Intelligent control system for preventing diffusion of polluted underground water in storage yard based on rainfall backflow circulation
By setting up a groundwater hydraulic control well group and an intelligent control system for water level in the well downstream of the yard, combined with the return pipeline to form an internal circulation, the problem of the diffusion of polluted groundwater in the yard is solved and low-cost and effective pollution control is achieved.
Patent Information
- Application Number
- CN202510573598.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2025-07-18
AI Technical Summary
The prior art has the problem of high operating costs and difficulty in continuously controlling the diffusion of polluted groundwater in the yard, especially under complex geological conditions, where traditional methods are costly and ineffective.
The groundwater hydraulic control well group system, the well-in-the-well water level intelligent control system and the groundwater return system are adopted. By setting up the groundwater hydraulic control well group to cover the downstream seepage section of the yard, forming an internal circulation, using the water level difference in the well and the submersible pump to pump water, combined with the return pipeline, the polluted water is returned to the yard to prevent its diffusion.
Effective control of polluted groundwater has been achieved, operating costs have been reduced, system structure has been simplified, and the damage to wells by ground activities has been reduced, and the cost has been low, which can continuously prevent the spread of polluted water to the downstream.
Smart Images
Figure CN120331281A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of yard pollution control, and specifically relates to an intelligent control system for preventing the diffusion of polluted groundwater in a yard based on precipitation return circulation. Background Art
[0002] At present, there are a large number of yards of various types, such as mine tailings, industrial solid waste, domestic waste, agricultural solid waste, etc. Due to the long-term operation of the yards, and the fact that early solid waste yards often did not have anti-seepage measures or the anti-seepage measures were not in place, a large amount of solid waste leachate continuously leaks into the groundwater and migrates and diffuses to the surrounding environment along with the groundwater, threatening human health and the ecological environment. The pollutants in these leachates vary according to the nature of the solid waste, and the components are often very complex, with a large pollution volume, mobility, and high harm, making the treatment very difficult.
[0003] Commonly used technologies for treating polluted groundwater in yards include cut-off walls, permeable reactive barriers (PRBs), pumping and treatment, in-situ injection repair, and bioremediation, etc. At present, the use of cut-off walls has poor water-stopping effect in areas with large yard water volume, high overflow risk, and for areas with complex regional hydrogeological conditions, the technical requirements and economic costs for constructing cut-off walls are relatively high, and the complex geological environment poses a certain threat to the safety of the construction of cut-off walls and the reliability of operation, and the uncertainty of project implementation is relatively large. The capacity of traditional PRB media is limited, the groundwater flux in the yard is very large, the reactive wall materials quickly become saturated, and need to be replaced frequently, with a high economic cost. Pumping and treatment requires the construction of a ground water treatment system, the system is relatively complex, and the operation cost is high; at the same time, there are problems of groundwater quality rebound and tailing effect. The bioremediation method is greatly affected by environmental conditions, with a long repair cycle and slow effect. The in-situ injection of chemical agents method has a high cost, requires long-term detection and maintenance, and may introduce secondary pollution; some inorganic pollutants such as sulfates and chlorides cannot be treated by chemical oxidation methods. In particular, the yard continuously discharges polluted groundwater, with a large amount and long duration. The above technologies generally have problems of high operation costs and being unaffordable, and the pollution treatment is not sustainable. Therefore, there is a need to provide an intelligent control system for preventing the diffusion of polluted groundwater in a yard based on precipitation return circulation to solve the above problems. Summary of the Invention
[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an intelligent control system for preventing the diffusion of polluted groundwater in a yard based on precipitation return circulation to solve the problems in the above background art.
[0005] The present invention is implemented as follows. An intelligent control system for preventing the diffusion of polluted groundwater in a yard based on precipitation return circulation includes: a groundwater hydraulic control well group system, an intelligent control system for the water level in the well, and a groundwater return system. The groundwater hydraulic control well group system is arranged downstream of the yard. The groundwater hydraulic control well group is composed of connected or contiguous groundwater hydraulic control wells. The coverage area of the groundwater hydraulic control well group can completely contain the cross-section of the groundwater seepage downstream from the yard, and groundwater cannot flow around the edge of the well group into the downstream.
