１で発生したオゾンガスがオゾン配管１２を通して注入される。オゾン処理槽５内の酸処理汚泥は、オゾンガスによる改質が促進されるため、酸処理汚泥のＰＨ値に応じて汚泥を改質するためのオゾンガス量は減少する。このように、オゾンガスによって改質された酸処理汚泥は、オゾン処理汚泥となり、オゾン処理汚泥配管１３を介してオゾン処理槽５から引き抜かれる。また、オゾン排出管３２から排オゾンが排出される。 The acid-treated sludge treated in the acid treatment tank 6 flows into the ozone treatment tank 5 via the sludge pipe 10. Ozone gas generated by the ozone generator 11 is injected into this ozone treatment tank 5 through the ozone pipe 12. The acid-treated sludge in the ozone treatment tank 5 is promoted to be reformed by the ozone gas, so the amount of ozone gas required to reform the sludge decreases according to the pH value of the acid-treated sludge. In this way, the acid-treated sludge reformed by the ozone gas becomes ozone-treated sludge, and is drawn out of the ozone treatment tank 5 via the ozone-treated sludge pipe 13. In addition, waste ozone is discharged from the ozone discharge pipe 32.
オゾン処理槽５における酸処理汚泥のオゾン処理方式としては、バッチ処理方式と、連続処理方式とがある。バッチ処理方式は、酸処理槽６で生成された酸処理汚泥をオゾン処理槽５に貯留し、液面計１６で計測する液面の高さが設定値に達すると、制御部５０の制御により酸処理汚泥の流入を停止する。その後、オゾンガスがオゾン処理槽５に注入され酸処理汚泥と反応して改質を行う。酸処理汚泥が吸収したオゾンガス量が所定値に達すると、オゾンガスの注入を停止する。前記所定値は、制御部５０において貯留した酸処理汚泥量から固形物重量、注入したオゾンガス濃度とオゾン処理槽５に設けられたオゾン排出管３２から流出したオゾン濃度の差と、処理時間の積から、オゾン吸収量を算出することで吸収量の所定値としている。引き続きオゾン処理槽５からオゾン処理汚泥配管１３を介してオゾン処理汚泥を引き抜いた後、再度酸処理槽６から酸処理汚泥をオゾン処理槽５に貯留してバッチ処理方式によるオゾン処理を繰り返す。 There are two types of ozone treatment methods for acid-treated sludge in the ozone treatment tank 5: batch treatment and continuous treatment. In the batch treatment method, the acid-treated sludge generated in the acid treatment tank 6 is stored in the ozone treatment tank 5, and when the liquid level measured by the liquid level gauge 16 reaches a set value, the inflow of the acid-treated sludge is stopped by the control of the control unit 50. After that, ozone gas is injected into the ozone treatment tank 5 and reacts with the acid-treated sludge to modify it. When the amount of ozone gas absorbed by the acid-treated sludge reaches a predetermined value, the injection of ozone gas is stopped. The predetermined value is determined by calculating the amount of ozone absorption from the amount of acid-treated sludge stored in the control unit 50, the solid weight, the difference between the injected ozone gas concentration and the ozone concentration flowing out from the ozone exhaust pipe 32 installed in the ozone treatment tank 5, and the treatment time. Next, the ozone-treated sludge is extracted from the ozone treatment tank 5 via the ozone-treated sludge pipe 13, and then the acid-treated sludge is again stored in the ozone treatment tank 5 from the acid treatment tank 6, and the ozone treatment is repeated using the batch treatment method.
連続処理方式の場合、酸処理槽６からオゾン処理槽５へ連続的に投入する酸処理汚泥の量と、オゾン処理槽５から引き抜くオゾン処理汚泥の量が同じになるようにして汚泥処理を行う。すなわち、液面計１６が計測する液面が所定の液面高を保持するよう投入量を一定として引き抜き量が制御される。 In the case of the continuous treatment method, sludge treatment is carried out so that the amount of acid-treated sludge continuously fed from the acid treatment tank 6 to the ozone treatment tank 5 is the same as the amount of ozone-treated sludge withdrawn from the ozone treatment tank 5. In other words, the amount fed is kept constant and the amount withdrawn is controlled so that the liquid level measured by the liquid level gauge 16 maintains a predetermined liquid level height.
