CN116393501A - Repairing system and method for trichloromethane polluted site - Google Patents
Repairing system and method for trichloromethane polluted site Download PDFInfo
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- CN116393501A CN116393501A CN202310672458.0A CN202310672458A CN116393501A CN 116393501 A CN116393501 A CN 116393501A CN 202310672458 A CN202310672458 A CN 202310672458A CN 116393501 A CN116393501 A CN 116393501A
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- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 title claims abstract description 182
- 238000000034 method Methods 0.000 title claims abstract description 53
- 229960001701 chloroform Drugs 0.000 title description 82
- 239000003814 drug Substances 0.000 claims abstract description 139
- 238000002347 injection Methods 0.000 claims abstract description 115
- 239000007924 injection Substances 0.000 claims abstract description 115
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 101
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- 239000003513 alkali Substances 0.000 claims abstract description 44
- 229940079593 drug Drugs 0.000 claims abstract description 32
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- 150000001875 compounds Chemical class 0.000 claims abstract description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 74
- 230000008439 repair process Effects 0.000 claims description 43
- 239000000243 solution Substances 0.000 claims description 15
- 238000012544 monitoring process Methods 0.000 claims description 14
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 12
- 238000005067 remediation Methods 0.000 claims description 10
- 238000001914 filtration Methods 0.000 claims description 5
- 238000004062 sedimentation Methods 0.000 claims description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 4
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 4
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 4
- 239000000920 calcium hydroxide Substances 0.000 claims description 4
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 4
- 239000012670 alkaline solution Substances 0.000 claims 1
- 238000006731 degradation reaction Methods 0.000 abstract description 23
- 230000015556 catabolic process Effects 0.000 abstract description 18
- 238000006298 dechlorination reaction Methods 0.000 abstract description 18
- 238000006243 chemical reaction Methods 0.000 abstract description 9
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- 230000000593 degrading effect Effects 0.000 abstract description 2
- 238000005728 strengthening Methods 0.000 abstract 1
- LCPVQAHEFVXVKT-UHFFFAOYSA-N 2-(2,4-difluorophenoxy)pyridin-3-amine Chemical group NC1=CC=CN=C1OC1=CC=C(F)C=C1F LCPVQAHEFVXVKT-UHFFFAOYSA-N 0.000 description 24
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- 238000007254 oxidation reaction Methods 0.000 description 8
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- CHQMHPLRPQMAMX-UHFFFAOYSA-L sodium persulfate Substances [Na+].[Na+].[O-]S(=O)(=O)OOS([O-])(=O)=O CHQMHPLRPQMAMX-UHFFFAOYSA-L 0.000 description 8
- 238000011835 investigation Methods 0.000 description 7
- 239000007800 oxidant agent Substances 0.000 description 7
- 230000003647 oxidation Effects 0.000 description 7
- 239000000356 contaminant Substances 0.000 description 6
- 238000001514 detection method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 239000000543 intermediate Substances 0.000 description 6
- 230000001590 oxidative effect Effects 0.000 description 6
- JRKICGRDRMAZLK-UHFFFAOYSA-L peroxydisulfate Chemical compound [O-]S(=O)(=O)OOS([O-])(=O)=O JRKICGRDRMAZLK-UHFFFAOYSA-L 0.000 description 6
- 238000010276 construction Methods 0.000 description 5
- 238000011109 contamination Methods 0.000 description 5
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 4
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- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 4
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- 239000004568 cement Substances 0.000 description 2
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- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000001112 coagulating effect Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 238000005695 dehalogenation reaction Methods 0.000 description 2
- 238000001212 derivatisation Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000003795 desorption Methods 0.000 description 2
- PFBUKDPBVNJDEW-UHFFFAOYSA-N dichlorocarbene Chemical class Cl[C]Cl PFBUKDPBVNJDEW-UHFFFAOYSA-N 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 235000019253 formic acid Nutrition 0.000 description 2
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- 239000012855 volatile organic compound Substances 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 239000012028 Fenton's reagent Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 150000008280 chlorinated hydrocarbons Chemical class 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
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- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
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- 238000012377 drug delivery Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000003933 environmental pollution control Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000003203 everyday effect Effects 0.000 description 1
- 229940052308 general anesthetics halogenated hydrocarbons Drugs 0.000 description 1
- 239000010438 granite Substances 0.000 description 1
- 239000000383 hazardous chemical Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