[0006] As a further solution of the present invention: The pumping influence radii between two adjacent groundwater hydraulic control wells partially overlap, and the length of the overlapping part is between one-fourth and one-half of the radius of the groundwater hydraulic control well; the groundwater level within the coverage area of the well group is lower than the groundwater level downstream of the yard, and the water level difference is greater than two meters, so that groundwater cannot pass through the well group into the downstream.
[0007] As a further solution of the present invention: The groundwater hydraulic control well group is set as underground or protected by constructing a concrete pedestal. The groundwater hydraulic control well group is a complete well, the diameter of the well pipe is 20 cm - 50 cm, and the depth of the control well reaches the bottom aquitard of the target aquifer.
[0008] As a further solution of the present invention: The pumping influence radius R is calculated from the water level drop value S, the aquifer thickness H, and the permeability coefficient K, and R = 2S√HK.
[0009] As a further solution of the present invention: The intelligent control system for the water level in the well consists of a water level sensor and a submersible pump in the control well; the water level in the well is lowered by pumping water with the submersible pump to form a water level difference with the downstream water level, so that the polluted water cannot continue to spread; when the groundwater level rises to the set water level, the water level sensor gives a signal to start the submersible pump to pump water for dewatering, and the submersible pump stops working when the water level drops to the lowest level.
[0010] As a further solution of the present invention: The groundwater return system is used to return the groundwater pumped out by the submersible pump to the yard through a return pipeline, thereby forming an internal circulation of polluted groundwater between the hydraulic control well and the yard to prevent the polluted groundwater flowing out of the yard from spreading to the downstream area.
[0011] As a further solution of the present invention: The return pipeline is buried underground and is buried in the tailings dam of the yard.
[0012] As a further solution of the present invention: A number of monitoring wells are arranged in the upstream direction of the groundwater flow downstream of the yard, and the monitoring wells are used to monitor the concentration of sulfate in the groundwater.
[0013] Compared with the prior art, the beneficial effects of the present invention are:
[0014] Through the setting of the groundwater hydraulic control well group system, groundwater cannot flow around the edge of the well group and enter the downstream, so that the polluted water cannot continue to spread and is thus effectively controlled. Through the setting of the intelligent water level control system in the well and the groundwater reflux system, a continuous internal circulation state is formed between the control well and the storage yard for the polluted groundwater, and the polluted groundwater is controlled and cannot enter the downstream area. Moreover, the system has a simple structure and low operation cost. The construction is convenient and the cost is low, which can effectively solve the risk of the spread of polluted groundwater in the storage yard. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of an intelligent control system for preventing the spread of polluted groundwater in a storage yard based on precipitation reflux circulation.
[0016] Figure 2 It is a schematic diagram of an intelligent anti-spread control system for groundwater leakage reflux circulation in a certain tailings pond.
[0017] Figure 3 It is a schematic diagram of the sulfate concentration in a groundwater monitoring well.
[0018] Reference numerals: 1 - storage yard, 2 - tailings dam, 4 - flow-through section, 5 - groundwater hydraulic control well, 6 - water level sensor, 7 - submersible pump, 8 - reflux pipeline, 9 - target aquifer, 10 - bottom aquitard. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0020] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.
[0021] As Figure 1 shown, an embodiment of the present invention provides an intelligent control system for preventing the spread of polluted groundwater in a storage yard based on precipitation reflux circulation, including: a groundwater hydraulic control well group system, an intelligent water level control system in the well, and a groundwater reflux system. The groundwater hydraulic control well group system is arranged downstream of the storage yard 1. The groundwater hydraulic control well group is composed of connected or contiguous groundwater hydraulic control wells 5. The coverage area of the groundwater hydraulic control well group can completely contain the flow-through section 4 of the groundwater seepage downstream of the storage yard, and groundwater cannot flow around the edge of the well group and enter the downstream.
[0022] In the embodiments of the present invention, first, it is necessary to carry out hydrogeological surveys around the yard 1, draw the groundwater flow field map, and determine the cross-section 4 of the groundwater flowing through the bottom of the yard 1; then construct a groundwater hydraulic control well group. According to the hydrogeological conditions, calculate the influence radius of the groundwater hydraulic control well 5. The pumping influence radii of adjacent two groundwater hydraulic control wells 5 partially overlap, and the length of the overlapping part is between one-fourth and one-half of the radius of the groundwater hydraulic control well 5; the groundwater level within the area covered by the well group is lower than the groundwater level downstream of the yard, and the water level difference is greater than two meters, so that the groundwater cannot pass through the well group and enter the downstream. To reduce the damage to the wells caused by ground activities, the groundwater hydraulic control well group is set to be underground or a concrete pedestal is constructed for protection. The groundwater hydraulic control well 5 is a complete well, and the diameter of the well pipe is 20 cm - 50 cm; the depth of the control well generally reaches the bottom aquitard 10 of the target aquifer 9, and the bottom aquitard 10 is generally clay or bedrock.
[0023] As a preferred embodiment of the present invention, the pumping influence radius R is calculated through the water level drop value S, the aquifer thickness H, and the permeability coefficient K, and R = 2S√HK. S is the height of the groundwater level drop after pumping; K represents the ability of the aquifer to allow water to permeate.
[0024] As a preferred embodiment of the present invention, the intelligent water level control system in the well consists of a water level sensor 6 and a submersible pump 7 in the control well; the water level in the well is lowered by pumping water with the submersible pump 7 to form a water level difference with the downstream water level. The water level difference generally needs to be at least greater than 2 m. The groundwater downstream flows reversely into the control well under the action of the reverse water level difference, so that the polluted water cannot continue to spread; when the groundwater level rises to the set water level, the water level sensor 6 gives a signal to start the submersible pump 7 to pump water for dewatering. When the water level drops to the lowest level, the submersible pump 7 stops working, and this cycle repeats.
[0025] As a preferred embodiment of the present invention, the groundwater return system is used to return the groundwater pumped out by the submersible pump 7 to the yard 1 through the return pipeline 8, thereby forming an internal circulation of the polluted groundwater between the groundwater hydraulic control well 5 and the yard 1, and preventing the polluted groundwater flowing out of the yard 1 from spreading to the downstream area.
[0026] As a preferred embodiment of the present invention, the return pipeline 8 is buried underground, and the return pipeline 8 is buried in the tailings dam 2 of the yard 1.
[0027] As Figure 2 and Figure 3As shown, the present invention is described through specific examples. A hydrogeological survey and a pollution characteristics survey are carried out on the tailings pond and the surrounding area. It is obtained that the groundwater in the tailings pond area is basically perpendicular to the main groundwater flow direction. Downstream of the tailings pond, the groundwater generally converges towards the main flow direction. Therefore, the maximum cross-section of the seepage outflow from the tailings pond is the AB section in the figure. By detecting the groundwater quality, it is known that the sulfate concentration in the groundwater ranges from 2000 mg / L to 5000 mg / L, far exceeding the limit value (350 mg / L) of Class IV water quality in the "Groundwater Quality Standard" (GB / T 14848 - 2017). The stratum structure of the tailings pond and downstream can be divided into 4 main layers according to their sedimentary environment, genetic type, differences in physical and mechanical properties, and regional geological data. The distribution and characteristics of each exposed stratum from top to bottom are as follows:
[0028] 1. Miscellaneous fill: Yellowish-brown, mainly medium-coarse sand, containing a small amount of clay, loose, slightly wet - saturated. The average thickness of this layer is 0.52 m.
[0029] 2. Yellowish-brown, the main mineral components are feldspar and quartz, moderately rounded, poorly graded, with medium sorting. The average thickness of this layer in this exploration is 4.6 m.
[0030] 3. Strongly weathered granite: Grayish-green, with a relatively high degree of weathering fissure development, the core is disturbed and in a fragmented state, the rock mass is extremely broken, belonging to soft rock. The main minerals are composed of feldspar, quartz and biotite. The average thickness of this layer is 2.3 m.
[0031] 4. Medium weathered granite: Grayish-brown, medium-coarse grained - massive structure, joint fissures developed, the core is in short columnar - columnar shape, the main minerals are composed of feldspar, quartz and biotite. The average thickness of this layer is 2.5 m.
[0032] Next, determine the flow control surface (i.e., the cross-section of flow) of the groundwater outside the downstream dam of the tailings pond. The groundwater flow direction on the site is perpendicular to the isohyet. At the junction of the downstream retaining dams on both sides of the tailings pond and the groundwater level line, the groundwater flow direction here is consistent with the main groundwater flow direction. Therefore, the groundwater in the lower part of the reservoir area on the left side of the intersection cannot flow out of the corresponding tailings dam, that is, the AB section on the right side of the dam area is the two ends of the flow control surface.
[0033] Then, groundwater hydraulic control wells are arranged. According to the analysis of the site hydrogeological conditions, as long as the hydraulic control well group covers section AB, the groundwater in the reservoir area can be effectively controlled and cannot flow into the downstream across the hydraulic control wells. First, determine the number and spacing of the control wells: According to the geological exploration results, the average thickness of the aquifer in this area is about 7.42 m; the aquifer mainly consists of miscellaneous fill and yellowish-brown gravel sand, with an average permeability coefficient K of 10 m / d, and the set precipitation depth is 2 m. According to the Kusakin formula, the influence radius of the precipitation well is estimated to be 34 m. There is a road adjacent to the outside of the tailings pond, and it is not possible to arrange the well group. The control wells are set in a line, that is, single wells are connected in a line. Since the interception effect of a single well is worse than that of a well group, in order to ensure the control effect, based on conservative conditions, the designed influence radius of the control wells should be reduced, and the actual distance between wells is taken as 20 m. A total of 12 wells are arranged, and the control wells are set at the position where they intersect with the ground outside the tailings dam. Then determine the structure of the control wells: The well diameter of the control wells is 650 mm, the well pipe uses Φ300 PVC corrugated pipe, the well depth is 8 m, and the filter pipe is from 1 m to 8 m below the pipe top, with a length of 7.0 m. To prevent the influence of ground activities on the wells, a 600*600*500 mm concrete base is set at the wellhead, and it is sealed with a steel cover plate.
[0034] Furthermore, submersible pumps and water level control systems are set. A submersible pump and a water level control system are installed in each control well. The water level in the downstream is lowered by pumping water through an intelligent control system. A QS20-30 / 2-3 type submersible pump is set in the well, and a liquid level controller is used to control the operation of the pump, and the groundwater level is controlled to be 2 m lower than the normal water level in the downstream area. When the groundwater level rises to be less than the set water level difference, the intelligent control system of the submersible pump starts and stops pumping water for precipitation.
[0035] Furthermore, a groundwater reflux circulation pipe network is set. The circulating reflux intelligent control system returns the pumped groundwater back to the stacking yard along the pipeline. A reflux pipe is set for each control well, using Φ63 PE drainage pipe. The drainage pipe is buried 10 cm below the slope of the tailings dam, and the outlet is exposed inside the dam of the reservoir area. After the groundwater flows into the dam, it seeps into the tailings in the dam. Thus, the overall groundwater level in the downstream area of the dam is reduced, and the groundwater cannot migrate and diffuse downstream under the action of reverse water pressure, thereby effectively controlling the anti-diffusion of polluted groundwater in the tailings pond.
[0036] Furthermore, several monitoring wells are set in the direction of the groundwater flow downstream of the stacking yard. The monitoring wells are used to monitor the concentration of sulfates in the groundwater. A J1 monitoring well is set between the control wells, and J2, J3, J4, and J5 monitoring wells are set at 20 m, 50 m, 100 m, and 200 m downstream respectively. The aperture of the groundwater monitoring well is 150 mm, the well pipe uses PVC pipe, the well depth is 8 m, the length of the filter pipe is 7.0 m from the bottom of the well upwards, the well pipe protrudes 10 cm above the ground, a Φ300*500 mm concrete base is set at the wellhead, and it is sealed with a steel cover plate.
[0037] Finally, the anti-diffusion control effect of the contaminated groundwater was verified. After the system construction was completed and started to operate, the concentrations of sulfate in the groundwater of the monitoring wells were as shown in the figure after 10 days and 1 year of operation. As can be seen from the figure, the overall change trend of the sulfate concentration in the downstream groundwater after 10 days of operation was not significant. This was because the perennial leakage of the contaminated groundwater in the tailings pond caused widespread pollution of the groundwater in the downstream area of the reservoir area. Although the hydraulic control system was operated in time and the groundwater could not flow into the downstream, the downstream groundwater was slowly diluted by natural diffusion, but this effect was relatively slow. Therefore, the groundwater still maintained a relatively high sulfate concentration. When one year later, the sulfate concentration in the groundwater of the monitoring wells at a relatively far distance downstream decreased significantly and was close to the regional groundwater background value. This shows that the present reflux circulation intelligent control system has played an important role and achieved the expected goal.
[0038] For those skilled in the art, although several embodiments and examples of the present invention have been described, these embodiments and examples are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention and are included in the invention described in the claims and its equivalents.
[0039] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
[0040] After considering the disclosure in the specification and the embodiments, those skilled in the art will easily think of other implementation schemes of the present disclosure. This application aims to cover any variations, uses, or adaptive changes of the present disclosure, and these variations, uses, or adaptive changes follow the general principles of the present disclosure and include the common general knowledge or conventional technical means in the technical field not disclosed in the present disclosure. The specification and the embodiments are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the claims.
Claims
1. An intelligent control system for preventing the diffusion of polluted groundwater in a yard based on the precipitation reflux cycle, characterized in that, Including: A groundwater hydraulic control well group system, an intelligent water level control system in the well, and a groundwater backflow system. The groundwater hydraulic control well group system is arranged downstream of the yard. The groundwater hydraulic control well group consists of connected or contiguous groundwater hydraulic control wells. The coverage area of the groundwater hydraulic control well group can completely contain the cross-section of the groundwater seepage downstream from the yard, and the groundwater cannot flow around the edge of the well group into the downstream.
2. The intelligent control system for preventing the diffusion of polluted groundwater in the yard based on precipitation backflow cycle according to claim 1, characterized in that, The pumping influence radius between two adjacent groundwater hydraulic control wells partially overlaps, and the length of the overlapping part is between one-fourth and one-half of the radius of the groundwater hydraulic control well; the groundwater level within the coverage area of the well group is lower than the groundwater level downstream of the yard, and the water level difference is greater than two meters, so the groundwater cannot pass through the well group into the downstream.
3. The intelligent control system for preventing the diffusion of polluted groundwater in the yard based on precipitation backflow cycle according to claim 2, characterized in that, The groundwater hydraulic control well group is set as underground or protected by constructing a concrete foundation. The groundwater hydraulic control well group is a complete well, the well pipe diameter is 20 cm - 50 cm, and the depth of the control well reaches the bottom aquitard of the target aquifer.
4. The intelligent control system for preventing the diffusion of polluted groundwater in the yard based on precipitation return circulation according to claim 2, characterized in that, The pumping influence radius R is calculated by the water level drawdown value S, the aquifer thickness H, and the hydraulic conductivity K, and R = 2S√HK.
5. The intelligent control system for preventing the diffusion of polluted groundwater in the yard based on precipitation reflux circulation according to claim 1, wherein The intelligent water level control system in the well consists of a water level sensor and a submersible pump in the control well; the submersible pump is used to pump water to lower the water level in the well, forming a water level difference with the downstream water level, so that the polluted water cannot continue to spread; when the groundwater level rises to the set water level, the water level sensor gives a signal to start the submersible pump to pump water for dewatering, and the submersible pump stops working when the water level drops to the lowest level.
6. The intelligent control system for preventing the diffusion of polluted groundwater in the yard based on precipitation backflow cycle according to claim 5, characterized in that, The groundwater backflow system is used to return the groundwater pumped out by the submersible pump to the yard through a backflow pipeline, thereby forming an internal circulation of the polluted groundwater between the hydraulic control well and the yard, preventing the polluted groundwater flowing out of the yard from spreading to the downstream area.
7. The intelligent control system for preventing the diffusion of polluted groundwater in the yard based on precipitation reflux circulation according to claim 6, characterized in that, The backflow pipeline is buried underground and buried in the tailings dam of the yard.
8. The intelligent control system for preventing the diffusion of polluted groundwater in the yard based on precipitation backflow cycle according to claim 1, characterized in that, Several monitoring wells are arranged in the direction of the underground water flow downstream of the yard, and the monitoring wells are used to monitor the concentration of sulfate in the groundwater.