River network area flood control and purification agricultural non-point source pollution closed system and its regulation method

Abstract

The application discloses a kind of river network area flood control and purification's agricultural non-point source pollution closed system and its regulation and control method, the system includes main river, regional internal purification system and intelligent control system.Automatic monitoring station in main river monitors the water quality of monitoring section, and data is transmitted to intelligent control system, and intelligent control system connects regional internal purification system and controls the opening of regional internal purification system according to detection result.The application can monitor river water quality and regulate river water volume, utilize ecological pit pond to purify agricultural non-point source pollution and stabilize river water level, promote the healthy development of river ecosystem, utilize intelligent control system, scientific, accurate, timely, optimize the scheduling regional internal purification system, and ensure that river water quality monitoring section is stable and up to standard.It has the advantages of long-term management benefit, easy operation, high regulation and control efficiency, stable performance and the like.

Description

Technical Field

[0001] This invention relates to the field of water ecological restoration technology, specifically to a closed system and control method for agricultural non-point source pollution in river network areas that combines flood control and purification. Background Technology

[0002] With rapid industrialization and urbanization, pollutant emissions from various industries, agricultural non-point source pollution, and domestic wastewater have exacerbated water pollution. Water pollution poses a serious threat to the environment and human health, making it necessary to monitor and manage river water quality. River water quality monitoring sections can be categorized into national, provincial, municipal, and county-level sections. Currently, there is a lack of timely, scientific, and effective means for monitoring river water quality; therefore, achieving compliance with standards at these monitoring sections is becoming increasingly urgent.

[0003] Patent application CN202311394341.7 discloses a river water quality detection device, belonging to the field of water quality detection technology. It includes a housing with fixed bases at each of the four external corners. In this invention, during the movement of the housing driven by the propulsion device, water flow in the direction of travel enters the interior of the circular cavity, driving the inclined blades, second rotating shaft, third gear, second ring gear, arc frame, arc bracket, and cleaning block to rotate. The cleaning block periodically cleans the aquatic plants or adhering impurities entangled on the outside of the circular filter cover online, preventing blockage of the filter cover after prolonged use and thus avoiding impact on the detection effect of the detection head. This device converts the moving force during the movement into periodic cleaning force at the detection end, reducing energy efficiency while ensuring detection accuracy, thereby effectively improving the applicability of the device. However, it does not consider how to purify the river water resources.

[0004] Patent application CN202311358467.9 discloses a method for river water quality detection and early warning. The method includes the following steps: Step 1: The detection system detects river water quality information; Step 2: Based on a preset threshold, if the water quality information is not lower than the preset threshold, or if it is lower, the water quality information is simultaneously transmitted to both the system's central terminal and individual terminals; Step 3: After receiving the warning information, the central terminal and individual terminals process the alerted river section, and the detection system re-detects the river water quality information. This method employs multi-point deployment and timed detection, enabling precise location of river sections with numerous pollution sources through segmented detection combined with multi-element detection of flow velocity, temperature, and heavy metal content. It also combines location information from the detection agency with changes in pollution source parameters to accurately determine the location of illegal sewage discharge, facilitating timely detection and early warning. However, this method lacks measures for ensuring water quality standards are met at specific sections.

[0005] Patent application CN202311321494.9 discloses a river ecological environment restoration device and method, including: a hull, a lifting assembly, and a filtering assembly. The hull has a collection tank inside and an inlet tank connected to the collection tank at its outer end. An installation slot is located at the bottom of the hull, and a power assembly is installed thereon. The lifting assembly includes a pair of guide rails and an electromagnet. The guide rails are fixed to the bottom of the hull. This invention achieves the raising and lowering of the filter plate by changing the direction of the current in the electromagnet. When the filter plate moves from top to bottom, it intercepts suspended impurities in the water. The filter plate resonates with the damping plate, generating vibration, causing the impurities collected on the filter plate surface to detach from the filter plate, achieving an effective self-cleaning effect. The detached impurities are then guided to the collection tank through the inlet tank for convenient collection and treatment. With the continuous reciprocating raising and lowering of the filter plate, suspended impurities in the water are effectively removed, improving the purification effect of the river water. However, it does not adequately consider the self-purification capacity of the water body. Furthermore, setting up treatment facilities in the river can affect flood discharge. Summary of the Invention

