JP2005021733A

JP2005021733A - Method and system for treating human waste or the like

Info

Publication number: JP2005021733A
Application number: JP2003186771A
Authority: JP
Inventors: Masahito Fujita; 雅人藤田; Hiroto Haruki; 裕人春木; Tomoyuki Doi; 知之土井; Junichi Baba; 淳一馬場
Original assignee: Takuma Co Ltd
Current assignee: Takuma Co Ltd
Priority date: 2003-06-30
Filing date: 2003-06-30
Publication date: 2005-01-27

Abstract

<P>PROBLEM TO BE SOLVED: To treat human waste or the like to attain sewage water discharge level with a simple system. <P>SOLUTION: The human waste treatment system comprises a flocculation process 5 for adding a flocculant 4 into a material 1 to be treated 1 to make phosphorus insoluble, denitrification/nitrification processes 6, 7 and 8 for decomposing and removing nitrogen and organic materials by biologically treating the material to be treated sent from the flocculation process, a sludge separation process 9 for separating sludge from the denitrified/nitrified material sent from the denitrification/nitrification processes by a solid-liquid separation apparatus, an adjustment process 2 for adjusting the separated liquid separated from the sludge to the legal level to discharge the liquid to a sewer 13, a returning pipe 14 for returning 0-100 wt.% separated sludge as returning sludge to the denitrification process and a sludge dehydration process 17 for dehydrating the non-returned residual sludge with a dehydrator to form a dehydrated cake 18. In the system constituted of a small scaled system, the load of sewer is made small, the treatment cost is reduced and the eutrophication of waste water is avoided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、し尿、浄化槽汚泥、畜糞、生ごみバイオガスプラントの排水など（以下、し尿等という）を、下水道放流に適合するレベルにまで効率よく処理する、し尿等の処理方法及びその装置に関する。
【０００２】
【従来の技術】
従来のし尿等の処理は、大半が、いわゆる「標準脱窒素法」、「高負荷脱窒素法」、「膜分離・高負荷脱窒素法」のいずれかを採用している。これらの方式は、いずれも放流先を河川等の公共水域に想定しているために、処理工程が多く複雑であって建設費、ランニングコストが高く、多くの操業人員が必要であった。また、その多くが固液分離に分離膜を利用し装置の維持管理コストを押し上げる要因ともなっている。
【０００３】
上記の既存処理システムの問題を解決するため、例えば特開２００１−１７９２８４号公報には、し尿と浄化槽汚泥とを含むし尿廃水に活性汚泥を混合し、さらに鉄系凝集剤とシリカ系凝集剤とを添加して酸化還元電位を調整し、凝集ばつ気して固液分離し、分離された処理水を生物処理する方法が開示されている。