図２は無機酸と余剰汚泥４を効率よく混合させるための酸処理槽６を示す断面図である。酸処理槽６には酸処理汚泥が通過可能なサイズを有する貫通穴１５と羽根１４を設けた撹拌棒１７を通す穴１８が設けられた仕切板１９によって、上下方向に多段の部屋、この場合３つの部屋に分けられている。余剰汚泥４を投入する投入配管２０と、無機酸を添加する注入配管２１は酸処理槽６の最下段の部屋に設けられている。羽根１４は各部屋毎に設けられている。ＰＨ計９は最下段の部屋に設けられているが、これに限定されるものではなく、また各部屋に設けてもよい。酸処理汚泥が流出する汚泥配管１０は、酸処理槽６の上部に設けられている。最下段の部屋に注入の余剰汚泥４は、無機酸が添加され、羽根１４によって混合されて酸処理汚泥となり、貫通穴１５を通して上部の部屋、この場合２段目の部屋に流動、移動し、再度羽根１４によって撹拌されて酸処理汚泥の内部における無機酸の濃度分布が均等化され、さらに最上段部屋において流動した酸処理汚泥が羽根１４で攪拌されることにより無機酸の濃度分布がさらに均等になる。このように、酸処理槽６を仕切板１９で多段に分割して多段の部屋を設け、各部屋で酸処理汚泥を撹拌するので、撹拌するための動力を低減して、無機酸の濃度分布を均等化可能とし、結果として使用電力量の低減およびオゾンガスの使用量を低減する。 Figure 2 is a cross-sectional view showing an acid treatment tank 6 for efficiently mixing inorganic acid and excess sludge 4. The acid treatment tank 6 is vertically divided into multiple chambers, in this case three chambers, by a partition plate 19 provided with a through hole 15 having a size that allows the acid treatment sludge to pass through and a hole 18 for passing a stirring rod 17 with a blade 14. An input pipe 20 for inputting the excess sludge 4 and an injection pipe 21 for adding inorganic acid are provided in the lowest chamber of the acid treatment tank 6. A blade 14 is provided in each chamber. A pH meter 9 is provided in the lowest chamber, but this is not limited thereto, and may be provided in each chamber. A sludge pipe 10 from which the acid treatment sludge flows out is provided in the upper part of the acid treatment tank 6. The excess sludge 4 injected into the bottom chamber is mixed with inorganic acid by the blades 14 to become acid-treated sludge, which then flows and moves through the through holes 15 to the upper chamber, in this case the second chamber, where it is stirred again by the blades 14 to equalize the concentration distribution of the inorganic acid inside the acid-treated sludge, and the acid-treated sludge that has flowed in the top chamber is further stirred by the blades 14 to further equalize the concentration distribution of the inorganic acid. In this way, the acid treatment tank 6 is divided into multiple stages by partitions 19 to provide multiple chambers, and the acid-treated sludge is stirred in each chamber, reducing the power required for stirring and making it possible to equalize the concentration distribution of the inorganic acid, which results in a reduction in the amount of electricity used and the amount of ozone gas used.