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- 239000002245 particle Substances 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
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- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- PRAJLVIUHUDWDZ-UHFFFAOYSA-M sodium;chloroform;hydroxide Chemical compound [OH-].[Na+].ClC(Cl)Cl PRAJLVIUHUDWDZ-UHFFFAOYSA-M 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
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Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/08—Reclamation of contaminated soil chemically
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- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The application provides a system and a method for repairing a chloroform polluted site, comprising the following steps: the device comprises a dispensing station, a medicine injection device, a water pumping device, a sewage treatment system and a well group; the well group is arranged on a pollution site and consists of a first well and a second well which are adjacently arranged at intervals; the medicine injection device is connected with the medicine dispensing station and connected with the first well through a first pipeline; the water pumping device is connected with the second well through a second pipeline; the sewage treatment system is connected with the water pumping device. The method comprises the steps of injecting alkali liquor into a polluted site to maintain the pH value of soil and/or groundwater at 9-13, and dechlorinating and degrading chloroform into pollution-free compounds under the condition. The first well and the second well are adjacently arranged, so that the medicine injection can be realized while pumping water, the medicine injection quantity of the land is improved, and the medicines are more fully mixed; the alkali is used for strengthening dechlorination and degradation, no additional medicament is needed, the price is low, the reaction is rapid, the restoration is thorough, and the method is particularly suitable for degradation treatment of chloroform in soil and underground water and large-scale engineering application.
Description
Technical Field
The invention belongs to the technical field of environmental pollution control, and relates to a system and a method for repairing a chloroform polluted site.
Background
Along with the rapid development of the economic society in China, the industrialization and modernization processes are accelerated, and some high-pollution chemical plants are required to be moved and even closed. These plants leave many contaminated sites around the city, with chloroform contaminated sites being one of the more common and most difficult to treat contaminants. Meanwhile, chloroform is one of the most highly ranked halogenated volatile organic compounds on the priority list of toxic and disease register (ATSDR) hazardous materials in the united states. Therefore, development of efficient degradation technology for chloroform contaminated sites is highly necessary.
The conventional repairing technology for repairing the halogenated hydrocarbon polluted site comprises the following steps: thermal desorption repair technology, chemical oxidation repair technology, and microbial repair technology. The thermal desorption repair technology has the problems of thorough repair and higher energy consumptionThe method comprises the steps of carrying out a first treatment on the surface of the The microbial repair technology has a slow repair progress, and is difficult to meet the requirements of project construction period; the chemical oxidation repair technology has rapid reaction and relatively low repair cost, and is widely applied to the fields related to the repair of soil and groundwater pollutants. The oxidant commonly used in chemical repair is mainly H 2 O 2 Fenton reagent, persulfate and O 3 And KMnO 4 The method comprises the steps of carrying out a first treatment on the surface of the The oxidants are introduced into polluted areas of soil and groundwater in a liquid or gas form to react with pollutants, so that the pollutants are eliminated, and the purpose of restoration is achieved. Although chemical oxidative remediation techniques can remove many types of halogenated hydrocarbons, the reactivity towards chloroform is poor.
For repairing halogenated hydrocarbon, CN 114214071A discloses a technology for repairing chlorinated hydrocarbon by coupling heat, alkali conversion and heat-activated persulfate, wherein the technology adopts heat, alkali conversion or heat-activated persulfate, the operation steps are complex, the energy consumption is high, and sulfate radical generated after the persulfate oxidation reaction can influence the re-development and the utilization of sites. CN 112387772A discloses a method for in-situ spraying the mixture of oxidant, catalyst and cement into underground to repair chlorohydrocarbon polluted site, which has the problems of small effective injection amount, insufficient contact between the medicament and soil, unfavorable for repairing low permeability soil, influence on site development and utilization after cement is added, etc. CN 113290041A discloses a method for degrading halogenated hydrocarbon by combining soil in-situ thermal analysis restoration technology and auxiliary agent reinforced microorganism dehalogenation restoration technology, which has the problems of slow microorganism dehalogenation reaction, damage to original flora structure of a site, high energy consumption of thermal analysis technology and the like. Therefore, a new system and technology for repairing chloroform polluted soil and groundwater have to be invented.