【０００４】
また、下水道放流を取り入れ、処理システムの簡素化を図るのも一つの有力な手段である。例えば、特開２００１−０９６９２７号公報には、し尿等を生物学的に硝化・脱窒素、さらに脱リン処理して再ばつ気した後、凝集剤を添加して固液分離し、分離液を下水道放流する手段が開示されている。また、生物処理を使用しないで脱水分離のみを実施し、分離水が下水道放流基準を満たすように大量の希釈水を用いて希釈し、下水道放流する手段もある。後者の例をフローチャートにより図５に示した。しかし上記のいずれの方法も立地上の制約、設備規模がそれほど簡素化されない、大量の水を必要とし下水道料金等の操業費が膨大なものになる等の課題が残されている。
【０００５】
【特許文献】特開２００１−１７９２８４号公報
【特許文献】特開２００１−０９６９２７号公報
【発明が解決しようとする課題】
本発明は、前記したし尿処理手段の実状に鑑み、畜糞、生ごみバイオガスプラントの排水を含むし尿等を、簡易な手段によって下水道放流に適合するレベルにまで合理的に効率よく処理することのできる、かつ、設置条件の制約が少ない、し尿等の処理方法及びその処理システムを目的に研究した結果、完成されたものである。
【０００６】
【課題を解決するための手段】
本発明について図面を参照してその概要を説明する。前記の課題を解決するために本発明は、し尿等からなる被処理液に、凝集剤を添加して被処理液に含まれているリンを不溶化させ、ついで、生物的処理を施して含まれる窒素及び有機物を脱窒素し硝化した後、固液分離装置に導入して液と汚泥とを分離し、分離液は適法な下水道放流水に調整して下水道に放流し、分離汚泥はその０〜１００重量％を返送汚泥として前記の生物的脱窒素の工程に返送し、残りの余剰汚泥を排出することを特徴とするし尿等の処理方法を開示する。
【０００７】
さらに本発明は、し尿等からなる被処理液１に、凝集剤４を添加して被処理液に含まれるリンを不溶化する凝集工程５と、凝集工程から送られる被処理液に生物的処理を施して窒素化合物及び有機物を分解、除去する、脱窒素槽６、硝化槽７及び消化液返送配管８とからなる脱窒素・硝化工程と、脱窒素・硝化工程から送られる脱窒素・硝化処理液を、固液分離装置を用いて分離液１０と分離汚泥１５とに分離する汚泥分離工程９と、分離汚泥１５の０〜１００重量％を返送汚泥として脱窒素槽に返送する汚泥返送配管１４と、からなることを特徴とするし尿等の処理システムを開示する。
【０００８】
前記のし尿等の処理システムでは、想定される分離液の組成あるいは組成変動に対処できるように、希釈水等１１により適法な下水道放流水に調整して下水道１３に放流できるように調整工程１２を備えることが望ましい。さらに、返送汚泥の残りの余剰汚泥１６を脱水機により脱水して脱水ケーキ１８とし、脱水分離液１９を調整工程に送る汚泥脱水工程１７を設けておくとよい。
【０００９】
また、汚泥の分離をすすめる必要のある場合には、前記汚泥分離工程９に凝集剤４’を添加するとよい。そして、好ましくは汚泥脱水工程１７において分離された脱水分離液１９を脱窒素槽６に返送する。さらに完全に処理して下水道放流水量を削減するためには、前記の処理システムにおいて、凝集工程の後に、固液分離工程２０を設けて汚泥２１を分離し汚泥脱水工程１７に送ることもできる。固液分離工程及び／又は汚泥分離工程においては、重力沈降槽、遠心濃縮機及びスクリーン濃縮機の中から選ばれた１又は複数種の分離装置を好ましく利用できる。
【００１０】
【発明の実施の形態】
本発明に係るし尿等の処理方法および処理システムについて図面を参照し具体例を挙げながら詳しく説明する。本発明は、畜糞、生ごみバイオガスプラントの排水などを含む、し尿、浄化槽汚泥等を、効率よく合理的に処理してその廃水が下水道に放流できるレベルにするものである。図１は本発明の代表的な実施形態を例示するフローチャートであり、図２〜図４はその他の実施形態を例示するフローチャートである。図中、点線で囲った工程、貯槽等は、必要により設けられる。
【００１１】
本発明の基本的な流れを概論的に説明すると、処理するため受け入れたし尿等１は、必要により、受入・前処理段階２においてビニール袋や繊維類などのし渣がスクリーンなどを用いて除去され、被処理液として貯留３される。そして、し渣を取り除いた被処理液は、凝集工程５に送られ、ついで脱窒素６・硝化７工程、汚泥分離工程９を経て分離液１０と汚泥１５とに分離される。分離液１０は、必要により調整工程１１において希釈水等１１を加え、下水道放流に適合するレベルに希釈、調整されて下水道１３に放流される。他方、分離汚泥１５は、脱窒素・硝化工程に返送１４され、或いは脱水１７されて脱水ケーキ１８として取り出される。
【００１２】
