CN110282685B

CN110282685B - High purification efficiency groundwater circulation well clean system

Info

Publication number: CN110282685B
Application number: CN201910551168.4A
Authority: CN
Inventors: 张斌; 孙加山; 李燕明; 高连东; 江胜国; 吴丛杨慧
Original assignee: Suzhou Hongyu Environment Technology Co ltd
Current assignee: Suzhou Hongyu Environment Technology Co ltd
Priority date: 2019-06-24
Filing date: 2019-06-24
Publication date: 2021-09-24
Anticipated expiration: 2039-06-24
Also published as: CN110282685A

Abstract

The invention discloses a high-purification-efficiency underground water circulating well purification system, which relates to the technical field of in-situ remediation of underground water and soil, and adopts the technical scheme that the system comprises a plurality of installation pipes which are distributed at equal intervals around the axis of an inner well and have the same length direction and the same axial direction of the inner well, wherein the top ends of the installation pipes are open ends and extend out from the top of the inner well, and the bottom ends of the installation pipes are closed ends and are positioned below the water surface of well water; the installation pipe is inserted with the filter pipe, the filter pipe intussuseption is filled with the absorption filtration material, all open the filtration pore on the pipe wall of installation pipe and filter pipe. The invention has the advantages of purifying volatile organic pollutants, simultaneously having the effect of purifying heavy metal pollutants, and having the advantage of high purification efficiency compared with the conventional underground water circulating well.

Description

High purification efficiency groundwater circulation well clean system

Technical Field

The invention relates to the technical field of in-situ remediation of underground water and soil, in particular to a high-purification-efficiency underground water circulating well purification system.

Background

Soil is an important component of ecological environment and one of the main resources on which human society is based. Due to unreasonable disposal of organic wastes, accident leakage and the like, serious water and soil pollution is caused, the ecological environment and the human health are seriously harmed, and the repair and treatment are urgent.

Groundwater pollutants mainly include three types of heavy metals, inorganic pollutants, and organic pollutants. (1) Heavy metals such as copper, zinc, lead, cadmium, chromium, nickel, arsenic, mercury, selenium, antimony, silver, thallium, beryllium, hexavalent chromium and the like, wherein arsenic is commonly used, and chromium and lead are used secondly; (2) inorganic pollutants such as nitrate, nitrite, ammonia nitrogen, sulfate, chloride, fluoride and the like; (3) organic pollutants such as POPs, VOCs, SVOCs (PAHs and PCBs), organic solvents, petroleum products and the like, and halogenated VOCs are the most common.

Wherein the organic contaminants are often present in groundwater environments as aqueous and non-aqueous liquids (NAPLs). Aiming at the characteristic that organic matters have volatility, researchers have conducted a great deal of research on some in-situ remediation technologies, such AS GCW (ground water circulation well), AS (air pumping, in-situ air disturbance), SVE (soil vapor extraction), PRB (permeable reactive barrier), and the like, and have obtained a good site remediation effect. GCW is also known as in-situ well stripping or steam stripping and is widely used due to its special double well-screen structure.

The working principle of the underground water circulating well (GCW) is that the formed gas-water mixture continuously rises through aeration of the inner well, freely falls after reaching the top end of the inner well of the circulating well, reversely seeps back to a water-bearing layer through a perforated pipe at the upper part of the outer well, gas is discharged through a gas-water separator, underground water around the well continuously flows into the circulating well due to density difference of fluid inside and outside the well formed at the moment of aeration at the lower part of the circulating well, and three-dimensional circulation of the underground water is finally formed around the circulating well through continuous aeration. In the process, the volatile and semi-volatile organic compounds in the underground water are volatilized from the water phase into the gas phase through mass transfer between the gas phase and the water phase and are removed through aeration stripping, and meanwhile, oxygen carried in the air is dissolved into the water phase and is continuously diffused under the action of concentration gradient, so that an enhanced in-situ aerobic biodegradation area is formed around the circulating well. The organic matters adsorbed or remained in the pores of the medium are gradually desorbed or dissolved into the water phase by the action of vertical hydraulic flushing, and are removed by a physical and chemical method or biodegradation.

