CN105672448B - A kind of efficient closure works system of agricultural non-point source pollution and control method - Google Patents

Abstract

The invention discloses a kind of efficient closure works system of agricultural non-point source pollution and control method, closure works system includes gate, the headstock gear of regulating gate opening and closing, ultrasonic open-channel meter and the control unit for being used to be opened and closed the mouth that dams.Ultrasonic open-channel meter, which is arranged on, is used for the flow for measuring the WIH that dams in Vatch basin, its output connects control unit；Control unit output end is connected with headstock gear, simple in construction with the keying of the flow that is detected according to ultrasonic open-channel meter by headstock gear regulating gate, can be dammed by difference in flow change.The present invention is according to agriculture irrigation ditch canal run-off and the correlation of DTP concentration and the occurrence law of peak concentration, using flow and ageing control mode, realization is dammed to agricultural area source sewage, more pollutants can be retained in the case of identical retention water to the full extent, than existing stopped flow technique more simple and effective.

Description

A high-efficiency interception system and control method for agricultural non-point source pollution

technical field

The invention relates to the collection of agricultural sewage, in particular to an efficient interception system and control method for agricultural non-point source pollution, belonging to the technical field of sewage treatment.

Background technique

With the continuous deepening and progress of intensive agriculture in our country's economy, the ensuing environmental pollution problem is also becoming more and more serious. Rural non-point source pollution has become a prominent problem in my country's agricultural development. Dianchi Lake, located in the central part of Yunnan Province, is one of the largest inland freshwater lakes in my country. Kunming City is located on the shore of Dianchi Lake. The drainage area of Dianchi Lake is 2920km ² , and its water resources play a vital role in Kunming's industrial and agricultural production and the lives of the people. However, due to the massive discharge of pollutants, Dianchi Lake has become one of the most eutrophic lakes . In recent years, the state and local governments have invested a lot of money in the pollution control of Dianchi Lake, and implemented a large number of point source pollution control projects with quick results and mature treatment technologies. The deterioration of the water quality of Dianchi Lake has been controlled to a certain extent. However, the signs of eutrophication in Dianchi Lake have not been significantly improved, especially the "bloom" in the outer sea of its main body still occurs in a large area and for a long time. The reason is that rural non-point source pollution has not been effectively controlled in the pollution load of Dianchi Lake, while the contribution rate of nitrogen and phosphorus to agricultural non-point source pollution has exceeded 50%. Therefore, it is particularly urgent to strengthen the treatment of rural agricultural sewage at present.

At present, the types of agricultural planting around Dianchi Lake are mainly vegetable and flower greenhouses. There are hundreds of agricultural irrigation ditches distributed in the greenhouse area, and a large amount of pollutants are discharged into Dianchi Lake through agricultural irrigation ditches every year. At present, the sewage interception canals around Dianchi Lake and the supporting sewage plants have been built and put into operation, but their treatment capacity is still limited, and they cannot collect all the sewage from all agricultural irrigation ditches. And because greenhouse cultivation is different from traditional crop cultivation, agricultural non-point source pollution in greenhouse areas has its own characteristics, and its main pollutants are total phosphorus (TP), especially dissolved total phosphorus (DTP). Changes in water quality and quantity are also different from traditional agricultural non-point source pollution. Due to the coverage of greenhouses, the water storage capacity of depressions on the surface decreases and the impermeability increases, resulting in an increase in the runoff coefficient of the greenhouse area, faster rainfall production and confluence, and increased runoff. Certain initial flushing, so the concentration of pollutants in the early runoff of rainfall is higher than that in the later runoff. In addition, most of the current interception wells are designed for urban sewage, which is not suitable for agricultural non-point source pollution.

Based on the above factors, it is necessary to design an interception system for agricultural non-point source pollution in Dianchi Lake, so as to intercept more pollutants to the greatest extent with the same interception water volume, which will affect the stable operation of subsequent sewage plants and the water environment of Dianchi Lake. protection plays a vital role.

In other rural areas or suburban areas, there are also problems of similar agricultural planting types to Dianchi Lake, similar agricultural non-point source pollution, and insufficient treatment capacity of sewage plants.

Contents of the invention

Aiming at the above-mentioned deficiencies in the prior art, the problem to be solved by the present invention is how to provide an efficient interception system for agricultural non-point source pollution that can intercept more pollutants with the same amount of intercepted water.

The invention also provides an efficient interception control method for agricultural non-point source pollution.

In order to achieve the above object, the present invention adopts the following technical solutions:

An efficient interception system for agricultural non-point source pollution. An interception channel is provided at the end of the agricultural irrigation ditch. The interception channel is composed of an interception well, an interception control device and an inspection well; A water outlet is provided, which constitutes the water inlet corresponding to the interception well, and the outlet water of the interception well enters the inspection well through the interception opening, and the water outlet of the inspection well is connected to the sewage pipe;

The closure control device includes a gate, a hoist, a super-declared canal flowmeter and a control unit. The gate is arranged in the interception shaft and is close to the closure opening for opening and closing the closure opening; the hoist is connected with the gate to provide gate opening and closing. Closing power; the probe of the super-declared channel flowmeter is arranged on the top position of the highest water level in the intercepting well, and the super-declared channel flowmeter is used to measure the flow of water in the intercepting well; the output of the super-declared channel flowmeter is connected to the control unit, and the output terminal of the control unit is connected to the control unit The hoist is connected to control the opening and closing of the gate through the hoist according to the flow detected by the ultra-declared canal flowmeter.

As a further optimization of the above scheme, the interception well is provided with a trash grid near the water inlet, and the grid spacing of the trash grid is 30 mm; a water measuring weir is provided in the interception shaft.

As a further optimization of the above scheme, a grit chamber is provided at the interface between the interception well and the agricultural irrigation ditch, the bottom of the grit chamber is lower than the bottom of the interception well, and the bottom of the interception well is lower than the bottom of the agricultural irrigation ditch.

As a further optimization of the above scheme, the inspection well includes the bottom of the well, a well body composed of side walls, and a well cover. There is a ladder for maintenance, which is located under the well cover.

As a further optimization of the above solution, the control unit is remotely connected to the central control system through a wireless signal remote transmission device, and the central control system sends an instruction signal to remotely control the hoist to drive the gate to open and close.

The present invention also provides a high-efficiency interception control method for agricultural non-point source pollution. In this method, the sewage of the agricultural irrigation ditch enters the interception channel through the water outlet of the side wall, and enters the sewage treatment system through the interception channel, wherein the opening and closing of the interception port is controlled by the gate. control; it is characterized in that: the opening and closing of the gate is controlled as follows:

1) Set the initial state of the gate to open;

2) Detect the flow signal before the cut-off port, and feed back the signal to the control unit according to the set time interval, and the control unit calculates the flow difference σ in each time interval according to the flow rate at the next moment minus the flow rate at the previous moment;

3) When σ>0, and |σ| is greater than the preset flow difference threshold σ ₁ , it is judged that runoff is formed, and the control unit starts the time controller at the same time to start timing;

4) When σ<0, and |σ| is greater than the preset flow difference threshold σ ₂ , or when the timing of the time controller exceeds the set value in step 3), close the gate and stop timing;

5) When σ<0, and |σ| is less than the preset flow difference threshold σ ₃ , it is judged that the runoff is over and the gate is reopened;

Repeat steps 2)-5) continuously to achieve real-time control of the gate.

As a further optimization of the above scheme, two control methods can be selected for the opening and closing of the gate: on-site control of the control unit and remote/remote control of wireless signals.

The principle on which the present invention is based is as follows:

According to research, the change trend of agricultural irrigation ditch runoff is consistent with the change of DTP concentration in water quality. All occurred within 2 hours of rainfall, and the total amount of TP in this period could account for 62.2% to 82.5% of the total amount of TP in the runoff during the entire rainfall period. From the perspective of high-efficiency interception, the present invention adopts a combination control mode of flow (liquid level) and time to realize efficient interception of agricultural non-point source sewage.

Compared with the prior art, the present invention has the following advantages:

1. The high-efficiency interception system for agricultural non-point source pollution provided by the present invention adopts the method of flow (liquid level) and time combined control, which can intercept more pollutants to the greatest extent under the same interception water volume, compared with the existing Closure technology is simpler and more efficient.

2. The high-efficiency interception system for agricultural non-point source pollution provided by the present invention can be controlled by a single control unit, or can be remotely controlled by wireless signal transmission, which is more perfect and convenient than the control method of the prior art.

3. The control method of a high-efficiency interception system for agricultural non-point source pollution provided by the present invention is designed according to the typical pollutant index DTP concentration of rural non-point source pollution and different types of cultivated land. Compared with the prior art, the control method for rural non-point source sewage Closure control is better and more targeted.

Description of drawings

Fig. 1 is the plane view of high-efficiency interception system of the present invention;

Fig. 2 is a sectional view along line A-A of Fig. 1;

Fig. 3 is a sectional view along line B-B of Fig. 1 .

In the figure, 1-retention well, 2-gate, 3-hoist, 4-ultra-declaration channel flowmeter, 5-control unit, 6-sewage interception pipe, 7-trash grid, 8-irrigation ditch, 81 - Bottom of agricultural irrigation ditches, 9 - grit chamber, 10 - water measuring weir, 11 - inspection well, 12 - well cover, 13 - climbing ladder.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example:

An efficient interception system for agricultural non-point source pollution, as shown in FIGS.

On the side wall of the agricultural irrigation ditch 8, a water outlet is provided at the position corresponding to each interception well 1, and the water outlet constitutes the water inlet of the corresponding interception well 1, and the water outlet of the interception well enters the inspection well 11 through the interception opening, and the inspection well 11 water outlet It is connected with the sewage pipe 6, and the width of the retention well is 800mm.

The closure control device includes a gate 2, a headstock 3, a super-declared channel flowmeter 4 and a control unit 5. The gate 2 is arranged in the closure well and is close to the closure for opening and closing the closure; the gate 3 and The gate 2 is connected to provide the opening and closing power of the gate 2; the probe of the super-declaration channel flowmeter 4 is arranged above the highest water level in the interception well 1, and the ultra-declaration channel flowmeter 4 is used to measure the flow of water in the interception well 1; The output of the open channel flowmeter 4 is connected to the control unit 5, and the output end of the control unit 5 is connected to the hoist 3 to control the opening and closing of the gate 2 through the hoist 3 according to the flow detected by the ultra-clear channel flowmeter 4 .

The inspection well 11 includes the bottom of the well, a well body made of side walls, and a well cover 12. The thickness of the side walls is 200mm. The sewage pipe 6 is arranged on the well body opposite to the closure port. There is a ladder 13 for maintenance, which is located under the well cover 12, which is convenient for maintenance personnel to enter the inspection well 11 for inspection and maintenance; the well cover is made of composite plastic; in order to improve the waterproof performance, the inside of the well body is coated with 20mm thick cement mortar.

The interception well 1 is provided with a trash grid 7 near the water inlet, with a height of 800mm, and the grid spacing of the trash grid 7 is 30mm; the trash grid 7 is used to intercept some larger sundries in the water, Its size depends on the size of the intercepting channel 1 . A water measuring weir 10 is arranged in the interception well.

A grit chamber 9 is provided at the interface between the interception well 1 and the agricultural irrigation ditch 8 , the bottom of the grit chamber 9 is 1000 mm lower than the bottom of the interception well 1 , and the bottom of the interception well 1 is 700 mm lower than the bottom 81 of the agricultural irrigation ditch.

The control unit 5 is remotely connected to the central control system through a wireless signal remote transmission device, and the central control system sends an instruction signal to remotely control the hoist 3 to drive the gate 2 to open and close. Data and signal remote transmission is based on wireless 3G network.

The invention also provides a control method for an efficient interception system for agricultural non-point source pollution. In this method, the sewage of the agricultural irrigation ditch enters the interception channel through the water outlet on the side wall, and enters the sewage treatment system through the interception channel, wherein the opening and closing of the interception Controlled by the gate; the opening and closing of the gate is controlled as follows:

1) Set the initial state of the gate to open;

2) Detect the flow signal before the cut-off port, and feed the signal back to the control unit according to the set time interval (1min in the embodiment), and the control unit calculates the flow rate in each time interval by subtracting the flow rate at the previous moment from the flow rate at the next moment difference σ;

3) When σ>0 (the flow rate increases at this time), and |σ| is greater than the preset flow difference threshold σ ₁ (in the embodiment of Dianchi Lake, the flow difference threshold σ ₁ is set to 0.5L·S ^-1 ·min ^-1 ) , it is judged that the runoff is formed, and the control unit starts the time controller to start timing at the same time;

4) When σ<0 (the flow rate drops at this time), and |σ| is greater than the preset flow difference threshold σ ₂ (in the embodiment of Dianchi Lake, the flow difference threshold σ ₂ is set to 0.5L·S ^-1 ·min ^-1 ; ), or when the timing of the time controller in step 3) exceeds the set value (120min in the example of Dianchi Lake), the peak value of DTP/TP and DTP concentration has passed, indicating that most of the pollutants have been intercepted. Stop timing and close the gate, stop the interception, and let the clean rainwater flow directly into the water body through the agricultural irrigation ditch;

5) When σ<0 (the flow rate drops at this time), and |σ| is less than the preset flow difference threshold σ ₃ (in the embodiment of Dianchi Lake, the flow difference threshold σ ₃ is set to 0.1L·S ^-1 ·min ^-1 ) When the runoff is judged to be over, the gate is reopened.