実施の形態２．
図３は、実施の形態２による下水汚泥処理装置１００を示すブロック図である。この図３は前述した実施の形態１のバッチ処理方式を示す図２の酸処理槽６と、オゾン処理槽５とを一つの槽にまとめたオゾン処理槽５Ａを設けたものである。図３において、オゾン処理槽５Ａには、投入配管２０、攪拌機８、羽根１４、酸添加装置７、ＰＨ計９、液面計１６が設けられている。以下、図３に基づく動作を説明する。余剰汚泥４を投入配管２０を介してオゾン処理槽５Ａに投入すると同時に、酸添加装置７を用いて無機酸を添加する。余剰汚泥４を投入する際には、攪拌機８の運転による羽根１４の回転で、余剰汚泥４を撹拌する。無機酸の添加量はＰＨ計９によって計測されるＰＨ値を基に制御部５０によって制御される。液面計１６による所定量の余剰汚泥４が貯留されると、余剰汚泥４の投入を停止する。ＰＨ値が所定の値となるまで無機酸の添加と羽根１４による撹拌は継続される。酸処理汚泥のＰＨ値が所定の値、たとえばＰＨ５となり、かつＰＨ値の時間変動が±０．３以下になると、無機酸の添加が停止される。次に、オゾン発生器１１で生成されたオゾンガスをオゾン処理槽５Ａに注入してオゾン処理を行う。このオゾン処理を行っている間も羽根１４の回転でオゾンガスと酸処理汚泥の接触効率を高めることが可能となる。このオゾン処理槽５Ａにおける処理が完了する、すなわち実施の形態１で前述した制御部５０による所定値を判断すると、オゾンガス注入を停止する。その後、オゾン処理汚泥をオゾン処理汚泥配管１３を介して引き抜く。このような実施の形態２においても、撹拌動力が低減される。また、オゾン発生器１１からのオゾンガス注入運転は、余剰汚泥４の貯留時、汚泥引き抜き時は停止されるので、オゾンガス使用量および使用電力量の低減となる。
Embodiment 2.
FIG. 3 is a block diagram showing a sewage sludge treatment apparatus 100 according to a second embodiment. In FIG. 3, an ozone treatment tank 5A is provided in which the acid treatment tank 6 and the ozone treatment tank 5 shown in FIG. 2, which show the batch treatment method according to the first embodiment, are integrated into one tank. In FIG. 3, the ozone treatment tank 5A is provided with an input pipe 20, an agitator 8, a blade 14, an acid addition device 7, a pH meter 9, and a liquid level gauge 16. The operation based on FIG. 3 will be described below. The excess sludge 4 is input into the ozone treatment tank 5A via the input pipe 20, and at the same time, inorganic acid is added using the acid addition device 7. When the excess sludge 4 is input, the excess sludge 4 is agitated by the rotation of the blade 14 caused by the operation of the agitator 8. The amount of inorganic acid added is controlled by the control unit 50 based on the pH value measured by the pH meter 9. When a predetermined amount of excess sludge 4 is stored as measured by the liquid level gauge 16, the input of the excess sludge 4 is stopped. The addition of inorganic acid and the stirring by the blades 14 are continued until the pH value reaches a predetermined value. When the pH value of the acid-treated sludge reaches a predetermined value, for example, pH 5, and the time variation of the pH value is within ±0.3, the addition of inorganic acid is stopped. Next, the ozone gas generated by the ozone generator 11 is injected into the ozone treatment tank 5A to perform ozone treatment. Even during this ozone treatment, the rotation of the blades 14 makes it possible to increase the contact efficiency between the ozone gas and the acid-treated sludge. When the treatment in the ozone treatment tank 5A is completed, that is, when the control unit 50 described in the first embodiment judges that the predetermined value has been reached, the injection of ozone gas is stopped. Then, the ozone-treated sludge is extracted through the ozone-treated sludge pipe 13. In this second embodiment as well, the stirring power is reduced. In addition, the operation of injecting ozone gas from the ozone generator 11 is stopped when the excess sludge 4 is stored and when the sludge is extracted, so that the amount of ozone gas and the amount of electricity used are reduced.