順を追って前記各工程を具体的に説明する。受け入れたし尿等の被処理液１は、必要により前処理２によりし渣を取り除いた後、凝集工程５に送られて凝集剤４を添加・混合される。凝集剤４としては鉄系、アルミニウム系等の無機凝集剤や高分子凝集剤を適宜に選択し、必要があれば２種類以上の凝集剤を混合して用いる。凝集剤４の添加、混合によって、リン化合物の多くが凝集汚泥側に移行し凝集、不溶化される。従来、液中に存在するリン化合物は、生物処理において微生物の体内に取り込まれ、沈殿槽底部などの酸素濃度が低い状態で再溶解し、富栄養化の原因になっていた。本発明においてリン化合物は、生物処理に先立つ凝集処理により、凝集物中に取り込まれて液中に再溶解するおそれがなくなり、凝集物として確実に分離され除去される。そして、本発明システムから下水道中に放出される廃水中のリン含有量を低減させ、富栄養化を防止する効果を奏する。使用する凝集剤濃度や混合装置は、し尿等の組成や濃度などに基づき、従来の経験、先行試験等を参考にして適宜に選択し決めればよい。
【００１３】
ついで、脱窒素・硝化工程（６，７，８）では、通常、脱窒素槽６と硝化槽７とをこの順に配置して前工程からの被処理液を生物的に処理し、脱窒素、硝化する。具体的には、硝化槽７から硝酸化反応が完了した硝化液を抜き出して脱窒素槽６に返送・循環８し、脱窒素槽６に投入されているし尿等と混合し、し尿中のＢＯＤを有機炭素源とする脱窒素反応を起こさせ、し尿等中の有機物及び窒素を除去する。また、両槽における被処理液の平均処理時間は、被処理液に含まれる被処理成分濃度により適宜に決められるが、一般的にはそれぞれ０．５〜３日程度である。硝化液の脱窒素槽６への返送率は、被処理液量の２〜５０倍程度である。被処理液は、さらに汚泥分離工程９に送られる。
【００１４】
汚泥分離工程９では被処理液（硝化液）中の汚泥１５と液１０とを分離する。汚泥分離には重力沈降槽が好ましく利用されるが、この他、遠心濃縮機やスクリーン濃縮機なども利用し、或いは前記装置を適宜に組合せて利用することができる。通常、分離液１０は、調整工程１２において希釈水等１１を加えて適法に放流が許容される状態に水質を調整し下水道１３に放流される。条件によっては汚泥脱水工程１７からの脱水分離液１９を併合して水質を調整し放流する。分離液１０等がすでに下水道放流に適合するレベルにある場合は、そのまま希釈水等を加えずに下水道１３に放流してもよい。
【００１５】
一方、分離汚泥１５は、０〜１００％を脱窒素槽６に返送１４する。残った余剰汚泥１６はそのまま系外に排出してもよいが、搬送や次工程の処理のためには汚泥脱水工程１７を設けて脱水、減容し脱水ケーキ１８にしておくことが望ましい。脱水機には、遠心脱水機、スクリュープレス脱水機、ベルトプレス脱水機などを適宜に選択して利用すればよい。
【００１６】
以上は本発明の代表的な流れを説明したものであるが、本発明は適宜に実地の条件に合わせて編成することができるので、その実施形態を例示し説明する。例えば、図２に示されるように汚泥分離工程９での汚泥の分離性能を高める目的で凝集剤添加設備を設け、凝集剤４’を添加してもよい。凝集剤４’の種類や添加量等は被処理液の特性等に合わせて適宜に選定すればよい。また、下水道放流水の水質を向上する目的では、図３に示されるように、汚泥脱水工程１７からの脱水分離液１９を下水道に放流する分離液１０に併合させないで、脱窒素槽６に返送することができる。ＳＳ成分やリンを確実に除去する必要のある場合には、図４に示されるように、凝集工程５と次工程との間に固液分離工程２０を設け、分離汚泥２１を汚泥脱水工程１７に導いて脱水処理を施こす。図１〜４に示された形態は、本発明の目的を逸脱しない限り本発明として適宜に組み合わせて実施することができる。
【００１７】
【実施例】
本発明について実験室的にその効果を確認したので説明する。本実験では、従来の下水道放流方式を採用する某処理場において、し渣を除去して処理中のし尿等を被処理液に使用した。この処理場では、し尿等に生物処理を行わず、図５に示したプロセス同様に、凝集剤を添加して固形分を脱水分離した後、分離液を希釈し下水道に放流していた。本実験に用いた被処理液には、約５０％のし尿と約５０％の浄化槽汚泥とが含まれ、２５リットル／日を連続流通方式で処理した。
【００１８】
まず、被処理水に凝集剤（ポリ硫酸第２鉄）を２，０００ｍｇ／ｌ添加し、ついで脱窒、硝化処理を施した。脱窒槽、硝化槽における平均滞留時間はそれぞれ１．５日、硝化槽から脱窒槽への硝化液の返送量は被処理液量に対し約５倍であった。硝化槽から抜き取った硝化液は、沈殿槽を用いて汚泥を分離した。分離された希釈前の分離液、原液に用いたし尿等の被処理液のＢＯＤ、ＳＳ、窒素含有量（ｍｇ／ｌ）、りん含有量（ｍｇ／ｌ）測定値を表１に示した。また、比較のために同処理場において同じし尿等を処理したときの希釈前における放流水の測定値、及び下水道法により定められた下水道放流基準値を共に表１に示す。なお、測定方法はいずれもＪＩＳＫ０１０２又は下水試験法に準拠した。
【００１９】
【表１】