Repeat steps 2)-5) continuously to achieve real-time control of the gate.

Two control methods can be selected for the opening and closing of the gate in the above closure control method: PLC single control and wireless signal remote transmission/remote control, among which the remote control method is preferred.

The specific parameters in the above closure control method vary from place to place and should be set through debugging.

The characteristic of the closure control method of the present invention is that the flow rate and time are combined to control the gate, which can be used for automatic control transformation of other existing closure systems, and can also be used for the high-efficiency closure system proposed by the present invention.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Any modification or equivalent replacement without departing from the spirit and scope of the technical solution of the invention shall be covered by the scope of the claims of the present invention.

Claims (7)

1. A high-efficiency interception control method for agricultural non-point source pollution. In this method, the sewage of the agricultural irrigation ditch enters the interception channel through the water outlet of the side wall, and enters the sewage treatment system through the interception channel, wherein the opening and closing of the interception port is controlled by a gate; It is characterized in that the opening and closing of the gate is controlled by the following method: 1) Set the initial state of the gate to open; 2) Detect the flow signal before the cut-off port, and feed back the signal to the control unit according to the set time interval, and the control unit calculates the flow difference σ in each time interval according to the flow rate at the next moment minus the flow rate at the previous moment; 3) When σ>0, and |σ| is greater than the preset flow difference threshold σ ₁ , it is judged that runoff is formed, and the control unit starts the time controller at the same time to start timing; 4) When σ<0, and |σ| is greater than the preset flow difference threshold σ ₂ , or when the timing of the time controller exceeds the set value in step 3), close the gate and stop timing; 5) When σ<0, and |σ| is less than the preset flow difference threshold σ ₃ , it is judged that the runoff is over and the gate is reopened; Repeat steps 2)-5) continuously to achieve real-time control of the gate. 2. The high-efficiency control method for agricultural non-point source pollution interception according to claim 1, characterized in that two control modes can be selected for the opening and closing of the gate: on-site control by the control unit and remote/remote control by wireless signal. 3. The method for controlling high-efficiency closure of agricultural non-point source pollution according to claim 1, characterized in that: the control method is based on a high-efficiency closure system for agricultural non-point source pollution; The high-efficiency interception system for agricultural non-point source pollution is provided with an interception channel at the end of the agricultural irrigation ditch, and the interception channel is composed of an interception well, an interception control device and an inspection well; A water outlet is provided, which constitutes the water inlet corresponding to the interception well, and the outlet water of the interception well enters the inspection well through the interception opening, and the water outlet of the inspection well is connected to the sewage pipe; The closure control device includes a gate, a hoist, a super-declared canal flowmeter and a control unit. The gate is arranged in the interception shaft and is close to the closure opening for opening and closing the closure opening; the hoist is connected with the gate to provide gate opening and closing. Closing power; the probe of the super-declared channel flowmeter is arranged on the top position of the highest water level in the intercepting well, and the super-declared channel flowmeter is used to measure the flow of water in the intercepting well; the output of the super-declared channel flowmeter is connected to the control unit, and the output terminal of the control unit is connected to the control unit The hoist is connected to control the opening and closing of the gate through the hoist according to the flow detected by the ultra-declared canal flowmeter. 4. The high-efficiency interception control method for agricultural non-point source pollution according to claim 3, characterized in that: the interception well is provided with a trash grid near the water inlet, and the grid spacing of the trash grid is 30 mm; A water measuring weir is arranged in the interception well. 5. the agricultural non-point source pollution efficient interception control method according to claim 3 is characterized in that: a grit chamber is provided at the interface of the interception well and the agricultural irrigation ditch, the bottom of the grit chamber is lower than the bottom of the interception well, and the interception The bottom of the well is lower than the bottom of the agricultural irrigation ditch. 6. The method for controlling agricultural non-point source pollution with high efficiency interception according to claim 3, characterized in that: the inspection well includes the bottom of the well, a well body composed of side walls, and a well cover, and the sewage pipe is arranged in the well opposite to the interception port On the body, the bottom of the sewage pipe is lower than the bottom of the interception port; there is a ladder for maintenance on the well body, and the ladder is located under the well cover. 7. The high-efficiency interception control method for agricultural non-point source pollution according to claim 3, characterized in that: the control unit is remotely connected to the central control system through a wireless signal remote transmission device, and the central control system sends an instruction signal to remotely control the start-up Shutdown drives the gate to open and close.