実施の形態３．
図４は、実施の形態３による下水汚泥処理装置１００を示すブロック図である。実施の形態１で示した図１に、オゾン処理槽５と酸処理槽６とを接続するとともに、ポンプ２２が設けられた循環配管２３が設けられた構成を追加したもので、それ以外は図１と同様である。次に、図４の構成による連続処理方式で、酸処理とオゾン処理を行う動作を説明する。沈殿槽２から生物処理槽１に戻す活性汚泥３の一部を引き抜いた余剰汚泥４は、酸処理槽６に投入され、羽根１４によって撹拌される。酸添加装置７から注入された無機酸は、余剰汚泥４の内部に分散され、余剰汚泥４の粘度が低下した酸処理汚泥を生成後、オゾン処理槽５に流入される。上記状態に達した後、この実施の形態３における定常状態の連続処理が開始される。すなわち、ポンプ２２の運転によりオゾン処理槽５からオゾン処理汚泥を引き抜く。この引き抜き量は、オゾン処理槽５に流入する量の５０％～１００％である。引き抜いた粘度の低下したオゾン処理汚泥は循環配管２３を介して酸処理槽６に投入される。このため、酸処理槽６内における余剰汚泥４と、循環配管２３から投入されるオゾン処理汚泥とが混合された混合汚泥の粘度は、余剰汚泥単独の場合よりも低下し、羽根１４による撹拌による混合が効率的に進む。従って、撹拌に要する動力が低減されるとともに、余剰汚泥４に無機酸をより分散させることが可能となる。
Embodiment 3.
FIG. 4 is a block diagram showing a sewage sludge treatment apparatus 100 according to a third embodiment. The ozone treatment tank 5 and the acid treatment tank 6 are connected to each other, and a circulation pipe 23 equipped with a pump 22 is added to the configuration shown in FIG. 1 shown in the first embodiment, and the rest is the same as that shown in FIG. 1. Next, the operation of performing acid treatment and ozone treatment in the continuous treatment method according to the configuration shown in FIG. 4 will be described. The excess sludge 4, which is a part of the activated sludge 3 returned to the biological treatment tank 1 from the settling tank 2, is introduced into the acid treatment tank 6 and stirred by the blades 14. The inorganic acid injected from the acid addition device 7 is dispersed inside the excess sludge 4, and the excess sludge 4 is reduced in viscosity to produce acid-treated sludge, which then flows into the ozone treatment tank 5. After the above state is reached, the steady-state continuous treatment in this third embodiment is started. That is, the pump 22 is operated to extract ozone-treated sludge from the ozone treatment tank 5. The amount of the extracted sludge is 50% to 100% of the amount flowing into the ozone treatment tank 5. The withdrawn ozone-treated sludge with reduced viscosity is fed into the acid treatment tank 6 via the circulation pipe 23. Therefore, the viscosity of the mixed sludge, which is a mixture of the excess sludge 4 in the acid treatment tank 6 and the ozone-treated sludge fed from the circulation pipe 23, is lower than that of the excess sludge alone, and mixing by stirring with the blades 14 proceeds efficiently. This reduces the power required for stirring and enables the inorganic acid to be more dispersed in the excess sludge 4.
オゾン処理槽５から酸処理槽６に循環させるオゾン処理汚泥の量は、ＰＨ計９によって得られる酸処理槽６の酸処理汚泥のＰＨ値を基に制御される。この理由は、オゾン処理槽５から引き抜いた汚泥を混合させると、酸処理槽６での汚泥の粘度が下がるため撹拌による混合が短時間で完了し、ＰＨ値の時間変動が小さく、このためＰＨ値のみで判断可能となる故である。一方、オゾン処理汚泥の循環量が増加すると、ポンプ２２の大容量化とともに使用電力増となる。従って循環量は、ポンプ２２の動力、酸処理槽６の攪拌機８の動力の合計が最小となるよう設定されている。 The amount of ozone-treated sludge circulated from the ozone treatment tank 5 to the acid treatment tank 6 is controlled based on the pH value of the acid treatment sludge in the acid treatment tank 6 obtained by the pH meter 9. The reason for this is that when the sludge extracted from the ozone treatment tank 5 is mixed, the viscosity of the sludge in the acid treatment tank 6 decreases, so mixing by stirring is completed in a short time and the pH value fluctuates little over time, making it possible to judge based on the pH value alone. On the other hand, if the amount of ozone-treated sludge circulated increases, the capacity of the pump 22 increases and the power consumption increases. Therefore, the amount of circulation is set so that the sum of the power of the pump 22 and the power of the agitator 8 in the acid treatment tank 6 is minimized.
