Detailed Description
The following describes the detailed implementation of the embodiments of the present invention with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.
Fig. 1 is a schematic diagram of a soil and groundwater co-remediation system according to a first embodiment of the present invention. Wherein, soil and groundwater are repair system in coordination includes: a dosing device 100, an injection well group 101, a pumping well group 102 and a permeable reactive barrier device 103. The dosing device 100 is used for injecting a medicament into each injection well of the injection well group 101; the injection wells are used for injecting the medicament into a pollution site so as to oxidize and decompose the underground water of the pollution site and organic pollutants in soil; the pumping well group 102 is used for pumping out the underground water after oxidative decomposition; and the permeable reactive barrier device 103 is used for repairing the underground water after oxidative decomposition, and rewetting the repaired underground water to the aquifer through the injection well group 101.
Specifically, the soil and groundwater collaborative remediation system is built in a polluted site to be remediated. The agent is injected into each injection well in the injection well group 101 by the agent adding device 100, and the agent is injected into the contaminated site through each injection well. In the process of injecting the ground water of the polluted site through each injection well, the medicament simultaneously washes the soil around the ground water so as to achieve the purpose of simultaneously carrying out oxidative decomposition on organic pollutants in the soil and the ground water, such as chloroethylene, benzene and other harmful substances. In order to make the concentrations of the underground water and the organic pollutants in the soil in the polluted site reach standards (for example, reach industry standards or set restoration target values), the underground water after oxidative decomposition is pumped into the permeable reactive barrier device 103 through the pumping well group 102, and the underground water after oxidative decomposition is further restored, for example, harmful substances are adsorbed, oxidized and reduced or degraded. And finally, the restored groundwater is infiltrated back to the aquifer through the injection well group 101, so that the cooperative restoration of the groundwater and the soil of the polluted site is realized.
According to the embodiment of the invention, the underground water in the polluted site is formed into the circulating water flow by utilizing the suction effect of the injection well group and the pumping well group, and the permeable reactive barrier device is arranged on the circulating water flow, so that the concentration of organic pollutants in the underground water (such as the underground water in an aquifer) which is subjected to multiple cycles is gradually reduced by the effect of the circulating water flow until the industrial standard or the repair target value is met, and the collaborative repair of the soil and the underground water is completed. Illustratively, by surveying the pollution status of a contaminated site by prior art means, an injection well group may be located at a location where the concentration of organic contaminants is high (e.g., upstream of the contaminated site), and a pumping well group may be located at a location where the concentration of organic contaminants is low (e.g., downstream of the contaminated site). The embodiment of the invention can be applied to the field of in-situ remediation of soil and groundwater.
Wherein the drug delivery device 100 comprises: the medicine injection pipe is connected with each injection well; and the air compressor is used for adding the medicament in the medicament barrel into each injection well through the medicament injection pipe.
The agent comprises an oxidant and a slow-release agent, wherein the oxidant can accelerate oxidative decomposition of groundwater in a polluted site and organic pollutants in soil, and can be at least one of persulfate, potassium permanganate, ozone, peroxide and the like. The slow release agent can stimulate the growth of microorganisms in the soil and accelerate the repair speed of the polluted groundwater and the soil, and the slow release agent can be preferably calcium peroxide.
Further, fig. 2 is a block diagram of a soil and groundwater collaborative remediation system according to a second embodiment of the present invention. On the basis of the first embodiment, the monitoring device 200 is further added to the embodiment of the present invention, and the monitoring device 200 is used for monitoring the repair process of the groundwater so as to determine the repair progress of the groundwater and/or the working state of the permeable reactive wall device 103.
For example, 4 monitoring wells may be built in sequence at the boundary of the pollution plume of the pollution site, upstream and downstream of the pollution site, and pumping wells or injection wells may be used as the monitoring wells. The monitoring device 200 collects groundwater remediation data by monitoring the well, for example, monitoring the well at a frequency of every 6 days/time, mainly monitoring the concentration of benzene and vinyl chloride in organic pollutants, and also monitoring pH, eh (oxidation-reduction potential), DO (dissolved oxygen), conductivity, ca 2+ 、Mg 2+ 、Fe 2+ 、Mn 2+ 、HCO 3 - And the data such as the soluble silicon and the like are used for monitoring the repair process of the groundwater in the polluted site so as to determine the repair progress of the groundwater and/or the working state of the permeable reactive barrier device. According to the repair progress of the groundwater and/or the working state of the permeable reactive barrier device 103, the amount and type of the medicines injected into each injection well by the medicine adding device 100 can be adjusted in real time through the monitored concentration of the organic pollutants, so as to accelerate the repair speed. At the same time, by monitoringThe operation state of the permeable reactive barrier means 103 is such that the filling medium in said permeable reactive barrier means 103, which is deactivated by ageing, is replaced in time.
In the embodiment of the present invention, a total of 4 monitoring wells, namely, a monitoring well 1, a monitoring well 2, a monitoring well 3 and a monitoring well 4, corresponding to 16 injection wells and 8 pumping wells, are also provided, and specific simulation distribution details of each monitoring well, injection well and pumping well can be referred to fig. 4. Assuming 2 sets of permeable reactive barrier devices, wherein 8 injection wells corresponding to the first set of permeable reactive barrier devices are numbered: injection well 1, injection well 3, injection well 5, injection well 7, injection well 9, injection well 11, injection well 13, injection well 15; the serial numbers of the corresponding 4 pumping wells are respectively: pumping well 1, pumping well 3, pumping well 5, and pumping well 7. 8 injection wells corresponding to the second set of permeable reactive barrier device are respectively numbered: injection well 2, injection well 4, injection well 6, injection well 8, injection well 10, injection well 12, injection well 14, injection well 16; the serial numbers of the corresponding 4 pumping wells are respectively: pumping well 2, pumping well 4, pumping well 6, and pumping well 8. Wherein 4 monitoring wells can be monitored at a frequency of 6 days/time, and scheme 1 (i.e. injection well 1, injection well 3, injection well 5, injection well 7, injection well 9, injection well 11, injection well 13, injection well 15, pumping well 1, pumping well 3, pumping well 5, pumping well 7) can be adopted; and scheme 2 (i.e., injection well 2, injection well 4, injection well 6, injection well 8, injection well 10, injection well 12, injection well 14, injection well 16) alternately monitors each injection well and each pump.
The monitoring device monitors parameters such as flow rate, pressure of the pumping well, flow rate, pressure, water level and the like of the injection well through the monitoring well; benzene and vinyl chloride in organic contaminants, pH, eh, DO, conductivity, ca 2+ 、Mg 2+ 、Fe 2+ 、Mn 2+ 、HCO 3 - Parameters such as soluble silicon. The system is used for monitoring the repair process of the groundwater in the polluted site so as to determine the repair progress of the groundwater and/or the working state of the permeable reactive wall device.
Before the first and second embodiments, the number of injection wells and the first flow rate and the number of pumping wells and the second flow rate in the specific round iteration may be determined to be the target number of injection wells and the first target flow rate and the target number of pumping wells and the second target flow rate by a parameter determining device.
The soil and groundwater collaborative remediation system further comprises: parameter determining means for performing the following steps S300-S302, refer to fig. 3.
S300, constructing a three-dimensional groundwater flow model by utilizing the characteristic data of the polluted site.
Wherein, the characteristic data of the contaminated site includes: one or more of a stabilized water burial depth, a stabilized water level elevation, a gas-coated zone thickness, an aquifer thickness, and an original concentration of organic contaminants.
In particular, the characteristic data of contaminated sites, which are the areas where the soil and groundwater to be remediated are located, can be surveyed using prior art means. Wherein the range of groundwater to be remediated at least includes the range of pollution plume, and the soil to be remediated at least includes the soil surrounding the pollution plume. The characteristic data is actual initial data of the polluted site, and can comprise underground stable water burial depth, stable water level elevation, gas-coated zone thickness, aquifer thickness and original concentration of organic pollutants of the polluted site. And inputting the characteristic data into a parameter determining device to construct a three-dimensional groundwater flow model, wherein the three-dimensional groundwater flow model can be used for simulating an actual pollution site.
Illustratively, the characteristic data of groundwater surveyed to the contaminated site includes: the underground water stable water level burial depth of the polluted site is about 2.2-2.45 m under the natural ground surface, and the average value is 2.35m; the corresponding stable water level elevation is 40.11-40.37 m, and the average value is 40.24m; the thickness of the air-covering belt is 2-3 m, and the average value is 2.5m; the thickness of the water-bearing layer is 7.2-8.95 m, and the average thickness is 8.08m; the annual change range is 1-2 m, and the water supply degree is 0.21. The organic contaminants in the remediation of groundwater and soil comprised primarily benzene and vinyl chloride, assuming an original concentration of 9180 μg/L benzene and 3100 μ in the organic contaminants surveyedg/L, the area of polluted groundwater to be repaired is 825.78m 2 Wherein the repair area of the vinyl chloride is 825.78m 2 The benzene repair area is 289.05m 2 . Combining the average thickness and the water supply degree of the aquifer to obtain the polluted underground water with the square quantity of 1401.18m to be repaired 3 . The flat permeability coefficient 0.0864m/d, the vertical permeability coefficient 0.00864m/d, the water storage coefficient 0.00012/m, the porosity 0.25, the rainfall 630mm/a and the rainfall infiltration replenishment coefficient 0.21.
After the characteristic data of the underground water of the polluted site are obtained, a python language can be used for calling a Flopy module to couple a Modflow model (namely a modularized three-dimensional finite difference underground water flow model) and an MT3DMS model (namely an underground water organic pollutant migration model). Specifically, the characteristic data are input into a Modflow model and an MT3DMS model, a general water head boundary is set according to the periphery of a pollution site, and the original concentration of organic pollutants is used as an initial value. And (3) establishing a groundwater flow field by using the Flopy module and calling a Modflow model, setting a stress period and mesh subdivision into the number of layers, the number of rows and the number of columns of the aquifer, and introducing groundwater flow parameters to perform groundwater flow numerical simulation (which can be realized by adopting the prior art means). Setting a pumping well at the downstream position of a pollution site in the Modflow model, and simulating a water head change value according to the same flow as the groundwater flow so as to construct a three-dimensional groundwater flow model, and determining that the three-dimensional groundwater flow model meets simulation requirements when the error between the three-dimensional groundwater flow model and the actual pollution site is within 5%.
S301, in each round iteration in preset rounds of iterations, simulating the number of injection wells in the injection well group, the first flow rate, the number of pumping wells in the pumping well group and the second flow rate by using the three-dimensional groundwater flow model; and determining the value of the capital cost objective function according to the number of the injection wells, the first flow rate, the number of the pumping wells and the second flow rate.
Illustratively, to accomplish the collaborative remediation of soil and groundwater with minimal capital costs within a preset time (e.g., projected to accomplish the remediation of groundwater and soil at the contaminated site within 180 days), after a three-dimensional groundwater flow model is built, parameters such as pymoo (multi-objective optimization algorithm) module may be coupled and parameters such as injection well water injection rate or flow rate, extraction well extraction rate or flow rate, injection well run time, extraction well run time, organic contaminant concentration such as benzene and vinyl chloride may be constrained using the genetic algorithm carried by the pymoo module.
To satisfy the repair effect, a corresponding constraint may be entered in the pymoo module: the total flow of the injection well group is equal to the total flow of the pumping well group, so that the underground water outside the pollution plume is reduced to be polluted; the total water injection amount of the injection well group cannot be excessively large, namely the water level rise value caused by the total water injection amount of the injection well group is smaller than the thickness of the gas-packing belt (the thickness of the gas-packing belt is known by the characteristic parameters surveyed in the steps); the water pumping amount of the pumping well cannot be too large, namely the water level reduction value caused by the total water pumping amount of the pumping well group is smaller than or equal to the thickness of the aquifer (namely the well cannot be drained, and the characteristic parameters surveyed in the steps are known to be the thickness of the aquifer); the repair process run time is less than a preset time (e.g., 180 days); the concentrations of organic contaminants such as benzene and vinyl chloride in the groundwater and soil of the contaminated site are less than the respective remediation targets; for convenience of engineering implementation, the flow rate of each injection well in the injection well group is the same, and the flow rate of each pumping well in the pumping well group is the same.
For example, in the calculation using the genetic algorithm, the preset round iteration may be set first (may be set as needed, for example, the preset round is 40), and the population number is set to 100 (may be set as needed). Meanwhile, the initial number of injection wells in the injection well group can be automatically set to 20 according to the past experience or an optimization module, and the initial number of pumping wells in the pumping well group is set to 20 (the number of pumping wells or injection wells can be set according to the characteristic data of the field). Setting the flow rate of each injection well in the injection well group as a first flow rate and the flow rate of each pumping well in the pumping well group as a second flow rate. The first flow rate and the second flow rate may be set to be equal, or the first flow rate may be set to be smaller than the second flow rate. The present application may preferably provide for a first flow rate that is less than a second flow rate, which may increase the time for the agent in each injection well to react with soil and groundwater, which may be beneficial to increase the rate and effectiveness of soil and subsurface remediation.
And taking the number of the injection wells and the first flow rate in the injection well group and the number of the pumping wells and the second flow rate in the pumping well group as initial values of the objective function of the capital cost determined in a genetic algorithm. Meanwhile, in order to visually observe the iterative process and result of each round, the three-dimensional groundwater flow model is utilized to simulate the number of injection wells in the injection well group, the first flow rate, the number of pumping wells in the pumping well group and the second flow rate. For example, the method can realize the restoration of soil and groundwater without overflowing organic pollutants by manually or automatically arranging 20 injection wells in the three-dimensional groundwater flow model at the periphery of a pollution site in the three-dimensional groundwater flow model, namely at the upstream position of the pollution site (namely, injecting in a high pollution area) and arranging 20 pumping wells in the three-dimensional groundwater flow model at the inner part of the pollution site, namely, at the downstream position of the pollution site (namely, pumping out in a medium-low pollution area). Correspondingly, the three-dimensional groundwater flow model is provided with the position coordinates of each injection well and each pumping well, and can provide position references for actually constructing the pumping wells and the injection wells. Meanwhile, in order to distinguish the flow directions of the pumping well and the injection well, the flow amount of the injection well may be a positive value (or a negative value), and the flow amount of the pumping well may be a negative value (or a positive value). Exemplary, the first flow rates of the 20 injection wells are each set to 1.2m in the three-dimensional groundwater flow model 3 And the second flow rate of 20 pumping wells is 1.2m 3 And/d. And in each round of iteration of preset rounds (for example, 40 times), simulating the number of injection wells in the injection well group, the first flow rate, the number of pumping wells in the pumping well group and the second flow rate by using the three-dimensional groundwater flow model.
Further, from the feature data of the survey known in step S300, it is necessary to further determine the value of the capital cost objective function. Wherein the capital cost includes the sum of the construction cost of the injection wells in the injection well group and the construction cost of the pumping wells in the pumping well group, and the sum of the operation cost of each injection well and the operation cost of each pumping well. The fund cost objective function calculation method comprises the following steps:
wherein J is the capital cost; α1 is the unit price of the injection well; α2 is the unit price of pumping well; α3 is the running unit price of the injection well; α4 is the running unit price of the pumping well; y is 1i Is the state variable of the ith injection well, y 1i The state value of (2) is 0 or 1; y is 2i Is the state variable of the ith pumping well, y 1i The state value of (2) is 0 or 1; d, d 1i The well depth is the i-th injection well; d, d 2i The well depth is the well construction depth of the ith pumping well; q (Q) 1i A first flow rate for an ith injection well; q (Q) 2i The second flow of the pumping well at the ith port; Δt (delta t) 1i The running time of the ith injection well; Δt (delta t) 2i The running time of the ith pumping well; n1 is the number of injection wells and N2 is the number of injection wells.
Illustratively, the initial value of the number N1 of injection wells in the group of injection wells is known to be 20, the corresponding state variable y 11 ,y 12 ,y 13 ,......,y 120 The values are all 1; the initial value of the number N2 of pumping wells in the pumping well group is 20, and the corresponding state variable y 21 ,y 22 ,y 23 ,......,y 220 The values are all 1; the operating time of each injection well (assuming 180 days by 24 hours), the operating time of each pumping well (operating 180 days by 24 hours). Setting the well depth of each injection well in the injection well group to be 10m according to practical experience, namely d 11 ,d 12 ,d 13 ,......,d 120 The values of (2) are 10m (which can be determined according to the pollution condition of the polluted site). The depth of the pumping well is usually deeper than that of the injection well, and the depth of each pumping well in the pumping well group is set to be 15m according to practical experience, namely d 21 ,d 22 ,d 23 ,......,d 220 The values of (2) are 15m (which can be determined according to the pollution condition of the polluted site). Wherein alpha 1 is the well construction of the injection wellCost, e.g. price per meter, is a known value; α2 is the cost of pumping well construction and is typically equal to the cost of injection well. α3 is the running cost of the injection well, α4 is the running cost of the pumping well, e.g., the running cost is the electricity rate, which is a known value. First flow rate Q of each injection well 11 ,Q 12 ,Q 13 ,......,Q 120 Are all 1.2m 3 Second flow rate Q of each pumping well 21 ,Q 22 ,Q 23 ,......,Q 220 Are all 1.2m 3 And/d. The value of the cost objective function can thus be found from the initial values known in the above formula.
S302, under the condition that the value of the fund cost objective function in a specific round iteration in the preset round iterations is minimum, determining that the number of the injection wells and the first flow rate and the number of the pumping wells and the second flow rate in the specific round iteration are the target number of the injection wells and the first target flow rate and the target number of the pumping wells and the second target flow rate.
The value of the objective function of the capital cost obtained in the step S301 is not the minimum capital cost, and in order to finish the collaborative restoration of the groundwater and the soil of the polluted site within the preset time period with the minimum capital cost, the genetic algorithm may be used to iterate with a preset round (for example, 40 rounds), and when iterating to a specific round (for example, 30 rounds), the value of the objective function of the corresponding capital cost is the minimum. And selecting the number of the injection wells and the first flow rate corresponding to the result of the iteration of the specific round (30 rounds) and the number of the pumping wells and the second flow rate as the target number of the injection wells and the first target flow rate and the target number of the pumping wells and the second target flow rate.
Illustratively, the value that corresponds to the cost objective function is the smallest when the value of the cost objective function iterates to a particular round. Correspondingly, the first flow rate of 16 injection wells in the injection well group is calculated to be 1.5m 3 D (i.e. first target flow), 4-port no flow, i.e. y 11 ,y 12 ,y 13 ,......,y 120 Of which 16 have a state value of 1,4 have a state value of 0 (i.e. injection wellThe target number is 16). The second flow rate of the pumping well group with 8 pumping wells is 3m 3 D (i.e., second target flow), 12-port no flow, i.e., y 21 ,y 22 ,y 23 ,......,y 220 Of which 8 state values are 1 and 12 state values are 0 (i.e., the target number of pumping wells is 8).
And finally, constructing a corresponding number of injection wells and pumping wells in the actual polluted site by referring to the simulation result so as to finish the restoration of the underground water and soil of the polluted site with minimum capital cost in a preset time period. Well construction positions of the injection well and the pumping well can also be selected from actual pollution sites by referring to simulation positions in the three-dimensional groundwater flow model.
And then, the three-dimensional groundwater flow model simulates the first target flow rate and the second target flow rate according to the target number of the injection wells and the target number of the pumping wells so as to simulate the process of repairing groundwater and soil in a polluted site within a preset time period. Specifically, when the water head value of the periphery of the simulated polluted site is smaller than the actual water head value of the periphery of the polluted site, the underground water in the simulated polluted site is well controlled in the polluted site, namely, the underground water does not overflow out of the polluted site. After the simulation is operated stably for 180 days, when the benzene concentration is 2412 mug/L and the chloroethylene concentration is 787 mug/L, the organic pollutant concentration reaches the restoration target value. Meanwhile, the injection well and the pumping well can also adopt intermittent working modes, for example, the injection well and the pumping well are operated for 9 hours and intermittently for 3 hours, and the injection well and the pumping well are sequentially circulated for 180 days in total, so that the organic pollutant removal achieves the best effect. Under the condition of constant total flow, correspondingly, the first target flow of the injection well is increased to 2m 3 /d, i.e. the flow rate corresponding to each injection well is 0.111m 3 /h (cubic meters/hour); the second target flow rate of the pumping well is increased to 4m 3 /d, i.e. the flow rate per pumping well is 0.222m 3 /h。
After the calculation is completed, a permeable reactive barrier device matched with the injection well and the pumping well is further arranged according to the actual situation of the polluted site. For example, when organic pollutants in a polluted site are relatively concentrated, 1 set of permeable reactive barrier devices can be arranged, namely, one set of permeable reactive barrier devices corresponds to 16 injection wells and 8 pumping wells. When organic pollutants in the polluted site are relatively dispersed, for example, 2 sets of permeable reactive barrier devices can be further arranged, namely, each set of permeable reactive barrier device corresponds to 8 injection wells and 4 pumping wells, and referring to fig. 5, a simulated effect diagram is shown, wherein the direction of the water flow pipeline is the direction of circulating water flow of the injection wells and the pumping wells. It should be noted that, since the injection well and the pumping well may be operated intermittently, they may be used as monitoring wells when the injection well or the pumping well is not operated. In addition, in order to fully precipitate the groundwater passing through the permeable reactive barrier device, the groundwater passing through the permeable reactive barrier device may be placed in a temporary storage tank, and flows into each injection well of the injection well group through the temporary storage tank, and finally the restored groundwater is infiltrated back to the aquifer through each injection well. In addition, in order to effectively interfere with the oxidative decomposition of the organic pollutants in the underground water and the soil, the permeable reactive barrier device is preferably a permeable reactive barrier device (namely a horizontal permeable reactive barrier device) which is horizontally arranged and is arranged on the circulating water flow of the injection well group and the pumping well group, so that the repairing speed of the permeable reactive barrier device to the organic pollutants is accelerated under the suction action of each injection well and each pumping well. In the actual construction process, in order to facilitate construction and reduce construction cost, the permeable reactive barrier device may be disposed on the air-packing belt layer, and details refer to fig. 6, which is a manner of disposing the injection well group, the pumping well group, and a set of permeable reactive barrier device on the actual contaminated site.
Further, the permeable reactive barrier device comprises a water inlet, a multi-layer module assembly, a filter screen, a magnet bar assembly frame, a filling medium and a water outlet, wherein the water inlet is connected with each pumping well of the pumping well group, and the water outlet is connected with each injection well of the injection well group.
Wherein, the filler in the multilayer module assembly adopts composite materials for filling, and quartz sand, zero-valent iron, slow-release zero-valent iron material, persulfate slow-release material and granular activated carbon are filled in sequence. And each pumping well pumps the polluted groundwater subjected to oxidation remediation to the permeable reactive barrier device, and organic pollutants are converted and removed step by step through active fillers in the permeable reactive barrier device, so that the groundwater is further remediated.
Preferably, the sintered filter screen is 3 layers, and the mesh number is 80; the magnet rod group frames are longitudinally fixed in the multi-layer module assembly at intervals, each magnet rod group frame comprises 4 magnet rods, the surface magnetic field can reach 8000-12000 gauss, oxalic acid modified zero-valent iron in the module can be fully adsorbed to enable the oxalic acid modified zero-valent iron to suspend and contact with water, and the contact area and hydraulic retention time of the oxalic acid modified zero-valent iron are enhanced. The operation period of the permeable reactive barrier device is combined with the actual inlet water flow and outlet water flow to be monitored so as to be replaced in time.