Disclosure of Invention
The utility model aims to provide a system and a method for repairing a chloroform polluted site, which repair the chloroform polluted soil and underground water through alkali-enhanced dechlorination degradation, and have the advantages of low repair cost, high repair efficiency, no intermediate product and the like.
In order to achieve the above purpose, the present application adopts the following technical scheme:
in a first aspect, the present application provides a repair system for a chloroform contaminated site, comprising: a dispensing station 1, a medicine injection device, a water pumping device, a well group and a sewage treatment system 10; wherein,,
the well group is arranged on the trichloromethane pollution site and consists of a first well 51 and a second well 52 which are adjacently arranged at intervals;
the dispensing station 1 is used for preparing medicaments;
the medicine injection device is connected with the medicine dispensing station 1 and is connected with the first well 51 through a first pipeline 71, and is used for injecting medicine into the first well 51;
the pumping means is connected to the second well 52 by a second conduit 72 for pumping water from the site;
the sewage treatment system 10 is connected with the water pumping device and is used for receiving and treating water pumped by the water pumping device.
In the repairing system, the first well 51 and the second well 52 of the well group are adjacently arranged, so that the functions of pumping water and injecting medicines simultaneously can be realized, the medicine injection quantity of land parcels is improved, medicines are promoted to be more fully mixed, and the repairing effect is better.
The repair system of the trichloromethane contaminated site is also connected to a second pipe 72 as a preferred embodiment for injecting medicine into the second well 52 through the second pipe 72 when necessary; the pumping means is also connected to the first conduit 71 for pumping water from the first well 51 through the first conduit 71 when necessary; the rehabilitation system further comprises a pump-injection function switching system 4 for switching the pumping and injection operating states of the first well 51 and the second well 52. By the arrangement, the rotation of two working states of medicine injection and water pumping of the first well 51 and the second well 52 can be realized, the repairing effect can be improved, and the method is beneficial to thoroughly repairing a certain polluted site (the area near the first well 51 and the adjacent second well 52).
In the present application, the pump-injection function switching system 4 is disposed between the drug injection device/pumping device and the first well/second well, and may be composed of a plurality of pipes and valves 11 disposed on the pipes, and the pump-injection function switching system 4 is configured to switch between two operating states of pumping and drug injection of the first well 51 and the second well 52 by switching the states of the valves 11, such as opening and closing.
For example, referring to fig. 2 and 8, the pump-injection function switching system 4 may include: a first valve V1, a second valve V2, a third valve V3, a fourth valve V4, a fifth valve V5, a sixth valve V6, a seventh valve V7, an eighth valve V8, and a first switching pipe and a second switching pipe; wherein,,
the first valve V1 is arranged on a medicine outlet pipe of the medicine injection device;
the second valve V2 is arranged on a water pumping pipe of the water pumping device;
the third valve V3 is arranged on the first pipeline;
the fourth valve V4 is arranged on the second pipeline;
the first pipeline 71 is connected with the outlet end of the first valve V1, and the second pipeline 72 is connected with the water pumping pipe;
one end of the first switching pipeline is connected with the medicine injection pipe before the inlet end of the first valve V1, the other end of the first switching pipeline is connected with the second pipeline 72 before the fourth valve V4, and a fifth valve V5 is arranged on the first switching pipeline;
one end of the second switching pipeline is connected with the outlet end of the first valve V1, the other end of the second switching pipeline is connected with the second pipeline 72 or the pumping pipe before the inlet end of the second valve V2, and a seventh valve V7 is arranged on the second switching pipeline;
a sixth valve V6 is arranged on the first pipeline 71 and between the joint of the first pipeline 71 and the medicine outlet pipe and the third valve V3;
an eighth valve V8 is further provided on the second pipe 72 between the junction of the second pipe 72 and the water suction pipe and the junction of the first switching pipe and the second pipe 72.