実施の形態４．
図５は、実施の形態４による下水汚泥処理装置１００を示すブロック図であり、前述した実施の形態３の図４に濃縮装置２５と嫌気性消化槽２４を追加した構成としたもので、それ以外は図４と同様である。図５に示すように、酸処理槽６の前段に濃縮装置２５が設けられており、この濃縮装置２５によって余剰汚泥４に含まれる水分を除去することで余剰汚泥４の濃縮処理が行われる。この処理は、オゾン処理槽５の後段に設けられた嫌気性消化槽２４を小型化するためになされるものである。濃縮装置２５は浮上分離装置、遠心分離装置が用いられ、余剰汚泥４の水分を分離水として排出する。このことにより余剰汚泥４は濃度が高くなり粘度が上昇するが、酸処理槽６で無機酸を投入すること、実施の形態３で述べたオゾン処理槽５から引き抜いたオゾン処理汚泥も酸処理槽６に投入することにより、余剰汚泥４の粘度を低下させることが可能となり、撹拌に必要な動力の低減化が図れる。
Embodiment 4.
FIG. 5 is a block diagram showing a sewage sludge treatment apparatus 100 according to a fourth embodiment, which is similar to FIG. 4 in the configuration of the third embodiment, except that a thickening device 25 and an anaerobic digestion tank 24 are added to FIG. 4. As shown in FIG. 5, a thickening device 25 is provided in front of the acid treatment tank 6, and the excess sludge 4 is thickened by removing the water contained in the excess sludge 4 by the thickening device 25. This treatment is performed in order to reduce the size of the anaerobic digestion tank 24 provided in the rear of the ozone treatment tank 5. The thickening device 25 uses a floatation separation device and a centrifugal separator, and discharges the water from the excess sludge 4 as separated water. This causes the excess sludge 4 to become more concentrated and its viscosity to increase, but by adding inorganic acid to the acid treatment tank 6 and also adding the ozone-treated sludge extracted from the ozone treatment tank 5 described in the third embodiment to the acid treatment tank 6, it is possible to reduce the viscosity of the excess sludge 4, and the power required for stirring can be reduced.
実施の形態５．
図６は、実施の形態５による下水汚泥処理装置１００を示すブロック図であり、前述した実施の形態３で示した図４の酸処理槽６に代替してスタティックミキサ２６を設けたものである。従って、この実施の形態５では攪拌機８、羽根１４は設置されていない。図６において、投入配管２０を介する余剰汚泥４および循環配管２３を介するオゾン処理汚泥は、スタティックミキサ２６に投入される。尚、酸添加装置７はスタティックミキサ２６の前段に、ＰＨ計９はスタティックミキサ２６の後段に設けられている。このように、オゾン処理槽５から循環配管２３を介して引き抜いたオゾン処理汚泥と、酸添加装置７の無機酸とが混合すると、粘度が低下する。この粘度低下により、スタティックミキサ２６の内部に余剰汚泥４の投入がより容易となる。このような構成を備えているので、下水汚泥処理装置１００がコンパクト化され、かつ撹拌動力が不要となりランニングコストが低下する。
Embodiment 5.
FIG. 6 is a block diagram showing a sewage sludge treatment apparatus 100 according to a fifth embodiment, in which a static mixer 26 is provided instead of the acid treatment tank 6 shown in FIG. 4 of the third embodiment. Therefore, the agitator 8 and the blades 14 are not provided in this fifth embodiment. In FIG. 6, the excess sludge 4 through the input pipe 20 and the ozone-treated sludge through the circulation pipe 23 are input into the static mixer 26. The acid addition device 7 is provided in the front stage of the static mixer 26, and the pH meter 9 is provided in the rear stage of the static mixer 26. In this way, when the ozone-treated sludge extracted from the ozone treatment tank 5 through the circulation pipe 23 is mixed with the inorganic acid in the acid addition device 7, the viscosity is reduced. This reduction in viscosity makes it easier to input the excess sludge 4 into the static mixer 26. With this configuration, the sewage sludge treatment apparatus 100 is made compact, and no stirring power is required, thereby reducing the running cost.