Further, the volume of the permeable reactive wall device, and the length of the multi-layer module assembly, is calculated. The volume of the permeable reactive barrier device is calculated by multiplying the total flow of the pumping well by the residence time; the length of the multi-layer module assembly is calculated as follows: l=sf×t R ×K×I/n e Wherein t is R Indicating the residence time of the organic contaminant; SF represents a safety coefficient, which is a known value; k represents the effective permeability coefficient of the filler in the multi-layer module assembly, being a known value; i represents a hydraulic gradient, which is a known value; ne represents the effective porosity of the filler and is a known value.
For example, taking 2 sets of permeable reactive barrier devices as an example, namely, each set of permeable reactive barrier device corresponds to 8 injection wells and 4 pumping wells, and each injection well and each pumping well adopts an intermittent working mode, namely, the operation is carried out for 9 hours and 3 hours, and the operation is sequentially and circularly carried out for 180 days. The second target flow of each pumping well is 4m 3 The flow rate of each pumping well is 0.222m 3 Per hour (cubic meter/hour), so that the total flow rate of the 4-port pumping well is 0.888m 3 According to the small laboratory test, the hydraulic retention time is 0.5h, so that the volume of the single permeable reactive wall device can be calculated to be 0.444m 3 。
While considering water flow conditions and filler utilization, each layer of module assembly can be set to be cylindrical with a bottom radius of 70cm and a height of 100 cm. The effective porosity of the filler is, for example, 0.5, so that the length of the multi-layer module assembly can be further determined. In addition, in order to ensure that the groundwater repair is smoothly carried out, 4 groups of permeable reaction devices can be arranged, and a mode of 2-to-2-equipment is adopted, so that when any permeable reaction wall device fails, a standby device is used for timely replacing, and the groundwater repair is ensured to be uninterrupted. The filling medium in each set of permeable reactive barrier device is persulfate slow-release material and oxalic acid modified zero-valent iron, and the mass ratio is preferably 10:1. for example, each set of permeable reactive barrier device is filled with 2.5 tons of persulfate slow release material and 0.25 tons of oxalic acid modified zero-valent iron in a single batch.
Further, the soil and groundwater collaborative remediation system further comprises: and the hydraulic control device is used for controlling the groundwater of each injection well to flow at the first target flow rate and the groundwater in each pumping well to flow at the second target flow rate.
The invention accelerates the flow of groundwater by effectively intervening the orientation of the water field in the polluted area, and further enhances the in-situ repair rate and effect. Meanwhile, the connection links of different technical units enter each technological parameter of the horizontal permeable reaction device, and the process parameters are monitored in real time so as to ensure the restoration effect of soil and groundwater and the running stability of the system. The secondary pollution of groundwater and soil can be effectively prevented by the chemical adding control device. Compared with a single pumping and injecting well and a single permeable reactive barrier device, the method and the device for repairing the underground water in the polluted site can improve the tailing effect, so that the repairing efficiency is improved.
Meanwhile, the parameter determining module is utilized, the number of injection wells and pumping wells which are actually required to be built, the first target flow of the injection wells and the second target flow of each pumping well are calculated by taking the capital cost as an objective function, so that the repair of the underground water and soil of the polluted site is guaranteed to be completed within a preset time with the minimum capital cost, the repair efficiency is improved, and the cost investment is reduced.
Through the technical scheme, the groundwater and the soil of the polluted site are restored by adopting the soil and groundwater collaborative restoration system. The soil and groundwater collaborative remediation system comprises: the device comprises a dosing device, an injection well group, a pumping well group and a permeable reaction wall device; the dosing device is used for injecting a medicament into each injection well in the injection well group; the injection wells are used for injecting the medicament into a pollution site so as to perform oxidative decomposition on groundwater and soil of the pollution site; the pumping well group is used for pumping out the underground water after oxidative decomposition; and the permeable reactive barrier device is used for repairing the underground water after oxidative decomposition, and rewetting the repaired underground water to the aquifer through the injection well group. And constructing a soil and groundwater cooperative restoration system in the polluted site, so that restoration of groundwater and soil of the polluted site is effectively interfered.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises an element.
The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and changes may be made to the present application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. which are within the spirit and principles of the present application are intended to be included within the scope of the claims of the present application.