For example, the chinese patent CN103112915B in the prior art discloses a method for removing pollutants from underground water by using a GCW technology, wherein the circulating well is arranged in a polluted ground, and is arranged in a continuous plum blossom shape, square grid shape or hexahedron shape according to soil property, pollution degree and the radius of influence of equipment on soil, 1-N water wells with the diameter not less than 100mm and the depth more than 1 m are drilled in the circulating well, and the polluted water is treated by aeration, stripping, extraction and dosing treatment processes in the water wells; stripping by blowing: lifting well water, namely underground water to the top of the well and then spraying the well water downwards through a spray header; aeration and extraction: aeration and gas vacuum extraction in the well increase the gas-liquid mass transfer interface, strengthen the gas and blow off the effect, during aeration in the well, increase the dissolved oxygen content in the groundwater for the water that is polluted adds the medicine in aerobic environment: according to different pollution degrees and pollutants, an oxidant, a microbial agent, ozone or/and flocculation is added at an air inlet A of the high-pressure aeration pump 1 or a special dosing pipe.

However, the pollutants of the conventional groundwater are often characterized by a mixture of various kinds of pollution, and may contain heavy metal pollutants in addition to organic pollutants. The groundwater circulation well purification method disclosed in the aforementioned patent (CN 103112915B) has a good effect of removing volatile or semi-volatile organic pollutants from groundwater, but has no effect of purifying heavy metal pollutants in groundwater.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a high-purification-efficiency underground water circulating well purification system which has the purification effects of organic pollutants and heavy metal pollution and has the advantage of high purification efficiency.

In order to achieve the purpose, the invention provides the following technical scheme:

a high purification efficiency underground water circulating well purification system comprises an outer well with a closed well mouth, an inner well with a closed well mouth, a gas injection system, a gas extraction system and a medicament spraying system, wherein the inner well is arranged in the outer well, the gas injection system is used for introducing gas into well water of the inner well for aeration, one part of gas doped with organic pollutants after aeration is extracted by the gas extraction system and then is adsorbed and discharged by an activated carbon adsorption device, the other part of gas enters the outer well, and the medicament spraying system is used for spraying liquid medicament into the outer well; the inner well wall is provided with an upper screen pipe and a lower screen pipe, so that the inner well and the water body in the outer well can circulate, the bottom end of the upper screen pipe is lower than the water surface of the well, the inner well wall also comprises a plurality of mounting pipes which are distributed at equal intervals around the axis of the inner well and have the same length direction and the same axial direction of the inner well, the top end of each mounting pipe is an open end and extends out of the top of the inner well, and the bottom end of each mounting pipe is a closed end and is positioned below the water surface of the well; the installation pipe is inserted with the filter pipe, the filter pipe intussuseption is filled with the absorption filtration material, all open the filtration pore on the pipe wall of installation pipe and filter pipe.

Through adopting above-mentioned technical scheme, the installation pipe part is located well water surface below, the part is located well water surface above for gas in well water and the interior well all can get into in the filter tube through filtering the hole. Under the effect of adsorbing the filter material in the filter tube, partial heavy metal pollutants in the well water and organic pollutants in the air on the upper part of the inner well are adsorbed and removed, so that the purification effect and the purification efficiency of the underground water are improved. The filter pipe can be dismantled and set up, regularly to dismantling change of filter pipe can.

Furthermore, a first clamping groove is formed in the tube wall of the top end of the mounting tube along the axial direction, and the first clamping groove extends to the top end of the mounting tube to form an opening; one end, far away from the opening, of the first clamping groove is communicated with a second clamping groove, and the second clamping groove is arranged along the circumferential direction of the installation pipe; and a clamping block used for being clamped and matched with the first clamping groove and the second clamping groove to lock the filter pipe is arranged on the outer circumferential side wall at the top end of the filter pipe.

Through adopting above-mentioned technical scheme, when installing the filter tube, insert the filter tube from the open end of installation pipe. When the filter pipe is close to be inserted in place, adjusting the filter pipe until the clamping block is clamped into the first clamping groove; continuing to insert the filter tube downwards so that the clamping block is clamped into the second clamping groove; then, the filter pipe is rotated in the circumferential direction, and the clamping block is moved to the end part of the second clamping groove, so that the filter pipe is installed in place.

