JPS5814997A - Control method for biological denitrification process - Google Patents
Control method for biological denitrification processInfo
- Publication number
- JPS5814997A JPS5814997A JP11071881A JP11071881A JPS5814997A JP S5814997 A JPS5814997 A JP S5814997A JP 11071881 A JP11071881 A JP 11071881A JP 11071881 A JP11071881 A JP 11071881A JP S5814997 A JPS5814997 A JP S5814997A
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- amount
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- carbon source
- nitrogen
- circuit
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Abstract
Description
【発明の詳細な説明】
不発明は廃水中に溶解している窒素化合物を生物学的に
除去する硝化・脱窒素プロセスに係わり、特に、脱窒素
工程の有機炭素供給制御法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nitrification/denitrification process for biologically removing nitrogen compounds dissolved in wastewater, and particularly to a method for controlling organic carbon supply in the denitrification process.
廃水中の窒素化合物は湖沼や内海における富栄養化現象
の一因で、窒素化合物全除去する、いわゆる脱窒が重要
である。廃水の脱窒には各種の方法があるが、生物学的
に窒素ガス(以下N2と称す)として飛散させる生物学
的硝化脱窒素法が最も一般的に用いられている。生物学
的膜窒素プロセスはアンモニア性窒素を硝酸性あるいは
亜硝酸性窒素(総称してNOx Nと以下称す)に好
気条件下で酸化する心向化工程と、NOx Nk嫌気
条件下でN2ガスに還元する脱窒素工程とから一般的に
構成されている。脱窒素工程では脱窒素のための還元剤
が多裂となり、メタノール等の水素供与体である有機炭
素源が供給されている。この有機炭素源供給は生物学的
脱窒素゛プロセスにおける重要な操作の1つである。す
なわち、炭素源の過少添加はNOx N量を残留させ
るとともにプロセスの下流に設置さ扛る沈殿池で脱窒反
応が進むために汚泥浮上全発生させ処理水賃金悪化させ
る。一方、炭素源の過剰添加はNOx N量を完全還
元するものの炭素源を残留さぞ、この残留炭素源が処理
水の、有機物濃度を増大させるために処理水質が悪化す
るとともに、高価な炭素源を不当に消費し不経済である
。このために炭素源の供給は還元すべきNOx N量
に過不址のないように行わなければならない。Nitrogen compounds in wastewater are one of the causes of eutrophication in lakes and inland seas, so it is important to remove all nitrogen compounds, so-called denitrification. There are various methods for denitrifying wastewater, but the biological nitrification and denitrification method, which biologically disperses nitrogen gas (hereinafter referred to as N2), is most commonly used. The biological membrane nitrogen process consists of a centripetalization process in which ammonia nitrogen is oxidized to nitrate or nitrite nitrogen (hereinafter collectively referred to as NOx N) under aerobic conditions, and NOx Nk to N2 gas under anaerobic conditions. It generally consists of a denitrification process that reduces nitrogen to In the denitrification process, the reducing agent for denitrification becomes multi-fibered, and an organic carbon source such as methanol which is a hydrogen donor is supplied. This organic carbon source supply is one of the important operations in the biological denitrification process. That is, if too little carbon source is added, the amount of NOx and N will remain, and the denitrification reaction will proceed in the sedimentation tank installed downstream of the process, resulting in sludge floating and deteriorating the quality of treated water. On the other hand, excessive addition of a carbon source completely reduces the amount of NOx and N, but leaves a residual carbon source.This residual carbon source increases the organic matter concentration in the treated water, deteriorating the quality of the treated water and requiring the use of an expensive carbon source. It is unreasonable consumption and uneconomical. For this purpose, the carbon source must be supplied in such a way that the amount of NOx and N to be reduced is not excessive.
従来の炭素源供給法は過少添加時の不都合を避けるため
に過剰添771−行い、脱窒素工程流出液に残留した炭
素源を再曝気槽で微生物除去子るという矛盾した方法が
採ら扛ていた。ぼた、その他の方法としては窒素分析計
により廃水中の窒素量を測定し、その測定値あるいは測
定値と廃水流量の積に炭素源供給量を比例ζぜる例があ
る。しかし水質分析計は信頼性や保守性が十分でなく、
また、1 。Conventional carbon source supply methods have adopted a contradictory method of over-adding771- to avoid the inconveniences caused by under-adding, and removing microorganisms from the carbon source remaining in the denitrification process effluent in a re-aeration tank. . Another method is to measure the amount of nitrogen in wastewater using a nitrogen analyzer, and then increase the amount of carbon source supplied in proportion to the measured value or the product of the measured value and the flow rate of the wastewater. However, water quality analyzers lack sufficient reliability and maintainability.
Also, 1.
検水の前処理全必要とするなどの欠点があり制御法を確
立できないのが実情である。The reality is that it is difficult to establish a control method due to drawbacks such as the need for pre-treatment of the sample water.
本発明の目的は従来の有機炭素源供給制御法の欠点に対
処して考案されたもので、脱窒素工程に流入したN O
x 7 N量の完全還元に必要な炭素源全適正に供給し
、処理水の良質化とプロセスの安定化を図り、信頼性の
高い炭素源供給制御法を提供することにある。The purpose of the present invention was devised to address the shortcomings of conventional organic carbon source supply control methods.
The object of the present invention is to provide a highly reliable carbon source supply control method that appropriately supplies all the carbon sources necessary for complete reduction of the amount of x 7 N, improves the quality of treated water and stabilizes the process.
本発明は、窒素化合物と有機化合物を好気条件下で微生
物と接触する過程において酸化作用と脱窒作用により発
生するN2oガス及びCO2ガスと、さらに汚泥濃度と
流入水量から硝化窒素量全算出できることを基本と1同
様の現象が硝化工程で発生していることを利用し、硝化
工程における排ガス中のN20 t、 C02Ill
’度と、汚泥濃度及び流量から算出した硝化窒素量を完
全還元するに必要な炭素量を求め、この必要炭素量を脱
窒素工程に供給すること全特徴としてGる。The present invention is capable of calculating the total amount of nitrified nitrogen from N2o gas and CO2 gas generated by oxidation and denitrification in the process of bringing nitrogen compounds and organic compounds into contact with microorganisms under aerobic conditions, as well as sludge concentration and inflow water volume. Based on this, and using the fact that a similar phenomenon occurs in the nitrification process, we can calculate the amount of N20t, C02Ill in the exhaust gas in the nitrification process.
The overall feature is to determine the amount of carbon necessary to completely reduce the amount of nitrified nitrogen calculated from the sludge concentration and flow rate, and to supply this necessary amount of carbon to the denitrification process.
不発明は、好気的条件における排ガス中の亜酸化窒素(
以下N20と称す)発生量RN 20は第1図に示すよ
うに廃□水中のNOx N濃度tゎと有機物濃度fの
積に比例することと、有機物負荷lは第2図に示すよう
に排ガス中の炭素ガス(以下C02と称す)発生量Rc
o2により表現できることを実験的に見出したことに発
する。第1図からN20発生量は
RNO−に’。・f、tゎ ・・・・・・・・・(1)
で与えられるとともに次式の流量Q、とN20濃度CN
20によっても求められる。The invention is based on nitrous oxide (nitrous oxide) in exhaust gas under aerobic conditions.
The generated amount RN20 (hereinafter referred to as N20) is proportional to the product of the NOx N concentration t in the waste water and the organic matter concentration f as shown in Figure 1, and the organic matter load l is as shown in Figure 2 in the exhaust gas. Carbon gas (hereinafter referred to as C02) generation amount Rc
This is based on the experimental discovery that it can be expressed by o2. From Figure 1, the amount of N20 generated is RNO-'.・f、tゎ・・・・・・・・・(1)
The flow rate Q is given by the following equation, and the N20 concentration CN
It is also determined by 20.
RN2o=”’n ・CN?O”Qt/Sm ・U・・
・・・・・・・・・・(2)
ここで、S□は汚泥濃度、Uは反応容積1に’filk
″ユ は演算係数である。(1)、(2)式よりN0x
−N濃度1つは
ta=に−・CN2o−Qr/f−sm −cr・・・
・・・・・・・・・・・・(3)(k、 = k I、
” /に’I、)一方、有機物負荷tはC02発生量R
co2により、と表現でき、この式の右辺の第2項は微
生物の自家呼吸にCO2発生分で、k’c、A>> b
であるのでほぼ無視できる。k′Cは演算係数である。RN2o="'n ・CN?O"Qt/Sm ・U...
・・・・・・・・・・・・(2) Here, S□ is the sludge concentration, and U is 'filk in the reaction volume 1.
``U'' is a calculation coefficient. From equations (1) and (2), N0x
-One N concentration is ta=-・CN2o-Qr/f-sm -cr...
・・・・・・・・・・・・(3) (k, = k I,
”/ni'I,) On the other hand, the organic load t is the amount of CO2 generated R
The second term on the right side of this equation is the amount of CO2 generated by self-respiration of microorganisms, and k'c, A>> b
Therefore, it can be almost ignored. k'C is a calculation coefficient.
有機物負荷tは、
L= f−Qo/S、、・V ・・・・・・・・・・・
・ (5)ここにQ。は廃水流量である。筐た、CO2
発生量Rc o 2
RCo5−に//ceCco2・Qg/S0−■・・・
・・・・・・・・・ (6)
(4)、 (5)、 (6)式をfについて整理すれば
f = kc −CCO2”Q、g /Qo
(kC=k”C/に+1・・・・・・・・・・・・
(′I)
ここでCCO2は排ガス中のCO2濃度である。(3)
式に(7ン式を代入す扛ば、廃水中のNQx N濃度
1ゎが求1す、廃水中の全NOx N量TNT N
” ’ a・Q、。The organic matter load t is L= f-Qo/S, ・V ・・・・・・・・・・・
・ (5) Q here. is the wastewater flow rate. Cabinet, CO2
Generation amount Rco 2 RCo5-//ceCco2・Qg/S0-■...
・・・・・・・・・ (6) If we rearrange equations (4), (5), and (6) with respect to f, we get f = kc −CCO2”Q, g /Qo
(kC=k”C/+1・・・・・・・・・・・・
('I) Here, CCO2 is the CO2 concentration in the exhaust gas. (3)
By substituting the formula (7) into the equation, the NQx N concentration 1ゎ in the wastewater can be found, and the total NOx N amount in the wastewater TNT N
” 'a.Q.
・・・・・・・・・・・・ (8)
不発明は、汎用的な計測器によりNOx −N量?検知
でき為ことを基本としたもので、第3図において本発明
の一実施例を説明する。第3図は硝化工程lと脱窒素工
程2がシリーズとなっている一般的な生物学的膜窒素プ
ロセスを例とした。硝化工程lには流入水4と返送汚泥
10が流入し、曝気装置11からの空気8により曝気借
拌するとともに流入水4中のアンモニア性窒素を硝化菌
の作用によりNOx Nに酸化する。流入水4には有
機物質が含有さnており、この有機物質が還元剤となっ
て脱窒が発生しN20ガスを飛散させる。・・・・・・・・・・・・ (8) Is the non-invention the amount of NOx -N measured by a general-purpose measuring device? An embodiment of the present invention will be described with reference to FIG. 3, which is based on the fact that it can be detected. FIG. 3 shows an example of a general biological membrane nitrogen process in which a nitrification step 1 and a denitrification step 2 are a series. Inflow water 4 and return sludge 10 flow into the nitrification process 1, where they are aerated and agitated by air 8 from an aeration device 11, and ammonia nitrogen in the inflow water 4 is oxidized to NOx N by the action of nitrifying bacteria. The inflow water 4 contains organic substances, and this organic substance acts as a reducing agent to cause denitrification and scatter N20 gas.
また、流入水4の有機物質は酸化分解は扛てCO2ガス
に変換さ扛る。このことから、曝気後の排ガス中には硝
化過程で発生したN20 ガスとCO2ガスが含1れる
ことになる。したがって、硝化工程1の排ガスと汚泥濃
度及び硝化液量を監視することによってNOx N量
を事前に把握することができる。脱窒素工程2では硝化
液5のN0x−Nが炭素源供給装置12からの炭素源7
に還元されてN2ガスを飛散さザ、窒素が除去された脱
窒液6を流出する。このようなプロセスにおいて、実施
例は硝化工程lVC排ガス捕集器3を設置し、捕集した
排ガス9を亜酸化窒素分析計13と炭酸ガス分析計14
に導き、測定したN20濃度CN20とCO2濃度Cc
o2の信号全演算回路18に出力する。゛演算回路18
には硝化工程lに設置した汚泥濃度計15からの汚泥濃
度S0及び流量計16からの硝化液量Q。が入力し、(
8)式に基づいて硝化液5の全NOx N量TNが演
算さ扛る。Further, the organic substances in the inflow water 4 are oxidized and decomposed and converted into CO2 gas. From this, the exhaust gas after aeration contains N20 gas and CO2 gas generated during the nitrification process. Therefore, by monitoring the exhaust gas, sludge concentration, and nitrification liquid amount in the nitrification step 1, the amount of NOx N can be known in advance. In the denitrification process 2, N0x-N of the nitrification liquid 5 is supplied to the carbon source 7 from the carbon source supply device 12.
The denitrifying liquid 6 from which nitrogen has been removed is discharged. In such a process, in the embodiment, a nitrification process lVC exhaust gas collector 3 is installed, and the collected exhaust gas 9 is passed through a nitrous oxide analyzer 13 and a carbon dioxide gas analyzer 14.
The measured N20 concentration CN20 and CO2 concentration Cc
The o2 signal is output to the full calculation circuit 18.゛Arithmetic circuit 18
, the sludge concentration S0 from the sludge concentration meter 15 installed in the nitrification process 1 and the nitrified liquid amount Q from the flow meter 16. is input and (
8) The total NOx N amount TN of the nitrifying liquid 5 is calculated based on the formula.
脱窒素工程2に供給する炭素源量は流入する硝化液中の
NOx N量TNを還元するに必要な量Qc’x供給
す扛ばよい。この必要炭素源量QcはN Ox N
JL T Nより次式で求められる。ここで、kは炭素
源濃度
Qc−に−TN ・・・・・・・・・・・・ (9)こ
こでkは炭素源濃度や炭素源とNOx Nの反応係数
等全考慮した比例係数でるる。演算回路18では、きら
に組込1′n−た(9)式に基づいて必要炭素源量Qc
k算出し、制御回路19に出力する。The amount of carbon source supplied to the denitrification step 2 may be the amount Qc'x required to reduce the amount of NOxN TN in the inflowing nitrification liquid. This required amount of carbon source Qc is N Ox N
It is obtained from JL T N using the following formula. Here, k is the carbon source concentration Qc- to -TN (9) Here, k is the proportionality coefficient that takes into account the carbon source concentration and the reaction coefficient between the carbon source and NOx N. Out. The arithmetic circuit 18 calculates the required amount of carbon source Qc based on the equation (9) incorporated into Kirin.
k is calculated and output to the control circuit 19.
制御回路19は、脱窒素工程2への炭素源供給量が必要
炭素源量Qc k維持するように炭素源供給装置12を
調節するものである。、このような制御方法によって硝
化液中のNOx N量に対応した炭素源供給が常時操
作さn、NOx N及び炭素源が残留しない脱窒液全
提供できる。The control circuit 19 adjusts the carbon source supply device 12 so that the amount of carbon source supplied to the denitrification step 2 is maintained at the required amount Qck of carbon source. By using such a control method, the carbon source supply corresponding to the amount of NOx N in the nitrifying solution is constantly operated, and the entire denitrifying solution without residual NOx N and carbon sources can be provided.
なお、実施例において流量計16は硝化液5を対象とし
ているが、硝化工程が越流型であれば堰式流量計全硝化
工程に設置することによって計測遅れを解消することが
できる。また、炭素源はメタノール、ダルコース等の有
機炭素源の他に、有機汚染質を含有した汚水やメタン等
を含有した消化ガスなどであってもよい。さらに、硝化
工程における排ガス捕集や汚泥濃度測定の位置’に%に
限定するものでないが、硝化及び生物酸化が安定する後
方部とすることによって制御システムのむだ時間全短縮
できる。In the embodiment, the flowmeter 16 is intended for the nitrification liquid 5, but if the nitrification process is an overflow type, the measurement delay can be eliminated by installing the weir type flowmeter in the entire nitrification process. In addition to organic carbon sources such as methanol and dulcose, the carbon source may also be sewage containing organic pollutants, digestion gas containing methane, and the like. Furthermore, the dead time of the control system can be completely shortened by locating the exhaust gas collection and sludge concentration measurement in the nitrification process at the rear part where nitrification and biological oxidation are stabilized, although the position is not limited to %.
本発明によ扛ば、硝化した窒素量に対応した炭素供給が
行われるため、炭素源の節約を出来るとともに炭素源及
び窒素を残留させない良質の処理水を提供できる。また
、硝化窒素量を確立した計測器で検知できるので信頼性
の高い炭素源供給制御システムを実現できる。烙らに、
脱窒素工程前で硝化窒素量を予測できるのでフィードフ
ォワード制御が可能となる。According to the present invention, since carbon is supplied in proportion to the amount of nitrified nitrogen, carbon sources can be saved, and high-quality treated water without residual carbon sources and nitrogen can be provided. Furthermore, since the amount of nitrified nitrogen can be detected using established measuring instruments, a highly reliable carbon source supply control system can be realized. Hotly,
Since the amount of nitrified nitrogen can be predicted before the denitrification process, feedforward control becomes possible.
第1図は廃水中のNOx N濃度と有機物濃度の積に
対するN20発生量の特性図、第2図は有機物負荷とC
O2発生量の特性図、第3図は本発明の一実施例を示す
系統図である。
1・・・硝化工程、2・・・脱窒素工程−・3・・・排
ガス捕集器、4・・・流入水、5・・・硝化液、6・・
・脱窒液、7・・・炭素源、9・・・排ガス、11・・
・曝気装置、12・・・炭素源供給装置、13・・・亜
酸化窒素分析計、14・・・炭酸ガス分析計、15・・
・汚泥濃度計、16・・・流量計、18・・・演算回路
、19・・・制御回路、8・・・空気、、¥−l 固
;
茅2 固
!(η市瓢物/り、ss/i)
!3 目Figure 1 is a characteristic diagram of the amount of N20 generated versus the product of NOx N concentration and organic matter concentration in wastewater, and Figure 2 is a characteristic diagram of organic matter load and C
A characteristic diagram of the amount of O2 generated, FIG. 3 is a system diagram showing an embodiment of the present invention. 1... Nitrification process, 2... Denitrification process - 3... Exhaust gas collector, 4... Inflow water, 5... Nitrification liquid, 6...
・Denitrification liquid, 7... Carbon source, 9... Exhaust gas, 11...
・Aeration device, 12... Carbon source supply device, 13... Nitrous oxide analyzer, 14... Carbon dioxide gas analyzer, 15...
・Sludge concentration meter, 16...Flow meter, 18...Arithmetic circuit, 19...Control circuit, 8...Air, ¥-l Hard; Chi2 Hard! (ηichi gourd/ri, ss/i)! 3rd eye
Claims (1)
下で酸化する硝化工程と、該硝化工程から流出する硝化
液中の硝酸性窒素あるいは亜硝酸性窒素全有機炭素の存
在下で還元し、窒素性ガスとして除去する脱窒素工程を
有する生物学的膜窒素プロセスにおいて、前記硝化工程
から放散するガス甲の亜酸化窒素濃度及び二酸化炭素濃
度を測定し、さらに、前記硝化工程の汚泥濃度と前記硝
化液流量を測定し、該亜酸化窒素濃度、二酸化炭素濃度
、汚泥濃度及び硝化液流量から前記硝化液中の硝化窒素
t’r算出し、該硝化窒素量を完全に還元するのに必要
な有機炭素量を算出し、・該必9有機炭素量に基づいて
前記脱窒素工程への有機炭素供給量?調節すること’に
特徴とした生物学的膜窒素プロセスの制御方法。1. Nitrogen compounds and organic pollutants in influent wastewater are oxidized under aerobic conditions, and nitrate nitrogen or nitrite nitrogen is reduced in the presence of total organic carbon in the nitrification solution flowing out from the nitrification process. In a biological membrane nitrogen process that includes a denitrification process in which nitrogenous gas is removed, the nitrous oxide and carbon dioxide concentrations of the gas emitted from the nitrification process are measured, and the sludge concentration from the nitrification process is measured. and the flow rate of the nitrifying solution, and calculating the nitrified nitrogen t'r in the nitrifying solution from the nitrous oxide concentration, carbon dioxide concentration, sludge concentration, and nitrifying solution flow rate. Calculate the amount of organic carbon required, and determine the amount of organic carbon to be supplied to the denitrification process based on the amount of organic carbon. A method for controlling biological membrane nitrogen processes characterized by 'regulation'.
Priority Applications (1)
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JP11071881A JPS5814997A (en) | 1981-07-17 | 1981-07-17 | Control method for biological denitrification process |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11071881A JPS5814997A (en) | 1981-07-17 | 1981-07-17 | Control method for biological denitrification process |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5814997A true JPS5814997A (en) | 1983-01-28 |
Family
ID=14542718
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4705633A (en) * | 1986-10-02 | 1987-11-10 | Bogusch Eugene D | Nitrification with sludge reaeration and ammonia enrichment |
JP2012245422A (en) * | 2011-05-25 | 2012-12-13 | Hitachi Ltd | Water treatment process control device |
JP2015044197A (en) * | 2014-10-31 | 2015-03-12 | メタウォーター株式会社 | Sewage treatment system |
-
1981
- 1981-07-17 JP JP11071881A patent/JPS5814997A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4705633A (en) * | 1986-10-02 | 1987-11-10 | Bogusch Eugene D | Nitrification with sludge reaeration and ammonia enrichment |
JP2012245422A (en) * | 2011-05-25 | 2012-12-13 | Hitachi Ltd | Water treatment process control device |
JP2015044197A (en) * | 2014-10-31 | 2015-03-12 | メタウォーター株式会社 | Sewage treatment system |
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