JPS6120357B2 - - Google Patents
Info
- Publication number
- JPS6120357B2 JPS6120357B2 JP11742278A JP11742278A JPS6120357B2 JP S6120357 B2 JPS6120357 B2 JP S6120357B2 JP 11742278 A JP11742278 A JP 11742278A JP 11742278 A JP11742278 A JP 11742278A JP S6120357 B2 JPS6120357 B2 JP S6120357B2
- Authority
- JP
- Japan
- Prior art keywords
- sludge
- concentration
- organic
- ratio
- nitrogen
- 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.)
- Expired
Links
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 95
- 239000010802 sludge Substances 0.000 claims description 68
- 229910052757 nitrogen Inorganic materials 0.000 claims description 47
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 42
- 238000005273 aeration Methods 0.000 claims description 25
- 239000002957 persistent organic pollutant Substances 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 11
- 229910052799 carbon Inorganic materials 0.000 claims description 11
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 claims description 4
- 230000002123 temporal effect Effects 0.000 claims 1
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 48
- 239000007789 gas Substances 0.000 description 26
- 229910002092 carbon dioxide Inorganic materials 0.000 description 24
- 239000005416 organic matter Substances 0.000 description 19
- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical compound [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 description 14
- 239000001569 carbon dioxide Substances 0.000 description 14
- 108020004414 DNA Proteins 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 239000010865 sewage Substances 0.000 description 6
- 238000004062 sedimentation Methods 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000002351 wastewater Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 3
- 239000000356 contaminant Substances 0.000 description 3
- 239000003344 environmental pollutant Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 125000001477 organic nitrogen group Chemical group 0.000 description 3
- 231100000719 pollutant Toxicity 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 238000012851 eutrophication Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 102000053602 DNA Human genes 0.000 description 1
- 101710093543 Probable non-specific lipid-transfer protein Proteins 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000003311 flocculating effect Effects 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000010841 municipal wastewater Substances 0.000 description 1
- 239000001272 nitrous oxide Substances 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 229920002477 rna polymer Polymers 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- -1 that is Proteins 0.000 description 1
- 239000003403 water pollutant Substances 0.000 description 1
Classifications
-
- 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
- Y02W10/10—Biological treatment of water, waste water, or sewage
Landscapes
- Activated Sludge Processes (AREA)
Description
【発明の詳細な説明】
本発明は、有機物を含む汚水を活性汚泥法によ
り処理する活性汚泥水処理装置の制御方法に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling an activated sludge water treatment apparatus for treating wastewater containing organic matter by an activated sludge method.
活性汚泥プロセスは都市下水ならびに産業廃水
中の有機汚染質の除去に広く用いられている。こ
のプロセスは、空気吹込みによつて酸素を供給さ
れる曝気槽において活性汚泥と呼ばれる微生物群
の同化作用により廃水中の有機性物質を汚泥に変
換し、沈殿池において汚泥を濃縮分離し、濃縮さ
れた汚泥の一部分を余剰汚泥として系外に引抜く
ことを特徴とする。 Activated sludge processes are widely used for the removal of organic pollutants in municipal and industrial wastewater. This process converts organic substances in wastewater into sludge through the assimilation action of a group of microorganisms called activated sludge in an aeration tank that is supplied with oxygen by air blowing, and then concentrates and separates the sludge in a settling tank. A part of the sludge produced is drawn out of the system as surplus sludge.
活性汚泥プロセスの一例を第１図に示す。ここ
で、流入水１は沈殿池４から還流された返送汚泥
７と曝気槽２において混合され、送風機９から送
られる空気１０によつて撹拌されつつ酸素を供給
される。曝気槽２においては、流入水中の有機汚
染質が微生物の同化作用によつて汚泥に変換さ
れ、混合液３は沈殿池４において処理水５と返送
汚泥７および余剰汚泥８に分けられ、余剰汚泥８
は系外に取出される。活性汚泥プロセスにおける
曝気槽２と沈殿池４は一体のものであり、どちら
か一方の性能が悪くても汚水浄化の機能を発揮す
ることはできない。沈殿池において、活性汚泥と
処理水との分離を行なうに際して最も重要なこと
は、活性汚泥が十分な凝集性を有し、沈降性がす
ぐれていることである。これを達成するには有機
物負荷量を適正値に保てばよいことが知られてい
る。炭酸ガス濃度を指標とする有機物質負荷量一
定制御系はすでに提案されている（特願昭50−
41273）。 An example of an activated sludge process is shown in Figure 1. Here, the inflow water 1 is mixed with the return sludge 7 returned from the settling tank 4 in the aeration tank 2, and is supplied with oxygen while being stirred by the air 10 sent from the blower 9. In the aeration tank 2, organic pollutants in the inflow water are converted to sludge by the assimilation action of microorganisms, and the mixed liquid 3 is divided into treated water 5, return sludge 7, and surplus sludge 8 in the settling tank 4. 8
is taken out of the system. The aeration tank 2 and settling tank 4 in the activated sludge process are integrated, and even if the performance of either one is poor, the sewage purification function cannot be achieved. The most important thing when separating activated sludge and treated water in a settling tank is that the activated sludge has sufficient flocculating properties and excellent settling properties. It is known that this can be achieved by keeping the organic matter load at an appropriate value. A constant organic substance load control system using carbon dioxide concentration as an index has already been proposed (patent application 1972-
41273).