When the pumping-injecting function switching system 4 works, referring to fig. 8 (a), the first valve V1 and the eighth valve V8 are closed, and the other valves are opened, so that the pumping of the region a and the injection of the region B can be realized, that is, the medicine is injected into each second well 52 of the well group through the first switching pipeline (the fifth valve V5) and the second pipeline 72 (the fourth valve V4) sequentially through the pipe network, while at the same time, the water pumped from the first well 51 sequentially flows through the first pipeline 71 (the third valve V3 and the sixth valve V6), the second switching pipeline (the seventh valve V7) and the pumping pipe (the second valve V2) to enter the sewage treatment system 10, and works for a period of time in the mode; then, referring to fig. 8 (B), the fifth valve V5 and the seventh valve V7 are closed, the first valve V1, the eighth valve V8 and other valves are opened, at this time, the functions of pumping water from the B area and injecting medicine from the a area can be achieved, that is, the medicine is injected into each first well 51 of the well group through the first valve V1, the first pipe 71 (the sixth valve V6 and the third valve V3) in sequence through the pipe network, and at the same time, the water pumped from the second well 52 sequentially flows through the second pipe 72 (the fourth valve V4 and the eighth valve V8) and the pumping pipe (the second valve V2) into the sewage treatment system 10, and is operated for a period of time in this mode; and then switching back to the original working mode, and repeatedly switching in this way until the repair is qualified.
Illustratively, the pump-injection function switching system 4 may include:
a three-way valve a arranged on a medicine outlet pipe of the medicine injection device; a three-way valve b arranged on the pumping pipe of the pumping device; a three-way valve c provided on the first pipe 71; a three-way valve d provided on the second pipe 72;
a first drug injection tube connecting the first outlet of the three-way valve a and the first inlet of the three-way valve c (leading to the first conduit 71);
a second fill tube connecting the second outlet of three-way valve a and the first inlet of three-way valve d (leading to second conduit 72);
a first pumping pipe connecting the first inlet of the three-way valve b and the second outlet of the three-way valve d (communicating with the second pipe 72);
a second pumping pipe connecting the second inlet of the three-way valve b and the second outlet of the three-way valve c (communicating with the first pipe 71).
The switching of the pumping and injection operation states of the first well 51 and the second well 52 can be realized by controlling the switching of the three-way valve a, b, c, d. Specifically, when the above-described pump-up function switching system 4 is operated, by switching the state of the three-way a, B, c, d, the communicating outlet pipe, the first pump pipe, and the first pipe 71 constitute a pump pipe, and the communicating pump pipe, the first pump pipe, and the second pipe 72 constitute a pump pipe, at this time, the functions of pump-up in the region a and pump-up in the region B can be realized, and the pump-up in the region B can be operated for a while in this mode. Then, by switching the state of the tee a, B, c, d, the drug outlet pipe, the second drug injection pipe and the second pipeline 72 are communicated to form a drug injection pipeline, and the water pumping pipe, the second water pumping pipe and the first pipeline 71 are communicated to form a water pumping pipeline, at this time, the functions of pumping water in the area A and injecting drugs in the area B can be realized, and the mode is operated for a period of time. And then switching back to the original working mode, and repeatedly switching in this way until the repair is qualified.
Illustratively, the dispensing station 1 includes a dispensing canister, an automatic agitator disposed within the dispensing canister, a water injection device, a dosing device, a corrosion resistant pump; the dispensing station 1 is mainly used for dispensing medicaments for delivery to a site contaminated with chloroform, in particular a first well 51 or a second well 52, for treatment of the contaminants with chloroform. The medicament mainly comprises 0.1-1 mol/L alkali liquor, and generally comprises one or more of sodium hydroxide, calcium hydroxide, potassium hydroxide and ammonia water, preferably sodium hydroxide solution. The water is added into the dispensing tank through the water injection device according to the proportion, a proper amount of raw material medicament such as sodium hydroxide is added into the dispensing tank through the medicament adding device, the raw material medicament is stirred by the automatic stirrer to accelerate dissolution, the medicament with proper concentration is prepared, and then the medicament is conveyed to the medicament injection device through the corrosion-resistant pump.
