CN102491603B

CN102491603B - Air injection system and method for in situ restoration of volatile pollutant in underground water

Info

Publication number: CN102491603B
Application number: CN 201110449705
Authority: CN
Inventors: 姜林; 张丹; 樊艳玲; 姚珏君; 钟茂生
Original assignee: Beijing Municipal Research Institute of Environmental Protection
Current assignee: Beijing Municipal Research Institute of Environmental Protection
Priority date: 2011-12-29
Filing date: 2011-12-29
Publication date: 2013-01-02
Anticipated expiration: 2031-12-29
Also published as: CN102491603A

Abstract

An air injection system and a method for in situ restoration of volatile pollutants in underground water. The system comprises air feed equipment, an air injection well, an underground water monitoring well and a soil gas monitoring well. The air feed equipment comprises two parts of underground air feed equipment and overground air feed equipment. The underground air feed equipment comprises a gas injection steel pipe and an expansion-type gas obstruct device; and the overground air feed equipment comprises a gas injection pipeline connected with the gas injection steel pipe and a gas filled pipeline connected with an inflation interface of the expansion-type gas obstruct device. The invention requires low-cost equipment, has high working efficiency and guarantees rapid restoration of underground water. In addition, an underground water restoration process causes no secondary pollution on the ecological environment; therefore, the technology is suitable to be widely applied to underground water restoration of polluted places to solve a problem of underground water pollution efficiently and fast.

Description

Original position is repaired air ejector system and the method for volatile contaminant in the underground water

Technical field

The original position that the invention belongs to groundwater pollution is repaired the field, is specifically related to a kind of contaminated site underground water repair system and method.

Background technology

Along with industrial high speed development, the problem of China's groundwater pollution becomes increasingly conspicuous, and the impact on the environment and economy development that groundwater pollution brings also appears increasingly.At present, developed country has dropped into a large amount of manpower and materials the zone of getting dirty has been repaired, and the based technique for in-situ remediation of underground water has also obtained rapidly development.For the safety of guarantee Eco-Environment System and the sustainable use of underground water, must repair the underground water that has been polluted, therefore, the research and development of associated restoration technology are extremely urgent.

China starts late in contaminated site reparation field, for the reparation of the underground water volatile organic contaminant in the contaminated site, and at present also not on a large scale recovery project application on the spot.At present, the based technique for in-situ remediation of underground water mainly contains biological restoration, physical chemistry reparation etc.Wherein, biological restoration mainly comprises subterranean microorganisms degraded and ground phytoremediation, and this kind reparation can not destroy ecotope, but repair process is slow; The physics reparation comprises that the processing of drawing water, isolation seal, solidify stable, the soil technology such as aeration, ultrasonic wave and microwave treatment and electrodynamics reparation of bleeding, and these technology can be removed pollution preferably, but cost is higher, and may influence ecological environment.Desirable environmental pollution recovery technique is should cost low, repairing effect good and do not destroy ecotope.

Existing air sparging technology is to adopt the mode of direct injection, pressurized air is injected into the underground water saturation region by the stripping effect, pollutent is risen with pressurized air enter non-saturated region, gaseous pollutant can be processed by the non-saturated region biological degradation, or directly extracts out and carry out subsequent disposal.Its essence is that volatile contaminant is transferred to gas phase from liquid phase, and in gas phase, removed.The design variable of air ejector system need to obtain by the on-the-spot test in early stage, but so far, the research of relevant underground water air sparging recovery technique also is in the laboratory study stage mostly, lack supporting proven technique system, thereby hindered the application of air sparging technology heavy industrialization.When the application of air injection technique is repaired underground water, need to make up the air sparging well, obstructing instrument is installed in well simultaneously.This device is that the crucial support equipment of whole technology, main purpose are to guarantee that pressurized air injects to the underground water saturation region effectively, can not produce backflow simultaneously in injector well.Existing support equipment for the air sparging utilization, complex structure and can not reusing, price is comparatively expensive, uses operation easier larger, and engineering cost is high.Therefore, when the application of air injection technique is repaired volatility organic contamination underground water, must develop reusable and cheap crucial support equipment, the air sparging technology is more widely used.

Summary of the invention

The invention provides a kind of original position and repair air ejector system and the method for volatile contaminant in the underground water, the original position that solve underground water is repaired the technical problem that progress is slow, rehabilitation cost is high, ecotope is damaged, is difficult to the large-scale industrialization application.

The technical solution adopted for the present invention to solve the technical problems is:

This original position is repaired the air ejector system of volatile organic contaminant in the underground water, comprises air feed equipment, air sparging well, groundwater monitoring well and soil gas monitor well, and described air feed equipment is made of underground air feed equipment and ground air feed equipment two portions;

Underground air feed equipment comprises gas injection steel pipe and the expanded polystyrene veneer gas-barrier device that is positioned at the air sparging well, and expanded polystyrene veneer gas-barrier device is installed in the middle and lower part of gas injection steel pipe; Described expanded polystyrene veneer gas-barrier device comprises the main air injection pipe that is connected with the gas injection steel pipe, the packing element assembly of the flexible material of cover on the main air injection pipe, main air injection pipe also have one group of packing element joint, protective sleeve, intermediate head, adapter sleeve at the up and down symmetrical cover of packing element assembly respectively; The upper orifice of described packing element assembly is placed in packing element joint I lower outside, the upper orifice outside that protective sleeve I is placed in the packing element assembly tightens with packing element joint I outer wall middle part simultaneously, intermediate head I is placed in packing element joint I upper outside, and adapter sleeve I is connected between intermediate head I and the top connection; Enclose the gas injection cavity between top connection, adapter sleeve I, intermediate head I and the main air injection pipe outer wall, and between intermediate head I and packing element joint I the two and main air injection pipe outer wall, leave gas passage, gas passage one end is communicated with the gas injection cavity, and the other end is communicated with the space between main air injection pipe and the packing element assembly; Top connection is provided be used to the upper interface that main air injection pipe is connected with the gas injection steel pipe, and at the other inflatable interface that is provided with of upper interface, the inflatable interface upper end is connected with outside gas-filled valve, and the inflatable interface lower end is connected with the gas injection cavity to downward-extension; The lower nozzle of described packing element assembly is placed in packing element joint II upper outside, the lower nozzle outside that protective sleeve II is placed in the packing element assembly tightens with packing element joint II outer wall middle part simultaneously, intermediate head II is placed in packing element joint II lower outside, adapter sleeve II is connected between intermediate head II and the box cupling, and the box cupling lower end connects lower sub; The two closely is placed in main air injection pipe outer wall packing element joint II and intermediate head II;

Air feed equipment comprises the gas injection pipeline that is connected with the gas injection steel pipe on the ground, and the loading line that is connected with the inflatable interface of expanded polystyrene veneer gas-barrier device; Described air injection pipe route air compressor, helium steel cylinder, storage tank, pneumatic tube, air injection pipe, gas injection valve, ball valve, under meter and tensimeter consist of; The air outlet of air compressor is connected with an inlet mouth of storage tank through pneumatic tube I, be provided with successively ball valve I and under meter I on the pneumatic tube I, the air outlet of helium steel cylinder is connected with another inlet mouth of storage tank through pneumatic tube II, is provided with successively ball valve II and under meter II on the pneumatic tube II; The air outlet of storage tank is connected with gas injection steel pipe in the air sparging well through air injection pipe, is provided with successively ball valve III, under meter III, tensimeter and gas injection valve on the air injection pipe, the gas injection valve and and tensimeter between air injection pipe through branch road and ball valve Connect; Described loading line is by small-sized air compressor, gas-filled valve and ball valve

Consist of, the air outlet of small-sized air compressor is connected through the inflatable interface of gas-filled valve with expanded polystyrene veneer gas-barrier device, and gas-filled valve is provided with ball valve

Described air sparging well is made of air sparging well well casing and packing layer, and air sparging well well casing sealed bottom, air sparging well well casing are followed successively by precipitation pipeline section, sieve tube segment and straight length from the bottom to the top; Sediment tube segment length 30～50cm, sieve tube segment is arranged at following 0.3～1.5m place, target stains district, the straight length upper end extends to more than the ground, described packing layer is by the quartz sand filtering layer, bentonite bed and concrete layer consist of, the quartz sand filtering layer is filled in around the sieve tube segment, it grows 30cm than sieve tube segment in two ends up and down at least, a bentonite bed part is filled between quartz sand filtering layer and the concrete layer, its end face flushes with the aquitard upper end of rock stratum, another part is filled in the quartz sand filtering layer between the air sparging well borehole bottom, and concrete layer is filled in bentonite bed between the ground;