活性汚泥の沈降性は、有機物負荷量の他に流入
水中の窒素量の影響も大きいことが知られてい
る。これは、汚泥の細胞内に摂取される窒素量に
よるものである。ところが、流入水中の窒素量を
オンラインで長期間にわたり連続測定できる装置
が開発されていないため、窒素量を制御すること
はできないのが実情である。このように、従来技
術では、活性汚泥の沈降性を支配する直接の原因
に対する対策がなされていないため、次のような
欠点を有している。 It is known that the sedimentation property of activated sludge is greatly influenced by the amount of nitrogen in the influent water as well as the amount of organic matter load. This is due to the amount of nitrogen taken into the cells of the sludge. However, since no device has been developed that can continuously measure the amount of nitrogen in influent water online over a long period of time, the reality is that the amount of nitrogen cannot be controlled. As described above, the conventional technology has the following drawbacks because no measures have been taken to deal with the direct causes governing the settling properties of activated sludge.
(1) 流入水中の窒素量が少なくなると汚泥の細胞
内に取り込まれる窒素が少なくなるため、バル
キングを起こしやすくなり汚泥が沈降しにくく
なる。(1) When the amount of nitrogen in the inflow water decreases, less nitrogen is taken into the cells of the sludge, making bulking more likely to occur and making it difficult for the sludge to settle.
(2) 流入水中の窒素量が多いときは汚泥の沈降性
は良好に保たれるが富栄養化の誘因となり、二
次公害の発生原因になる。(2) When the amount of nitrogen in the inflow water is high, the settling properties of sludge are maintained well, but this can lead to eutrophication and cause secondary pollution.
(3) 前記(1)の現象のため、沈殿池において処理水
中に汚泥が同伴し、処理水の水質が悪くなる。
また、沈殿池での汚泥の圧密性が低下するた
め、返送汚泥濃度が低くなり、曝気槽汚泥濃度
（以下MLSSと略称する）を所定の値に保つこ
とが困難になり処理効率が低下する。(3) Due to the phenomenon described in (1) above, sludge is entrained in the treated water in the settling tank, and the quality of the treated water deteriorates.
In addition, since the compactability of the sludge in the settling tank decreases, the concentration of returned sludge decreases, making it difficult to maintain the aeration tank sludge concentration (hereinafter abbreviated as MLSS) at a predetermined value, resulting in a decrease in treatment efficiency.
本発明は従来技術の前記欠点に対処してなされ
たもので、その目的とするところは流入下水中の
汚染質濃度と窒素濃度の比を一定に保ち、活性汚
泥による水処理を効率よく行なうための制御法を
提供するにある。 The present invention has been made to address the above-mentioned drawbacks of the prior art, and its purpose is to maintain a constant ratio of pollutant concentration to nitrogen concentration in inflowing sewage and to efficiently perform water treatment using activated sludge. The aim is to provide a control method for
本発明の特徴とするところは、流入水汚染質濃
度と総窒素濃度（以下ＴNと略称する）の比を設
定値に保つように曝気槽流入水中に窒素源あるい
は有機炭素源を添加して活性汚泥の沈降性を良好
に保つようにしたものである。 A feature of the present invention is that a nitrogen source or organic carbon source is added to the aeration tank inflow water so as to maintain the ratio of the inflow water pollutant concentration to the total nitrogen concentration (hereinafter abbreviated as TN ) at a set value. This is designed to maintain good settling properties of activated sludge.
まず、本発明の基本的構成を詳細に説明する。
汚泥容量指標（Sludge Volume Index、以下SVI
と略称する）に対するBOD基準の有機汚染質濃
度とＴNの比および有機汚染質濃度とアンモニア
態窒素濃度（以下NH− ４−Ｎと略称する）の比の関
係を第２図に示す。ここで、SVIは曝気槽混合液
を１のメスシリンダにとり、30分間静置した後
の汚泥沈殿容量の百分率から(1)式で計算される。 First, the basic configuration of the present invention will be explained in detail.