Illustratively, the injection device comprises an automatic injection system 2 and a flow meter 3, the inlet of the automatic injection system 2 being connected to the outlet of the dosing station 1 (or to a corrosion resistant pump provided on the outlet tube), the outlet of which is connected to a first conduit 71 and thus to the first well 51 via said first conduit 71. The automatic medicine injection system 2 can accurately inject medicines, eliminates the influence of human factors on the treatment effect, has stable and reliable operation, greatly improves the automation degree and reduces the labor intensity of staff. The flow meter 3 can monitor the amount of the injected medicine, and an operator or a control system can adjust at any time according to the flow data and the processing effect requirement. Both the automatic drug delivery system 2 and the flow meter 3 may be commercially available products.
Illustratively, the pumping device comprises a vacuum pump 9, an inlet of the vacuum pump 9 is connected with the second pipeline 72 and/or the first pipeline 71, an outlet is generally connected with the sewage treatment system 10, and the pumping device can timely pump out water to assist the diffusion of the medicament;
for example, the wastewater treatment system 10 may include modules such as a conditioning tank, a stripping tower, a coagulating sedimentation unit, an advanced oxidation unit, an activated carbon adsorption unit, etc., that may treat the water pump effluent.
Illustratively, referring to FIG. 2, a first well 51 and an adjacent second well 52 in a cluster are arranged in parallel rows, wherein the adjacent wells are typically spaced apart by 2-5 m, preferably 3 m; preferably, each row of first wells 51 is offset from the adjacent row of second wells 52 in parallel. For example, referring to the well group shown in fig. 2, a total of three rows of first wells A1, A2, A3 are provided, a total of four rows of second wells B1, B2, B3, B4 are provided, and the rows are arranged in parallel in the order of B1, A1, B2, A2, B3, A3, B4, wherein each first well 51 of the row A1 forms a regular triangle with two second wells 52 closest to the row B1, B2 of the adjacent row a, or all second wells 52 adjacent to a certain first well 51 are connected to form a regular hexagon, and the first well 51 is located at the center of the regular hexagon.
Illustratively, referring to fig. 9, the pump-injector wells, i.e., the first well 51 and the second well 52, comprise a well casing comprising a casing section 531, a filtrate section 532 and a precipitation section 533 arranged sequentially from top to bottom, a filter layer 534 surrounding at least the filtrate section 532 and the precipitation section 533 being provided around the well casing, and a cement mortar layer 535 being provided above the filter layer 534. The well pipes of the first well 51 and the second well 52 are generally made of PVC, stainless steel or other materials, parallel interval transverse slits perpendicular to the central axis of the well pipe are arranged on the water filtering pipe section 532 and used for water permeation, and stainless steel wire meshes are wrapped on the outer side of the water filtering pipe section 532 and used for blocking sediment and the like.
Illustratively, the well depths of the first well 51 and the second well 52 are generally 0.5-1.0 m higher than the site maximum pollution depth; the length of the casing 531 is determined by the depth of the well and the depth of contamination, and the length of the filtered water pipe 532 is kept consistent with the distance between the minimum depth of contamination and the maximum depth of contamination, and the length of the sediment pipe 533 is typically 0.5m.
Preferably, the remediation system of the trichloromethane contaminated site further comprises a monitoring well 6 for monitoring groundwater, such as water level and water quality, and is especially suitable for the remediation situation of the groundwater contaminated site; further, the monitoring well 6 is generally centered in the regular triangle formed by the adjacent first and second wells.
In a second aspect, the application also provides a method for repairing a chloroform contaminated site, wherein the method is used for injecting alkali liquor with a certain concentration into the chloroform contaminated site to enable the chloroform in soil and/or groundwater to be subjected to dechlorination and degradation reaction to form pollution-free compounds.
The method for repairing the chloroform polluted site is implemented by adopting the system as a preferred implementation mode.