Described groundwater monitoring well is made of groundwater monitoring well well casing, well cap and packing layer, and described groundwater monitoring well well casing sealed bottom, groundwater monitoring well well casing are followed successively by precipitation pipeline section, sieve tube segment and straight length three parts from the bottom to the top; Described sediment tube segment length 30～50cm, sieve tube segment are positioned in the target stains district scope, and length can satisfy the change in the target stains district that change of level causes, straight length extends upwardly to ground, and pipe cap is added a cover on its top; Described packing layer is made of quartz sand filtering layer, bentonite bed and concrete layer, the quartz sand filtering layer is filled in around the sieve tube segment, it grows 30cm than sieve tube segment in two ends up and down at least, a bentonite bed part is filled between quartz sand filtering layer and the concrete layer, its end face flushes with the aquitard upper end of rock stratum, another part is filled in the quartz sand filtering layer between the groundwater monitoring well borehole bottom, and concrete layer is filled in bentonite bed between the ground;

Described soil gas monitor well is made of soil gas probe, soft air-guide pipe, quick-connecting valve, pillar, pipe cap and packing layer, on the tube wall of described soil gas probe crack in the interval, it is inner that the soil gas probe is stretched in described soft air-guide pipe lower end, be above the ground level 30cm at least and link to each other with above the ground quick-connecting valve of upper end, quick-connecting valve outside cover has pillar, and pipe cap is arranged on the pillar; Described packing layer is made of quartz sand filtering layer, bentonite bed and concrete layer, the quartz sand filtering layer is filled in around the soil gas probe, it grows 30cm than the soil gas probe in two ends up and down at least, a bentonite bed part is filled between quartz sand filtering layer and the concrete layer, its end face flushes with the aquitard upper end of rock stratum, another part is filled in the quartz sand filtering layer between the soil gas monitor well borehole bottom, and concrete layer is filled in bentonite bed between the ground.

The material of described air sparging well well casing, groundwater monitoring well well casing, soil gas probing shell is chemical grade UPVC, and the material of soft air-guide pipe is PVC.

Described packing element assembly is quality of rubber materials, and the material of this device remaining part is the 35CrMo structural alloy steel; The upper orifice inwall of packing element assembly is provided be used to the inner groovy that holds packing element joint I bottom, and the upper orifice outer wall is provided be used to the outer groove that holds protective sleeve I; The lower nozzle of described packing element assembly is identical with the upper orifice shape.

The upper interface of described main air injection pipe and top connection all is set for the eccentric, and inflatable interface is positioned at interface away from a side at top connection center.

Described intermediate head I has groove and is provided with sealing-ring at the contact surface with packing element joint I and adapter sleeve I, and top connection has groove and is provided with sealing-ring at the contact surface with adapter sleeve I and main air injection pipe outer wall;

Described intermediate head II has groove and is provided with sealing-ring at the contact surface with packing element joint II, adapter sleeve II and main air injection pipe outer wall, and box cupling has groove and is provided with sealing-ring at the contact surface with adapter sleeve II and main air injection pipe outer wall;

Described intermediate head I inwall is to be cooperate each other step-like with packing element joint I shaped upper part, and intermediate head I outer wall top and top connection outer wall bottom are respectively equipped be used to the groove that holds adapter sleeve I;

Described intermediate head II inwall is to be cooperate each other step-like with packing element joint II shaped upper part, and intermediate head II outer wall bottom and box cupling outer wall top are respectively equipped be used to the groove that holds adapter sleeve II.

Described protective sleeve I is suitable for reading to be provided with interior edge, and there is flange at packing element joint I outer wall middle part, the flange chucking on the interior edge of protective sleeve I and the packing element joint I;

The end opening of described protective sleeve II is provided with interior edge, and there is flange at packing element joint II outer wall middle part, the flange chucking on the interior edge of protective sleeve II and the packing element joint II.

This original position is repaired the air sparging method of volatile contaminant in the underground water, and step is as follows:

Step 1, by site investigation, obtain place hydrogeological parameter and pollution condition, the feasibility that the preliminary judgement technology is used;

Step 2, in selection area, adopt direct bore mode to lay air sparging well, groundwater monitoring well, soil gas monitor well, air ejector system is provided with at least one, groundwater monitoring well and is provided with at least two, soil gas monitor well and is provided with at least five; Gas injection system is installed, and the operation of expanded polystyrene veneer gas-barrier device is tested,

Open first small-sized air compressor, pressurized air is entered by the inflatable interface of expanded polystyrene veneer gas-barrier device, enter space between main air injection pipe and the packing element assembly through gas injection cavity, gas passage again, and make the packing element assembly formation annular seal space that expands gradually, the borehole wall final and the air sparging well is adjacent to, and plays the iris action with down-hole liquid and gas; When gas injection begins, open air compressor, pressurized air is delivered to the underground water saturation region by the gas injection steel pipe; When gas injection finishes, close first air compressor, close again small-sized air compressor, slowly discharge pressurized air, after the rubber of packing element assembly reverts to original state, expanded polystyrene veneer gas-barrier device is recycled to ground;

Step 3, carry out the test of underground water dissolved oxygen background, the test of soil gas background, gas injection pressure and flow rate test, groundwater pressure response test, the test of underground water dissolved oxygen, helium tracer flow, soil gas test; By gas injection pressure and flow rate test, obtain best gas injection pressure, gas flow; By groundwater pressure response test, the test of underground water dissolved oxygen, helium tracer flow, soil gas test, obtain 4 air sparging radiuses of influence, final air sparging radius of influence scope is between the minimum value and maximum value of test result;

Described underground water dissolved oxygen background test concrete steps are as follows:

Step 1 is measured ground water table among the groundwater monitoring well G1 with the underground water liquidometer;

Step 2 is put into submersible pump below the groundwater monitoring well G1 water surface, extracts the underground water of 3～5 times of sieve tube segments out, until the underground water of extracting out is comparatively limpid;

Step 3 is taken out submersible pump from groundwater monitoring well G1;

Step 4 is measured ground water table with the underground water liquidometer, until water level return to or near initial level after measure underground content of oxygen dissolved in water with dissolved oxygen instrument;

Step 5, repeating step 1～4 carries out the dissolved oxygen test to other groundwater monitoring wells;

Described soil gas background test concrete steps are as follows:

Step 1 is opened pipe cap on the soil gas monitor well and the quick-connecting valve on soft air-guide pipe top, and soft air-guide pipe is connected to the inlet mouth of Portable exhaust gas analyzer, observation CO ₂, O ₂Reading;

Step 2, the air outlet that after the Portable exhaust gas analyzer stable reading VOC tester PID is placed on Portable exhaust gas analyzer is located, record VOC concentration;

Described gas injection pressure and flow rate test concrete steps are as follows:

Step 1 is calculated the minimum gas injection pressure Pmin in place and maximum gas injection pressure Pmax, and method of calculation are as follows: Pmin (psig)=0.43H+ packing material resistance P+ inwall resistance P, Pmax=0.73D.In the formula, the H=ground water table is to the height ft of sieve tube segment upper end; The air Injection resistance that annular packing material and well inner wall structure cause in the packing material resistance P+ well inwall resistance P=well, general sandy soil＜0.2psig; D=ground is to the height of sieve tube segment upper end;

Step 2, the groundwater monitoring well that chosen distance air sparging well is nearer is placed the ground water table registering instrument;

Step 3 is opened ball valve

, ball valve

With the gas injection ball valve, and close other valves, open air compressor, regulate ball valve

Opening degree, make air gas input well wellhead pressure meter reading P1 be a bit larger tham Pmin, record simultaneously air gas input well well head under meter Reading, every ground water table registering instrument reading of 5min record;

Step 4 behind underground stable level, is closed gas injection ball valve, ball valve

And air compressor, every ground water table registering instrument reading of 5min record, until ground water table returns to or near initial level;

Step 5, repeating step 3～4 is wherein regulated ball valve

Opening degree, its open degree is progressively diminished greatly, injector well mouth pressure meter reading Pn is increased gradually, but Pn can not surpass Pmax;

Step 6, draw under the different gas injection pressure conditions ground water table height with the gas injection time variation diagram, along with gas injection pressure constantly increases, when underground elevation of water surface amplification begins to reduce or ground water table when beginning to descend, determine that this gas injection pressure is best gas injection pressure Pop, the gas flow corresponding with it is as best gas flow Fop;

Described groundwater pressure response test concrete steps are as follows:

Step 1 is respectively placed a ground water table registering instrument in each groundwater monitoring well;

Step 2 is opened ball valve

, ball valve

With the gas injection ball valve, and close other valves, open air compressor, regulate the ball valve ball valve

Opening degree, make air gas input well well head pressure gauge and under meter

Reading reach best gas injection pressure and flow (Pop, Fop);

Step 3, begin timing this moment, records respectively ground water table registering instrument reading one time every 5min, until reach steady state;

And air compressor, record respectively ground water table registering instrument reading one time every 5min, until ground water table returns to or near initial level;

Step 5 is drawn ground water table temporal evolution graphic representation in the different groundwater monitoring wells, and change of level relatively obviously distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Described underground water dissolved oxygen test concrete steps are as follows:

Step 1 is opened ball valve

, ball valve With the gas injection ball valve, and close other valves, open air compressor, regulate ball valve

Opening degree, make air gas input well well head pressure gauge and under meter Reading reach best gas injection pressure and flow (Pop, Fop);

Step 2, the beginning gas injection, gas injection time outline is longer than that the underground water response reaches the stable time in the pressure-responsive test, has reached the gas injection equilibrium state to guarantee underground water;

Step 3 according to distance air sparging well order from the close-by examples to those far off, is carried out the measurement of well-flushing and dissolved oxygen to all groundwater monitoring wells, and specific practice is tested with the dissolved oxygen background;

Step 4, groundwater monitoring well dissolved oxygen test result and dissolved oxygen background test result are compared, dissolved oxygen concentration changes relatively obviously that distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Described helium tracer flow step is as follows:

Step 1 is opened ball valve

Reading reach best gas injection pressure and flow (P _Op, F _Op);

Step 2 is closed the gas injection ball valve, opens ball valve

, regulate gradually ball valve

Open degree, make air gas input well well head pressure gauge and under meter

Reading is shown as (P _Op, F _Op);

Step 3 is opened ball valve , adjust ball valve

And ball valve , make under meter

With under meter Reading become the 1:10 ratio, keep simultaneously air gas input well well head pressure gauge and under meter

Reading be (P _Op, F _Op);

Step 4 uses Nitrogen Detector at ball valve

Concentrations of helium is measured at the place;

Step 5 is closed ball valve , open the gas injection ball valve, guarantee ball valve

The degree that the degree of closing and gas injection ball valve are opened is consistent, and namely begins to inject helium and compressed-air actuated mixed gas in the air sparging well;

Step 6 is opened the pipe cap on the soil gas monitor well, opens the quick-connecting valve of soft air-guide pipe end, and soft air-guide pipe is connected to the inlet mouth of Portable exhaust gas analyzer, observation CO ₂, O ₂Reading, the air outlet that after the stable reading Nitrogen Detector is placed on Portable exhaust gas analyzer is located, every concentrations of helium of 5min record;

Step 7 after concentrations of helium is stable, is closed gas injection ball valve, ball valve

, ball valve

, ball valve And air compressor, every concentrations of helium of 5min record, until concentrations of helium is 0 or minimum;

Step 8, repeating step 1～7 according to distance air sparging well order from the near to the remote, carries out the helium tracer flow in other soil gas monitor well, will guarantee that the helium residual concentration was very little in the soil before carrying out a new helium test;

Step 9 is drawn concentrations of helium temporal evolution graphic representation to each soil gas monitor well, and concentrations of helium changes relatively obviously that distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Described soil gas test concrete steps are as follows:

Step 1 is opened ball valve

, ball valve

Reading reaches best gas injection pressure and flow (P _Op, F _Op);

Step 2, the beginning gas injection, gas injection time outline is longer than that the helium spike reaches stable required time in the helium tracer flow process;

Step 3 is carried out the soil gas test to each soil gas monitor well, and concrete grammar is tested with the soil gas background;

Step 4, soil gas test concentrations test result and soil gas background test result are compared, Volatile Organic Compounds in Soil concentration, namely the relative above the fold of VOC change in concentration all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Step 4, according to the radius of influence and gas injection operating mode that test obtains, carry out that the air sparging well is arranged and the laying of air compressor, and groundwater monitoring well and soil gas monitor well be set;

Step 5, begin to repair before, before air sparging, by small-sized air compressor expanded polystyrene veneer gas-barrier device is inflated, intercept down-hole liquid and gas, open again air compressor and carry pressurized air to carry out the gas injection reparation to the underground water saturation region; Simultaneously, Pollutant levels in gas injection operating mode, underground water and the soil gas are monitored, reach the reparation target value of regulation when Pollutant levels after, close first air compressor, close again small-sized air compressor, expanded polystyrene veneer gas-barrier device is recycled to ground, repair and finish.

In the described step 1, the place hydrogeological parameter comprises soil type, size distribution, fluid conductivity, gas permeability, porosity etc.; Pollution condition comprises whether whether pollutent composition, pollutent character, pollutent only are present in the water table aquifer, have nonaqueous phase liquid NPALs to compose mutually and deposit; The application feasibility that possesses skills must meet the following conditions simultaneously: do not have NAPLs to compose in the Water table to deposit, contaminated underground water is positioned at water table aquifer, the lithology in waterbearing stratum needs that isotropic and particle are thick, soil permeability 〉=1.0 * 10 ^-9Cm ², pollutent at room temperature need have the vapour pressure of volatility, pollutent the Henry's constant of the boiling point of 0.5mmHg, pollutent＜250 ~ 300 ℃, pollutent 100atm.

In the described step 4, according to the radius of influence that obtains in the test, the triangulation calculation methods such as employing are determined the spacing of air sparging well, make three lines between the adjacent air injector well consist of an equilateral triangle, guarantee not exist between well and the well reparation dead angle with this, air compressor is made as a well one machine or many wells one machine according to on-the-spot place and economic budget situation cloth, each air sparging well well head palpus setting pressure table and under meter, the laying of groundwater monitoring well should be followed following principle: one, the groundwater monitoring well should be contained the restoring area upstream, restoring area, the restoring area downstream; Two, the quantity of groundwater monitoring well is decided according to project demands and place environment with distribution; There are the sensitive body such as vault, underground utilities to exist if repair the place, then need near these sensitive body, lay the soil gas monitor well.

In the described step 5, repair the initial stage, carry out gas injection pressure and gas flow monitoring to each injector well, behind the system run all right, can suitably reduce the monitoring frequency of gas injection operating mode; Before repairing beginning, need to detect pollution concentration in the underground water; In the repair process, at regular intervals underground water pollutant concentration is detected, grasp removal of pollutants rule in the underground water, Pollutant levels still will be carried out continuing to monitor of certain hour to underground water after reaching and repairing target value, guarantee the not bounce-back of underground water pollutant; If the Pollutant levels that monitor in the soil gas monitor well in the repair process reach the degree that near crowd or environment are worked the mischief, then need to set up the soil vapor extraction system.

Beneficial effect of the present invention is as follows:

The present invention is expelled to the gas (usually adopting air or oxygen) after the pressurization in the saturation zone of underground water, the concentration that is adsorbed on soil and is dissolved in the volatile material in the underground water with reduction.Simultaneously, air sparging can also increase the oxygen in the underground water, thereby promotes biological degradation.

During repairing construction, the specially designed expanded polystyrene veneer gas-barrier of the present invention device is transferred corresponding position to the air sparging well, by loading line to injecting compressed air between main air injection pipe outer wall and the packing element assembly, the packing element assembly is expanded gradually form airtight annular space, final and the borehole wall is adjacent to, thereby guarantee by the unidirectional injection underground reservoir of the pressurized air of main air injection pipe, realize the obstruct of mine gas and liquid.This device has solved a crucial difficult problem of air sparging technology practical engineering application effectively.When whole recovery project finishes, can slowly discharge pressurized air by the pipeline that is connected with inflatable interface, make the rubber of packing element assembly slowly revert to original state, namely install by deblocking, the device that solution is honored as a queen can utilize the proprietary instrument such as elevator to be recycled to ground.This expanded polystyrene veneer gas-barrier device is the quality of rubber materials except the rubber of packing element assembly, and all the other materials all adopt the 35CrMo structural alloy steel, have higher static strength, impelling strength and safe range of stress.Main air injection pipe and the upper interface eccentric setting in top connection can guarantee that inflatable interface is connected smoothly with the packing element annular seal space.Expanded polystyrene veneer gas-barrier device simple in structure, be convenient to install and use, setting reliable, good airproof performance, the dwell time is long, iris action is obvious, energy consumption is low, can be from withdrawal in the injector well, deblocking, taking-up to realize recycling after the device pressure release, use cost is cheap.Use expanded polystyrene veneer gas-barrier device can guarantee in the air sparging well, to realize quick, unidirectional gas injection, can satisfy the needs that the underground water of volatile organic matter contaminated site adopted extensive original position air sparging technology reparation.

Original position of the present invention is repaired the air sparging method of volatile contaminant in the underground water by gas injection pressure and flow rate test, can obtain best gas injection pressure, gas flow; By groundwater pressure response test, the test of underground water dissolved oxygen, helium tracer flow, soil gas test, can obtain the air sparging radius of influence, thereby make the remediation efficiency of system reach best, in the control rehabilitation cost, guaranteed repairing effect.

The present invention overcome that the traditional method progress is slow, cost is high, to the shortcoming that ecotope damages, solved and be difficult to the technical problem that large-scale industrialization is used in the underground water reparation field.

The present device expense is low, and high efficiency can guarantee that underground water repairs fast.In addition, in the underground water repair process, can not cause secondary pollution to destroy to ecotope, be a kind of technology that is adapted at large-scale application in the reparation of contaminated site underground water, can solve in order to efficient quick ground the problem of groundwater pollution.

Description of drawings

The present invention is further described below in conjunction with drawings and Examples.

Fig. 1 is the plot plan of test procedure of the present invention.

Fig. 2 is the structural representation of air feed equipment.

Fig. 3 is the sectional view of air sparging well.

Fig. 4 is the sectional view of groundwater monitoring well.

Fig. 5 is the sectional view of soil gas monitor well.

Fig. 6 is the structural representation of expanded polystyrene veneer gas-barrier device.

Fig. 7 is the enlarged view on Fig. 6 top.

Fig. 8 is the enlarged view of Fig. 6 bottom.

Fig. 9 is the plan structure synoptic diagram of Fig. 6.

Figure 10 is the using method synoptic diagram of expanded polystyrene veneer gas-barrier device.

Reference numeral: 1-air sparging well; 2-groundwater monitoring well; 3-soil gas monitor well; 4-expanded polystyrene veneer gas-barrier device; 4.1-top connection; 4.2-adapter sleeve I; 4.3-intermediate head I; 4.4-protective sleeve I; 4.5-packing element joint I; 4.6-packing element assembly; 4.7-main air injection pipe; 4.8-box cupling; 4.9-lower sub; 4.10-adapter sleeve II; 4.11-intermediate head II; 4.12-protective sleeve II; 4.13-packing element joint II; 4.14-sealing-ring; 4.15-gas injection cavity; 4.16-gas passage; 4.17-annular seal space; 4.18-inflatable interface; 4.19-upper interface; 5-helium steel cylinder; 6-ball valve I; 7-ball valve II; 8-under meter I; 9-under meter II; the 10-storage tank; 11-ball valve III; 12-under meter III; the 13-tensimeter; the 14-ball valve

, 15-gas injection valve, 16-gas injection steel pipe, 17-air compressor, 18-small-sized air compressor, 19-ball valve

20-pneumatic tube I, 21-pneumatic tube II, the 22-branch road, the 23-air injection pipe, the 24-gas-filled valve, 25-air sparging well well casing, 25.1-straight length, 25.2-sieve tube segment, 25.3-precipitation pipeline section, 26-quartz sand filtering layer, the 27-bentonite bed, the 28-concrete layer, the 29-pipe cap, 30-groundwater monitoring well well casing, 30.1-straight tube, 30.2-screen casing, 30.3-sediment tube, the 31-pillar, the 32-quick-connecting valve, the 33-soft air-guide pipe, 34-soil gas probe, 35-underground water top water-level, 36-ground.

Embodiment

Embodiment is referring to Fig. 1, shown in Figure 2, and this original position is repaired the air ejector system of volatile organic contaminant in the underground water, comprises air feed equipment, air sparging well 1, groundwater monitoring well 2 and soil gas monitor well 3.Described air feed equipment is made of underground air feed equipment and ground air feed equipment two portions.When air sparging impact test, air ejector system 1 is provided with at least one, groundwater monitoring well 2 and is provided with at least two, soil gas monitor well 3 and is provided with at least five, groundwater monitoring well 2 is that mark G1, G2 among Fig. 1, G3, soil gas monitor well 3 are mark S1, S2, S3, S4, S5, S6 among Fig. 1, described groundwater monitoring well 2 should be able to obtain apart from the air-flow distribution situation on the air sparging well 1 different distance different directions with the laying of soil gas monitor well 3, and concrete deployment scenarios can adjust accordingly according to field condition.

Referring to shown in Figure 2, underground air feed equipment comprises gas injection steel pipe 16 and the expanded polystyrene veneer gas-barrier device 17 that is positioned at air sparging well 1, and expanded polystyrene veneer gas-barrier device 17 is installed in the middle and lower part of gas injection steel pipe 16.

Air feed equipment comprises the gas injection pipeline that is connected with gas injection steel pipe 16 on the ground, and the loading line that is connected with the inflatable interface 4.18 of expanded polystyrene veneer gas-barrier device 4; Described air injection pipe route air compressor 17, helium steel cylinder 5, storage tank 10, pneumatic tube, air injection pipe, gas injection valve, ball valve, under meter and tensimeter consist of; The air outlet of air compressor 17 is connected with an inlet mouth of storage tank 10 through pneumatic tube I20, be provided with successively ball valve I6 and under meter I8 on the pneumatic tube I, the air outlet of helium steel cylinder 5 is connected with another inlet mouth of storage tank 10 through pneumatic tube II21, and helium purity is 99.999% in the helium steel cylinder 5; Be provided with successively ball valve II7 and under meter II9 on the pneumatic tube II; The air outlet of storage tank 10 is connected with gas injection steel pipe 16 in the air sparging well 1 through air injection pipe 23, be provided with successively ball valve III11, under meter III12, tensimeter 13 and gas injection valve 15 on the air injection pipe 23, the gas injection valve and and tensimeter between air injection pipe 23 through branch road 22 and ball valve

14 connect; Described loading line is by small-sized air compressor 18, gas-filled valve 24 and ball valve

19 consist of, and the air outlet of small-sized air compressor 18 is connected through the inflatable interface 4.18 of gas-filled valve 24 with expanded polystyrene veneer gas-barrier device 4, and gas-filled valve 24 is provided with ball valve

19.

Referring to shown in Figure 3, described air sparging well 1 is made of air sparging well well casing 25 and packing layer, air sparging well well casing 25, material be chemical grade UPVC, air sparging well well casing sealed bottom is followed successively by precipitation pipeline section 25.3, sieve tube segment 25.2 and straight length 25.1 from the bottom to the top; Sediment tube segment length 30～50cm, sieve tube segment are arranged at following 0.3～1.5m place, target stains district, and sieve tube segment stitches wide 0.05mm, kerf spacing 1cm, and length is 0.3m-1.5m; The straight length upper end extends to more than the ground, described packing layer is made of quartz sand filtering layer 26, bentonite bed 27 and concrete layer 28, quartz sand filtering layer 6 is filled in around the sieve tube segment 25.2, it grows 30cm than sieve tube segment in two ends up and down at least, bentonite bed 27 parts are filled between quartz sand filtering layer 26 and the concrete layer 28, its end face flushes with the aquitard upper end of rock stratum, another part is filled in quartz sand filtering layer 26 between the air sparging well borehole bottom, and concrete layer 28 is filled in bentonite bed 27 between the ground 36.

Referring to shown in Figure 4, described groundwater monitoring well 2 is made of with packing layer groundwater monitoring well well casing 30, well cap 29, the material of groundwater monitoring well well casing 30 is chemical grade UPVC, groundwater monitoring well well casing 30 sealed bottoms are followed successively by precipitation pipeline section 30.3, sieve tube segment 30.2 and straight length 30.1 three parts from the bottom to the top; Described precipitation pipeline section 30.3 long 30～50cm, sieve tube segment 30.2 is positioned in the target stains district scope, and length can satisfy the change in the target stains district that change of level causes, and straight length 30.1 extends upwardly to ground, and pipe cap 24 is added a cover on its top; Described packing layer is made of quartz sand filtering layer 26, bentonite bed 27 and concrete layer 28, quartz sand filtering layer 26 is filled in around the sieve tube segment 30.2, it grows 30cm than sieve tube segment in two ends up and down at least, bentonite bed 27 parts are filled between quartz sand filtering layer 26 and the concrete layer 28, its end face flushes with the aquitard upper end of rock stratum, another part is filled in quartz sand filtering layer 26 between the groundwater monitoring well borehole bottom, and concrete layer 28 is filled in bentonite bed 27 between the ground 36.Need after the shaft building of groundwater monitoring well finishes with Beile's pipe or other well washing equipment well-flushings, until water quality parameter value stabilizations such as the pH value of underground water, specific conductivity, redox potential, dissolved oxygen, turbidity, water temperatures, well-flushing finishes.

Referring to shown in Figure 5, described soil gas monitor well 3 is by soil gas probe 34, soft air-guide pipe 33, quick-connecting valve 32, pillar 31, pipe cap 29 and packing layer consist of, it is chemical grade UPVC that described soil gas probe 34 adopts material, external diameter 25mm, on its tube wall crack in the interval, stitch wide 0.5mm, kerf spacing 5mm, length is 0.15m at least, the material of soft air-guide pipe 33 is the PVC flexible pipe, external diameter 10mm, soil gas 34 inside of popping one's head in are stretched in soft air-guide pipe 33 lower ends, be above the ground level 30cm at least and link to each other with above the ground quick-connecting valve 32 of upper end, quick-connecting valve outside cover has pillar 31, pillar 31 bottoms are embedded in 20cm in the concrete layer 28, and elevate above the soil and be not less than 30cm in top, pipe cap 29 is arranged on the pillar; Described packing layer is made of quartz sand filtering layer 26, bentonite bed 27 and concrete layer 28, quartz sand filtering layer 26 is filled in around the soil gas probe 34, it grows 30cm than soil gas probe 34 in two ends up and down at least, bentonite bed 27 parts are filled between quartz sand filtering layer 26 and the concrete layer 28, its end face flushes with the aquitard upper end of rock stratum, another part is filled in quartz sand filtering layer 26 between the soil gas monitor well borehole bottom, and concrete layer 28 is filled in bentonite bed 27 between the ground 36.

Shown in Fig. 6～8, described expanded polystyrene veneer gas-barrier device comprises the main air injection pipe 4.7 that is connected with gas injection steel pipe 16, the packing element assembly 4.6 of the flexible material of cover on the main air injection pipe, main air injection pipe 4.7 also have one group of packing element joint, protective sleeve, intermediate head, adapter sleeve at the up and down symmetrical cover of packing element assembly respectively; The upper orifice of described packing element assembly 4.6 is placed in packing element joint I4.5 lower outside, the upper orifice outside that protective sleeve I4.4 is placed in packing element assembly 4.6 tightens with packing element joint I4.5 outer wall middle part simultaneously, intermediate head I4.3 is placed in packing element joint I4.5 upper outside, and adapter sleeve I4.2 is connected between intermediate head I4.3 and the top connection 4.1; Enclose gas injection cavity 4.15 between top connection 4.1, adapter sleeve I4.2, intermediate head I4.3 and main air injection pipe 4.7 outer walls, and between intermediate head I4.3 and packing element joint I4.5 the two and main air injection pipe 4.7 outer walls, leave gas passage 4.16, gas passage one end is communicated with gas injection cavity 4.15, and the other end is communicated with the space between main air injection pipe 4.7 and the packing element assembly 4.6; Top connection 4.1 is provided be used to the upper interface 4.19 that main air injection pipe 4.7 is connected with gas injection steel pipe 16, and at the upper interface 4.19 other inflatable interfaces 4.18 that are provided with, the inflatable interface upper end is connected with outside gas-filled valve 17, and inflatable interface 4.18 lower ends are connected with gas injection cavity 4.15 to downward-extension; The lower nozzle of described packing element assembly 4.6 is placed in packing element joint II4.13 upper outside, the lower nozzle outside that protective sleeve II4.12 is placed in packing element assembly 4.6 tightens with packing element joint II4.13 outer wall middle part simultaneously, intermediate head II4.11 is placed in packing element joint II4.13 lower outside, adapter sleeve II4.10 is connected between intermediate head II4.11 and the box cupling 4.8, and box cupling 4.8 lower ends connect lower sub 4.9; The two closely is placed in main air injection pipe 4.7 outer walls packing element joint II4.13 and intermediate head II4.11.

Described packing element assembly 4.6 is quality of rubber materials, and the material of this device remaining part is the 35CrMo structural alloy steel; The upper orifice inwall of packing element assembly 4.6 is provided be used to the inner groovy that holds packing element joint I4.5 bottom, and the upper orifice outer wall is provided be used to the outer groove that holds protective sleeve I4.4; The lower nozzle of described packing element assembly 4.6 is identical with the upper orifice shape.

Described intermediate head I4.3 has groove and is provided with sealing-ring 4.14 at the contact surface with packing element joint I4.5 and adapter sleeve I4.2, and top connection 4.1 has groove and is provided with sealing-ring 4.14 at the contact surface with adapter sleeve I4.2 and main air injection pipe 4.7 outer walls;

Described intermediate head II4.11 has groove and is provided with sealing-ring 4.14 at the contact surface with packing element joint II4.13, adapter sleeve II4.10 and main air injection pipe 4.7 outer walls, and box cupling 4.8 has groove and is provided with sealing-ring 4.14 at the contact surface with adapter sleeve II4.10 and main air injection pipe 4.7 outer walls;

Described intermediate head I4.3 inwall is to be cooperate each other step-like with packing element joint I4.5 shaped upper part, and intermediate head I4.3 outer wall top and top connection 4.1 outer wall bottoms are respectively equipped be used to the groove that holds adapter sleeve I4.2;

Described intermediate head II4.11 inwall is to be cooperate each other step-like with packing element joint II4.13 shaped upper part, and intermediate head II4.11 outer wall bottom and box cupling 4.8 outer wall tops are respectively equipped be used to the groove that holds adapter sleeve II4.10.

Described protective sleeve I4.4 is suitable for reading to be provided with interior edge, and there is flange at packing element joint I4.5 outer wall middle part, the flange chucking on the interior edge of protective sleeve I4.4 and the packing element joint I4.5;

The end opening of described protective sleeve II4.12 is provided with interior edge, and there is flange at packing element joint II4.13 outer wall middle part, the flange chucking on the interior edge of protective sleeve II4.12 and the packing element joint II4.12.

Referring to shown in Figure 9, the upper interface 4.19 of described main air injection pipe 4.7 and top connection 4.1 all is set for the eccentric, and inflatable interface 4.18 is positioned at interface 4.19 away from a side at top connection center.

Step 1, by site investigation, obtain place hydrogeological parameter and pollution condition, the feasibility that the preliminary judgement technology is used; The place hydrogeological parameter comprises soil type, size distribution, fluid conductivity, gas permeability, porosity etc.; Pollution condition comprises whether whether pollutent composition, pollutent character, pollutent only are present in the water table aquifer, have nonaqueous phase liquid NPALs to compose mutually and deposit; The application feasibility that possesses skills must meet the following conditions simultaneously: do not have NAPLs to compose in the Water table to deposit, contaminated underground water is positioned at water table aquifer, the lithology in waterbearing stratum needs that isotropic and particle are thick, soil permeability 〉=1.0 * 10 ^-9Cm ², pollutent at room temperature need have the vapour pressure of volatility, pollutent the Henry's constant of the boiling point of 0.5mmHg, pollutent＜250 ~ 300 ℃, pollutent 100atm;

Step 2, in selection area, adopt direct bore mode to lay air sparging well 1, groundwater monitoring well 2, soil gas monitor well 3, air ejector system 1 is provided with at least one, groundwater monitoring well 2 and is provided with at least two, soil gas monitor well 3 and is provided with at least five; Gas injection system is installed, and the operation of expanded polystyrene veneer gas-barrier device is tested,

Open first small-sized air compressor 18, pressurized air is entered by the inflatable interface 4.18 of expanded polystyrene veneer gas-barrier device, enter space between main air injection pipe 4.7 and the packing element assembly 4.6 through gas injection cavity 4.15, gas passage 4.16 again, and packing element assembly 4.6 is expanded gradually form annular seal space 4.17, the borehole wall final and air sparging well 1 is adjacent to, and plays the iris action with down-hole liquid and gas; When gas injection begins, open air compressor 17, pressurized air is delivered to the underground water saturation region by gas injection steel pipe 16; When gas injection finishes, close first air compressor 17, close again small-sized air compressor 18, slowly discharge pressurized air, after the rubber of packing element assembly 4.6 reverts to original state, expanded polystyrene veneer gas-barrier device 4 is recycled to ground 36; It is 0.6Mpa that described small-sized air compressor 18 is set top hole pressure, and when pressure was higher than 0.6Mpa, compressor quit work; When pressure is lower than 0.4Mpa, compressor starts work;

Step 3 is taken out submersible pump from groundwater monitoring well G1;

Described soil gas background test concrete steps are as follows:

Step 1 is opened the quick-connecting valve 32 on pipe cap 29 and soft air-guide pipe 33 tops on the soil gas monitor well, and soft air-guide pipe is connected to the inlet mouth of Portable exhaust gas analyzer, observation CO ₂, O ₂Reading;

Step 2, the groundwater monitoring well 2 that chosen distance air sparging well 1 is nearer is placed the ground water table registering instrument;

Step 3 is opened ball valve 6, ball valve

11 with gas injection ball valve 15, and close other valves, open air compressor 17, regulate ball valve 11 opening degree makes air gas input well 1 well head pressure gauge 13 reading P1 be a bit larger tham Pmin, records simultaneously air gas input well 1 well head under meter

12 reading is every ground water table registering instrument reading of 5min record;

Step 4 behind underground stable level, is closed gas injection ball valve 15, ball valve

6 and air compressor 17, every ground water table registering instrument reading of 5min record, until ground water table returns to or near initial level;

Step 5, repeating step 3～4 is wherein regulated ball valve

11 opening degree progressively diminishes greatly its open degree, injector well mouth pressure meter reading Pn is increased gradually, but Pn can not surpass Pmax;

Described groundwater pressure response test concrete steps are as follows:

Step 2 is opened ball valve

6, ball valve

11 with gas injection ball valve 15, and close other valves, open air compressor 17, regulate the ball valve ball valve

Opening degree, make air gas input well well head pressure gauge 13 and under meter

12 reading reaches best gas injection pressure and flow Pop, Fop;

6 and air compressor 17, record respectively ground water table registering instrument reading one time every 5min, until ground water table returns to or near initial level;

Step 5 is drawn ground water table temporal evolution graphic representation in the different groundwater monitoring wells 2, and change of level relatively obviously distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Step 1 is opened ball valve

6, ball valve

11 with gas injection ball valve 15, and close other valves, open air compressor 17, regulate ball valve Opening degree, make air gas input well well head pressure gauge 13 and under meter 12 reading reaches best gas injection pressure and flow Pop, Fop;

Step 3 according to distance air sparging well 1 order from the close-by examples to those far off, is carried out the measurement of well-flushing and dissolved oxygen to all groundwater monitoring wells 2, and specific practice is tested with the dissolved oxygen background;

Step 4, groundwater monitoring well 2 dissolved oxygen test results and dissolved oxygen background test result are compared, dissolved oxygen concentration changes relatively obviously that distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Described helium tracer flow step is as follows:

Step 1 is opened ball valve

6, ball valve

11 with gas injection ball valve 15, and close other valves, open air compressor 17, regulate ball valve

12 reading reaches best gas injection pressure and flow P _Op, F _Op

Step 2 is closed gas injection ball valve 15, opens ball valve

14, regulate gradually ball valve Open degree, make air gas input well well head pressure gauge 13 and under meter

12 readings are shown as P _Op, F _Op

Step 3 is opened ball valve 7, adjust ball valve And ball valve

, make under meter

9 and under meter 8 reading becomes the 1:10 ratio, keeps simultaneously air gas input well well head pressure gauge 13 and under meter

12 reading is P _Op, F _Op

Step 4 uses Nitrogen Detector at ball valve

Concentrations of helium is measured at 14 places;

Step 5 is closed ball valve

14, open gas injection ball valve 15, guarantee ball valve

The degree that 14 degree of closing and gas injection ball valve 15 are opened is consistent, and namely begins to inject helium and compressed-air actuated mixed gas in the air sparging well;

Step 6 is opened the pipe cap 29 on the soil gas monitor well, opens the quick-connecting valve 32 of soft air-guide pipe 33 ends, and soft air-guide pipe is connected to the inlet mouth of Portable exhaust gas analyzer, observation CO ₂, O ₂Reading, the air outlet that after the stable reading Nitrogen Detector is placed on Portable exhaust gas analyzer is located, every concentrations of helium of 5min record;

Step 7 after concentrations of helium is stable, is closed gas injection ball valve 15, ball valve

11, ball valve

7, ball valve

6 and air compressor, every concentrations of helium of 5min record, until concentrations of helium is 0 or minimum;

Step 8, repeating step 1～7 according to distance air sparging well 1 order from the near to the remote, carries out the helium tracer flow in other soil gas monitor well 3, will guarantee that the helium residual concentration was very little in the soil before carrying out a new helium test;

Step 9 is drawn concentrations of helium temporal evolution graphic representations to each soil gas monitor well 3, and concentrations of helium changes relatively obviously that distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Described soil gas test concrete steps are as follows:

Step 1 is opened ball valve

6, ball valve

12 readings reach best gas injection pressure and flow P _Op, F _Op

Step 3 is carried out the soil gas test to each soil gas monitor well 3, and concrete grammar is tested with the soil gas background;

Step 4, according to the radius of influence and gas injection operating mode that test obtains, carry out that the air sparging well is arranged and the laying of air compressor, and groundwater monitoring well and soil gas monitor well be set; According to the radius of influence that obtains in the test, the triangulation calculation methods such as employing are determined the spacing of air sparging well, make three lines between the adjacent air injector well consist of an equilateral triangle, guarantee not exist between well and the well reparation dead angle with this, air compressor is made as a well one machine or many wells one machine according to on-the-spot place and economic budget situation cloth, each air sparging well well head palpus setting pressure table and under meter, the laying of groundwater monitoring well should be followed following principle: one, the groundwater monitoring well should be contained restoring area upstream, restoring area, restoring area downstream; Two, the quantity of groundwater monitoring well is decided according to project demands and place environment with distribution; There are the sensitive body such as vault, underground utilities to exist if repair the place, then need near these sensitive body, lay the soil gas monitor well;

Step 5, begin to repair before, before air sparging, by small-sized air compressor expanded polystyrene veneer gas-barrier device is inflated, intercept down-hole liquid and gas, open again air compressor 17 and carry pressurized air to carry out the gas injection reparation to the underground water saturation region; Simultaneously, Pollutant levels in gas injection operating mode, underground water and the soil gas are monitored, reach the reparation target value of regulation when Pollutant levels after, close first air compressor 17, close again small-sized air compressor 18, expanded polystyrene veneer gas-barrier device 4 is recycled to ground 36, repair and finish.Repair the initial stage, carry out gas injection pressure and gas flow monitoring to each injector well, behind the system run all right, can suitably reduce the monitoring frequency of gas injection operating mode; Before repairing beginning, need to detect pollution concentration in the underground water; In the repair process, at regular intervals underground water pollutant concentration is detected, grasp removal of pollutants rule in the underground water, Pollutant levels still will be carried out continuing to monitor of certain hour to underground water after reaching and repairing target value, guarantee the not bounce-back of underground water pollutant; If the Pollutant levels that monitor in the soil gas monitor well in the repair process reach the degree that near crowd or environment are worked the mischief, then need to set up the soil vapor extraction system.

Adopt underground water repairing test test result of the present invention as follows:

Pollutent is mainly volatility benzene, composes mutually without NAPLs and deposits; Bury of groundwater is 13.5m, and clay seam buried depth 14.5m, Water table thickness are 1m, and the waterbearing stratum lithology is mainly medium sand and fine sand, and permeability coefficient is 10m/d, the about 1 ~ 2m of natural rangeability in water level year.Air sparging well boring buried depth 15.3m, the well casing external diameter is 63mm, sediment tube length 0.3m, air sparging well screen casing length 0.5m, the screen casing top is positioned at the following 0.5m of the water surface; Groundwater monitoring well boring buried depth 15.3m, the well casing external diameter is 63mm, sediment tube length 0.3m, groundwater monitoring well screen casing length 3.0m, the screen casing top is positioned at the above 2m of the water surface; Soil gas monitor well boring buried depth 12.0m, soil gas probe external diameter is 25mm, and length is 0.6m, and soil gas probe bottom buried depth is 11.5m.Determine that by on-the-spot test the best gas injection pressure in this place and flow are 0.03MPa, 23.2m ³/ h, the radius of influence are 5m.

Claims

1. an original position is repaired the air ejector system of volatile organic contaminant in the underground water, comprise air feed equipment, air sparging well (1), groundwater monitoring well (2) and soil gas monitor well (3), it is characterized in that: described air feed equipment is made of underground air feed equipment and ground air feed equipment two portions;

Underground air feed equipment comprises gas injection steel pipe (16) and the expanded polystyrene veneer gas-barrier device (17) that is positioned at air sparging well (1), and expanded polystyrene veneer gas-barrier device (17) is installed in the middle and lower part of gas injection steel pipe (16); Described expanded polystyrene veneer gas-barrier device comprises the main air injection pipe (4.7) that is connected with gas injection steel pipe (16), the packing element assembly (4.6) of the flexible material of cover on the main air injection pipe, main air injection pipe (4.7) also have one group of packing element joint, protective sleeve, intermediate head, adapter sleeve at the up and down symmetrical cover of packing element assembly respectively; The upper orifice of described packing element assembly (4.6) is placed in packing element joint I(4.5) lower outside, protective sleeve I(4.4) the upper orifice outside that is placed in packing element assembly (4.6) simultaneously and packing element joint I(4.5) outer wall middle part chucking, intermediate head I(4.3) be placed in packing element joint I(4.5) upper outside, adapter sleeve I(4.2) be connected in intermediate head I(4.3) and top connection (4.1) between; Top connection (4.1), adapter sleeve I(4.2), intermediate head I(4.3) and main air injection pipe (4.7) outer wall between enclose gas injection cavity (4.15), and at intermediate head I(4.3) and packing element joint I(4.5) leave gas passage (4.16) between the two and main air injection pipe (4.7) outer wall, gas passage one end is communicated with gas injection cavity (4.15), and the other end is communicated with the space between main air injection pipe (4.7) and the packing element assembly (4.6); Top connection (4.1) is provided be used to the upper interface (4.19) that main air injection pipe (4.7) is connected with gas injection steel pipe (16), and at the other inflatable interface (4.18) that is provided with of upper interface (4.19), the inflatable interface upper end is connected with outside gas-filled valve (17), and inflatable interface (4.18) lower end is connected with gas injection cavity (4.15) to downward-extension; The lower nozzle of described packing element assembly (4.6) is placed in packing element joint II(4.13) upper outside, protective sleeve II(4.12) the lower nozzle outside that is placed in packing element assembly (4.6) simultaneously and packing element joint II(4.13) outer wall middle part chucking, intermediate head II(4.11) be placed in packing element joint II(4.13) lower outside, adapter sleeve II(4.10) be connected in intermediate head II(4.11) and box cupling (4.8) between, box cupling (4.8) lower end connects lower sub (4.9); Packing element joint II(4.13) and intermediate head II(4.11) the two closely is placed in main air injection pipe (4.7) outer wall;

Air feed equipment comprises the gas injection pipeline that is connected with gas injection steel pipe (16) on the ground, and the loading line that is connected with the inflatable interface (4.18) of expanded polystyrene veneer gas-barrier device (4); Described air injection pipe route air compressor (17), helium steel cylinder (5), storage tank (10), pneumatic tube, air injection pipe, gas injection valve, ball valve, under meter and tensimeter consist of; The air outlet of air compressor (17) is through pneumatic tube I(20) be connected with an inlet mouth of storage tank (10), be provided with successively ball valve I(6 on the pneumatic tube I) and under meter I(8), the air outlet of helium steel cylinder (5) is through pneumatic tube II(21) be connected with another inlet mouth of storage tank (10), be provided with successively ball valve II(7 on the pneumatic tube II) and under meter II(9); The air outlet of storage tank (10) is connected with gas injection steel pipe (16) in the air sparging well (1) through air injection pipe (23), air injection pipe is provided with ball valve III(11 on (23) successively), under meter III(12), tensimeter (13) and gas injection valve (15), the gas injection valve and and tensimeter between air injection pipe (23) be connected with ball valve IV (14) through branch road (22); Described loading line is made of small-sized air compressor (18), gas-filled valve (24) and ball valve V (19), the air outlet of small-sized air compressor (18) is connected with the inflatable interface (4.18) of expanded polystyrene veneer gas-barrier device (4) through gas-filled valve (24), and gas-filled valve (24) is provided with ball valve V (19);

Described air sparging well (1) is made of air sparging well well casing (25) and packing layer, and air sparging well well casing sealed bottom, air sparging well well casing are followed successively by precipitation pipeline section (25.3), sieve tube segment (25.2) and straight length (25.1) from the bottom to the top; Sediment tube segment length 30～50cm, sieve tube segment is arranged at following 0.3～1.5m place, target stains district, the straight length upper end extends to more than the ground, described packing layer is by quartz sand filtering layer (26), bentonite bed (27) and concrete layer (28) consist of, quartz sand filtering layer (6) is filled in sieve tube segment (25.2) on every side, it grows 30cm than sieve tube segment in two ends up and down at least, bentonite bed (a 27) part is filled between quartz sand filtering layer (26) and the concrete layer (28), its end face flushes with the aquitard upper end of rock stratum, another part is filled in quartz sand filtering layer (26) between the air sparging well borehole bottom, and concrete layer (28) is filled in bentonite bed (27) between ground (36);

Described groundwater monitoring well (2) is made of with packing layer groundwater monitoring well well casing (30), well cap (29), described groundwater monitoring well well casing (30) sealed bottom, groundwater monitoring well well casing are followed successively by precipitation pipeline section (30.3), sieve tube segment (30.2) and straight length (30.1) three parts from the bottom to the top; Long 30～the 50cm of described precipitation pipeline section (30.3), sieve tube segment (30.2) is positioned in the target stains district scope, length can satisfy the change in the target stains district that change of level causes, straight length (30.1) extends upwardly to ground, and pipe cap (24) is added a cover on its top; Described packing layer is made of quartz sand filtering layer (26), bentonite bed (27) and concrete layer (28), quartz sand filtering layer (26) is filled in sieve tube segment (30.2) on every side, it grows 30cm than sieve tube segment in two ends up and down at least, bentonite bed (a 27) part is filled between quartz sand filtering layer (26) and the concrete layer (28), its end face flushes with the aquitard upper end of rock stratum, another part is filled in quartz sand filtering layer (26) between the groundwater monitoring well borehole bottom, and concrete layer (28) is filled in bentonite bed (27) between ground (36);

Described soil gas monitor well (3) is made of soil gas probe (34), soft air-guide pipe (33), quick-connecting valve (32), pillar (31), pipe cap (29) and packing layer, on the tube wall of described soil gas probe (34) crack in the interval, soil gas probe (34) inside is stretched in described soft air-guide pipe (33) lower end, be above the ground level 30cm at least and link to each other with above the ground quick-connecting valve (32) of upper end, quick-connecting valve outside cover has pillar (31), and pipe cap (29) is arranged on the pillar; Described packing layer is by quartz sand filtering layer (26), bentonite bed (27) and concrete layer (28) consist of, quartz sand filtering layer (26) is filled in soil gas probe (34) on every side, it grows 30cm than soil gas probe (34) in two ends up and down at least, bentonite bed (a 27) part is filled between quartz sand filtering layer (26) and the concrete layer (28), its end face flushes with the aquitard upper end of rock stratum, another part is filled in quartz sand filtering layer (26) between the soil gas monitor well borehole bottom, and concrete layer (28) is filled in bentonite bed (27) between ground (36);

Described packing element assembly (4.6) is quality of rubber materials, and the material of this device remaining part is the 35CrMo structural alloy steel; The upper orifice inwall of packing element assembly (4.6) is provided be used to holding packing element joint I(4.5) inner groovy of bottom, the upper orifice outer wall is provided be used to holding protective sleeve I(4.4) outer groove; The lower nozzle of described packing element assembly (4.6) is identical with the upper orifice shape;

The upper interface (4.19) of described main air injection pipe (4.7) and top connection (4.1) all is set for the eccentric, and inflatable interface (4.18) is positioned at interface (4.19) away from a side at top connection center.

2. original position according to claim 1 is repaired the air ejector system of volatile organic contaminant in the underground water, it is characterized in that: the material of described air sparging well well casing (25), groundwater monitoring well well casing (30), soil gas probe (34) shell is chemical grade UPVC, and the material of soft air-guide pipe (33) is PVC.

3. original position according to claim 1 is repaired the air ejector system of volatile organic contaminant in the underground water, it is characterized in that: described intermediate head I(4.3) with packing element joint I(4.5) and adapter sleeve I(4.2) contact surface have groove and be provided with sealing-ring (4.14), top connection (4.1) with adapter sleeve I(4.2) and the contact surface of main air injection pipe (4.7) outer wall have groove and be provided with sealing-ring (4.14);

Described intermediate head II(4.11) with packing element joint II(4.13), adapter sleeve II(4.10) and the contact surface of main air injection pipe (4.7) outer wall have groove and be provided with sealing-ring (4.14), box cupling (4.8) with adapter sleeve II(4.10) and the contact surface of main air injection pipe (4.7) outer wall have groove and be provided with sealing-ring (4.14);

Described intermediate head I(4.3) inwall is and packing element joint I(4.5) shaped upper part is cooperate each other step-like, intermediate head I(4.3) outer wall top and top connection (4.1) outer wall bottom be respectively equipped be used to holding adapter sleeve I(4.2) and groove;

Described intermediate head II(4.11) inwall is and packing element joint II(4.13) shaped upper part is cooperate each other step-like, intermediate head II(4.11) outer wall bottom and box cupling (4.8) outer wall top is respectively equipped be used to holding adapter sleeve II(4.10) and groove.

4. original position according to claim 1 is repaired the air ejector system of volatile organic contaminant in the underground water, it is characterized in that: described protective sleeve I(4.4) suitable for reading is provided with interior edge, packing element joint I(4.5) there are flange, protective sleeve I(4.4 in outer wall middle part) interior edge and packing element joint I(4.5) on the flange chucking;

Described protective sleeve II(4.12) end opening is provided with interior edge, packing element joint II(4.13) there are flange, protective sleeve II(4.12 in outer wall middle part) interior edge and packing element joint II(4.12) on the flange chucking.

5. an application rights requires the air sparging method that the original position of the described system of 1～4 any one is repaired volatile contaminant in the underground water, it is characterized in that step is as follows:

Step 2, in selection area, adopt direct bore mode to lay air sparging well (1), groundwater monitoring well (2), soil gas monitor well (3), air ejector system (1) is provided with at least one, groundwater monitoring well (2) and is provided with at least two, soil gas monitor well (3) and is provided with at least five; Gas injection system is installed, and the operation of expanded polystyrene veneer gas-barrier device is tested,

Open first small-sized air compressor (18), pressurized air is entered by the inflatable interface (4.18) of expanded polystyrene veneer gas-barrier device, enter space between main air injection pipe (4.7) and the packing element assembly (4.6) through gas injection cavity (4.15), gas passage (4.16) again, and packing element assembly (4.6) is expanded gradually form annular seal space (4.17), the borehole wall final and air sparging well (1) is adjacent to, and plays the iris action with down-hole liquid and gas; When gas injection begins, open air compressor (17), pressurized air is delivered to the underground water saturation region by gas injection steel pipe (16); When gas injection finishes, close first air compressor (17), close again small-sized air compressor (18), slowly discharge pressurized air, after the rubber of packing element assembly (4.6) reverts to original state, expanded polystyrene veneer gas-barrier device (4) is recycled to ground (36);

Step 3 is taken out submersible pump from groundwater monitoring well G1;