Sludge Volume Index (SVI)
Figure 2 shows the relationship between the BOD standard organic pollutant concentration and the ratio of T N and the ratio of the organic pollutant concentration and ammonia nitrogen concentration (hereinafter abbreviated as NH - 4 -N) with respect to the BOD standard. Here, SVI is calculated by formula (1) from the percentage of sludge sedimentation volume after the aeration tank mixture is placed in a graduated cylinder and left to stand for 30 minutes.
また、有機汚染質濃度は排水中に含有される有
機物の濃度を示すもので、COD（化学的酸素要
求量：Chemical Oxygen Demand）及びBOD
（生物化学的酸素要求量：Biochemical Oxygen
Demand）等で表わされる値である。 In addition, organic pollutant concentration indicates the concentration of organic matter contained in wastewater, including COD (Chemical Oxygen Demand) and BOD.
(Biochemical Oxygen Demand)
This is the value expressed as (Demand), etc.
SVI（ml/g）＝混合液の汚泥沈殿率×１０４／曝気槽
汚泥濃度（mg／）…(1)
第２図から、SVIはBOD基準の有機汚染質濃度
とＴNの比が25付近で、またBOD基準の有機汚染
質濃度とNH− ４−Ｎの比が40付近で最小値を示すこ
とが分る。 SVI (ml/g) = sludge sedimentation rate of mixed solution x 10 4 / aeration tank sludge concentration (mg/)... (1) From Figure 2, SVI is the ratio of organic pollutant concentration of BOD standard to T N of 25 It can also be seen that the ratio of BOD standard organic pollutant concentration to NH - 4 -N shows a minimum value around 40.
第２図は、第１図の装置において、曝気槽２の
容量を25、沈殿池４の容積を8.5として実測
した結果を示したものである。この場合の測定条
件は、実機の汚水処理場のものに近い値を選び、
曝気槽内滞留時間6.3時間、曝気槽内温度17℃、
曝気空気量180/h、返送汚泥量２/h、活性汚
泥濃度1300mg/、排水内の有機物（汚染質）濃
度をBOD40〜250ppmとした。 FIG. 2 shows the results of actual measurements in the apparatus shown in FIG. 1, with the capacity of the aeration tank 2 being 25 and the capacity of the settling tank 4 being 8.5. In this case, the measurement conditions are chosen to be close to those of the actual sewage treatment plant.
Residence time in the aeration tank 6.3 hours, temperature inside the aeration tank 17℃,
Aeration air flow rate was 180/h, return sludge flow rate was 2/h, activated sludge concentration was 1300 mg/h, and organic matter (pollutant) concentration in wastewater was BOD 40 to 250 ppm.
次にSVIと汚泥内デオキシリボ核酸（Deoxy
Ribo Nucleic Acid、以下DNAと略称する）の関
係を第４図に示す。SVIはDNAの増加に従つて低
い値になつている。DNAはほとんどが塩基性の
蛋白質であることがわかつており、細胞物質へ転
換された窒素は、蛋白質中に含まれる有機態窒素
すなわち、DNAになつている。したがつて、
DNAの増加と共に汚泥の沈降性は向上する。上
記第２図から活性汚泥の沈降性は流入水中の有機
汚染質濃度と窒素濃度の比を設定値に維持するこ
とによつて、良好に保つことが可能であることが
わかる。実際には前記比ｒ＝BOD／ＴNの値を18
〜35の範囲に設定するのが望ましい。 Next, SVI and deoxyribonucleic acid (Deoxy) in sludge
Figure 4 shows the relationship between Ribo Nucleic Acid (hereinafter abbreviated as DNA). SVI becomes lower as DNA increases. It is known that most of DNA is a basic protein, and the nitrogen converted into cellular substances becomes organic nitrogen contained in proteins, that is, DNA. Therefore,
The sedimentability of sludge improves as DNA increases. From FIG. 2 above, it can be seen that the sedimentation property of activated sludge can be maintained well by maintaining the ratio of organic pollutant concentration to nitrogen concentration in the inflow water at a set value. Actually, the value of the ratio r=BOD/T N is 18
It is preferable to set it in the range of ~35.
前述の有機汚染質濃度は曝気槽排ガス中の炭酸
ガス発生速度ＲCO2（縦軸）と有機物負荷量Ｌ
（横軸）の関係を示す第５図を利用して求められ
る。すなわち、第５図に基づいて炭酸ガス発生速
度ＲCO2から有機物負荷量Ｌを求め、この有機物
負荷量Ｌ，MLSS、曝気槽容積Ｖ及び流入水量Ｑ
から後述の(5)式により有機汚染質濃度ＯCを求め
る。このようにすれば、有機汚染質濃度を水質計
で直接測定しなくても求めることが可能である。 The above-mentioned organic pollutant concentration is determined by the carbon dioxide generation rate R CO2 (vertical axis) and the organic matter load L in the aeration tank exhaust gas.