[0006] Purpose of the Invention: Addressing the prominent issues of poor river water quality stability, initial rainwater runoff pollution, flood control during the flood season, and agricultural non-point source pollution, this invention provides a closed-loop system and control method for agricultural non-point source pollution in river network areas, combining flood control and pollution purification. By monitoring river water quality and regulating river flow, it utilizes ecological ponds to purify agricultural non-point source pollution and stabilize river water levels, promoting the healthy development of the river ecosystem. Employing an intelligent control system, it scientifically, accurately, and promptly optimizes the internal purification system, ensuring stable compliance of river water quality monitoring sections. This achieves efficient control under conditions of non-constant river water quality and quantity changes, ensuring long-term excellent and stable river water quality and enabling recycling. This invention offers advantages such as high long-term management benefits, convenient operation, high control efficiency, and stable performance.

[0007] Technical solution: The objective of this invention is achieved through the following technical solution:

[0008] A closed system for agricultural non-point source pollution in river network areas that combines flood control and purification includes a main river channel (1), an internal purification system (2), and an intelligent control system (3). The main river channel (1) has a certain slope. The internal purification system is connected to the main river channel, and the intelligent control system is connected to both the internal purification system and the main river channel. The system controls the internal purification system based on detection data to achieve purification of agricultural non-point source pollution and stabilization of river water level.

[0009] The aforementioned regional internal purification system (2) includes: gates, main stream, nearby tributaries, farmland, drainage ditches, main canal, branch canals, drainage ponds, and ecological purification floating beds, aeration and oxygenation purification equipment, aquatic plants, pumping stations, and automatic monitoring stations; wherein, the main river channel has one or more main streams and nearby tributaries, farmland is arranged between the main stream and nearby tributaries, one or more branch canals (2-8) are arranged between the farmland and nearby tributaries, and one or more branch canals (2-8) converge into the main canal (2-9), and gates are provided between the main canal and nearby tributaries. (2-14) A drainage pond (2-10) is provided on the side of the gate near the main channel (2-9). The opening of the gate is controlled by an intelligent control system. The pump house (2-16) is located next to the gate to provide power. An ecological purification floating bed (2-12), an aeration and oxygenation purification device (2-11), and aquatic plants (2-13) are installed in the main channel (2-9) to purify the pollution sources in the water. The monitoring section is set in the middle of the main channel near the bank, and the automatic monitoring station (2-15) is located on the bank of the river (1-1).

[0010] The intelligent control system (3) includes: a data processing system, an information feedback system, and an intelligent decision-making system; the automatic monitoring station of the regional internal purification system is connected to the data processing system of the intelligent control system. The data processing system transmits the obtained data to the information feedback system. The information feedback system is connected to the gate of the regional internal purification system to control the gate to open, thereby controlling the farmland runoff, rainfall runoff and some mainstream non-compliant river water in the region to enter the regional internal purification system (2) for purification. When the water quality meets the standard, that is, the pollutants are reduced to the target value, it can be discharged into nearby tributaries, mainstreams, and finally into the main river channel.

[0011] The pollution sources of the agricultural non-point source pollution containment system mainly include endogenous and non-point source pollution. Endogenous pollution primarily originates from bottom sediments generated in drainage ditches and ponds surrounding farmland, while non-point source pollution mainly originates from farmland runoff. The pollutants are CODcr, NH3-N, and TP, with concentrations of C... CODcr C NH3-N C TP The unit is kg / m³ 3 Let the pollutant concentration be C1 and the target value be C0 when calculating the generation and reduction of a single pollutant.

[0012] A method for regulating a closed-loop system for agricultural non-point source pollution in river network areas, combining flood control and water purification, is disclosed. Automatic monitoring stations in the main river channel monitor water quality at monitoring sections and transmit the data to an intelligent control system. This intelligent control system connects to an internal purification system and controls its activation based on the monitoring results. Addressing prominent issues such as poor river water quality stability, initial rainwater runoff pollution, flood control during the flood season, and agricultural non-point source pollution, this invention monitors river water quality and regulates river flow. It utilizes ecological ponds to purify agricultural non-point source pollution and stabilize river water levels, promoting the healthy development of the river ecosystem. The intelligent control system scientifically, accurately, and promptly optimizes the scheduling of the internal purification system, ensuring that the river water quality monitoring sections consistently meet standards. Specific steps are as follows:

[0013] Step 1) First, determine the area of ​​farmland in the river network area as A. f Then the amount of endogenous pollution generated is W1 = (A m +A d )×P1×365d, unit 10 -6 kg, of which:

[0014] A m Main canal area, unit: m² 2

[0015] A d Area of ​​branch canals, in m² 2

[0016] P1: Endogenous pollutant release intensity, unit mg / (m³)2 ·d)

[0017] Non-point source pollution refers to the amount of pollution generated by farmland runoff, W2 = V f ×C1=A f ×A c ×10%×C1, unit kg, of which:

[0018] V f The amount of water discharged from farmland in this area, in cubic meters (m³). 3

[0019] C1: Pollutant concentration, mg / L, i.e., kg / m³ 3

[0020] A f Farmland area, unit: m 2

[0021] A C The water quota for farmland in this area, in cubic meters. 3 / m 2

[0022] Pollutant target quantity W0 = V f ×C0=A f ×A c ×10%×C0, unit kg, of which:

[0023] V f The amount of water discharged from farmland in this area, in cubic meters (m³). 3

[0024] C0: Target concentration of pollutant, mg / L, i.e., kg / m³ 3

[0025] A f Farmland area, unit: m 2

[0026] Pollutant reduction amount W3 = W1 + W2 - W0, unit kg.

[0027] Step 2) From Step 1), the pollutant reduction amount W3 can be obtained. Agricultural non-point source pollution is purified through ecological purification floating beds, aeration and oxygenation equipment, and aquatic plants. The ecological purification area intensity of the ecological purification floating beds is P2, in g / (m²). 2 ·d), the purification area intensity of aquatic plants is P3, unit g / (m²). 2 ·d), the aeration and oxygenation purification area is P4, unit g / (m²). 2 ·d) then requires purification time. Where ∝ represents the daily amount of pollutants purified (kg / d). The daily amount of pollutants purified is deduced from the required purification time. The purification areas A2 (ecological floating bed), A3 (aquatic plant), and A4 (aeration and oxygenation) are then adjusted and designed to arrange the purification system.

[0028] Step 3) ensures that, under the most unfavorable conditions (during the receding flood season, if there is rainfall), V is guaranteed during the receding flood season. p +V m +V d >V f +V 雨 And always maintain H p <90% H0, i.e., V p <90%V0, which can be used to design the size of drainage channels and ponds.

[0029] Step 4) While always keeping H p When the water level is less than 90%, during the receding period of farmland, the valves should not be opened to introduce river water into the regional purification system.

[0030] Operating Condition 1: During the period of receding water in farmland, when there is no rainfall in the river, the water quality can be purified through the internal purification system (2);

[0031] Condition 2: During the drainage period of farmland and if there is rainfall, some rainwater can be stored in drainage ditches and ponds. When C1 < C0, the intelligent decision-making system can appropriately discharge the water in the drainage ponds into nearby rivers via pumping stations. The rainfall amount... The unit is 10 -3 m 3 ,in:

[0032] Comprehensive runoff coefficient

[0033] q: Rainfall intensity, mm / h

[0034] A: Catchment area, m 2

[0035] t: duration of rainfall, h

[0036] Operating Condition 3: When it is not during the receding period of farmland flooding and there is no rainfall, some river water can be diverted. 河 =90%V0-V p The water is diverted to drainage channels and ponds for purification.

[0037] Condition 4: When it is not the period of farmland flooding and there is rainfall, rainwater can be stored in drainage ditches and ponds, and some river water can be drained. 河 =90%V0-V p -V 雨When C1 < C0, the intelligent decision-making system appropriately discharges the water in the drainage pond into a nearby river via a pumping station. Among these, rainfall... The unit is 10 -3 m 3 ,in:

[0038] Comprehensive runoff coefficient

[0039] q: Rainfall intensity, mm / h

[0040] A: Catchment area, m 2

[0041] t: Duration of rainfall, h.

[0042] Compared with the prior art, the advantages of this invention are:

[0043] (1) Adapt to local conditions and do not affect flood control. Make reasonable use of existing river channels and farmland, and the purification effect is good. Green and ecological, with no secondary pollution.

[0044] (2) This invention takes the compliance of river water quality monitoring sections as its core. Based on the pollution index and degree of the river water quality monitoring section, the flow rate of the bypass purification system is reasonably determined through an intelligent control system, which can ensure the stable compliance of the water quality monitoring section in a timely and accurate manner.

[0045] (3) The present invention can carry out targeted and effective purification treatment of rivers according to different river water quality conditions, and ensure the excellent quality and stability of river water in the long term. Attached Figure Description

[0046] Figure 1 A plan view of a closed-loop system for agricultural non-point source pollution control in river network areas, which combines flood control and pollution purification.

[0047] Figure 2 A schematic diagram of a control method for a closed-loop system for agricultural non-point source pollution in river network areas that combines flood control and pollution purification.

[0048] In the diagram: Main channel-1, Main channel-1-1;

[0049] Internal purification system of the area -2, Main stream I -2-1, Main stream II -2-2, Main stream III -2-3, Nearby tributary I -2-4, Nearby tributary II -2-5, Nearby tributary III -2-6, Farmland -2-7, Branch canal -2-8, Main canal -2-9, Drainage pond -2-10, Aeration and oxygenation purification equipment -2-11, Ecological purification floating bed -2-12, Aquatic plants -2-13, Gate -2-14, Automatic monitoring station -2-15, Pumping station -2-16;

[0050] Intelligent control system-3, intelligent decision-making system-3-1, information feedback system-3-2, data processing system-3-3. Detailed Implementation

[0051] The technical solution of the present invention will be further described through the following specific embodiments.

[0052] The area of ​​farmland is A f Unit: m 2 The area of ​​the ecological pond is A. p Unit m 2 Actual water level H P Design water level H0, unit: m, actual volume V P Design volume V0, unit m 3 The area of ​​the ecological purification floating bed is A2, in m². 2 The purification area of ​​aquatic plants is A3, in m². 2 The aeration and oxygenation purification area is A4, in meters. 2 ;

[0053] The width of the main canal is B m The unit is meters (m), and the length is L. m The unit is meters (m), and the depth is H. m Unit: m, Main canal area A m =B m ×L m Unit m 2 Main canal volume V m =B m ×L m ×H m Unit m 3 ;

[0054] The width of the branch canal is B d The unit is meters (m), and the length is L. d The unit is meters (m), and the depth is H. d Unit: m, Area A of the branch canal d =B d ×L d Unit m 2 The volume of the branch canal V d =B d ×L d ×H d Unit m 3 ;

[0055] The mainstream width is B R The unit is meters (m), and the length is L. R The unit is meters (m), and the depth is H. R Unit: m, Main area A R =B R ×L R Unit m2 Mainstream volume V R =B R ×L R ×H R Unit m 3 ;

[0056] The tributary width is B t The unit is meters (m), and the length is L. t The unit is meters (m), and the depth is H. t Unit: m, Main area A t =B t ×L t Unit m 2 Mainstream volume V t =B t ×L t ×H t Unit m 3 .

[0057] Example 1

[0058] A main river channel 1-1 is a medium-sized river with a width of b = 50m and a depth of h = 5m. The monitoring section is located in the middle of the main river channel 1-1 near the bank, and is marked to prevent damage. Automatic monitoring station 2-15 is located on the bank of the main river channel 1-1 and is equipped with monitoring devices for CODcr, NH3-N, and TP. The main water quality assessment indicators are Class III of the "Surface Water Environmental Quality Standard" (GB3838-2002) (CODcr ≤ 20mg / L, NH3-N ≤ 1.0mg / L, TP ≤ 0.2mg / L).

[0059] The target value for pollutants in the monitored river section is C. 0CODcr =20mg / L; C 0NH3-N =1.0 mg / L; C 0TP =0.2mg / L.

[0060] Step 1) First, determine the area of ​​farmland in the river network area as A. f =250000m 2 The amount of endogenous pollution generated is:

[0061] W1=(A m +A d )×P1×365d, unit 10 -6 kg,

[0062] Among them: Main canal area A m =2000m 2 The area of ​​the branch canal A d =300m 2 Pollutant release intensity P 1CODcr =15mg / (m2 ·d), P 1NH3-N =8mg / (m 2 ·d), P 1TP =5mg / (m 2 ·d). Then:

[0063] W 1CODcr =(A m +A d )×P 1CODcr ×365d=12.59kg;

[0064] W 1NH3-N =(A m +A d )×P 1NH3-N ×365d=6.72kg;

[0065] W 1TP =(A m +A d )×P 1TP ×365d=4.20kg;

[0066] Non-point source pollution refers to the amount of pollution generated by farmland runoff.

[0067] W2 = V f ×C1=A f ×A c ×10%×C1, unit: kg

[0068] Among them: the amount of farmland drainage in this area, V f =27500m 3 Pollutant concentration C 1CODcr =0.04kg / m 3 C 1NH3-N =0.003kg / m 3 C 1TP =0.0005kg / m 3 Farmland area A f =25000m 2 The farmland water use quota A in this area C =1.1m 3 / m 2 .but:

[0069] W 2CODcr =V f ×C 1CODcr =A f ×A c ×10%×C 1CODcr =1100kg;

[0070] W 2NH3-N =V f ×C1NH3-N =A f ×A c ×10%×C 1NH3-N =82.5kg;

[0071] W 2TP =V f ×C 1TP =A f ×A c ×10%×C 1TP =13.75kg.

[0072] The target amount of pollutants is:

[0073] W0 = V f ×C0=A f ×A c ×10%×C0, unit: kg

[0074] Among them: the amount of farmland drainage in this area, V f =27500m 3 Target concentration of pollutants C 0CODcr =0.02kg / m 3 C 0NH3-N =0.001kg / m 3 C 0TP =0.0002kg / m 3 Farmland area A f =250000m 2 .but:

[0075] W 0CODcr =V f ×C 0CODcr =A f ×A c ×10%×C 0CODcr =550kg;

[0076] W 0NH3-N =V f ×C 0NH3-N =A f ×A c ×10%×C 0NH3-N =27.5kg;

[0077] W 0TP =V f ×C 0TP =A f ×A c ×10%×C 0TP =5.5kg.

[0078] Pollutant reduction amount W3 = W1 + W2 - W0, in kg. Therefore:

[0079] W 3CODcr =W 1CODcr +W 2CODcr -W 0CODcr =12.59+1100-550=562.59kg;

[0080] W 3NH3-N =W 1NH3-N +W 2NH3-N -W 0NH3-N =6.72+82.5-27.5=61.72kg;

[0081] W 3TP =W 1TP +W 2TP -W 0TP =4.20 + 13.75 - 5.5 = 12.45 kg

[0082] Step 2) From Step 1), the pollutant reduction amount W can be obtained. 3CODcr W 3NH3-N W 3TP Agricultural non-point source pollution is purified through ecological purification floating beds, aeration and oxygenation equipment, and aquatic plants. The ecological purification area intensity of the ecological purification floating beds is:

[0083] P 2CODcr =0.005g / (m 2 ·d),

[0084] P 2NH3-N =0.0006g / (m 2 ·d),

[0085] P 2TP =0.00006gTP / (m 2 ·d).

[0086] The purification area intensity of aquatic plants is:

[0087] P 3CODcr =0.003g / (m 2 ·d),

[0088] P 3NH3-N =0.0003g / (m 2 ·d),

[0089] P 3TP =g / (m 2 ·d)

[0090] The aeration and oxygenation purification area is:

[0091] P 4CODcr =g / (m 2 ·d),

[0092] P 4NH3-N =g / (m 2 ·d)

[0093] P 4TP =g / (m 2 •d) Then, purification time is required:

[0094]

[0095]

[0096]

[0097] in The daily pollutant purification capacity is expressed in kg / d. Based on the required purification time, the daily pollutant purification capacity is calculated. The purification areas A2 (ecological floating bed), A3 (aquatic plant), and A4 (aeration and oxygenation) are then adjusted and designed. This yields the ecological floating bed purification area that can be deployed as a purification system: A2 = 150 m². 3 ,

[0098] Aquatic plant purification area: A3 = 300m² 3

[0099] Aeration and oxygenation purification area A4 = 100m² 3 .

[0100] Step 4) ensures that, under the most unfavorable conditions (during the receding flood season, if there is rainfall), the following is guaranteed during the receding flood season:

[0101] V p +V m +V d >V f +V 雨 ,

[0102] V P V: Actual volume of farmland; m Main canal volume; V d Volume of branch canals;

[0103] Rainfall

[0104] And always maintain H p <90% H0,

[0105] H0: Design water level for farmland; H P Actual water level in farmland;

[0106] H0 = 3m, i.e., V pSince V0 is less than 90%, the dimensions of the drainage canals and ponds can be designed accordingly. Therefore, the designed volume of farmland is V0 = 28550 m³. 3 Actual volume of farmland V p <25695m 3 Main canal depth H m =3m, branch canal depth H d =1.5m.

[0107] Step 5) When it is not during the receding flood season in farmland and there is rainfall, when V p =15000m 3 At times, some river water can be diverted. 河 =90%V0-V p =10695m 3 The water is diverted to drainage channels and then drained into ponds for purification, thus achieving a cycle.

[0108] Example 2

[0109] A main river channel 1-1 is a medium-sized river with a width of b = 60m and a depth of h = 4m. The monitoring section is located in the middle of channel 1-1 near the bank, and is marked to prevent damage. Automatic monitoring station 2-15 is located on the bank of the main river channel 1-1 and is equipped with monitoring devices for CODcr, NH3-N, and TP. The main water quality assessment indicators are Class III of the "Surface Water Environmental Quality Standard" (GB3838-2002) (CODcr ≤ 20mg / L, NH3-N ≤ 1.0mg / L, TP ≤ 0.2mg / L).

[0110] The target value for pollutants in the monitored river section is C. 0CODcr =20mg / L; C 0NH3-N =1.0 mg / L;; C 0TP =0.2mg / L.

[0111] Step 1) First, determine the area of ​​farmland in the river network area as A. f =300000m 2 Then the amount of endogenous pollution generated is W1 = (A m +A d )×P1×365d, unit 10 -6 kg, of which: the area of ​​the main canal A m =5000m 2 The area of ​​the branch canal A d =700m 2 Pollutant release intensity P 1CODcr =15mg / (m 2 ·d), P 1NH3-N =8mg / (m 2 ·d), P 1TP =5mg / (m2 ·d). Then:

[0112] W 1CODcr =(A m +A d )×P 1CODcr ×365d=31.21kg;

[0113] W 1NH3-N =(A m +A d )×P 1NH3-N ×365d=16.64kg;

[0114] W 1TP =(A m +A d )×P 1TP ×365d=10.40kg;

[0115] Non-point source pollution refers to the amount of pollution generated by farmland runoff, W2 = V f ×C1=A f ×A c ×10%×C1, unit kg, where: V is the amount of farmland drainage in this area. f =36000m 3 Pollutant concentration C 1CODcr =0.035kg / m 3 C 1NH3-N =0.0025kg / m 3 C 1TP =0.00044kg / m 3 Farmland area A f =300000m 2 The farmland water use quota A in this area C =1.2m 3 / m 2 Then W 2CODcr =V f ×C 1CODcr =A f ×A c ×10%×C 1CODcr =1260kg; W 2NH3-N =V f ×C 1NH3-N =A f ×A c ×10%×C 1NH3-N =90kg; W 2TP =V f ×C 1TP =A f ×A c ×10%×C 1TP =15.84kg.

[0116] Pollutant target quantity W0 = V f ×C0=A f ×A c ×10%×C0, unit kg, where: V is the amount of farmland drainage in this area. f =36000m 3 Target concentration of pollutants C 0CODcr =0.02kg / m 3 C 0NH3-N =0.001kg / m 3 C 0TP =0.0002kg / m 3 Farmland area A f =300000m 2 .but:

[0117] W 0CODcr =V f ×C 0CODcr =A f ×A c ×10%×C 0CODcr =720kg;

[0118] W 0NH3-N =V f ×C 0NH3-N =A f ×A c ×10%×C 0NH3-N =36kg;

[0119] W 0TP =V f ×C 0TP =A f ×A c ×10%×C 0TP =7.2kg.

[0120] Pollutant reduction amount W3 = W1 + W2 - W0, in kg.

[0121] W 3CODcr =W 1CODcr +W 2CODcr -W 0CODcr =571.21kg;

[0122] W 3NH3-N =W 1NH3-N +W 2NH3-N -W 0NH3-N =70.64kg;

[0123] W 3TP =W 1TP +W 2TP -W0TP =4.20 + 13.75 - 5.5 = 19.04 kg

[0124] Step 2) From Step 1), the pollutant reduction amount W can be obtained. 3CODcr W 3NH3-N W 3TP Agricultural non-point source pollution is purified through ecological purification floating beds, aeration and oxygenation equipment, and aquatic plants. The ecological purification area intensity of the ecological purification floating beds is P. 2CODcr =0.005g / (m 2 ·d), P 2NH3-N =0.0006g / (m 2 ·d),P 2TP =0.00006g / (m 2 ·d). The purification area intensity of aquatic plants is: P 3CODcr =0.003g / (m 2 ·d), P 3NH3-N =0.0003g / (m 2 ·d),P 3TP =g / (m 2 ·d); The aeration and oxygenation purification area is P 4CODcr =g / (m 2 ·d), P 4NH3-N =g / (m 2 ·d),P 4TP =g / (m 2 ·d) requires purification time

[0125]

[0126]

[0127]

[0128] Where ∝ represents the daily amount of pollutants purified, in kg / d. Based on the required purification time, the daily amount of pollutants to be purified is deduced. The purification areas A2 (ecological floating bed), A3 (aquatic plant), and A4 (aeration and oxygenation) are then adjusted and designed, resulting in a purification area of ​​A2 = 120 m² for the ecological floating bed system. 3 The purification area of ​​aquatic plants is A3 = 310m² 3 Aeration and oxygenation purification area A4 = 85m² 3 .

[0129] Step 4) ensures that, under the most unfavorable conditions (during the receding flood season, if there is rainfall), V is guaranteed during the receding flood season. p +V m +V d >V f+V 雨 Rainfall

[0130] And always maintain H p <90%H0, H0 = 3.2m, V p With V0 < 90%, the dimensions of the drainage channel and pond can be designed accordingly, and the volume of the ecological pond can be designed as V0 = 17900 m³. 3 V p <16100m 3 The main canal is H deep m = 3.5m, branch canal depth H d =1.5m.

[0131] Step 5) When it is not during the receding flood season in farmland and there is rainfall, when V p =10000m 3 At times, some river water can be diverted. 河 =90%V0-V p =6110m 3 The water is diverted to drainage channels and then drained into ponds for purification, thus achieving a cycle.

Claims

1. A closed-loop system for agricultural non-point source pollution control in river network areas, combining flood control and pollution purification, characterized in that... It includes a main river channel (1), an internal regional purification system (2), and an intelligent control system (3); wherein the main river channel (1) has a slope; the internal regional purification system is connected to the main river channel, and the intelligent control system is connected to both the internal regional purification system and the main river channel. It controls the internal regional purification system based on the detection data to achieve the purification of agricultural non-point source pollution and the stabilization of river water level; the internal regional purification system (2) includes: gate, main stream, nearby tributaries, farmland, drainage ditch, main canal, branch canal, drainage pond, and ecological purification floating bed, aeration and oxygenation purification equipment, aquatic plants, pump house, and automatic monitoring station; The main channel has one or more main streams and nearby tributaries. Farmland is located between the main stream and nearby tributaries. Between the farmland and nearby tributaries, there is one or more branch canals (2-8). These branch canals (2-8) converge into the main channel (2-9). A gate (2-14) is located between the main channel and nearby tributaries. A drainage pond (2-10) is located on the side of the gate closest to the main channel (2-9). The opening of the gate is controlled by an intelligent control system. A pumping station (2-16) is located next to the gate to provide power. Ecological purification floating beds (2-12), aeration and oxygenation purification equipment (2-11), and aquatic plants (2-13) are installed in the main channel (2-9) to purify pollutants in the water. Monitoring is conducted on... The automatic monitoring station (2-15) is located on the bank of the river (1-1) in the middle of the main river channel. The intelligent control system (3) includes: a data processing system, an information feedback system, and an intelligent decision-making system. The automatic monitoring station of the regional purification system is connected to the data processing system of the intelligent control system. The data processing system transmits the obtained data to the information feedback system. The information feedback system is connected to the gate of the regional purification system and controls the gate to open. This controls the farmland runoff, rainfall runoff, and some mainstream non-compliant river water in the region to enter the regional purification system (2) for purification. Once the water quality meets the standard, that is, the pollutants are reduced to the target value, they can be discharged into nearby tributaries, mainstreams, and finally into the main river channel.

2. The closed-loop system for agricultural non-point source pollution control in river network areas, which combines flood control and pollution purification, as described in claim 1, is characterized in that... The pollution sources of the agricultural non-point source pollution containment system mainly include endogenous and non-point source pollution. Endogenous pollution primarily originates from bottom sediments generated in drainage ditches and ponds surrounding farmland, while non-point source pollution mainly originates from farmland runoff. The pollutants are CODcr, NH3-N, and TP, with concentrations of [missing information]. , , The unit is kg / ; Assume that the pollutant concentration is given when calculating the generation and reduction of a single pollutant. The target value is The amount of endogenous pollution generated is: =( ) 365d, unit kg, of which: Main canal area, unit ; Area of ​​branch canals, unit ; Endogenous pollutant release intensity, per unit ; The amount of non-point source pollution, i.e., pollution generated by farmland runoff, is: = = The unit is kg, where: The amount of water receding from farmland in this area, in units of ; Pollutant concentration, mg / L, i.e., kg / L ; Farmland area, unit ; The water quota for farmland in this area, in units of / ; The target amount of pollutants is: = = Unit: kg, of which: The amount of water receding from farmland in this area, in units of ; Target concentration of pollutants, mg / L, i.e., kg / ; Farmland area, unit Pollutant reduction = , unit: kg.

3. The regulation method for a closed-loop system for agricultural non-point source pollution control in river network areas, which combines flood control and pollution purification, as described in claim 1, is characterized in that... An automatic monitoring station set up on the bank of the river (1-1) monitors the water level and water quality of the farmland drainage pond and transmits the data to the intelligent control system (3). The intelligent control system (3) is connected to the gate of the internal purification system (2). The intelligent control system controls the gate to open according to the detection results on the bank of the river (1-1). The farmland drainage, rainfall runoff and some mainstream non-compliant river water in the area enter the internal purification system (2). The water is purified by the use of ecological purification floating beds (2-12), aeration and oxygenation purification equipment (2-11) and aquatic plants (2-13). When the water quality meets the standard, that is, the pollutants are reduced to the target value, it can be discharged into the nearby tributaries and mainstream, and finally flow into the main river. The specific steps include: Step 1) Based on the area of ​​farmland in the river network region Determine the amount of pollutant reduction : = Unit: kg; Endogenous pollution generation =( ) 365d, unit kg, of which: Main canal area, unit ; Area of ​​branch canals, unit ; Endogenous pollutant release intensity, per unit ; Non-point source pollution refers to the amount of pollution generated by farmland runoff. = = The unit is kg, where: The amount of water receding from farmland in this area, in units of ; Pollutant concentration, mg / L, i.e., kg / L ; Farmland area, unit ; The water quota for farmland in this area, in units of / ; Pollutant target quantity = = Unit: kg, of which: The amount of water receding from farmland in this area, in units of ; Target concentration of pollutants, mg / L, i.e., kg / ; Farmland area, unit ; Step 2) The amount of pollutant reduction can be obtained from Step 1). Agricultural non-point source pollution is purified through ecological purification floating beds, aeration and oxygenation equipment, and aquatic plants. The ecological purification area intensity of the ecological purification floating beds is [missing information]. Unit The purification area intensity of aquatic plants is Unit The aeration and oxygenation purification area is Unit Then purification time is required. ,in Daily pollutant purification capacity (kg / d); the daily pollutant purification capacity is calculated based on the required purification time, and the purification area of ​​the ecological purification floating bed is adjusted and designed accordingly. Aquatic plant purification area Aeration and oxygenation purification area Therefore, a purification system can be installed; Step 3) During the drainage period of farmland, under the most unfavorable condition of rainfall, ensure that the farmland drainage period is... + + > + And always maintain < ,Right now < This allows us to design the dimensions of drainage channels and ponds; Step 4) Maintaining < In the event of the receding water period in farmland, the valves should not be opened to introduce river water into the area's internal purification system; Operating Condition 1: During the period of receding water in farmland, when there is no rainfall in the river, the water quality can be purified by the internal purification system (2); Operating Condition 2: During the drainage period of farmland and in the event of rainfall, some of the rainwater can be stored in drainage ditches and ponds. < At appropriate times, the intelligent decision-making system will use pumping stations to discharge water from the receding ponds into nearby waterways; among which rainfall... = The unit is ,in: : Combined runoff coefficient; Rainfall intensity, mm / h; Catchment area ; Rainfall duration, in hours (h); Operating Condition 3: When it is not the period of farmland flooding and there is no rainfall, some river water can be diverted. = The water is diverted to drainage channels and ponds for purification. Condition 4: When it is not the period of farmland flooding and there is rainfall, rainwater can be stored in drainage ditches and ponds, which can drain some of the river water. = < At appropriate times, the intelligent decision-making system will use pumping stations to discharge water from the receding ponds into nearby waterways; among which rainfall... = The unit is ,in: : Combined runoff coefficient; Rainfall intensity, mm / h; Catchment area ; Rainfall duration, in hours (h).

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