【００２０】
【発明の効果】
本発明し尿等の処理方法及びその処理システムは、順不同に
設備が下水道放流レベルの処理に必要な小規模設備のみで構成され、高価で複雑な膜分離等を必要としないこと、
生物処理工程を含むのでＢＯＤ等の汚濁成分が十分に除去され希釈水量の大幅な節約が可能であり、下水道設備にかける負担の小さいこと、
生物処理の前段階で凝集処理を実施するので確実にリンが除去され、廃水の富栄養化を防止できること
などの、顕著な効果を奏する。その結果、浄化槽汚泥、し尿汚泥など廃水処理を従来に較べて簡潔な手段を用い、建設費、用役等の操業費、労務費、設備の維持管理費等を節約することができ、かつ、放流水質の悪化を防止できる。
【図面の簡単な説明】
【図１】本発明し尿等処理システムの代表的な実施形態を示すフローチャート
【図２】本発明し尿等処理システムの他の実施形態を例示するフローチャート
【図３】本発明し尿等処理システムの他の実施形態を例示するフローチャート
【図４】本発明し尿等処理システムの他の実施形態を例示するフローチャート
【図５】従来のし尿等下水道放流処理の実施形態を示すフローチャート
【符号の説明】
１：し尿等の被処理液２：受入・前処理段階
３：貯留（槽、工程）４，４’：凝集剤
５：凝集工程６：脱窒素工程（槽）
７：硝化工程（槽）８：消化液返送配管
９：汚泥分離工程１０：分離液
１１：希釈水１２：調整工程
１３：下水道１４：返送汚泥（汚泥返送配管）
１５：分離汚泥１６：余剰汚泥（貯留槽）
１７，１７’：汚泥脱水工程１８：脱水ケーキ
１９：脱水分離液（配管）２０：固液分離工程
２１：固液分離工程の排出汚泥（配管）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for treating human waste, such as human waste, septic tank sludge, livestock dung, wastewater from garbage biogas plants (hereinafter referred to as human waste) and the like, which efficiently treats the wastewater to a level suitable for sewage discharge. .
[0002]
[Prior art]
Most of the conventional treatments for human waste and the like employ one of the so-called “standard denitrification method”, “high load denitrification method”, and “membrane separation / high load denitrification method”. All of these methods assume the discharge destination in public water areas such as rivers, so that the treatment process is complicated, the construction costs and running costs are high, and a large number of operators are required. In addition, many of them also use a separation membrane for solid-liquid separation, which increases the maintenance cost of the apparatus.
[0003]
In order to solve the problems of the above existing treatment system, for example, Japanese Patent Application Laid-Open No. 2001-179284 discloses that activated sludge is mixed with urine wastewater containing human waste and septic tank sludge, and further, an iron-based flocculant and a silica-based flocculant Is added to adjust the oxidation-reduction potential, agglomerate aeration, solid-liquid separation, and biological treatment of the separated treated water.
[0004]
Another effective method is to simplify the treatment system by introducing sewer discharge. For example, in Japanese Patent Laid-Open No. 2001-096927, human waste is biologically nitrified / denitrogenated and dephosphorized after dephosphorization, followed by addition of a flocculant and solid-liquid separation. Means for draining sewers are disclosed. There is also a means of performing only dehydration separation without using biological treatment, diluting with a large amount of dilution water so that the separated water satisfies the sewer discharge standard, and discharging the sewer. The latter example is shown in FIG. However, any of the above-mentioned methods still have problems such as location restrictions, the facility scale is not so simplified, a large amount of water is required, and operation costs such as sewerage charges become enormous.
[0005]
[Patent Document] Japanese Patent Application Laid-Open No. 2001-179284 [Patent Document] Japanese Patent Application Laid-Open No. 2001-096927 [Problem to be Solved by the Invention]
In view of the actual state of the above-described means for treating human waste, the present invention can be used to treat animal manure, human waste including waste biogas plant wastewater, etc. reasonably and efficiently to a level suitable for sewer discharge by simple means. This was completed as a result of research aimed at a treatment method and treatment system for human waste and the like, which can be performed and has few restrictions on installation conditions.
[0006]
[Means for Solving the Problems]
The outline of the present invention will be described with reference to the drawings. In order to solve the above-mentioned problems, the present invention includes a liquid to be treated consisting of human waste and the like by adding a flocculant to insolubilize phosphorus contained in the liquid to be treated, and then performing biological treatment. Nitrogen and organic matter are denitrified and nitrified, and then introduced into a solid-liquid separator to separate the liquid and sludge. The separated liquid is adjusted to legal sewer effluent and discharged into the sewer. Disclosed is a method for treating urine or the like, characterized in that 100% by weight is returned to the biological denitrification step as return sludge and the remaining excess sludge is discharged.
[0007]
Furthermore, the present invention provides a biological treatment for the liquid to be treated 1 that is added to the liquid to be treated 1 such as human waste by adding a flocculant 4 to insolubilize phosphorus contained in the liquid to be treated. Denitrification / nitrification process consisting of denitrification tank 6, nitrification tank 7 and digestive liquid return pipe 8 for decomposing and removing nitrogen compounds and organic substances, and denitrification / nitrification treatment liquid sent from denitrification / nitrification process A sludge separation step 9 for separating the separated sludge 15 into a separated liquid 10 and a separated sludge 15 using a solid-liquid separator, and a sludge return pipe 14 for returning 0 to 100% by weight of the separated sludge 15 as a return sludge to a denitrification tank; A treatment system for human waste or the like is disclosed.