(horizontal axis) using FIG. 5, which shows the relationship. That is, the organic matter load L is determined from the carbon dioxide gas generation rate R CO2 based on Fig. 5, and this organic matter load L, MLSS, aeration tank volume V, and inflow water volume Q
The organic pollutant concentration O C is determined from Equation (5) described below. In this way, it is possible to determine the organic pollutant concentration without directly measuring it with a water quality meter.
また、流入水中の総窒素濃度は総窒素濃度（縦
軸）とN2Oガス発生速度（横軸）の関係を示す第
６図から求めることができる。通常の都市下水で
は、有機態窒素が総窒素の約2/3、アンモニア態
窒素が残り1/3であり、また有機態窒素は生物処
理によつてほとんどアンモニア態窒素に分解され
る。好気的条件においてアンモニアは亜硝酸に酸
化され、亜硝酸は硝酸に酸化される（硝化過
程）。硝酸及び亜硝酸を含む液を嫌気的条件に保
つと窒素ガスとN2Oガスに還元される（脱窒過
程）。硝化過程及び脱窒過程は(2)及び(3)式で表わ
される。 Further, the total nitrogen concentration in the inflow water can be determined from FIG. 6, which shows the relationship between the total nitrogen concentration (vertical axis) and the N 2 O gas generation rate (horizontal axis). In normal urban sewage, organic nitrogen accounts for about 2/3 of the total nitrogen, and ammonia nitrogen accounts for the remaining 1/3, and most of the organic nitrogen is decomposed into ammonia nitrogen through biological treatment. Under aerobic conditions, ammonia is oxidized to nitrite, and nitrite is oxidized to nitric acid (nitrification process). When a liquid containing nitric acid and nitrite is kept under anaerobic conditions, it is reduced to nitrogen gas and N 2 O gas (denitrification process). The nitrification process and denitrification process are expressed by equations (2) and (3).
このように、溶液中の総窒素濃度とN2Oガス発
生速度の間に比例関係が存在するということは、
総窒素濃度を水質計で直接測定しなくても求める
ことが可能であることを意味している。 Thus, the existence of a proportional relationship between the total nitrogen concentration in the solution and the N 2 O gas generation rate means that
This means that it is possible to determine the total nitrogen concentration without directly measuring it with a water quality meter.
本発明はこれらのような基本的事象の解明に基
づいてなされたもので、その実施例を第７図を参
照して説明する。図において第１図と同一記号は
相当物を示し、２０は曝気ポンプ、２１はMLSS
測定器、２２は排ガス捕集器、２３は曝気空気量
を測定する流量計、２４は炭酸ガス濃度計で、例
えば赤外線分析計あるいはガスクロマトグラフ分
析装置が用いられる。また１１は返送汚泥弁、１
２は硝化槽、１３は脱窒槽である。２６は亜酸化
窒素N2O濃度計で、例えば赤外線分析計及びガス
クロマトグラフ分析装置が用いられる。２７は脱
窒槽１３のMLSS測定器、２８は曝気ガス流量計
で、例えばアルゴンガス流量を測定する。２９は
後記(4)式により炭酸ガス発生速度ＲCO2を求める
第１演算回路、３０は炭酸ガス発生速度ＲCO2か
ら、第５図の関係を利用して有機物負荷量Ｌを求
める第２演算回路、３１は有機物負荷量Ｌから(5)
式にしたがつて有機汚染質濃度ＯCを求める第３
演算回路、３２は後記(6)式によつてN2Oガス発生
速度ＲN2Oを求める第４演算回路、３３はN2Oガ
ス発生速度ＲN2Oから第６図の関係を利用して総
窒素濃度ＴNを求める第５演算回路、３４は有機
汚染質濃度ＯCと総窒素濃度ＴNの比ｒを求める第
６演算回路、３５は以上のようにして求められた
現実の有機汚染質濃度と総窒素濃度比ｒとその目
標値ｒOの偏差Δｒに応じて窒素源または有機炭
素源注入弁３７Ａ，Ｂの開度制御を行なう制御回
路である。また、２５は流入水流量計、３６Ａ，
３６Ｂは窒素源および有機炭素源の貯留タンクで
ある。 The present invention was made based on the elucidation of these basic phenomena, and an embodiment thereof will be described with reference to FIG. In the figure, the same symbols as in Figure 1 indicate equivalents, 20 is the aeration pump, 21 is the MLSS
The measuring instruments include an exhaust gas collector 22, a flow meter 23 for measuring the amount of aerated air, and a carbon dioxide concentration meter 24, such as an infrared analyzer or a gas chromatograph analyzer. In addition, 11 is a return sludge valve, 1
2 is a nitrification tank, and 13 is a denitrification tank. 26 is a nitrous oxide N 2 O concentration meter, for example, an infrared analyzer and a gas chromatograph analyzer are used. 27 is an MLSS measuring device for the denitrification tank 13, and 28 is an aeration gas flow meter, which measures, for example, the argon gas flow rate. 29 is a first calculation circuit that calculates the carbon dioxide gas generation rate R CO2 using equation (4) described later; 30 is a second calculation circuit that calculates the organic matter load L from the carbon dioxide gas generation rate R CO2 using the relationship shown in FIG. 5. , 31 is from the organic matter load L (5)
Third step: Find the organic pollutant concentration O C according to the formula.