In the above method for repairing a chloroform contaminated site, as a preferred embodiment, firstly, a valve on a first pipe is opened, a pumping device is communicated with a first well 51 through a first pipe 71, the pumping device is started to pump water from the first well 51 (see (a) in fig. 8, namely, a zone a pumping mode is started), meanwhile, a valve of a second pipe 72 is opened, a drug injection device is communicated with a second well 52 through the second pipe 72, and the drug injection device is started to inject drugs into the second well 52 (see (a) in fig. 8, namely, a zone B drug injection mode is started); after the operation is performed for 1-5 days, the pumping and medicine injection modes are mutually switched, namely, a valve on a first pipeline 71 is opened, a medicine injection device and a first well 51 are communicated through the first pipeline 71, the medicine pumping and injection device is started to inject medicine into the first well 51 (see (B) in fig. 8, namely, the medicine injection mode in a region A is opened), meanwhile, a valve of a second pipeline 72 is opened, a pumping device and a second well 52 are communicated through the second pipeline 72, and the pumping device is started to pump water from the second well 52 (see (B) in fig. 8, namely, the pumping mode in a region B is opened); and repeatedly switching the working modes in this way until the repair is qualified.
According to the method for repairing the chloroform polluted site, as a preferred implementation mode, the injected medicament mainly comprises 0.1 mol/L-1 mol/L alkali liquor (such as 0.2 mol/L, 0.3 mol/L, 0.4 mol/L, 0.5 mol/L, 0.6 mol/L, 0.7 mol/L, 0.8 mol/L, 0.9 mol/L and the like), wherein the alkali liquor is one or more configured solutions selected from sodium hydroxide, calcium hydroxide, potassium hydroxide and ammonia water, and sodium hydroxide solution is preferred.
Preferably, a single well is filled 1-8 times (e.g., 2 times, 3 times, 4 times, 5 times, 6 times, 7 times) per day, and the single well is filled with 50-150L (e.g., 60L, 70L, 80L, 90L, 100L, 110L, 120L, 130L, 140L, etc.). After the injection is completed, the pH value of soil and/or groundwater is maintained at 9-13, an alkali-enhanced dechlorination degradation reaction environment is provided, and the pH value is preferably maintained at 9-11.
According to the method for repairing the chloroform contaminated site, as a preferred implementation mode, the injection pressure is 10-60 kPa (such as 15 kPa, 20 kPa, 30 kPa, 40 kPa, 50 kPa, 55 kPa and the like), preferably 20 kPa, the injection flow rate is 50-150L/min (such as 60L/min, 70L/min, 80L/min, 90L/min, 100L/min, 110L/min, 120L/min, 130L/min, 140L/min and the like), and preferably 50L/min.
The repairing method of the invention mainly injects alkali liquor with a certain concentration into the chloroform polluted site through the injection well, so that the trichloromethane in the soil and the underground water is dechlorinated and degraded to be reacted into pollution-free compounds, and the chemical reaction principle is as follows: trichloromethane rapidly deprotonates under alkaline conditions (H + ) To generate the carbanion trichloride (CCl) 3 - ）。CCl 3 - And (5) continuously dechlorinating to form dichloro carbene. The generated dichloro carbene is very active, and can rapidly dechlorinate and degrade under alkaline conditions to generate formic acid anions and chloride ions. The alkali-enhanced dechlorination degradation reaction comprises the following steps:
compared with the prior art, the beneficial effects of the application include, but are not limited to:
(1) The process is thorough in repair and rapid in reaction, and the chloroform is subjected to alkali-enhanced dechlorination and degradation to generate formic acid anions and chloride ions, so that other intermediate products are avoided. The process has good repairing effect, saves project construction period and avoids secondary pollution in the repairing process.
(2) The alkali liquor added in the process can promote the chloroform to be desorbed from soil particles into the water phase, thereby being beneficial to the contact of the alkali and the chloroform, improving the repair efficiency and avoiding the rebound and tailing phenomena of the concentration of pollutants. The degradation treatment of the chloroform can be realized by only adding the alkali liquor medicament, so that the investment of the oxidation medicament is reduced, and meanwhile, excessive repair can be avoided.