[0008]
In the treatment system for human waste and the like, the adjustment step 12 is performed so that it can be adjusted to legal sewer effluent water by the diluted water 11 so that it can be discharged into the sewer 13 so as to cope with an assumed composition of the separation liquid or composition variation. It is desirable to provide. Further, it is preferable to provide a sludge dewatering step 17 in which the remaining surplus sludge 16 of the returned sludge is dehydrated by a dehydrator to form a dehydrated cake 18 and the dehydrated separation liquid 19 is sent to the adjustment step.
[0009]
Further, when it is necessary to promote the separation of sludge, a flocculant 4 ′ may be added to the sludge separation step 9. And preferably, the dewatered separation liquid 19 separated in the sludge dewatering step 17 is returned to the denitrification tank 6. In order to reduce the amount of sewage effluent by further complete treatment, the solid-liquid separation step 20 can be provided after the flocculation step to separate the sludge 21 and send it to the sludge dewatering step 17. In the solid-liquid separation step and / or the sludge separation step, one or more kinds of separation devices selected from a gravity sedimentation tank, a centrifugal concentrator, and a screen concentrator can be preferably used.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The processing method and processing system for human waste and the like according to the present invention will be described in detail with reference to the drawings with specific examples. The present invention efficiently and rationally treats human waste, septic tank sludge, etc., including livestock excrement, garbage biogas plant wastewater, etc., to a level at which the wastewater can be discharged into sewers. FIG. 1 is a flowchart illustrating a typical embodiment of the present invention, and FIGS. 2 to 4 are flowcharts illustrating other embodiments. In the figure, a process surrounded by a dotted line, a storage tank, and the like are provided as necessary.
[0011]
In general, the basic flow of the present invention will be described. The manure 1 that is received for processing is removed, if necessary, in the receiving / preprocessing stage 2 such as plastic bags and fibers using screens. And stored 3 as a liquid to be treated. Then, the liquid to be treated from which the residue has been removed is sent to the agglomeration process 5 and then separated into the separation liquid 10 and the sludge 15 through the denitrification 6, nitrification 7 process and the sludge separation process 9. The separation liquid 10 is diluted and adjusted to a level suitable for the sewer discharge, and added to the sewer 13 after adding diluted water 11 in the adjustment step 11 as necessary. On the other hand, the separated sludge 15 is returned 14 to the denitrification / nitrification step, or dehydrated 17 and taken out as a dehydrated cake 18.
[0012]
Each step will be specifically described in order. The liquid 1 to be treated such as human urine is removed by pretreatment 2 if necessary, and then sent to the agglomeration step 5 where the aggregating agent 4 is added and mixed. As the flocculant 4, an inorganic flocculant such as iron or aluminum, or a polymer flocculant is appropriately selected, and if necessary, two or more kinds of flocculants are mixed and used. By adding and mixing the flocculant 4, most of the phosphorus compound moves to the flocculent sludge side and is aggregated and insolubilized. Conventionally, phosphorus compounds present in liquids are taken into the body of microorganisms during biological treatment and redissolved in a state where the oxygen concentration at the bottom of the precipitation tank is low, causing eutrophication. In the present invention, the phosphorous compound is reliably separated and removed as an agglomerate by the agglomeration treatment prior to the biological treatment without being feared of being taken into the agglomerate and re-dissolved in the liquid. And the phosphorus content in the wastewater discharged | emitted in a sewer from this invention system is reduced, and there exists an effect which prevents eutrophication. The concentration of the flocculant and the mixing device to be used may be appropriately selected and determined based on the composition and concentration of human waste and the like, with reference to conventional experience and prior tests.
[0013]