A calculation circuit 32 calculates the N 2 O gas generation rate R N2O using equation (6) described later; 33 calculates the total nitrogen from the N 2 O gas generation rate R N2O using the relationship shown in Figure 6. A fifth arithmetic circuit for calculating the concentration T N ; 34 a sixth arithmetic circuit for calculating the ratio r between the organic contaminant concentration O C and the total nitrogen concentration T N ; and 35 the actual organic contaminant concentration determined in the above manner. This is a control circuit that controls the opening degree of the nitrogen source or organic carbon source injection valves 37A and 37B in accordance with the deviation Δr between the total nitrogen concentration ratio r and its target value r O . In addition, 25 is an inflow water flow meter, 36A,
36B is a storage tank for nitrogen source and organic carbon source.
さて、第７図の構成において、汚泥濃度Ｍ、炭
酸ガス濃度ＣCO2および曝気空気量Ｇはそれぞれ
MLSS計２１、炭酸ガス濃度計２４および流量計
２３により検出され第１演算回路２９に与えられ
る。第１演算回路２９は次式によつて単位汚泥量
当りの炭酸ガス発生速度ＲCO2を求める。 Now, in the configuration shown in Figure 7, the sludge concentration M, carbon dioxide concentration C CO2 , and aeration air amount G are each
It is detected by the MLSS meter 21 , the carbon dioxide concentration meter 24 and the flow meter 23 and is provided to the first arithmetic circuit 29 . The first arithmetic circuit 29 calculates the carbon dioxide gas generation rate R CO2 per unit amount of sludge using the following equation.
ＲCO2＝K1・Ｇ・ＣCO2／Mv ……(4)
ここで、Ｇは空気流量（m3/h）、ＣCO2は炭酸ガ
ス濃度（mol％）、Ｍは汚泥濃度（g/m3）、ｖは
（排ガス捕集器断面積）×（混合液液深）で相当容
積（m3）、K1は換算係数である。第１演算回路２
９で求めた炭酸ガス発生速度ＲCO2は第２演算回
路３０に与えられる。 R CO2 = K 1・G・C CO2 /Mv ...(4) Here, G is air flow rate (m 3 /h), C CO2 is carbon dioxide concentration (mol%), and M is sludge concentration (g/m 3 ), v is the equivalent volume (m 3 ) of (cross-sectional area of exhaust gas collector) x (mixed liquid depth), and K 1 is a conversion factor. First arithmetic circuit 2
The carbon dioxide gas generation rate R CO2 determined in step 9 is provided to the second arithmetic circuit 30.
第２演算回路３０は例えば第５図に示す如き直
線関係に基き有機物負荷量Ｌを演算する。 The second calculation circuit 30 calculates the organic matter load amount L based on a linear relationship as shown in FIG. 5, for example.
第３演算回路３１は(5)式によつて有機汚染質濃
度ＯCを求める。 The third arithmetic circuit 31 determines the organic pollutant concentration O C using equation (5).
ＯC＝Ｌ・Ｍ・Ｖ／Ｑ ……(5)
ここで、Ｌは有機物負荷量（ｇ汚染質濃度／ｇ
汚泥／ｈ）、ＭはMLSS濃度（ｇ汚泥／m3）、Ｖは
曝気槽溶積（m3）、Ｑは流入下水量（m3/h）であ
る。 O C =L・M・V/Q...(5) Here, L is the organic matter load (g pollutant concentration/g
sludge/h), M is the MLSS concentration (g sludge/m 3 ), V is the aeration tank volume (m 3 ), and Q is the amount of inflowing sewage (m 3 /h).
第４演算回路３２は(6)式によつて単位汚泥量当
りのN2Oガス発生速度ＲN2Oを求める。 The fourth calculation circuit 32 calculates the N 2 O gas generation rate R N2O per unit amount of sludge using equation (6).