Furthermore, an elastic cushion block is arranged in the mounting pipe and at the bottom of the mounting pipe.

Through adopting above-mentioned technical scheme, its bottom makes the elastic cushion be in by compression state when the filter tube installation targets in place, and the filter tube receives axial effort under the elastic cushion effect for the fixture block supports tightly in the second draw-in groove, is difficult for breaking away from the second draw-in groove because of the circumferential direction of filter tube, has increased the installation stability of filter tube.

Further, an elastic sealing layer is arranged on the inner circumferential side wall of the part, extending out of the inner diameter, of the mounting pipe.

By adopting the technical scheme, the tightness between the filter pipe and the installation pipe is increased, negative pressure is favorably formed in the inner well, and gas in the inner well is extracted.

Furthermore, the top end of the filter pipe is an open end, and is detachably connected with a metal corrugated hose, and one end of the metal corrugated hose, which is far away from the filter pipe, is communicated with the gas extraction system.

By adopting the technical scheme, negative pressure can be generated in the filter pipe through the corrugated metal hose and the extraction system, so that the filter pipe is beneficial to the permeation of well water and gas in the inner well to the inside of the filter pipe, the utilization rate of filter materials adsorbed in the filter pipe is improved, and the adsorption and purification efficiency of heavy metal pollutants in the well water and organic pollutants in the gas in the inner well is also improved.

Furthermore, the aeration system comprises an air pump, an aeration pipe arranged at the air outlet end of the air pump, a first valve arranged on the aeration pipe and an aeration head arranged at one end of the aeration pipe far away from the air pump, wherein the aeration head is positioned in the inner well and at the position of the sieve pipe at the lower layer.

Through adopting above-mentioned technical scheme, utilize air pump and aeration pipe can constantly pump into air or the air of mixing ozone in to the interior well, form updraft in the interior well to catch or oxidize the pollutant in the air current rising in-process to groundwater. The aeration uniformity is increased by the arrangement of the aeration head, so that the pollutants are better captured and oxidized.

Furthermore, the gas extraction system comprises an extraction pump, an exhaust pipe and a second valve, wherein one end of the exhaust pipe is connected with the extraction pump through the second valve and then communicated with the activated carbon adsorption device, and the other end of the exhaust pipe is inserted into the inner well and is arranged above the water surface of the well water.

Through adopting above-mentioned technical scheme, can form the negative pressure in the well head, lead out the gas that has organic pollutant in the well head, carry to active carbon adsorption device, adsorb filtration and purify.

Further, the medicament spraying system comprises a medicament injection pump, a third valve and a medicament injection pipe, wherein one end of the medicament injection pipe is connected with the medicament injection pump through the third valve, and the other end of the medicament injection pipe is inserted into the outer well and is arranged above the water surface of the well water.

By adopting the technical scheme, the chemical agent can spray oxidant, microbial agent or nutrient substances and the like into the outer well, enters the chemical agent spraying pipe through the chemical injection pipe, is sprayed by the chemical agent spraying pipe and then enters the surrounding environment of the well body along with circulating underground water flow, and effectively removes residual pollutants.

Further, the adsorption filtering material is prepared from the following components in a mass ratio of 1: (0.1-0.5) a mixture of a block activated carbon and a modified viscose fiber.

By adopting the technical scheme, the activated carbon has porous characteristic and has excellent adsorption and purification effects on organic pollutants and heavy metal pollutants; the viscose fiber belongs to cellulose fiber, the molecules of the viscose fiber contain a large amount of hydroxyl groups with metal chelation, the effect of removing heavy metal ions is good, and the adsorption effect of the modified viscose fiber is better.

Further, the modified viscose fiber is prepared by the following process,

p1, adding 1-8wt% of nano-porous micro powder into the viscose stock solution, and stirring and mixing uniformly; the nano-scale porous micro powder is a mixture of nano bamboo charcoal powder and nano calcium carbonate;

p2, standing and defoaming in vacuum at the temperature of 0-10 ℃ to obtain defoaming solution;

p3, spinning the defoaming solution into semi-finished filaments by adopting a wet spinning process;

p4, drawing, washing and drying the semi-finished filaments to obtain the finished modified viscose fiber for later use.