Described soil gas background test concrete steps are as follows:

Step 1 is opened the quick-connecting valve (32) on pipe cap (29) and soft air-guide pipe (33) top on the soil gas monitor well, and soft air-guide pipe is connected to the inlet mouth of Portable exhaust gas analyzer, observation CO ₂, O ₂Reading;

Step 1 is calculated the minimum gas injection pressure Pmin in place and maximum gas injection pressure Pmax, and method of calculation are as follows: Pmin (psig)=0.43H+ packing material resistance P+ inwall resistance P, Pmax=0.73D;

In the formula, the H=ground water table is to the height ft of sieve tube segment upper end; The air Injection resistance that annular packing material and well inner wall structure cause in the packing material resistance P+ well inwall resistance P=well, general sandy soil＜0.2psig; D=ground is to the height of sieve tube segment upper end;

Step 2, the groundwater monitoring well (2) that chosen distance air sparging well (1) is nearer is placed the ground water table registering instrument;

Step 3, unlatching ball valve I(6), ball valve III(11) with gas injection ball valve (15), and close other valves, open air compressor (17), adjusting ball valve III(11) opening degree, make air gas input well (1) well head pressure gauge (13) reading P1 be a bit larger tham Pmin, record simultaneously air gas input well (1) well head under meter III(12) reading, every ground water table registering instrument reading of 5min record;

Step 4 behind underground stable level, is closed gas injection ball valve (15), ball valve I(6) and air compressor (17), every ground water table registering instrument reading of 5min record, until ground water table returns to or near initial level;

Step 5, repeating step 3～4 is wherein regulated ball valve III(11) opening degree, its open degree is progressively become greatly, injector well mouth pressure meter reading Pn is increased gradually, but Pn can not surpass Pmax;

Described groundwater pressure response test concrete steps are as follows:

Step 2, unlatching ball valve I(6), ball valve III(11) with gas injection ball valve (15), and close other valves, open air compressor (17), regulate the opening degree of ball valve ball valve III, make air gas input well well head pressure gauge (13) and under meter III(12) reading reach best gas injection pressure and flow (Pop, Fop);

Step 4 behind underground stable level, is closed gas injection ball valve (15), ball valve I(6) and air compressor (17), record respectively ground water table registering instrument reading one time every 5min, until ground water table returns to or near initial level;

Step 5 is drawn ground water table temporal evolution graphic representation in the different groundwater monitoring wells (2), and change of level relatively obviously distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Step 1, unlatching ball valve I(6), ball valve III(11) with gas injection ball valve (15), and close other valves, open air compressor (17), regulate the opening degree of ball valve III, make air gas input well well head pressure gauge (13) and under meter III(12) reading reach best gas injection pressure and flow (Pop, Fop);

Step 3 according to distance air sparging well (1) order from the close-by examples to those far off, is carried out the measurement of well-flushing and dissolved oxygen to all groundwater monitoring wells (2), and specific practice is tested with the dissolved oxygen background;

Step 4, groundwater monitoring well (2) dissolved oxygen test result and dissolved oxygen background test result are compared, dissolved oxygen concentration changes relatively obviously that distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Described helium tracer flow step is as follows:

Step 1, unlatching ball valve I(6), ball valve III(11) with gas injection ball valve (15), and close other valves, open air compressor (17), regulate the opening degree of ball valve III, make air gas input well well head pressure gauge (13) and under meter III(12) reading reach best gas injection pressure and flow (P _Op, F _Op);

Step 2 is closed gas injection ball valve (15), opens ball valve IV (14), regulates gradually the open degree of ball valve IV, makes air gas input well well head pressure gauge (13) and under meter III(12) reading is shown as P _Op, F _Op

Step 3 is opened ball valve II(7), adjust ball valve I and ball valve II, make under meter II(9) with under meter I(8) reading become the 1:10 ratio, keep simultaneously air gas input well well head pressure gauge (13) and under meter III(12) reading be P _Op, F _Op

Step 4 locates to measure concentrations of helium with Nitrogen Detector in ball valve IV (14);

Step 5 is closed ball valve IV (14), opens gas injection ball valve (15), guarantees that the degree that degree that ball valve IV (14) is closed and gas injection ball valve (15) are opened is consistent, and namely begins to inject helium and compressed-air actuated mixed gas in the air sparging well;

Step 6 is opened the pipe cap (29) on the soil gas monitor well, opens the terminal quick-connecting valve (32) of soft air-guide pipe (33), and soft air-guide pipe is connected to the inlet mouth of Portable exhaust gas analyzer, observation CO ₂, O ₂Reading, the air outlet that after the stable reading Nitrogen Detector is placed on Portable exhaust gas analyzer is located, every concentrations of helium of 5min record;

Step 7 after concentrations of helium is stable, is closed gas injection ball valve (15), ball valve III(11), ball valve II(7), ball valve I(6) and air compressor, every concentrations of helium of 5min record, until concentrations of helium is 0 or minimum;

Step 8, repeating step 1～7 according to distance air sparging well (1) order from the near to the remote, carries out the helium tracer flow in other soil gas monitor well (3), will guarantee that the helium residual concentration was very little in the soil before carrying out a new helium test;

Step 9 is drawn concentrations of helium temporal evolution graphic representation to each soil gas monitor well (3), and concentrations of helium changes relatively obviously that distance corresponding to curve all is positioned at the air sparging range of influence, and wherein farthest distance is the air sparging radius of influence;

Described soil gas test concrete steps are as follows:

Step 1, unlatching ball valve I(6), ball valve III(11) with gas injection ball valve (15), and close other valves, open air compressor (17), regulate the opening degree of ball valve III, make air gas input well well head pressure gauge (13) and under meter III(12) reading reaches best gas injection pressure and flow (P _Op, F _Op);

Step 3 is carried out the soil gas test to each soil gas monitor well (3), and concrete grammar is tested with the soil gas background;

Step 5, begin to repair before, before air sparging, by small-sized air compressor expanded polystyrene veneer gas-barrier device is inflated, intercept down-hole liquid and gas, open again air compressor (17) and carry pressurized air to carry out the gas injection reparation to the underground water saturation region; Simultaneously, Pollutant levels in gas injection operating mode, underground water and the soil gas are monitored, reach the reparation target value of regulation when Pollutant levels after, close first air compressor (17), close again small-sized air compressor (18), expanded polystyrene veneer gas-barrier device (4) is recycled to ground (36), repairs and finish.

6. the described original position air sparging method of repairing volatile organic contaminant in the underground water according to claim 5, it is characterized in that: in the described step 1, the place hydrogeological parameter comprises soil type, size distribution, fluid conductivity, gas permeability, porosity; Pollution condition comprises whether whether pollutent composition, pollutent character, pollutent only are present in the water table aquifer, have nonaqueous phase liquid NPALs to compose mutually and deposit; The application feasibility that possesses skills must meet the following conditions simultaneously: do not have NAPLs to compose in the Water table to deposit, contaminated underground water is positioned at water table aquifer, the lithology in waterbearing stratum needs that isotropic and particle are thick, soil permeability 〉=1.0 * 10 ^-9Cm ², pollutent at room temperature need have the vapour pressure of volatility, pollutent the Henry's constant of the boiling point of 0.5mmHg, pollutent＜250 ~ 300 ℃, pollutent 100atm.

7. the described original position air sparging method of repairing volatile organic contaminant in the underground water according to claim 5, it is characterized in that: in the described step 4, according to the radius of influence that obtains in the test, the triangulation calculation methods such as employing are determined the spacing of air sparging well, make three lines between the adjacent air injector well consist of an equilateral triangle, guarantee not exist between well and the well reparation dead angle with this, air compressor is made as a well one machine or many wells one machine according to on-the-spot place and economic budget situation cloth, each air sparging well well head palpus setting pressure table and under meter, the laying of groundwater monitoring well should be followed following principle: one, the groundwater monitoring well should be contained the restoring area upstream, restoring area, the restoring area downstream; Two, the quantity of groundwater monitoring well is decided according to project demands and place environment with distribution; There are vault, underground utilities sensitive body to exist if repair the place, then need near these sensitive body, lay the soil gas monitor well.

8. the described original position air sparging method of repairing volatile organic contaminant in the underground water according to claim 5, it is characterized in that: in the described step 5, repair the initial stage, to carry out gas injection pressure and gas flow monitoring to each injector well, behind the system run all right, suitably reduce the monitoring frequency of gas injection operating mode; Before repairing beginning, need to detect pollution concentration in the underground water; In the repair process, at regular intervals underground water pollutant concentration is detected, grasp removal of pollutants rule in the underground water, Pollutant levels still will be carried out continuing to monitor of certain hour to underground water after reaching and repairing target value, guarantee the not bounce-back of underground water pollutant; If the Pollutant levels that monitor in the soil gas monitor well in the repair process reach the degree that near crowd or environment are worked the mischief, then need to set up the soil vapor extraction system.