(3) The technology uses alkali to strengthen dechlorination and degradation, has low price of the used medicament, avoids the input of additional medicament, saves repair cost, and is suitable for degradation treatment of chloroform in soil and underground water and large-scale engineering application.
(4) The process has good field applicability, adopts the pumping-injection well to pump water and inject medicine simultaneously, namely pumps water from the area A and injects medicine to the adjacent area B, thus increasing the medicine injection amount of the land, promoting the medicine to be fully mixed with soil and groundwater, reducing the occurrence of slurry returning phenomenon, and being applicable to the repair of the low-permeability stratum chloroform polluted field. Further, after adopting to draw water from the area A and simultaneously injecting medicine to the adjacent area B for a period of time, exchanging operation, namely, drawing water from the area B and simultaneously injecting medicine to the adjacent area A; by repeating the steps, the repairing effect can be improved.
(5) The process has the advantage of accurately controlling the dosage of the medicament, and avoids the conditions of poor repairing effect caused by insufficient medicament injection amount or medicament waste caused by excessive injection amount and the like in single medicament injection by adopting high-pressure rotary spraying and other processes.
Drawings
FIG. 1 is a flow chart of a method for repairing a chloroform contaminated site according to a preferred embodiment of the present application;
FIG. 2 is a schematic diagram of a remediation system for a chloroform contaminated site according to a preferred embodiment of the present application;
FIG. 3 is a schematic diagram showing the effect of chloroform repair in example 1 of the present application;
FIG. 4 is a schematic diagram showing the effect of chloroform repair in example 2 of the present application;
FIG. 5 is a schematic diagram showing the effect of chloroform repair in example 3 of the present application;
FIG. 6 is a schematic diagram showing the effect of chloroform repair in example 4 of the present application;
FIG. 7 is a schematic view showing the effect of chloroform repair in example 5 of the present application
Fig. 8 (a) shows a working mode of pumping water in a region a and injecting medicine in a region B of a repairing system of a chloroform contaminated site according to a preferred embodiment of the present application; fig. 8 (B) shows the working modes of the repair system of the trichloromethane contaminated site in the preferred embodiment of the application, namely, the injection of the medicine in the area a and the pumping of water in the area B;
FIG. 9 is a schematic diagram of the structure of a first well and a second well;
reference numerals in the drawings are as follows:
1-a dispensing station; 2-an automatic drug injection system; 3-a flow meter; 4-a pump-pump function switching system; 51-a first well; 52-a second well; 6-monitoring the well; 71-a first pipe; 72-a second conduit; 8-a pressure gauge; 9-a vacuum pump; 10-a sewage treatment system; 11-valve; 531-a casing section; 532-a water filter section; 533-a precipitation section; 534-a filter layer; 535-cement mortar layer.
Detailed Description
The method for repairing soil and groundwater in a chloroform polluted site through alkali-enhanced dechlorination and degradation provided by the application, referring to fig. 1, mainly comprises the following steps:
(1) And (5) carrying out site pollution investigation.
Soil investigation was performed at a point of no more than 20m by 20m, and groundwater pollution investigation was performed at a point of no more than 80m by 80 m. The site investigation is mainly conducted aiming at related parameters such as the pollution concentration, the pollution depth, the pH value and the like of the chloroform in soil and underground water.
(2) Determining the dosage of the medicament.
And determining the adding amount of the alkali-enhanced dechlorination degradation medicament according to the related data such as the pollution concentration, the pollution depth, the pH value and the like of the chloroform in the soil and/or the groundwater, which are shown by investigation. After the injection is completed, the pH value of soil and groundwater is 9-13, an alkali-enhanced dechlorination degradation reaction environment is provided, and the pH value is preferably 9-11.
(3) And carrying out hydrogeological investigation.
And carrying out investigation aiming at the related parameters such as the distribution condition of the stratum of the land parcel, the porosity and permeability of the soil, the initial water level and the flow direction of the underground water and the like.
(4) Determining technical parameters.