ＲN2O＝K2・ｇ・ＣN2O／mVd ……(6)
ここで、ｇは曝気ガス流牢量（m3/h）、ＣN2Oは
脱窒槽排ガス中のN2Oガス濃度（mol％）、ｍは脱
窒槽中の汚泥濃度（g/m3）、Ｖdは脱窒槽容積
（m3）、K2は換算係数である。 R N2O = K 2・g・C N2O /mV d ...(6) Here, g is the aeration gas flow rate (m 3 /h), and C N2O is the N 2 O gas concentration in the denitrification tank exhaust gas (mol %), m is the sludge concentration in the denitrification tank (g/m 3 ), V d is the denitrification tank volume (m 3 ), and K 2 is a conversion factor.
第５演算回路３３は例えば第６図に示す如き直
線関係に基き流入水中の総窒素濃度ＴNを演算す
る。 The fifth calculation circuit 33 calculates the total nitrogen concentration T N in the inflow water based on a linear relationship as shown in FIG. 6, for example.
第６演算回路３４は第３演算回路で求めた有機
汚染質濃度ＯCと第５演算回路で求めた総窒素濃
度ＴNの比を次式によつて求める。 The sixth arithmetic circuit 34 calculates the ratio of the organic contaminant concentration O C found by the third arithmetic circuit to the total nitrogen concentration T N found by the fifth arithmetic circuit using the following equation.
ｒ＝ＯC／ＴN ……(7)
ここで、通常の下水処理場における流入水中の
NH− ４−ＮはＴNの1/3ないし2/3であり、ほぼ比例
関係にあることが実験によつて明らかにされてい
る。したがつて、ＴNの値としてNH− ４−Ｎ濃度の
値を使用することも可能である。 r=O C /T N ...(7) Here, the inflow water at a normal sewage treatment plant is
Experiments have revealed that NH - 4 -N is 1/3 to 2/3 of T N and has a nearly proportional relationship. Therefore, it is also possible to use the value of NH - 4 -N concentration as the value of T N.
このようにして求めた有機汚染質濃度ＯCと総
窒素濃度ＴNの比ｒおよび有機汚染質濃度と総窒
素濃度比の目標値ｒOの偏差値Δｒを制御回路３
５に与える。制御回路３５は偏差値Δｒに応じて
窒素源および有機炭素源注入弁３７Ａ，３７Ｂの
少なくとも１方を制御し、窒素源または有機炭素
源の流入水１への注入量を制御して前記比ｒを目
標値ｒOに合致させる。窒素源としては例えばア
ンモニア、尿素などが使用でき、有機炭素源とし
ては例えばメタノール、エタノールなどが使用で
きる。 The control circuit 3 calculates the deviation value Δr of the ratio r between the organic pollutant concentration O C and the total nitrogen concentration T N and the target value r O of the organic pollutant concentration and total nitrogen concentration ratio obtained in this way.
Give to 5. The control circuit 35 controls at least one of the nitrogen source and organic carbon source injection valves 37A and 37B according to the deviation value Δr, and controls the amount of nitrogen source or organic carbon source injected into the inflow water 1 to maintain the ratio r. match the target value r O. As the nitrogen source, for example, ammonia, urea, etc. can be used, and as the organic carbon source, for example, methanol, ethanol, etc. can be used.
上記の説明のように、本発明によれば曝気槽流
入水中の有機汚染質濃度と総窒素濃度の比ｒを設
定値ｒOに維持することができ、活性汚泥の沈降
性を良好に保つことができる。 As explained above, according to the present invention, the ratio r of the organic pollutant concentration to the total nitrogen concentration in the aeration tank inflow water can be maintained at the set value r O , and the settling properties of activated sludge can be maintained well. I can do it.
また、炭酸ガス濃度を指標とする有機物負荷一
定制御系（例えば特願昭50−41273）を本発明と
組み合わせることにより、より一層の効果を発揮
することができる。すなわち、有機物負荷量（横
軸）とSVIとの関係は第３図であらわされるが、
有機物負荷一定制御を行なえば、例えば図中斜線
で示した範囲内のほぼ一定値に有機物負荷量が保
持されることになるので、SVIに対する有機物負
荷量の影響が除去される。したがつて、SVIは
BODとＴNの比ｒのみによつて制御可能となり、
SVIをなるべく低く維持しようとする制御が簡単
かつ高精度で達成されるようになる。 Further, by combining the present invention with a constant organic matter load control system using carbon dioxide concentration as an index (for example, Japanese Patent Application No. 41273/1983), even greater effects can be achieved. In other words, the relationship between organic matter load (horizontal axis) and SVI is shown in Figure 3.