実施の形態６．
図７は、実施の形態６による下水汚泥処理装置１００を示すブロック図であり、前述した実施の形態５の図６に、沈殿槽２の後段に余剰汚泥４の水分を除去する濃縮装置２５と、オゾン処理槽５の後段に嫌気性消化槽２４を追加設置したものである。図７において、沈殿槽２から引き抜いた余剰汚泥４は、濃縮装置２５で水分を除去された濃縮汚泥と、オゾン処理槽５から引き抜かれたオゾン処理汚泥と、無機酸とが混合されて粘土が低下後、スタティックミキサ２６に注入される。このような構成を備えているので、前述の実施の形態５に加え、嫌気性消化槽２４の小型化が図れるという効果がある。
Embodiment 6.
Fig. 7 is a block diagram showing a sewage sludge treatment apparatus 100 according to a sixth embodiment, which is the same as Fig. 6 of the fifth embodiment, except that a thickening device 25 for removing moisture from the excess sludge 4 is added downstream of the settling tank 2, and an anaerobic digestion tank 24 is added downstream of the ozone treatment tank 5. In Fig. 7, the excess sludge 4 withdrawn from the settling tank 2 is mixed with the thickened sludge from which moisture has been removed in the thickening device 25, the ozone-treated sludge withdrawn from the ozone treatment tank 5, and inorganic acid to reduce the clay content, and then is injected into a static mixer 26. With this configuration, in addition to the effects of the fifth embodiment, the anaerobic digestion tank 24 can be made smaller.
本願は、様々な例示的な実施の形態及び実施例が記載されているが、１つ、または複数の実施の形態に記載された様々な特徴、態様、及び機能は特定の実施の形態の適用に限られるのではなく、単独で、または様々な組み合わせで実施の形態に適用可能である。
従って、例示されていない無数の変形例が、本願に開示される技術の範囲内において想定される。例えば、少なくとも１つの構成要素を変形する場合、追加する場合または省略する場合、さらには、少なくとも１つの構成要素を抽出し、他の実施の形態の構成要素と組み合わせる場合が含まれるものとする。
Although the present application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations.
Therefore, countless modifications not illustrated are conceivable within the scope of the technology disclosed in the present application, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment.