By adopting the technical scheme, the modified viscose fiber prepared by the process has good water absorption and excellent adsorption and purification effects on heavy metals and organic pollutants, and can have excellent adsorption and purification effects on the organic pollutants and the heavy metal pollutants after being mixed with the blocky activated carbon in proportion.

In conclusion, the invention has the following beneficial effects:

1. the mounting pipe part is positioned below the water surface of the well water and the mounting pipe part is positioned above the water surface of the well water, so that the well water and gas in the inner well can enter the filter pipe through the filter holes; under the action of adsorbing the filter material in the filter pipe, part of heavy metal pollutants in the well water and volatile organic pollutants analyzed from the middle part of the air at the upper part of the inner well are adsorbed and removed, so that the purification effect and the purification efficiency of the underground water are improved;

2. the activated carbon has porous characteristic and has excellent adsorption and purification effects on organic pollutants and heavy metal pollutants; the viscose fiber belongs to cellulose fiber, the molecules of the viscose fiber contain a large amount of hydroxyl groups with metal chelation, the effect of removing heavy metal ions is good, and the adsorption effect of the modified viscose fiber is better.

Drawings

FIG. 1 is a schematic structural diagram of a purification system of a groundwater circulating well with high purification efficiency in an embodiment;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a schematic structural view of an installation pipe, a filter pipe and a corrugated metal hose in the embodiment;

FIG. 4 is a method diagram of part B of FIG. 3;

FIG. 5 is a cross-sectional view of the mounting tube and the filter tube in the example;

FIG. 6 is an enlarged view of portion C of FIG. 5;

fig. 7 is an enlarged view of portion D of bitmap 5.

In the figure: 0. the ground water level; 1. an outer well; 11. a concrete filling layer; 12. a gravel pack; 2. an inner well; 21. an upper screen pipe; 22. a lower screen pipe; 3. installing a pipe; 31. a filtration pore; 32. an elastic cushion block; 33. an elastomeric sealing layer; 34. a first card slot; 35. a second card slot; 4. a filter tube; 41. adsorbing the filter material; 42. a clamping block; 5. a metal corrugated hose; 51. an end cap; 6. an activated carbon adsorption unit; 7. an aeration pipe; 71. an air pump; 72. a first valve; 73. an aeration head; 8. an air exhaust pipe; 81. an extraction pump; 82. a second valve; 83. an air exhaust branch pipe; 831. a fourth valve; 9. a medicine injection tube; 91. a medicine injection barrel; 92. a drug injection pump; 93. a third valve.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example 1:

a high purification efficiency underground water circulation well purification system, refer to fig. 1, it includes well head closed set up outer well 1, set up in outer well 1 and well head closed set up inner well 2, gas injection system, gas extraction system and medicament spraying system. The inner side wall of the bottom end of the inner well 2 is provided with a lower-layer sieve tube 22, the inner side wall of the top end is provided with an upper-layer sieve tube 21, and the bottom end of the upper-layer sieve tube 21 is lower than the well water level in the inner well 2. The inner well 2 and the outer well 1 are filled with filling materials, and gravel filling layers 12 are filled between the bottom wall of the inner well 2 and the inner bottom wall of the outer well 1 and between the part of the inner well 2, which is provided with the lower-layer screen pipe 22, and the well wall of the outer well 1; a concrete filling layer 11 is filled between the middle area of the inner well 2 and the wall of the outer well 1, and a gravel filling layer 12 is also filled between the part of the inner well 2, which is provided with the upper screen pipe 21, and the wall of the outer well 1. The underground water in the soil surrounding the circulation well can extend into the inner well 2 through the lower screen 22, and the water level of the underground water in the inner well 2 is higher than that of the underground water in the surrounding soil under the action of the extraction system, so that the underground water can circularly flow through the circulation well.

