CN102306021A - Joint debugging and joint control method for guaranteeing biosafety of pipe network water quality based on real-time ArcGis - Google Patents
Joint debugging and joint control method for guaranteeing biosafety of pipe network water quality based on real-time ArcGis Download PDFInfo
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- CN102306021A CN102306021A CN201110234425A CN201110234425A CN102306021A CN 102306021 A CN102306021 A CN 102306021A CN 201110234425 A CN201110234425 A CN 201110234425A CN 201110234425 A CN201110234425 A CN 201110234425A CN 102306021 A CN102306021 A CN 102306021A
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Abstract
The invention relates to a joint debugging and joint control method for guaranteeing biosafety of pipe network water quality based on real-time ArcGis. The method comprises the following steps: (1) importing the residual chlorine data of each water quality monitoring point of a water supply pipe network into a geographic information system; (2) according to the distribution of water works,, secondary pressurized pump stations and transmission and distribution pipe networks, analyzing the spatial variation rule of disinfectant attenuation in the water of current transmission and distribution pipe network to regulate and control residual chlorine of the pipe network; (3) performing secondary analysis on the distribution of residual chlorine of the pipe network, observing whether the most disadvantageous point of the pipe network transmission and distribution satisfy the minimum value of the residual chlorine required for model calculation to control a microbial indicator to be qualified; and (4) if the most disadvantageous point of the pipe network transmission and distribution cannot satisfy the minimum value required for the model, repeating the step (2) until the residual chlorine distribution of the pipe network basically satisfies the microbial indicator control condition at the most disadvantageous point in the pipe network transmission and distribution. Through the invention, the microbial indicator of the pipe network reaches the standard, the spatial distribution of the residual chlorine of the pipe network is more uniform, and the addition of disinfectant and the amount of disinfection byproduct are reduced.
Description
Technical field
What the present invention relates to is the technical method that a kind of ductwork water quality microbial safety ensures; Be particularly related to a kind of existing secondary pressing pump station water outlet residual chlorine amount of statistical model regulation and control that passes through, show in real time that through ArcGis (Geographic Information System) the ductwork water quality bio-safety of the regional regulating effect of water supply ensures that uniting and adjustment join the method for control techniques.
Background technology
The drinking water quality pollution problem has diversity and complicacy.To the user potable water of safe and high quality is provided, water undertaking must be towards whole water system, from the water source, water factory, pipe network take the corresponding safety guarantee measure to leading overall process, seeks systematized technical solution.Though and be clouded in the end that underground water supply network and secondary water supply system are positioned at water system, be key and weak link in the safety water supply, also be simultaneously the difficult point that drinking water safety ensures.
China's drinking water sanitary standard (GB5749-2006) promptly requires must not contain pathogenic microorganism in the Drinking Water to article one that the Drinking Water hygienic quality requires.Water quality conventional index and limit value article one also are microbiological indicators, the visible importance of microbiological indicator in drinking water quality.The quality problem that exists in the urban water supply, mainly show as pipe network tip water,tap turbidity, colourity, smell exceeding standard of flavor and indexs such as microorganism.This is that conventional water purifying process is difficult to remove the organism in the water fully, thereby has increased the microorganisms grow risk in the pipe network because one side pollution of waterhead degree is aggravated; Because the maintenance of pipe network distributing system and secondary water-supply facilities design is improper, pipe network leakage, negative pressure suction etc., also there are various microbial contamination phenomenons in terminal temperature difference in addition.Pipe network water and secondary water-supply deteriorating water quality have had a strong impact on the raising of water supply quality.In order to guarantee the water quality in the pipe network course of conveying, water undertaking updates water-purifying process on the one hand, upgrades water supply line material and exploitation science and safeguards control technique; Generally adopt the chlorination technology of residual chlorine concentration in order to sterilize antibacterial in the pipe network water of keeping on the other hand, this also is at present otherwise effective technique.
According to national potable water regulation and stipulation, pipe network tip residual chlorine concentration need keep more than or equal to 0.05mg/l.If output water keeps stable residual chlorine concentration; Certainly will cause the residual chlorine concentration in the pipe network because bigger fluctuation takes place in the variation of operating mode; Add higher residual chlorine concentration and not only waste medicament; Increase water producing cost; Bring the incompatibility of sense of smell to the user, and increased the risk that DBPs exceeds standard.
The optimal control of residual chlorine concentration is the problem of a more complicated in the water supply network; And because complicated topological structure of water supply network own and inner sanitary condition; Each period of the water consumption of the pressure of city supply water pipeline, flow velocity and node all might change, and the operating condition of dynamic change causes that the control of residual chlorine concentration is not easy to accomplish in the pipe network.Existing chlorination control mode is to keep the residual chlorine concentration in the output water constant, because the chlorine residue decay, existing method is difficult to guarantee suppress the required residual chlorine concentration of growth of microorganism in the pipe network tip water.
Through the prior art literature search is found; The water supply network chlorine residue decay microvisual model of the method that drives based on the Lagrange time has been set up in Dong Xiaolei, letter the Kunlun etc., uses Matlab software and Access database to set up water supply network chlorine residue decay dynamic simulator system.This simulation system can be carried out dynamic similation to the chlorine residue decay of different operating modes, different water supply networks constantly, can also dynamic drafting pipe network chlorine residue isogram and contour surface figure.Though can reflect the chlorine residue decay situation of different water supply networks constantly by the dynamic chlorine residue isopleth map of analysis mode result and system's drafting; But for a lot of cities multi-water resources, add the reality that the press pump station distributes; Its isogram and contour surface figure display effect are still complicated; And its decay micromodel is not based upon under the Various Seasonal condition on the basis with relevant monitoring point microbiological indicator corresponding relation; Therefore control pipe network microbial safety is lacked directive significance (Dong Xiaolei; Letter the Kunlun etc. based on the water supply network chlorine residue decay simulation of Matlab. Chinese water supply and drainage; 2009,25(1): 49-52).
Summary of the invention
The present invention is directed to the deficiency of present public supply mains microbial safety safeguards technique method; Provide a kind of based on the ArcGis Geographic Information System; The statistical model that utilizes pipe network on-line monitoring point chlorine content and long term monitoring microbiological indicator to set up; Through the technical method that visual real-time uniting and adjustment join control is carried out in water factory's output water chlorine residue and pipe network secondary pressing pump station water outlet chlorine residue; Realize that the pipe network microbiological indicator is up to standard more even with pipe network chlorine residue spatial and temporal distributions, reduces sanitizer dosage and DBPs growing amount.
The present invention realizes through following technical scheme,
The ductwork water quality bio-safety based on real-time ArcGis that the present invention relates to ensures that uniting and adjustment join control method, comprise the steps:
(1) with each Water-quality Monitoring Points chlorine residue data importing Geographic Information System of water supply network;
(2) contrast water factory distributes, secondary pressing pump station distributes and transmission and distribution network distributes, and analyzes the spatial variations rule of sanitizer decay in the current transmission and distribution network water, carries out pipe network chlorine residue regulation and control;
(3) carry out pipe network chlorine residue distribution secondary analysis, it is qualified with the control microbiological indicator whether observation pipe network transmission & distribution least favorable point satisfies the required chlorine residue minimum of Model Calculation;
(4) still do not satisfy the requirements of model minimum like pipe network transmission & distribution least favorable point, then repeating step (2) distributes until the pipe network chlorine residue and satisfies pipe network transmission & distribution least favorable point microbiological indicator controlled condition basically.
Preferably, said step (1) specifically: each Water-quality Monitoring Points chlorine residue data importing Geographic Information System of water supply network is done the spatial analysis of integration, the stack of gained chlorine residue distribution plan is shown on the potable water transmission and distribution network synoptic diagram.
Preferably; Pipe network chlorine residue in the said step (2) is regulated and control specifically: according to the statistical model of pipe network chlorine residue and microbiological indicator such as total number of bacteria or heterotroph plate count under the condition of different temperatures of historical data foundation, regulate corresponding regional water factory or the secondary pressing pump station chlorine-throwed quantity of belonging to that supply water.
Preferably; Pipe network chlorine residue distribution secondary analysis in the said step (3) is specifically: arrive pipe network transmission & distribution least favorable according to water factory and put required hydraulic detention time, collect regulation and control back water supply network on-line monitoring point chlorine content again and import Geographic Information System and do the integration spatial analysis.
Adopt regulate and control method provided by the invention can avoid considering influencing the various complicated factors of pipe network chlorine residue decay, simultaneously the statistical model of the chlorine content of the relevant monitoring point that accumulates for many years according to this laboratory and total number of bacteria and the foundation of heterotroph plate count data can be more near pipe network actual motion effect and effectively predict and the microbiological indicator controlled in the pipe network up to standard; Thereby the complicacy of having avoided model in the past is not with to lack the model application that relevant monitoring point microbiological indicator brought strong, shortcoming that accuracy is not high.
Description of drawings
Fig. 1 is chlorine residue initial distribution figure in the potable water transmission and distribution network water;
Fig. 2 is residual disinfectancy agent content and heterotroph graph of a relation and matched curve figure in the pipe network water;
Fig. 3 is measured value of the heterotroph among Fig. 2 and the residual error synoptic diagram between the match value;
Fig. 4 is chlorine residue distribution plan in the potable water transmission and distribution network water of regulation and control back.
Embodiment
Below in conjunction with specific embodiment the present invention is elaborated.Following examples will help those skilled in the art further to understand the present invention, but not limit the present invention in any form.Should be pointed out that to those skilled in the art, under the prerequisite that does not break away from the present invention's design, can also make some distortion and improvement.These all belong to protection scope of the present invention.
Embodiment
Embodiment is the water supply coverage pipe network chlorine residue regulation and control of Nanshi, Shanghai City water factory.Whole invention implementation procedure is following:
Adopt summer (water temperature>25 ℃) pipe network sampled result, do the chlorine residue index heterotroph index is suppressed the regression equation of effect, in order to as water system tip chlorine residue control criterion.
Residual error in the mapping expression pipe network water between residual disinfectancy agent content and heterotroph relation and measured value and the match value; In the pipe network water synoptic diagram of residual disinfectancy agent content and heterotroph relation and measured value and match value as shown in Figure 2, wherein the residual error synoptic diagram between measured value and the match value is as shown in Figure 3; Can find out that by Fig. 2,3 when chlorine content was higher in the water, model was all better to the degree of fitting of real data, but when the chlorine residue level was lower than a certain threshold value, equation can enlarge markedly to the fitting result and the difference between the actual value of heterotroph content.The reason that causes this result is tip sanitizer critical level of inhibition existence to content of microorganisms, and when sanitizer content was lower than this critical value in the water, sanitizer had just lost its effect to growth of microorganism in the inhibiting effect of regeneration.The threshold range that the pipe network water chlorine residue loses microorganism inhibition effect is 0.45～0.50mg/L.
Choose the sample data that chlorine content surpasses above scope, carry out regression fit, the result is following:
y?=?609.55?+?615849450.78*exp(-x/0.042)R
2?=?0.71
According to statistics related coefficient check table,, need related coefficient greater than 0.597 if want the straight line of above data point match to have 99.9% degree of confidence.Obviously, equation coincide fine to the fitting effect and the actual value of heterotroph number in the water.
It is thus clear that, 25 ℃ of water temperatures in summer higher (>) situation under, when residual chlorine amount is lower than 0.45～0.50mg/L in the pipe network water, exist sanitizer to lose the risks that the inhibition effect of microorganism caused a large amount of outbursts of microorganism.Therefore, when using chloramines to sterilize, should guarantee in the pipe network water chlorine residue, and reach microorganism purpose in the control water through chlorine residue in the control pipe network water according to above statistical model greater than 0.45mg/L as water system.
Step 3 is carried out pipe network chlorine residue distribution secondary analysis, specifically is to put required pipe network hydraulic detention time according to pipe network transmission & distribution least favorable, collects regulation and control back water supply network on-line monitoring point chlorine content again and imports the ArcGis Geographic Information System and do the integration spatial analysis; Observing least favorable point then, whether to satisfy the required chlorine residue minimum of Model Calculation qualified with the control microbiological indicator, and as shown in Figure 4, the overall chlorine residue level in regulation and control backs descends, and it is also more even to distribute, and has improved pipe network microbial safety safeguard level.
It is thus clear that; Adopt regulate and control method provided by the invention can avoid considering influencing the various complicated factors of pipe network chlorine residue decay, simultaneously the statistical model of the chlorine content of the relevant monitoring point that accumulates for many years according to this laboratory and total number of bacteria and the foundation of heterotroph plate count data can be more near pipe network actual motion effect and effectively predict and the microbiological indicator controlled in the pipe network up to standard; Thereby the complicacy of having avoided model in the past is not with to lack the model application that relevant monitoring point microbiological indicator brought strong, shortcoming that accuracy is not high.
Claims (4)
1. the ductwork water quality bio-safety based on real-time ArcGis ensures that uniting and adjustment join control method, it is characterized in that, comprises the steps:
(1) with each Water-quality Monitoring Points chlorine residue data importing Geographic Information System of water supply network;
(2) contrast water factory distributes, secondary pressing pump station distributes and transmission and distribution network distributes, and analyzes the spatial variations rule of sanitizer decay in the current transmission and distribution network water, carries out pipe network chlorine residue regulation and control;
(3) carry out pipe network chlorine residue distribution secondary analysis, it is qualified with the control microbiological indicator whether observation pipe network transmission & distribution least favorable point satisfies the required chlorine residue minimum of Model Calculation;
(4) still do not satisfy the requirements of model minimum like pipe network transmission & distribution least favorable point, then repeating step (2) distributes until the pipe network chlorine residue and satisfies pipe network transmission & distribution least favorable point microbiological indicator controlled condition basically.
2. the ductwork water quality bio-safety based on real-time ArcGis according to claim 1 ensures that uniting and adjustment join control method; It is characterized in that; Said step (1) is specifically: each Water-quality Monitoring Points chlorine residue data importing Geographic Information System of water supply network is done the spatial analysis of integration, the stack of gained chlorine residue distribution plan is shown on the potable water transmission and distribution network synoptic diagram.
3. the ductwork water quality bio-safety based on real-time ArcGis according to claim 1 ensures that uniting and adjustment join control method; It is characterized in that; Pipe network chlorine residue in the said step (2) is regulated and control specifically: according to the statistical model of pipe network chlorine residue and microbiological indicator such as total number of bacteria or heterotroph plate count under the condition of different temperatures of historical data foundation, regulate corresponding regional water factory or the secondary pressing pump station chlorine-throwed quantity of belonging to that supply water.