１ 生物処理槽、２ 沈殿槽、４ 余剰汚泥、５，５Ａ オゾン処理槽、
６ 酸処理槽、７ 酸添加装置、９ ＰＨ計、１４ 羽根、１６ 液面計、
１９ 仕切板、２２ ポンプ、２６ スタティックミキサ、５０ 制御部、
１００ 下水汚泥処理装置。
1 Biological treatment tank, 2 Sedimentation tank, 4 Excess sludge, 5, 5A Ozone treatment tank,
6 Acid treatment tank, 7 Acid addition device, 9 PH meter, 14 Blade, 16 Liquid level gauge,
19 Partition plate, 22 Pump, 26 Static mixer, 50 Control unit,
100 Sewage sludge treatment device.
Claims (7)
前記酸処理槽には、仕切板で多段に分離された部屋が設けられ、前記部屋毎に前記攪拌機で前記酸処理汚泥を撹拌し、前記酸処理汚泥を前記仕切板の貫通穴を介して、下段の部屋から上段の部屋に流動させ、
前記酸処理槽と前記オゾン処理槽を接続する循環配管にはポンプが設けられ、前記ポンプによって前記オゾン処理槽からオゾン処理汚泥を引き抜き、前記酸処理槽に投入する下水汚泥処理装置。 The system comprises a biological treatment tank for performing biological treatment, a settling tank downstream of the biological treatment tank for separating treated water from activated sludge, an acid treatment tank downstream of the settling tank and provided with an acid adding device and an agitator for adding inorganic acid to excess sludge that is a part of the activated sludge, and an ozone treatment tank downstream of the acid treatment tank for storing acid treated sludge and reforming the acid treated sludge with ozone gas delivered from an ozone generator ,
The acid treatment tank is provided with chambers separated into multiple stages by partition plates, and the acid treated sludge is stirred by the agitator in each of the chambers, and the acid treated sludge is caused to flow from the lower chamber to the upper chamber through the through holes in the partition plates ,
In the sewage sludge treatment apparatus , a pump is provided in a circulation pipe connecting the acid treatment tank and the ozone treatment tank, and the ozone-treated sludge is extracted from the ozone treatment tank by the pump and introduced into the acid treatment tank .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020168812A JP7462527B2 (en) | 2020-10-06 | 2020-10-06 | Sewage sludge treatment device and sewage sludge treatment method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020168812A JP7462527B2 (en) | 2020-10-06 | 2020-10-06 | Sewage sludge treatment device and sewage sludge treatment method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2022061055A JP2022061055A (en) | 2022-04-18 |
| JP7462527B2 true JP7462527B2 (en) | 2024-04-05 |
Family
ID=81206532
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2020168812A Active JP7462527B2 (en) | 2020-10-06 | 2020-10-06 | Sewage sludge treatment device and sewage sludge treatment method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7462527B2 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60118299A (en) * | 1983-11-29 | 1985-06-25 | Hitachi Metals Ltd | Method for modifying and dehydrating organic sludge |
| JPH0763602B2 (en) * | 1990-12-27 | 1995-07-12 | 株式会社ジャパンエナジー | Vertical multi-stage stirring tank and method for supplying copper to chemical copper plating solution using the stirring tank |
| JP3397096B2 (en) * | 1997-09-19 | 2003-04-14 | 栗田工業株式会社 | Apparatus and method for ozone treatment of biological sludge |
-
2020
- 2020-10-06 JP JP2020168812A patent/JP7462527B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2022061055A (en) | 2022-04-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2007136367A (en) | Biological wastewater treatment apparatus and biological wastewater treatment method | |
| JP3397096B2 (en) | Apparatus and method for ozone treatment of biological sludge | |
| KR100989213B1 (en) | Advanced treatment flotation method by dissolved nano air bubble water that do not need reaction, coagulation, neutralization tank (naf method) | |
| KR20010056230A (en) | Unified Tower-typed Water Treatment Plant | |
| JP6609107B2 (en) | Aerobic granule formation method, aerobic granule formation device, wastewater treatment method, and wastewater treatment device | |
| JP6594591B1 (en) | Sewage treatment apparatus and sewage treatment method | |
| JP7462527B2 (en) | Sewage sludge treatment device and sewage sludge treatment method | |
| US6162359A (en) | Method for recuperating vent gas coming from an ozonization reactor | |
| KR102005213B1 (en) | Sludge treatment method before dehydration | |
| CN109219580B (en) | Sludge treatment device and sludge treatment method | |
| JP3731806B2 (en) | Organic wastewater treatment method and apparatus | |
| CN101250016A (en) | Integrated processing technique for retting-hemp waste water and equipment thereof | |
| JPH09220592A (en) | Unaerobic treatment apparatus | |
| JP2766168B2 (en) | Solid-liquid separation equipment for digested sludge | |
| JP2001113150A (en) | Pressurized gas-liquid mixing device and waste liquid treating device using the same | |
| JP7262332B2 (en) | Water treatment method and water treatment equipment | |
| JP7144999B2 (en) | Water treatment method and water treatment equipment | |
| JP2004275996A (en) | Sludge volume reduction method | |
| JPH01123697A (en) | Aerobic biological treatment device for organic waste water | |
| TW201623155A (en) | Wastewater treatment method and wastewater treatment device | |
| JP3877262B2 (en) | Organic wastewater treatment method and equipment | |
| JP3848238B2 (en) | Colored wastewater treatment method and apparatus used therefor | |
| JP2007222830A (en) | Treatment method of nitrogen-containing organic wastewater, and treatment apparatus for it | |
| CN211814006U (en) | Anaerobic treatment device for waste incineration leachate | |
| JP7444643B2 (en) | Water treatment equipment and water treatment method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20201006 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20221018 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20230818 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20230829 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20230926 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20231212 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20240227 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20240326 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7462527 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |