Basin non-point source pollution control and river water environment improvement system and operation process thereof

Abstract

The invention discloses a drainage basin non-point source pollution control and river water environment improvement system and an operation process thereof. The system comprises a main river channel, a closed area internal purification system and an intelligent control system. The automatic monitoring station in the main river channel monitors the water quality of the monitoring section and transmits data to the intelligent control system, and the intelligent control system is connected with the purification system in the closed area and controls the opening of the purification system in the area according to a monitoring result. The system can purify agricultural non-point source pollution and industrial sewage and domestic sewage point source pollution in the closed area by detecting the water quality of the river channel and regulating and controlling the water quantity of the river channel, promotes healthy development of a river ecosystem, scientifically, accurately and efficiently optimizes a purification system in the closed area by utilizing an intelligent control system, and improves the purification efficiency of the closed area. Therefore, the water quality monitoring section stably reaches the standard. The system has the advantages of convenient operation, stable performance, long-term efficient operation management and the like.

Description

Technical Field

[0001] The present invention relates to the field of water ecological restoration, and specifically to a watershed non-point source pollution control and river water environment improvement system and a regulation method thereof. Background Art

[0002] With the acceleration of urbanization and industrialization, a series of reasons such as industrial sewage, urban domestic sewage and farmland drainage have led to the intensification of water pollution. In addition, sewage discharged from upstream will increase the cost of treating water bodies to meet standards when using water bodies downstream. Therefore, there are strict requirements for water discharge and water quality needs to be monitored and managed. River water quality sections can be divided into national control sections, provincial control sections and municipal control sections. In 2017, among the 1,940 surface water quality sections (points) in the country, 1,317 sections (points) were of Class I to III, accounting for 67.9%; 462 were of Class IV and V, accounting for 23.8%; and 161 were of Class V or below, accounting for 8.3%. Compared with 2016, the proportion of Class I to III water quality sections (points) increased by 0.1 percentage point, and that of Class V or below decreased by 0.3 percentage point.

[0003] The patent application document with application number CN202410955804.0 discloses a district sewage diversion control optimization system for improving quality and efficiency, which belongs to the field of water environment management, a total regulating reservoir, a first water purification plant, a second water purification plant, a third water purification plant and a pump station, wherein the total regulating reservoir transmits water to the second water purification plant and the third water purification plant through the pump station; the total regulating reservoir is provided with a total water output detection device, and the water inlets of the first water purification plant, the second water purification plant and the third water purification plant are all provided with pollutant component detection equipment, and the pump station is provided with a diversion control device, wherein the total water output detection device and the pollutant component detection device are respectively communicated and connected with the diversion control device; the diversion control device is used to calculate the diversion coefficient when the unit reduction amount corresponds to the lowest cost, and the valve switch amount of the pump station is controlled according to the obtained diversion coefficient. The present invention ensures the efficient operation of water purification plants at all levels by controlling the optimal treatment allocation ratio of water purification plants at all levels. However, it cannot purify the water in the river.

[0004] The patent application document with application number CN202323358804.2 discloses a source pollutant reduction device, which relates to the technical field of chemical or physical methods. The source pollutant reduction device includes a formaldehyde reduction tank and a tank support plate, the lower surface of the formaldehyde reduction tank is fixedly connected to the tank support plate, the formaldehyde reduction tank is fixedly connected to the formaldehyde reaction tank, the formaldehyde reduction tank is provided with a cleaning device, the formaldehyde reduction tank is provided with a constant temperature device, the electric heating pipe heats the water in the formaldehyde reduction tank, and preheats the liquid in the liquid supply pipeline to prevent the raw material liquid methanol at room temperature from suddenly flowing into the formaldehyde reaction tank in large quantities, reducing the temperature in the cavity, and then affecting the evaporation efficiency of methanol, so that the temperature inside the formaldehyde reaction tank will not change significantly, and the real-time temperature of the formaldehyde reaction tank is observed through the temperature display component, which reduces the generation of pollutants, ensures the quality of methanol gas, and increases practicality. However, it does not consider placing the device in a river water body to purify the river water body.

[0005] The patent application document with application number CN202311370749.0 discloses a water plant status assessment method, device, computer equipment and storage medium, including: obtaining multiple target assessment types of the water plant to be assessed and the target assessment indicators under each target assessment type; obtaining the associated indicator value of the target assessment indicator, and determining the evaluation indicator value of the target assessment indicator based on the associated indicator value; based on the evaluation indicator value, determining the target indicator score of the target assessment indicator; based on the target indicator score, determining the evaluation score of each target assessment type; based on the evaluation scores of multiple target assessment types, determining the status information of the water plant to be assessed. This application can automatically evaluate the water plant to be assessed in combination with the target assessment indicators under multiple target assessment types, thereby improving the accuracy of the assessment results. However, it does not provide a solution to the reduction of pollutants in the water body. Summary of the invention

[0006] Purpose of the invention: To remove pollutants in rivers within closed areas and make them meet the water quality requirements of water quality monitoring sections, the present invention discloses a system for controlling non-point source pollution in a watershed and improving the water environment of a river and its operation process. The system includes a main river channel, a purification system within a closed area, and an intelligent control system. The automatic monitoring station in the main river channel monitors the water quality of the monitoring section and transmits the data to the intelligent control system. The intelligent control system is connected to the purification system within the closed area and controls the opening of the purification system within the area according to the monitoring results. The present invention can detect the water quality of the river channel and regulate the water volume of the river channel, use artificial wetlands to purify agricultural non-point source pollution and industrial sewage and domestic sewage point source pollution within the closed area, promote the healthy development of the river ecosystem, and use an intelligent control system to scientifically, accurately and efficiently optimize the purification system within the closed area to ensure that the water quality monitoring section is stable and meets the standards. It has the advantages of convenient operation, stable performance, and long-term efficient operation and management.

[0007] Technical solution: The purpose of the present invention is achieved through the following technical solutions:

[0008] A closed area pollutant automatic reduction system comprises a main river channel (1), a closed area internal purification system (2) and an intelligent control system (3); wherein the main river channel has a certain slope; the closed area internal purification system is connected to the main river channel, and the intelligent control system is simultaneously connected to the main river channel and the closed area internal purification system, thereby achieving automatic purification of agricultural non-point source pollution and industrial sewage and domestic sewage point source pollution within the closed area, and promoting the healthy and steady development of the ecosystem in the basin.

[0009] The closed area internal purification system (2) includes: gates, overflow dams, mainstream, nearby tributaries, farmland, artificial wetlands, ecological purification floating beds, aeration purification equipment, aquatic plants, sewage treatment plants, pump houses and automatic monitoring stations:

[0010] The main river channel has more than one main stream and nearby tributaries, a gate (2-12) is provided between the main stream (2-1) and the main river channel, and the tributaries directly merge into the main stream. An overflow dam (2-10) is provided on the main stream to divide the main stream into several sections, and a pump house (2-21) is provided on the main stream section closest to the main river channel. The power provided by the pump house is used to transport the water flow to the front end of the main stream. The opening degree of the overflow dam and the opening of the gate are controlled by an intelligent control system. The farmland (2-13) in the closed area is arranged near the main stream and tributaries, and the farmland drainage is directly discharged into the main stream and tributaries. The artificial wetland (2-23) is arranged on both sides of the main stream. The main stream and tributaries are provided with ecological purification floating beds (2-24), aeration purification equipment (2-25) and aquatic plants (2-26) to cooperate with the artificial wetland to purify pollutants in the water body. The monitoring section is set at the shore of the main river channel, and the automatic monitoring station (2-22) is located at the place where the main stream merges into the main river channel.

[0011] The intelligent control system (3) comprises: a data processing system, an information feedback system and an intelligent decision-making system; the automatic monitoring station of the closed area internal purification system is connected to the data processing system of the intelligent control system, the data processing system transmits the acquired data to the information feedback system, the information feedback system is connected to the gate and overflow dam of the closed area internal purification system (2), controls the opening of the gate and the opening degree of the overflow dam, and further controls the flow rate and the residence time of pollutants in the closed area, and controls the mainstream that does not meet the standards to enter the closed area internal purification system for purification. After the water quality meets the standards, that is, the concentration of pollutants is reduced to the target, the gate can be opened and finally merged into the main river channel.

[0012] The sources of pollutants in the closed system mainly include point source pollution and non-point source pollution. Point source pollution includes industrial wastewater and urban wastewater treated by sewage treatment plants, and non-point source pollution mainly comes from farmland drainage. The pollutants are CODcr , NH3-N, TP, the concentrations are C CODcr , C NH3-N , C TP , unit is kg / m 3 When calculating the generation and reduction of a single pollutant, the pollutant concentration is C1 and the target value is C0.

[0013] The amount of non-point source pollution is:

[0014] W1=V f *C1=A f *A c *C1(1), unit: kg, where:

[0015] V f : The amount of water returned from farmland in this area, in m 3

[0016] C1: Pollutant concentration, mg / L, i.e. kg / m 3

[0017] A f : Farmland area, unit: m 2

[0018] A c : The farmland water quota in the area, in m 3 / m 2

[0019] The amount of point source pollution produced is:

[0020] W2=V g *P g *t+V c *P c *t(3), unit: kg, where:

[0021] V g : Factory wastewater discharge, unit: m 3 / d

[0022] P g : Factory pollution emission intensity, unit: kg / m 3

[0023] V c : Urban sewage discharge, unit: m 3 / d

[0024] P c : Urban pollution emission intensity, unit: kg / m 3

[0025] t: pollution emission time, in d, taking the whole year as the total time, t is 365d;

[0026] If there is no specific antibiotic concentration in the river, W1+W2 is obtained according to formula (1)+formula (3);

[0027] When there is a specific antibiotic concentration in the river, the value of W1+W2 is obtained according to the following formula (4):

[0028] or Unit: kg, where:

[0029] f(h, t, L): The concentration density of antibiotics in the river, which is related to the water level h, the length L and the time t.

[0030] The target amount of pollutants is: W0 = (V f +V g +V c )*C0, unit: kg, where:

[0031] V f : The amount of water returned from farmland in this area, in m 3

[0032] V g : Factory wastewater discharge, unit: m 3

[0033] V c : Urban sewage discharge, unit: m 3

[0034] C0: Target concentration of pollutants, mg / L, i.e. kg / m 3

[0035] V f =A f *A c , unit m 3 ,in:

[0036] A f : Farmland area, unit: m 2

[0037] A c : The farmland water quota in the area, in m 3 / m 2

[0038] Pollutant reduction W3 = W1 + W2 - W0, unit: kg.

[0039] The operating process of the watershed non-point source pollution control and river water environment improvement system is as follows: an automatic monitoring station is arranged on the bank of the mainstream to monitor the water quality and water volume of the mainstream, and transmit the data to the intelligent control system; the intelligent control system is connected to the gate (3-12), overflow dam (3-10) and pump station (2-21) of the internal purification system of the closed area; the intelligent control system (3) controls the opening of the overflow dam and the pump station according to the monitoring results of the automatic monitoring station (2-22) on the bank of the mainstream, transmits the inner river water of the terminal mainstream that does not meet the water quality standard to the front end of the mainstream, so that the river water flows into the internal purification system of the closed area; the water body is purified by means of artificial wetlands (2-23), ecological purification floating beds (2-24), aeration purification equipment (2-25) and aquatic plants (2-26); when the water quality meets the standard, that is, the pollutants are reduced to the target, the water can pass through the terminal mainstream and open the gate to be discharged into the main river.

[0040] The operation process of the watershed non-point source pollution control and river water environment improvement system comprises the following steps:

[0041] Step 1) According to the industrial wastewater discharge volume V in the closed area g , Urban domestic sewage discharge V c and farmland area, determine the amount of pollutant reduction W:

[0042] W3=W1+W2-W0,unit: kg

[0043] The amount of non-point source pollution W1 = V f *C1=A f *A c *C1(1), unit: kg, where:

[0044] V f : The amount of water returned from farmland in this area, in m 3

[0045] C1: Pollutant concentration, mg / L, i.e. kg / m 3

[0046] A f : Farmland area, unit: m 2

[0047] A c : The farmland water quota in the area, in m 3 / m 2

[0048] Point source pollution generation W2 = V g *P g *t+V c *P c *t(3), unit: kg, where:

[0049] V g : Factory wastewater discharge, unit: m 3 / d

[0050] P g : Factory pollution emission intensity, unit: kg / m 3

[0051] V c : Urban sewage discharge, unit: m 3 / d

[0052] P c : Urban pollution emission intensity, unit: kg / m 3

[0053] t: pollution emission time, in d, taking the whole year as the total time, t is 365d;

[0054] If there is no specific antibiotic concentration density in the river, W1+W2 is obtained according to formula (1)+formula (3);

[0055] Or when there is a specific antibiotic concentration density in the river, the value of W1+W2 is obtained according to the following formula (4):

[0056] Unit: kg, where:

[0057] f(h, t, L): The concentration density of antibiotics in the river, which is related to the water level h, the length L and the time t.

[0058] The target amount of pollutants is: W0 = V*C0, unit: kg, where:

[0059] V: The volume of water in the river, in m 3

[0060] C0: Target concentration of pollutants, mg / L, i.e. kg / m 3

[0061] Step 2) From step 1), the pollutant reduction amount W3 can be obtained. Select the surface organic load q of the artificial wetland os1 , unit: kg / (m 2 *d), calculate the area of ​​artificial wetland Where A1: artificial wetland area m 2 , P1: Daily pollutant purification amount of artificial wetland kg / d; Select the surface organic load of ecological purification floating bed q os2 , unit: kg / (m 2 *d), calculate the ecological purification floating bed Where A2: artificial wetland area m 2, P2: Daily pollutant purification amount of ecological purification floating bed kg / d; Select the surface organic load of aeration purification equipment q os3 , unit: kg / (m 2 *d), calculate the area of ​​aeration purification equipment Where A3: aeration purification equipment area m 2 , P3: Daily pollutant purification amount of aeration purification equipment kg / d; Surface organic load of selected aquatic plants q os4 , unit: kg / (m 2 *d), calculate the aquatic plant area A4: Aquatic plant area m 2 , P1: Daily pollutant purification amount of aquatic plants kg / d; At this time, it is necessary to ensure that W3≤(P1+P2+P3+P4)*365d. According to the selected artificial wetlands, ecological purification floating islands, aeration purification equipment and surface organic loads of aquatic plants, adjust and design the artificial wetland area A1, ecological purification floating island area A2, aeration purification equipment A3 and aquatic plant area A4 to coordinate the areas of various water treatment facilities.

[0062] Step 3) Ensure that the water depth H1 in the mainstream is less than 80% H, that is, V1 is less than 80% V, at any time throughout the year. If the water quality of the mainstream cannot meet the requirements, the height of the overflow dam can be increased to allow the mainstream to carry more water, but the water depth must not be higher than the mainstream depth.

[0063] Step 4) When the water quality meets the standard and the water depth H1≥80%H, open the gate to discharge excess river water into the main river channel to ensure that the water level H1 in the main stream is <80%H.

[0064] Working condition 1: During the period of farmland withdrawal and when there is no rainfall in the river, the water quality can be purified by the internal purification system in the closed area and the water body that meets the water quality standards can be discharged normally;

[0065] Working condition 2: During the period of farmland withdrawal, when there is rainfall in the river, the height of the overflow dam can be increased and the gates can be closed to increase the retention time of water in the purification system inside the closed area, so as to ensure that the water quality meets the standards before being discharged into the main river; the rainfall The unit is 10 -3 m 3 ,in:

[0066] Comprehensive runoff coefficient

[0067] q: rainfall intensity mm / h

[0068] A: catchment area, m 2

[0069] t: rainfall duration, h

[0070] Working condition 3: When the farmland is not in the water withdrawal period and there is no rainfall, the pump station is used normally to pump the substandard water in the mainstream to the early section of the mainstream, so that the water can be purified normally in the closed area purification system; if the water quality meets the standard, the gate can be opened normally to discharge the water into the main river;

[0071] Working condition 4: When the farmland is not in the water withdrawal period and there is rainfall, the intelligent decision-making system will open the gate appropriately to discharge the water that meets the water quality standards into the main river; the water that does not meet the water quality standards will be sent to the internal purification system of the closed area through the pump station for purification. The unit is 10 -3 m 3 .

[0072] Compared with the existing technology, the advantages of the present invention are:

[0073] (1) Rational use of existing rivers, good purification effect and no secondary pollution.

[0074] (2) With the compliance of water quality monitoring sections as the core, the purification amount is reasonably determined through intelligent control based on the pollution indicators and degree of the river water quality monitoring sections, so that it can ensure that the monitoring sections meet the standards in a timely and accurate manner.

[0075] (3) The present invention can ensure that the river is purified for a long time according to different situations, thereby ensuring the stability of the water quality of the river water body for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 A plan view of an automatic pollutant reduction system in an enclosed area;

[0077] Figure 2 A cross-sectional view of an automatic pollutant reduction system in an enclosed area;

[0078] Figure 3 A schematic diagram of a watershed non-point source pollution control and river water environment improvement system and its regulation method.

[0079] In the figure:

[0080] Main channel-1, main channel-1-1;

[0081] Internal purification system of closed area-2, mainstream I-2-1, mainstream I-2-2, mainstream I-2-3, tributary I-2-4, tributary II-2-5, tributary III-2-6, tributary IV-2-7, tributary V-2-8, tributary VI-2-9, overflow dam I-2-10, overflow dam II-2-11, gate-2-12, farmland I-2-13, farmland II-2-14, farmland III-2-15, farmland IV-2-16, city-2-17, township I-2-18, township II-2-19, sewage treatment plant-2-20, pumping station-2-21, automatic monitoring station-2-22, artificial wetland-2-23, ecological purification floating island-2-24, aeration purification equipment-2-25, aquatic plants-2-26;

[0082] Intelligent control system-3, intelligent decision-making system-3-1, information feedback system-3-2, data processing system-3-3. DETAILED DESCRIPTION

[0083] The technical solution of the present invention is further described through the following specific embodiments.

[0084] A system for controlling non-point source pollution in a watershed and improving the river water environment, the system comprising a main river channel 1, a purification system 2 inside a closed area and an intelligent control system 3; wherein the main river channel has a certain slope; the purification system inside the closed area is connected to the main river channel, and the intelligent control system is simultaneously connected to the main river channel and the purification system inside the closed area, so as to realize automatic purification of agricultural non-point source pollution and point source pollution of industrial sewage and domestic sewage in the closed area, and promote the healthy and steady development of the ecosystem in the watershed.

[0085] The closed area internal purification system 2 includes: gates, overflow dams, mainstreams, nearby tributaries, farmland, artificial wetlands, ecological purification floating beds, aeration purification equipment, aquatic plants, sewage treatment plants, pump houses and automatic monitoring stations:

[0086] The main river channel has more than one main stream and nearby tributaries, and the main river channel passes between towns or flows through the edge of towns; a gate (2-12) is set between the main stream (2-1) and the main river channel, and more than one tributary directly merges into the main stream. One or more overflow dams (2-10) are set along the main stream to divide the main stream into several sections. A pump house 2-21 is set on the main stream section closest to the main river channel, and the power provided by the pump house is used to transport the water flow to the front end of the main stream. The opening degree of the overflow dam and the opening of the gate are controlled by an intelligent control system; farmland 2-1 in the enclosed area 3 is arranged near the mainstream and tributaries (or the area between the mainstream and tributaries). The water level during farmland irrigation is higher than the tributary water level. Farmland drainage is directly discharged into the mainstream and tributaries. Artificial wetlands (2-23) are arranged on both sides of the mainstream and between the mainstream and farmland. Ecological purification floating beds (2-24), aeration purification equipment (2-25) and aquatic plants (2-26) are set in the mainstream and tributaries to purify pollutants in the water body in coordination with artificial wetlands. The monitoring section is set at the shore of the main river channel, and the automatic monitoring station 2-22 is located where the mainstream merges into the main river channel.

[0087] The intelligent control system 3 includes: a data processing system, an information feedback system and an intelligent decision-making system; the automatic monitoring station 2-22 of the closed area internal purification system is connected to the data processing system of the intelligent control system, the data processing system transmits the acquired data to the information feedback system, the information feedback system is connected to the gate and overflow dam of the closed area internal purification system (2), controls the opening of the gate and the opening degree of the overflow dam, and further controls the flow rate and the residence time of pollutants in the closed area, and the mainstream that does not meet the standards enters the closed area internal purification system for purification. After the water quality meets the standards, that is, the concentration of pollutants is reduced to the target, the gate can be opened and finally merged into the main river channel.

[0088] The sources of pollutants in the closed system mainly include point source pollution and non-point source pollution. Point source pollution includes industrial wastewater and urban sewage treated by sewage treatment plants, and non-point source pollution mainly comes from farmland runoff. The pollutants are COD cr , NH3-N, TP, the concentrations are C CODcr , C NH3-N , C TP , unit is kg / m 3 When calculating the generation and reduction of a single pollutant, the pollutant concentration is C1 and the target value is C0.

[0089] Example 1

[0090] Reference Figure 1As shown, the main river channel 1-1 involved in this embodiment is a small or medium-sized river channel, with a river channel width b = 50m and a depth h = 4m. The monitoring section is set in the main river channel 1-1 near the river bank, and signs are set on the main river channel 1-1 to prevent damage. The automatic monitoring station 2-22 is located on the bank where the mainstream 2-3 merges into the main river channel 1-1, and is equipped with CODcr, NH3-N, TP and other monitoring devices. The main water quality assessment indicators are Class III (COD cr ≤20mg / L, NH3-N≤1.0mg / L, TP≤0.2mg / L).

[0091] The target value of pollutants in the river channel of the monitoring section is C 0CODcr =20mg / L; C TP =0.2mg / L.

[0092] Step 1) Determine the amount of contaminant:

[0093] The amount of non-point source pollution W1 (in kg) is: W1 = V f *C1=A f *A c *C1

[0094] Where: V f : The amount of water returned from farmland in this area, in m 3

[0095] C1: Pollutant concentration, mg / L, i.e. kg / m 3

[0096] A f : Farmland area, unit: m 2

[0097] A c : The farmland water quota in the area, in m 3 / m 2

[0098] Pollutant release intensity C 1CODcr =30mg / L; C 1TP =2mg / L;

[0099] Farmland area f =4×10 7 m 2 ; The farmland water quota in this area is A c =0.8m 2 / m 2 .but:

[0100] W 1CODcr =Af ×A c ×C 1CODcr =9600kg

[0101]

[0102] W 1TP =A f ×A c ×C 1TP =640kg

[0103] The amount of point source pollution is: W2 = Vg*Pg*t+Vc*Pc*t, in kg, where:

[0104] V g : Factory wastewater discharge, unit: m 3 / d

[0105] P g : Factory pollution emission intensity, unit: kg / m 3

[0106] V c : Urban sewage discharge, unit: m 3 / d

[0107] P c : Urban pollution emission intensity, unit: kg / m 3

[0108] t: pollution emission time, unit is d, taking the whole year as an example, t is 365d; factory sewage and urban domestic sewage are discharged from sewage treatment plants, and the discharge volume of sewage treatment plants is V = 500m 3 / d; Pollutant release intensity P 2CODcr =100mg / L; P 2TP =3mg / L. Then:

[0109] W 2CODcr =V×P 2CODcr ×365d=18250kg

[0110]

[0111] W 2TP =V×P 2TP ×365d=1368.75kg

[0112] The target amount of pollutants is:

[0113] The volume of water in the rivers in this area is 720,000m 3 ;

[0114] The target value of pollutants in the river is C TP =0.2mg / L. Then:

[0115] W 0CODcr =V×C 0CODcr =14400kg

[0116]

[0117] W 0TP =V×C 0TP =144kg

[0118] Pollutant reduction W3 = W1 + W2 - W0, unit: kg. Then:

[0119]

[0120] W 3TP =W 1TP +W 2TP -W 0TP =1864.75kg

[0121] Step 2) Pollutant reduction calculated based on step 1) W 3TP , purification is carried out through artificial wetlands, ecological purification floating islands, aeration purification facilities and aquatic plants. The corresponding design parameters are as follows.

[0122] The surface organic load of the artificial wetland is q os1 , unit: kg / (m 2 *d):

[0123] q os1COD =3g / (m 2 *d)

[0124]

[0125] q os1TP =0.3g / (m 2 *d)

[0126] The surface organic load of the ecological purification floating island is q os2 , unit: kg / (m 2 *d):

[0127] q os2COD =0.5g / (m 2 *d)

[0128]

[0129] q os2TP =0.03g / (m 2 *d)

[0130] The surface organic load of the aeration purification facility is q os3 , unit: kg / (m 2 *d):

[0131] q os3COD =0.4g / (m 2 *d)

[0132]

[0133] q os3TP =0.02g / (m 2 *d)

[0134] The organic load on the surface of aquatic plants is q os4 , unit: kg / (m 2 *d):

[0135] q os4COD =0.3g / (m 2 *d)

[0136]

[0137] q os4TP =0.02g / (m 2 *d)

[0138] According to the surface organic load of artificial wetlands, ecological purification floating islands, aeration purification equipment and aquatic plants, the artificial wetland area A1, ecological purification floating island area A2, aeration purification equipment A3 and aquatic plant area A4 are adjusted and designed to coordinate the areas of various water treatment facilities. Artificial wetlands are used to purify 80% of pollutants, ecological purification floating islands are used to purify 5% of pollutants, aeration purification facilities are used to purify 5% of pollutants, and aquatic plants are used to purify 10% of pollutants. The area of ​​each facility is:

[0139]

[0140] The area of ​​artificial wetland is A1 = 17500m 2 .

[0141]

[0142] The area of ​​the ecological purification floating island is A1 = 8515m 2 .

[0143]

[0144] The area of ​​aeration purification facilities is A1 = 9825m 2 .

[0145]

[0146]

[0147] Then the area of ​​aquatic plants is A1 = 25545m 2 .

[0148] Step 3) Ensure that V 1+ V 雨 <90%V, including rainfall This ensures that the purification cycle can be completed continuously.

Claims

1. A system for controlling watershed non-point source pollution and improving river water environment, characterized in that: It includes a main river channel (1), a closed area internal purification system (2) and an intelligent control system (3); the main river channel is provided with a slope, and the main river channel passes between towns or flows through the edge of towns; the mainstream and tributaries are interspersed between farmlands; The main river channel, farmland, townships, mainstream and tributaries form a closed area; the internal purification system of the closed area is connected to the main river channel, and the intelligent control system is simultaneously connected to the main river channel and the internal purification system of the closed area, to achieve automatic purification of agricultural non-point source pollution and industrial sewage and domestic sewage point source pollution within the closed area.

2. The system for controlling watershed non-point source pollution and improving river water environment according to claim 1 is characterized in that: The closed area internal purification system (2) includes: gates, overflow dams, mainstream, nearby tributaries, artificial wetlands, ecological purification floating beds, aeration purification equipment, aquatic plants, pump rooms and automatic monitoring stations: The main river channel has one or more main streams and nearby tributaries. A gate (2-12) is provided between the main stream (2-1) and the main river channel. The tributaries directly flow into the main stream. One or more overflow dams (2-10) are provided on the main stream to divide the main stream into sections. A pump station (2-21) is provided on the main stream section closest to the main river channel. The power provided by the pump station is used to transport the water flow to the front end of the main stream. The opening degree of the overflow dam and the opening of the gate are controlled by an intelligent control system. The farmland (2-13) is arranged between the main stream and the tributaries. Near the main stream, the water level during the farmland irrigation period is higher than the tributary water level, and the farmland drainage is directly discharged into the mainstream and tributaries. Artificial wetlands (2-23) are arranged on both sides of the mainstream and between the mainstream and farmland. Ecological purification floating beds (2-24), aeration purification equipment (2-25) and aquatic plants (2-26) are set up in the mainstream and tributaries to purify pollutants in the water body in coordination with artificial wetlands. The monitoring section is set at the shore of the main river channel, and the automatic monitoring station (2-22) is located at the place where the mainstream merges into the main river channel.

3. The system for controlling watershed non-point source pollution and improving river water environment according to claim 2 is characterized in that: The intelligent control system (3) comprises: a data processing system, an information feedback system and an intelligent decision-making system; the automatic monitoring station of the closed area internal purification system is connected to the data processing system of the intelligent control system, the data processing system transmits the acquired data to the information feedback system, the information feedback system is connected to the gate and overflow dam of the closed area internal purification system (2), controls the opening of the gate and the opening degree of the overflow dam, and further controls the flow rate and the residence time of pollutants in the closed area, and the mainstream that does not meet the standards enters the closed area internal purification system for purification, and the concentration of pollutants is reduced to the target value. After the water quality meets the standards, the gate can be opened and finally merged into the main river channel.

4. The system for controlling watershed non-point source pollution and improving river water environment according to claim 1 is characterized in that: The sources of pollutants in the closed system mainly include point source pollution and non-point source pollution. Point source pollution includes domestic sewage and industrial sewage treated by sewage treatment plants in towns and villages, while non-point source pollution mainly comes from farmland runoff. The pollutants are COD cr , NH3-N, TP, the concentrations are C CODcr , C NH3-N , C TP , unit is kg / m 3 When calculating the generation and reduction of a single pollutant, the pollutant concentration is C1 and the target value is C0.

5. The system for controlling watershed non-point source pollution and improving river water environment according to claim 4 is characterized in that: The amount of non-point source pollution W1 (in kg) is: W1=V f *C1=A f *A c *C1(1) V f : The amount of water returned from farmland in this area, in m 3 C1: Pollutant concentration, mg / L, i.e. kg / m 3 A f : Farmland area, unit: m 2 A c : The farmland water quota in this area, in m 3 / m 2 or Unit: kg, where: f(h, t, L): the concentration of antibiotics in the river, which is related to the water level, length and time of the river; If there is a specific concentration of antibiotics in the river, formula (2) is used. If there is no specific concentration density, formula (1) is used. The point source pollution generation amount W2 (unit kg) is: W2=V g *P g *t+V c *P c *t(3) V g : Factory wastewater discharge, unit: m 3 / d P g : Factory pollution emission intensity, unit: kg / m 3 V c : Urban sewage discharge, unit: m 3 / d P c : Urban pollution emission intensity, unit: kg / m 3 t: pollution emission time, in d, taking the whole year as the total time, t is 365d; If there is a specific antibiotic concentration in the river, the point source pollution and non-point source pollution are obtained by formula (4): Unit: kg, where: f(h, t, L): The concentration density of antibiotics in the river, which is related to the water level h, the length L and the time t of the river; If there is no specific antibiotic concentration in the river, the value of W1+W2 is obtained by formula (1)+(3); The target amount of pollutants is: W0 = (V f +V g +V c )*C0, unit: kg, where: V f : The amount of water returned from farmland in this area, in m 3 V g : Factory wastewater discharge, unit: m 3 V c : Urban sewage discharge, unit: m 3 C0: Target concentration of pollutants, mg / L, i.e. kg / m 3 V f =A f *A c , unit m 3 ,in: A f : Farmland area, unit: m 2 A c : The farmland water quota in this area, in m 3 / m 2 Pollutant reduction W3 = W1 + W2 - W0, unit: kg.

6. The method for operating a watershed non-point source pollution control and river water environment improvement system according to any one of claims 1 to 3, characterized in that: The automatic monitoring station set up on the bank of the mainstream monitors the water quality and water volume of the mainstream and transmits the data to the intelligent control system. The intelligent control system is connected to the gate (3-12), overflow dam (3-10) and pump station (2-21) of the internal purification system of the closed area. The intelligent control system (3) controls the opening of the overflow dam and the pump station according to the monitoring results of the automatic monitoring station (2-22) on the bank of the mainstream, and transmits the inner river water of the terminal mainstream that does not meet the water quality standards to the front end of the mainstream, so that the river water flows into the internal purification system of the closed area, and the water body is purified with the help of artificial wetlands (2-23), ecological purification floating beds (2-24), aeration purification equipment (2-25) and aquatic plants (2-26). When the water quality meets the standards, that is, the pollutants are reduced to the target, it can pass through the terminal mainstream and open the gate to be discharged into the main river.