Next, in the denitrification / nitrification step (6, 7, 8), the denitrification tank 6 and the nitrification tank 7 are usually arranged in this order to biologically treat the liquid to be treated from the previous process, Nitrifies. Specifically, the nitrification solution that has undergone the nitrification reaction is extracted from the nitrification tank 7, returned to the denitrification tank 6 and circulated 8, mixed with urine or the like that has been put into the denitrification tank 6, and BOD in human waste The organic nitrogen source is used to cause a denitrification reaction to remove organic matter and nitrogen in human waste. Moreover, although the average processing time of the to-be-processed liquid in both tanks is decided suitably by the to-be-processed component density | concentration contained in a to-be-processed liquid, generally it is about 0.5 to 3 days, respectively. The rate of returning the nitrification liquid to the denitrification tank 6 is about 2 to 50 times the amount of liquid to be treated. The liquid to be treated is further sent to the sludge separation step 9.
[0014]
In the sludge separation step 9, the sludge 15 and the liquid 10 in the liquid to be treated (nitrification liquid) are separated. Gravity sedimentation tanks are preferably used for sludge separation. In addition, a centrifugal concentrator, a screen concentrator, or the like can be used, or the above devices can be used in appropriate combinations. In general, the separation liquid 10 is discharged into the sewer 13 after adjusting the water quality to a state where discharge is allowed in a proper manner by adding dilution water 11 or the like in the adjustment step 12. Depending on the conditions, the dewatering separation liquid 19 from the sludge dewatering step 17 is combined to adjust the water quality and discharge it. If the separation liquid 10 or the like is already at a level compatible with the sewer discharge, it may be discharged into the sewer 13 without adding dilution water or the like.
[0015]
On the other hand, the separated sludge 15 returns 14 to 0 to 100% to the denitrification tank 6. The remaining surplus sludge 16 may be discharged out of the system as it is, but it is desirable to provide a sludge dewatering step 17 for dehydration and volume reduction to provide a dewatered cake 18 for transport and subsequent processing. As the dehydrator, a centrifugal dehydrator, a screw press dehydrator, a belt press dehydrator or the like may be appropriately selected and used.
[0016]
The above is a description of the typical flow of the present invention. Since the present invention can be appropriately knitted in accordance with actual conditions, an embodiment will be exemplified and described. For example, as shown in FIG. 2, a flocculant addition facility may be provided for the purpose of improving the sludge separation performance in the sludge separation step 9, and the flocculant 4 ′ may be added. What is necessary is just to select suitably the kind, addition amount, etc. of flocculant 4 'according to the characteristic etc. of a to-be-processed liquid. Further, for the purpose of improving the quality of the sewage effluent water, as shown in FIG. 3, the dehydrated separation liquid 19 from the sludge dewatering step 17 is not returned to the separation liquid 10 discharged to the sewer, but returned to the denitrification tank 6. can do. When it is necessary to reliably remove the SS component and phosphorus, as shown in FIG. 4, a solid-liquid separation step 20 is provided between the aggregation step 5 and the next step, and the separated sludge 21 is sludge dewatering step 17. Guide to dehydration. The embodiments shown in FIGS. 1 to 4 can be implemented in appropriate combination as the present invention without departing from the object of the present invention.
[0017]
【Example】
Since the effect of the present invention has been confirmed in the laboratory, it will be described. In this experiment, in the waste treatment plant adopting the conventional sewer discharge method, the residue was removed and the manure etc. being processed was used as the liquid to be treated. In this treatment plant, biological treatment was not performed on human waste or the like, and the flocculant was added and the solid content was dehydrated and separated as in the process shown in FIG. 5, and then the separated liquid was diluted and discharged into the sewer. The liquid to be treated used in this experiment contained about 50% human waste and about 50% septic tank sludge, and 25 liters / day was treated in a continuous flow system.
[0018]
First, 2,000 mg / l of a flocculant (polyferric sulfate) was added to the water to be treated, followed by denitrification and nitrification. The average residence time in the denitrification tank and the nitrification tank was 1.5 days, respectively, and the return amount of the nitrification liquid from the nitrification tank to the denitrification tank was about 5 times the amount of the liquid to be treated. From the nitrification liquid extracted from the nitrification tank, sludge was separated using a precipitation tank. Table 1 shows measured values of BOD, SS, nitrogen content (mg / l), and phosphorus content (mg / l) of the separated liquid before dilution and a liquid to be treated such as urine used as a stock solution. For comparison, Table 1 shows both the measured values of the discharged water before dilution when the same urine was processed at the same treatment plant, and the sewage discharge standard values defined by the Sewerage Law. In addition, all the measuring methods were based on JIS K0102 or a sewage test method.
[0019]
[Table 1]

[0020]
【The invention's effect】
The treatment method of the present invention, such as urine, and its treatment system, the equipment is composed of only small-scale equipment necessary for processing at the sewer discharge level in random order, and does not require expensive and complicated membrane separation,
Since it includes a biological treatment process, pollutant components such as BOD are sufficiently removed, and the amount of diluted water can be saved significantly.
Since the agglomeration treatment is carried out at the pre-stage of the biological treatment, the phosphorous is surely removed, and the effluent can be prevented from being eutrophied. As a result, wastewater treatment such as septic tank sludge and human waste sludge can be made simpler than before, saving construction costs, operating expenses such as utilities, labor costs, equipment maintenance costs, etc. The deterioration of the discharged water quality can be prevented.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a typical embodiment of the urine treatment system of the present invention. FIG. 2 is a flowchart illustrating another embodiment of the urine treatment system of the present invention. FIG. 4 is a flowchart illustrating another embodiment of the treatment system for urine of the present invention. FIG. 5 is a flowchart illustrating an embodiment of conventional sewer discharge processing for human urine.
1: Liquid to be treated such as human waste 2: Acceptance / pretreatment stage 3: Storage (tank, process) 4, 4 ': Coagulant 5: Aggregation process 6: Denitrification process (tank)
7: Nitrification process (tank) 8: Digested liquid return pipe 9: Sludge separation process 10: Separation liquid 11: Diluted water 12: Adjustment process 13: Sewer 14: Return sludge (sludge return pipe)
15: Separation sludge 16: Surplus sludge (storage tank)
17, 17 ': Sludge dewatering step 18: Dehydrated cake 19: Dehydrated separation liquid (pipe) 20: Solid-liquid separation step 21: Discharged sludge (pipe) in the solid-liquid separation step