If the organic matter load is controlled to be constant, the organic matter load is maintained at a substantially constant value within the shaded range in the figure, for example, so that the influence of the organic matter load on the SVI is eliminated. Therefore, SVI is
It can be controlled only by the ratio r of BOD and T N ,
Control to maintain SVI as low as possible can be achieved easily and with high precision.
本発明の応用例・変形例として精度は落ちるが
簡単な方法として次のような制御方法が考えられ
る。 As an application/modification example of the present invention, the following control method can be considered as a simple method although the accuracy is lowered.
(1) 活性汚泥水処理装置において、直接曝気槽排
ガス中のN2Oガス量を測定し、第６図の関係か
ら流入水中の総窒素濃度を求め、窒素源又は有
機炭素源を添加して総窒素濃度と有機汚染質濃
度の比を制御する。(1) In activated sludge water treatment equipment, measure the amount of N 2 O gas in the direct aeration tank exhaust gas, calculate the total nitrogen concentration in the inflow water from the relationship shown in Figure 6, and add a nitrogen source or organic carbon source. Control the ratio of total nitrogen concentration to organic pollutant concentration.
(2) 個々の処理場ごとに予じめ流入水中の窒素濃
度及び有機汚染質濃度あるいは両者の比の日間
変動を予め求めておき、時刻に応じて窒素源あ
るいは有機炭素源を添加して総窒素濃度と有機
汚染質濃度の比を制御する。(2) For each treatment plant, determine in advance the daily fluctuations in the nitrogen concentration and organic pollutant concentration in influent water, or the ratio of the two, and add nitrogen sources or organic carbon sources depending on the time of day to calculate the total Control the ratio of nitrogen concentration to organic pollutant concentration.
以上の説明から明らかなように、本発明によれ
ば次のような効果がある。 As is clear from the above description, the present invention has the following effects.
(1) 活性汚泥の沈降性を支配する直接の原因であ
る流入水中の有機汚染質濃度と窒素濃度の比を
適正値に保つことができるため、汚泥の沈降性
を良好に保つことができ、バルキング防止にも
なる。(1) The ratio of organic pollutant concentration and nitrogen concentration in inflow water, which is the direct cause that controls the settling properties of activated sludge, can be maintained at an appropriate value, so the settling properties of sludge can be maintained at a good level. It also prevents bulking.
(2) 流入水中の有機汚染質濃度と窒素濃度の比を
適正値に保つことによつて、汚泥細胞内に摂取
される窒素量が増加するため、富栄養化による
二次公害の防止になる。(2) By maintaining the ratio of organic pollutant concentration and nitrogen concentration in influent water to an appropriate value, the amount of nitrogen taken into sludge cells increases, which prevents secondary pollution due to eutrophication. .
(3) 前記(1)の効果のため、沈殿池において処理水
中に同伴する汚泥が少なくなり、処理水水質が
向上する。(3) Due to the effect of (1) above, the amount of sludge entrained in the treated water in the settling tank is reduced, and the quality of the treated water is improved.
(4) 前記(1)の効果のため、沈殿池における沈殿汚
泥の圧密性が高くなり返送汚泥濃度を高めるこ
とができる。この結果として、曝気槽汚泥濃度
が増加し処理効率が向上する。(4) Due to the effect of (1) above, the compactability of the settled sludge in the settling tank becomes high, and the concentration of returned sludge can be increased. As a result, the aeration tank sludge concentration increases and treatment efficiency improves.
第１図は活性汚泥水処理装置の基本構成図、第
２図はSVIに対する有機汚染質濃度と窒素濃度の
比の関係を示す特性図、第３図はSVIと有機物負
荷量との関係を示す図、第４図はSVIとDNAの関
係を示す特性図、第５図は炭酸ガス発生速度と有
機物負荷量の関係を示す実測例図、第６図は総窒
素濃度とN2Oガス発生速度の関係を示す実測例
図、第７図は本発明の一実施例を示す構成図であ
る。
１…流入水、２…曝気槽、４…沈殿池、５…処
理水、７…返送汚泥、８…余剰汚泥、１３…脱窒
槽、２１…MLSS計、２３…空気流量計、２４…
炭酸ガス濃度計、２５…流入水流量計、２６…
N2Oガス濃度計、２９〜３４…演算器、３６Ａ…
窒素源、３６Ｂ…有機炭素源。
Figure 1 is a basic configuration diagram of activated sludge water treatment equipment, Figure 2 is a characteristic diagram showing the relationship between organic pollutant concentration and nitrogen concentration ratio with respect to SVI, and Figure 3 is a diagram showing the relationship between SVI and organic matter load. Figure 4 is a characteristic diagram showing the relationship between SVI and DNA, Figure 5 is an actual measurement example diagram showing the relationship between carbon dioxide gas generation rate and organic matter load, and Figure 6 is a graph showing the relationship between total nitrogen concentration and N 2 O gas generation rate. FIG. 7 is a block diagram showing an embodiment of the present invention. 1... Inflow water, 2... Aeration tank, 4... Sedimentation tank, 5... Treated water, 7... Return sludge, 8... Excess sludge, 13... Denitrification tank, 21... MLSS meter, 23... Air flow meter, 24...