7. The method for operating a watershed non-point source pollution control and river water environment improvement system according to claim 6 is characterized in that: The following steps are involved: Step 1) According to the industrial wastewater discharge volume V in the closed area g , Urban domestic sewage discharge V c and farmland area, the pollutant reduction amount W3 is determined by the following formula (5): W3=W1+W2-W0, unit: kg(5) The amount of non-point source pollution W1 = V f *C1=A f *A c *C1(1), unit: kg, where: V f : The amount of water returned from farmland in this area, in m 3 C1: Pollutant concentration, mg / L, i.e. kg / m 3 A f : Farmland area, unit: m 2 A c : The farmland water quota in this area, in m 3 / m 2 Point source pollution generation W2 = V g *P g *t+V c *P c *t(3), unit: kg, where: V g : Factory wastewater discharge, unit: m 3 / d P g : Factory pollution emission intensity, unit: kg / m 3 V c : Urban sewage discharge, unit: m 3 / d P c : Urban pollution emission intensity, unit: kg / m 3 t: pollution emission time, in d, taking the whole year as the total time, t is 365d; If there is no specific antibiotic concentration in the river, W1+W2 is obtained according to formula (1)+formula (3); Or when there is a specific antibiotic concentration in the river, the value of W1+W2 is obtained according to the following formula (4): Unit: kg, where: f(h, t, L): The concentration of antibiotics in the river, which is related to the water level h, the length L and the time t; The target amount of pollutants is: W0 = V*C0, unit: kg, where: V: The volume of water in the river, in m 3 C0: Target concentration of pollutants, mg / L, i.e. kg / m 3 Step 2) From step 1), the pollutant reduction amount W3 can be obtained. Select the surface organic load q of the artificial wetland os1 , unit: kg / (m 2 *d), calculate the area of ​​artificial wetland Where A1: artificial wetland area m 2 , P1: Daily pollutant purification amount of artificial wetland kg / d; Select the surface organic load q of the ecological purification floating bed os2 , unit: kg / (m 2 *d), calculate the ecological purification floating bed Where A2: artificial wetland area m 2 , P2: Daily pollutant purification amount of ecological purification floating bed kg / d; Select the surface organic load q of the aeration purification equipment os3 , unit: kg / (m 2 *d), calculate the area of ​​aeration purification equipment Where A3: aeration purification equipment area m 2 , P3: Daily pollutant purification amount of aeration purification equipment kg / d; Surface organic load q of selected aquatic plants os4 , unit: kg / (m 2 *d), calculate the aquatic plant area A4: Aquatic plant area m 2 , P1: Daily pollutant purification amount of aquatic plants kg / d; At this time, it is necessary to ensure that W3≤(P1+P2+P3+P4)*t Where t = 365d; According to the selected artificial wetlands, ecological purification floating islands, aeration purification equipment and surface organic loads of aquatic plants, the artificial wetland area A1, ecological purification floating island area A2, aeration purification equipment A3 and aquatic plant area A4 are adjusted and designed to coordinate the areas of various water treatment facilities; Step 3) Ensure that the water depth H1 in the mainstream is less than 80% H, that is, V1 is less than 80% V, at any time throughout the year. If the water quality of the mainstream cannot meet the requirements, the height of the overflow dam can be increased to allow the mainstream to carry more water, but the water depth H1 shall not be higher than the mainstream depth H; Step 4) When the water quality meets the standard and the water depth H1≥80%H, the gate is opened to discharge the excess river water into the main river channel to ensure that the water level H1 in the main stream is less than 80%H; Working condition 1: During the period of farmland withdrawal and when there is no rainfall in the river, the water quality can be purified by the internal purification system in the closed area and the water body that meets the water quality standards can be discharged normally; Working condition 2: During the period of farmland withdrawal, when there is rainfall in the river, the height of the overflow dam can be increased and the gates can be closed to increase the retention time of water in the purification system inside the closed area, so as to ensure that the water quality meets the standards before being discharged into the main river; the rainfall The unit is 10 -3 m 3 ; in: Comprehensive runoff coefficient; q: rainfall intensity, mm / h; A: catchment area, m 2 ; t: rainfall duration, h; Working condition 3: When the farmland is not in the water withdrawal period and there is no rainfall, the pump station is used normally to pump the substandard water in the mainstream to the early section of the mainstream, so that the water can be purified normally in the closed area purification system; if the water quality meets the standard, the gate can be opened normally to discharge the water into the main river; Working condition 4: When the farmland is not in the water withdrawal period and there is rainfall, the intelligent decision-making system appropriately opens the gate to discharge the water with qualified water quality into the main river; the water with unqualified water quality is sent to the internal purification system of the closed area through the pump station for purification; The unit is 10 -3 m 3 .

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