Referring to fig. 1, the gas injection system includes an air pump 71, a first valve 72 and an aeration pipe 7, one end of the aeration pipe 7 extends into the bottom of the inner well 2 and the end is connected with an aeration head 73, and the other end is connected with the air pump 71 through the first valve 72. Air or air containing ozone can be continuously introduced into the well water of the inner well 2 by means of a gas injection system. The aeration head 73 is arranged in the lower screen pipe 22, so that the introduced air or the air containing ozone can form uniform ascending airflow, and the precipitation of pollutants in well water is facilitated.

Referring to fig. 1, the gas extraction system includes an extraction pump 81, an extraction pipe 8, and a second valve 82, wherein one end of the extraction pipe 8 is communicated with the inner well 2, and the other end is connected to the extraction pump 81 through the second valve 82. The air outlet end of the extraction pump 81 is provided with an activated carbon adsorption device 6. Under the action of the gas extraction system, negative pressure is formed in the inner well 2, so that the water level of well water is higher than the water level of underground water around the circulating well. After aeration, one part of the gas doped with organic pollutants is extracted by the gas extraction system and then is absorbed and discharged by the activated carbon absorption device 6, and the other part of the gas enters the outer well 1.

Referring to fig. 1 and 2, the wellhead of the inner well 2 is further provided with a plurality of installation pipes 3, the installation pipes 3 are distributed around the axis of the inner well 2 at equal intervals, and the number of the installation pipes 3 is two in the embodiment. The bottom of the installation pipe 3 is a closed end, the bottom of the installation pipe is lower than the water level of the well water in the inner well 2, and the top of the installation pipe is an open end and penetrates through the well mouth of the inner well 2. Every is inserted in the installation pipe 3 and is equipped with a filter tube 4 that is used for adsorbing heavy metal pollutant and filters organic pollutant, and the top intercommunication of filter tube 4 has metal bellows 5. One end of the corrugated metal hose 5, which is far away from the filter pipe 4, is detachably connected with a branch air exhaust pipe 83 through a flange, one end of the branch air exhaust pipe 83, which is far away from the corrugated metal pipe, is communicated with the air exhaust pipe 8, and a fourth valve 831 is arranged on each branch air exhaust pipe 83.

Referring to fig. 3 and 4, a first clamping groove 34 is axially formed at the top end of the mounting tube 3, a second clamping groove 35 is communicated with one end, away from the opening of the mounting tube 3, of the first clamping groove 34, and the second clamping groove 35 is arranged along the circumferential direction of the mounting tube 3. The outer circumferential side wall of the filter tube 4 is provided with a clamping block 42 for clamping and matching with the first clamping groove 34 and the second clamping groove 35. When the filter pipe 4 is installed, the main body part of the filter pipe 4 is inserted into the installation pipe 3, and then the filter pipe 4 is rotated until the clamping blocks 42 are aligned with the first clamping grooves 34; the filter tube 4 is continuously inserted downwards until the clamping block 42 is clamped into the second clamping groove 35, and the filter tube 4 is rotated in the circumferential direction to enable the clamping block 42 to be clamped and embedded into the end portion of the second clamping groove 35, so that the filter tube 4 is installed in place. Meanwhile, an elastic sealing layer 33 is arranged on the inner side wall of the top of the mounting pipe 3, so that after the filter pipe 4 is mounted, the sealing between the mounting pipe 3 and the filter pipe 4 is good.

Referring to fig. 5 and 6, in order to increase the installation tightness between the filtering pipe 4 and the installation pipe 3, an elastic cushion block 32 is arranged in the installation pipe 3, and the elastic cushion block 32 is made of rubber. After the filter pipe 4 is inserted in place, the elastic cushion block 32 is in a compressed state, so that the filter pipe 4 tends to be separated from the installation pipe 3 along the axial direction, and the clamping block 42 is fixed on the second clamping groove 35 and is not easy to loosen.

Referring to fig. 5 and 7, the pipe walls of the installation pipe 3 and the filtering pipe 4 are provided with a plurality of filtering holes 31, and the filtering pipe 4 is filled with adsorption filtering material 41. As shown in figure 1, the installation pipe 3 is partially immersed in the well water and partially positioned above the well water level in the inner well 2, and the well water containing organic pollutant gas and heavy metal pollutant can be immersed in the filter pipe 4 through the filter holes 31 and is adsorbed and purified by the adsorption filter material 41 in the filter pipe 4. In order to facilitate the periodic replacement of the adsorbing filter 41 in the filtering pipe 4, the top end of the filtering pipe 4 is opened. An end cap 51 is connected to one end of the corrugated metal hose 5, and the end cap 51 is in threaded connection with the top of the filter pipe 4. When the adsorbing and filtering material 41 is replaced, the connection between the filtering pipe 4 and the corrugated metal hose 5 can be disconnected by unscrewing the end cover 51.

Referring to fig. 5 and 7, the adsorption filter material 41 filled in the filter pipe 4 is prepared from block activated carbon and modified viscose fiber in a mass ratio of 1: 0.1 by weight percent. Wherein the modified viscose fiber is prepared by the following process,

p1, adding 8wt% of nano-scale porous micro powder into the viscose stock solution, and stirring and mixing uniformly; the nano-scale porous micro powder is a mixture obtained by mixing nano bamboo charcoal powder and nano calcium carbonate according to the mass ratio of 1: 0.5;

p2, standing and defoaming in vacuum at the temperature of 0 ℃ to obtain defoaming solution;

The activated carbon has porous characteristic and has excellent adsorption and purification effects on organic pollutants and heavy metal pollutants; the viscose fiber belongs to cellulose fiber, contains a large amount of hydroxyl with metal chelation in molecules, has good effect of removing heavy metal ions, has better adsorption effect through the viscose fiber modified by nano bamboo charcoal and nano calcium carbonate, and has better effect of adsorbing and removing organic pollutants and heavy metal pollutants.

Referring to fig. 1, the drug spray system includes a drug injection barrel 91, a drug injection pump 92, a drug injection tube 9, and a third valve 93. One end of the medicine injection pipe 9 is inserted into the outer well 1, the other end of the medicine injection pipe is connected with the medicine injection pump 92 through the third valve 93, and the liquid inlet end of the medicine injection pump 92 is connected with the medicine injection barrel 91. An oxidant, a nutrient or microbial strains can be injected into the outer well 1 by means of the medicament spraying system, and the injected medicament can be diffused into soil around the circulating well along with well water to further purify pollutants in the soil.

The working principle is as follows:

through setting up installation pipe 3 and inserting at installation pipe 3 and establishing filter tube 4 that can dismantle the change, pack blocky activated carbon in filter tube 4 and regard as absorption filter material 41 with the modified viscose fiber of nanometer bamboo charcoal-nanometer calcium carbonate mixture, when making to groundwater circulation restoration, heavy metal contaminant in the well water, organic contaminant and the organic contaminant homoenergetic in the 2 top gases of interior well can be adsorbed by filter material 41 in filter tube 4 and purify, make the groundwater circulation well clean system of this application still have heavy metal contaminant purification ability concurrently when purifying organic pollution, be applicable to and purify the groundwater of the complicated soil of pollutant. On the other hand, compared with the conventional underground water circulating well, the underground water circulating well has the advantages of shorter purification period of pollutants and high purification efficiency.

Example 2:

a groundwater circulating well purification system with high purification efficiency is based on the embodiment 1, and is only different from the embodiment 1 in that: the adsorption filter material 41 filled in the filter pipe 4 comprises block active carbon and modified viscose fiber according to the mass ratio of 1:0.5 is mixed. Wherein the modified viscose fiber is prepared by the following process,

p1, adding 1wt% of nano-scale porous micro powder into the viscose stock solution, and stirring and mixing uniformly; the nano-scale porous micro powder is a mixture obtained by mixing nano bamboo charcoal powder and nano calcium carbonate according to the mass ratio of 1: 0.5;

p2, standing and defoaming in vacuum at 10 ℃ to obtain a defoaming solution;

The above-mentioned embodiments are merely illustrative and not restrictive, and those skilled in the art can modify the embodiments without inventive contribution as required after reading this specification, but only fall within the scope of the claims of the present invention.