Carbon dioxide concentration meter, 25... Inflow water flow meter, 26...
N 2 O gas concentration meter, 29-34...computer, 36A...
Nitrogen source, 36B...organic carbon source.
Claims (1)
し、混合された汚泥を沈殿させて、処理水、返送
汚泥および余剰汚泥に分離するようにした活性汚
泥水処理装置の制御方法であつて、曝気槽への流
入水中の有機汚染質濃度と総窒素濃度の比を18〜
35の範囲に維持するように、前記流入水に窒素源
および有機炭素源の少なくとも一方を添加するこ
とにより、汚泥容量指標を最小範囲に保持するこ
とを特徴とする活性汚泥水処理装置の制御方法。 ２ 総窒素濃度をアンモニア態窒素濃度から求め
ることを特徴とする前記特許請求の範囲第１項記
載の活性汚泥水処理装置の制御方法。 ３ 処理場ごとに有機汚泥質濃度と総窒素濃度の
比の時間的変動を予じめ求めておき、その比が予
じめ定めた目標値となるように窒素源および有機
炭素源の少なくとも一方を添加することを特徴と
する前記特許請求の範囲第１項記載の活性汚泥水
処理装置の制御方法。[Claims] 1. Control of an activated sludge water treatment device that mixes inflow water and return sludge in an aeration tank, settles the mixed sludge, and separates it into treated water, return sludge, and surplus sludge. A method in which the ratio of the organic pollutant concentration to the total nitrogen concentration in the influent water to the aeration tank is 18 to 18.
A method for controlling an activated sludge water treatment device, characterized in that the sludge capacity index is maintained within a minimum range by adding at least one of a nitrogen source and an organic carbon source to the inflow water so as to maintain the sludge capacity index within a minimum range of 35. . 2. The method for controlling an activated sludge water treatment apparatus according to claim 1, characterized in that the total nitrogen concentration is determined from the ammonia nitrogen concentration. 3 Determine in advance the temporal fluctuations in the ratio of organic sludge concentration to total nitrogen concentration for each treatment plant, and use at least one of the nitrogen source and organic carbon source so that the ratio reaches the predetermined target value. The method for controlling an activated sludge water treatment apparatus according to claim 1, characterized in that the method comprises adding:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11742278A JPS5544332A (en) | 1978-09-26 | 1978-09-26 | Control method of activated sludge water treating apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11742278A JPS5544332A (en) | 1978-09-26 | 1978-09-26 | Control method of activated sludge water treating apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5544332A JPS5544332A (en) | 1980-03-28 |
| JPS6120357B2 true JPS6120357B2 (en) | 1986-05-21 |
Family
ID=14711245
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11742278A Granted JPS5544332A (en) | 1978-09-26 | 1978-09-26 | Control method of activated sludge water treating apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5544332A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4772396A (en) * | 1986-11-26 | 1988-09-20 | Amoco Corporation | Method for controlling filamentous organisms in wastewater treatment processes |
| DE19638492C2 (en) * | 1996-09-19 | 2003-05-15 | Alfred Albert | Process for setting a mixture of microorganisms and the amount of food in a biotechnological process, in particular activated sludge process in wastewater treatment |
| AUPP860899A0 (en) * | 1999-02-11 | 1999-03-04 | Zeolite Australia Limited | Process for the removal of suspended and other material from waste water |
| JP4392111B2 (en) * | 2000-05-25 | 2009-12-24 | オルガノ株式会社 | Organic wastewater biological treatment equipment |
| JP5075907B2 (en) * | 2009-11-27 | 2012-11-21 | 株式会社日立製作所 | Water treatment equipment |
| JP5075926B2 (en) * | 2010-01-20 | 2012-11-21 | 株式会社日立製作所 | Sewage treatment apparatus and sewage treatment method |
| JP6105857B2 (en) * | 2012-05-15 | 2017-03-29 | メタウォーター株式会社 | Infrared analyzer pretreatment equipment |
-
1978
- 1978-09-26 JP JP11742278A patent/JPS5544332A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5544332A (en) | 1980-03-28 |
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