4. the ductwork water quality bio-safety based on real-time ArcGis according to claim 1 ensures that uniting and adjustment join control method; It is characterized in that; Pipe network chlorine residue distribution secondary analysis in the said step (3) is specifically: arrive pipe network transmission & distribution least favorable according to water factory and put required hydraulic detention time, collect regulation and control back water supply network on-line monitoring point chlorine content again and import Geographic Information System and do the integration spatial analysis.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103677826A (en) * | 2013-12-09 | 2014-03-26 | 河海大学 | Sub-basin dividing and information extracting method based on IDL and Mapinfo |
| CN105825047A (en) * | 2016-03-11 | 2016-08-03 | 广州地理研究所 | Pipe network tip water quality simulation method based on GIS |
| CN108468363A (en) * | 2018-02-08 | 2018-08-31 | 天津泛华清源水务科技发展有限公司 | Secondary water-supply safety convenience instrument |
| CN109933027A (en) * | 2019-02-28 | 2019-06-25 | 重庆工商大学 | Sewage management platform based on factory's group's monitoring water quality and modelling management |
| CN109976187A (en) * | 2019-02-28 | 2019-07-05 | 重庆工商大学 | The sewage management platform for being optimized based on biochemical wastewater treatment and being finely aerated |
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| CN111470608A (en) * | 2020-04-08 | 2020-07-31 | 河海大学 | Midway chlorine supplementing optimization method for long-distance drinking water transmission and distribution pipe network |
| CN112610902A (en) * | 2020-12-11 | 2021-04-06 | 吉林建筑大学 | Method for detecting biological scale of pipe network in old city area |
| CN113030303A (en) * | 2021-02-26 | 2021-06-25 | 浙江工业大学 | Prediction method for high-risk area of disinfection by-products of long-distance water supply pipe network |
| CN114693191A (en) * | 2022-06-01 | 2022-07-01 | 湖南长理尚洋科技有限公司 | Intelligent hydraulic engineering management method and system based on ecological monitoring |
-
2011
- 2011-08-16 CN CN2011102344255A patent/CN102306021B/en active Active
Non-Patent Citations (2)
| Title |
|---|
| 《中国优秀博硕士学位论文全文数据库（硕士）-工程科技Ⅱ辑》 20051115 黄雅芳 "城市配水管网二次加氯的优化研究" , 第07期 * |
| 黄雅芳: ""城市配水管网二次加氯的优化研究"", 《中国优秀博硕士学位论文全文数据库（硕士）-工程科技Ⅱ辑》 * |
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| CN103677826A (en) * | 2013-12-09 | 2014-03-26 | 河海大学 | Sub-basin dividing and information extracting method based on IDL and Mapinfo |
| CN103677826B (en) * | 2013-12-09 | 2017-01-04 | 河海大学 | Watershed partitioning based on IDL and Mapinfo and information extracting method |
| CN105825047A (en) * | 2016-03-11 | 2016-08-03 | 广州地理研究所 | Pipe network tip water quality simulation method based on GIS |
| CN108468363A (en) * | 2018-02-08 | 2018-08-31 | 天津泛华清源水务科技发展有限公司 | Secondary water-supply safety convenience instrument |
| CN109976270A (en) * | 2019-02-28 | 2019-07-05 | 重庆工商大学 | Municipal sewage treatment cloud management platform |
| CN109976187A (en) * | 2019-02-28 | 2019-07-05 | 重庆工商大学 | The sewage management platform for being optimized based on biochemical wastewater treatment and being finely aerated |
| CN109933027A (en) * | 2019-02-28 | 2019-06-25 | 重庆工商大学 | Sewage management platform based on factory's group's monitoring water quality and modelling management |
| CN109976187B (en) * | 2019-02-28 | 2021-08-17 | 重庆工商大学 | Sewage management platform based on sewage biochemical treatment optimization and fine aeration |
| CN111470608A (en) * | 2020-04-08 | 2020-07-31 | 河海大学 | Midway chlorine supplementing optimization method for long-distance drinking water transmission and distribution pipe network |
| CN112610902A (en) * | 2020-12-11 | 2021-04-06 | 吉林建筑大学 | Method for detecting biological scale of pipe network in old city area |
| CN112610902B (en) * | 2020-12-11 | 2022-07-08 | 吉林建筑大学 | Method for detecting biological scale of pipe network in old city area |
| CN113030303A (en) * | 2021-02-26 | 2021-06-25 | 浙江工业大学 | Prediction method for high-risk area of disinfection by-products of long-distance water supply pipe network |
| CN113030303B (en) * | 2021-02-26 | 2023-03-14 | 浙江工业大学 | Prediction method for high-risk area of disinfection byproducts of long-distance water supply pipe network |
| CN114693191A (en) * | 2022-06-01 | 2022-07-01 | 湖南长理尚洋科技有限公司 | Intelligent hydraulic engineering management method and system based on ecological monitoring |
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