Claims

1. A high purification efficiency underground water circulating well purification system comprises an outer well (1) with a closed wellhead, an inner well (2) with a closed wellhead, a gas injection system, a gas extraction system and a medicament spraying system, wherein the inner well (2) is arranged in the outer well (1), the gas injection system is used for introducing gas into well water of the inner well (2) for aeration, one part of gas doped with organic pollutants after aeration is extracted by the gas extraction system and then is adsorbed and discharged by an activated carbon adsorption device (6), the other part of gas enters the outer well (1), and the medicament spraying system is used for spraying a medicament into the outer well (1); have upper screen pipe (21) and lower floor screen pipe (22) on the wall of a well of interior well (2), make interior well (2) with the interior hydrologic cycle of outer well (1), upper screen pipe (21) bottom is less than well water surface, its characterized in that: the device is characterized by also comprising a plurality of mounting pipes (3) which are distributed at equal intervals around the axis of the inner well (2) and have the same length direction as the axial direction of the inner well (2), wherein the top ends of the mounting pipes (3) are open ends and extend out of the top of the inner well (2), and the bottom ends of the mounting pipes are closed ends and are positioned below the water surface of well water; a filter pipe (4) is inserted into the installation pipe (3), adsorption filter materials (41) are filled in the filter pipe (4), and filter holes (31) are formed in the pipe walls of the installation pipe (3) and the filter pipe (4);

an elastic sealing layer (33) is arranged on the inner circumferential side wall of the part of the mounting pipe (3) extending out of the inner well (2);

the top end of the filter pipe (4) is an open end and is detachably connected with a metal corrugated hose (5), and one end, far away from the filter pipe (4), of the metal corrugated hose (5) is communicated with the gas extraction system;

the adsorption filtering material (41) is prepared from the following components in a mass ratio of 1: (0.1-0.5) a mixture of a block activated carbon and a modified viscose fiber;

the modified viscose fiber is prepared by the following process,

2. A purification system of underground water circulating well with high purification efficiency as claimed in claim 1, wherein: a first clamping groove (34) is formed in the tube wall of the top end of the mounting tube (3) along the axial direction, and the first clamping groove (34) extends to the top end of the mounting tube (3) to form an opening; one end, far away from the opening, of the first clamping groove (34) is communicated with a second clamping groove (35), and the second clamping groove (35) is arranged along the circumferential direction of the mounting pipe (3); and a clamping block (42) which is used for being clamped and matched with the first clamping groove (34) and the second clamping groove (35) to lock the filter pipe (4) is arranged on the outer circumferential side wall of the top end of the filter pipe (4).

3. A purification system of underground water circulating well with high purification efficiency as claimed in claim 2, wherein: an elastic cushion block (32) is arranged in the mounting pipe (3) and at the bottom of the mounting pipe (3).

4. A purification system of underground water circulating well with high purification efficiency as claimed in claim 1, wherein: the gas injection system comprises an air pump (71), an aeration pipe (7) arranged at the air outlet end of the air pump (71), a first valve (72) arranged on the aeration pipe (7) and an aeration head (73) arranged at one end, far away from the air pump (71), of the aeration pipe (7), wherein the aeration head (73) is positioned in the inner well (2) and is positioned at the lower-layer sieve tube (22).

5. A purification system of underground water circulating well with high purification efficiency as claimed in claim 1, wherein: the gas extraction system comprises an extraction pump (81), an extraction pipe (8) and a second valve (82), wherein one end of the extraction pipe (8) is connected with the extraction pump (81) through the second valve (82) and then led to the activated carbon adsorption device (6), and the other end of the extraction pipe (8) is inserted into the inner well (2) and is arranged above the water surface of the well water.

6. A purification system of underground water circulating well with high purification efficiency as claimed in claim 1, wherein: the medicament spraying system comprises a medicament injection pump (92), a third valve (93) and a medicament injection pipe (9), one end of the medicament injection pipe (9) is connected with the medicament injection pump (92) through the third valve (93), and the other end of the medicament injection pipe is inserted into the outer well (1) and is arranged on the water surface of well water.