Claims

A flocculant is added to the liquid to be treated, such as human waste, to insolubilize phosphorus contained in the liquid to be treated, and then biological treatment is performed to denitrify and nitrify nitrogen and organic substances contained therein. It is introduced into a liquid separator to separate the liquid and sludge, and the separated liquid is adjusted to legal sewer effluent and discharged into the sewer. A method for treating human waste or the like, characterized by returning to the nitrogen process and discharging the remaining excess sludge.

A coagulation step (5) in which the flocculant (4) is added to the liquid to be treated (1) made of human waste or the like to insolubilize phosphorus contained in the liquid to be treated;
Denitrification consisting of a denitrification tank (6), a nitrification tank (7), and a digestive liquid return pipe (8), which biologically treats the liquid to be treated sent from the coagulation step to decompose and remove nitrogen compounds and organic substances.・ Nitrification process,
A sludge separation step (9) for separating the denitrification / nitrification treatment liquid sent from the denitrification / nitrification step into a separated liquid (10) and a separated sludge (15) using a solid-liquid separator;
A sludge return pipe (14) for returning 0 to 100% by weight of the separated sludge (15) as return sludge to a denitrification tank, and a treatment system for human waste or the like.

The treatment system for human waste or the like according to claim 2, further comprising an adjusting step (12) for adjusting the separated liquid to a legal sewer effluent by using diluted water (11) and discharging the sewer to the sewer (13).

The remaining sludge (16) of the returned sludge is dewatered by a dehydrator to form a dehydrated cake (18), and a sludge dewatering step (17) for sending the dewatered separation liquid (19) to the adjusting step is provided. A processing system for human waste or the like according to 2 or 3.

The treatment system for human waste or the like according to claim 2, 3 or 4, wherein in the sludge separation step, the flocculant (4 ') is added to separate the sludge.

The treatment system for human waste or the like according to any one of claims 2 to 5, wherein the dewatered separation liquid (19) in the sludge dewatering step is returned to the denitrification tank.

The treatment of human waste or the like according to any one of claims 2 to 6, wherein after the coagulation step, a solid-liquid separation step (20) is provided to separate the sludge, and the sludge (21) is sent to the sludge dewatering step. system.

8. The solid-liquid separation step and / or the sludge separation step, wherein one or a plurality of types of separation devices selected from gravity sedimentation tanks, centrifugal concentrators, and screen concentrators are used. A treatment system for human waste or the like according to any one of the above.