And determining the technical parameters such as the layout mode of the extraction- injection wells 51 and 52 and the monitoring well 6, well spacing, screening opening range, pressure and flow of injection and the like according to the hydrogeological survey parameters.
The extraction- injection wells 51,52 can be constructed according to regular triangles and regular hexagons, the well spacing is generally 2-5 m, preferably 3 m; if the device is applied to a ground water pollution site, a ground water monitoring well 6 needs to be built, and the monitoring well 6 is generally positioned at the center of the regular triangle and regular hexagon extraction- injection wells 51 and 52.
The pump-out and injection wells 51,52 are typically PVC and stainless steel tubing, and the drainage tube sections are parallel spaced transverse slits perpendicular to the well casing centerline, encased with stainless steel mesh. The well depth is generally 0.5-1.0 m beyond the pollution depth, the length of the water filtering pipe section is consistent with the distance between the minimum pollution depth and the maximum pollution depth, and the length of the sedimentation pipe is generally 0.5m.
The injection pressure is 10-60 kPa, preferably 20 kPa; the injection flow rate is 50-150L/min, preferably 50L/min.
(5) And (5) constructing a repairing system.
The repairing system mainly comprises a dispensing station 1, a medicine injection device, a water pumping device, a sewage treatment system 10 and a well group. The system can realize the functions of pumping water and injecting medicines simultaneously, improves the medicine injection quantity of land parcels, promotes the medicines to be more fully mixed, and enables the restoration to be more thorough.
The dispensing station 1 is used for dispensing medicaments and comprises a dispensing tank, an automatic stirrer, a water injection device, a medicament adding device and a corrosion-resistant pump. When the system operates, water is added into the dispensing tank through the water injection device according to the proportion, a proper amount of raw material medicines such as sodium hydroxide are added into the dispensing tank through the medicine adding device, the raw material medicines are stirred by the automatic stirrer to be dissolved in an accelerating mode, medicines with proper concentrations are prepared, and then the medicines are conveyed to the medicine injection device through the corrosion-resistant pump.
The medicine injection device comprises an automatic medicine injection system 2 and a flowmeter 3, wherein an inlet of the automatic medicine injection system 2 is connected with the medicine dispensing station 1, and an outlet of the automatic medicine injection system is connected with the first well 51 through a first pipeline 71 and is used for injecting medicine into the first well 51 when the automatic medicine injection system is conducted; the flow meter 3 is used to monitor the drug infusion flow.
The pumping means comprises a vacuum pump 9, the inlet of which is connected to the second well 52 by a second conduit 72 and the outlet of which is connected to the sewage treatment system 10 for pumping water from the site and to the sewage treatment system 10 for treatment.
The sewage treatment system 10 is connected to a vacuum pump 9 of a water pumping device for receiving and treating the pumped water, and typically the sewage treatment system 10 may include modules of a regulating tank, a stripping tower, a coagulating sedimentation unit, an advanced oxidation unit, an activated carbon adsorption unit, and the like.
The well group is arranged on a chloroform polluted site to be repaired and consists of a first well 51 and a second well 52 which are adjacently arranged at intervals; referring to fig. 2, the first wells 51 and the adjacent second wells 52 in the well group are arranged in parallel in a row, wherein the interval between the adjacent wells is generally 2-5 m, preferably 3 m; preferably, each row of first wells 51 is arranged in parallel and staggered with respect to the adjacent rows of second wells 52, the zone a is provided with a total of three rows of first wells 51 A1, A2, A3, the zone B is provided with a total of four rows of second wells 52B 1, B2, B3, B4, in order of B1, A1, B2, A2, B3, A3, B4 in parallel, wherein the so-called "staggering" may be the following: each first well 51 of row A1 forms an equilateral triangle with the two nearest second wells 52 of rows B1, B2 of its adjacent row, and so on. Each row of wells is internally provided with a branch pipe extending into the well, each branch pipe is connected with a main pipe, and the main pipe is provided with a pressure gauge 8 for monitoring the injection pressure.
The injection device is also connected to the second conduit 72 for injecting medicine through the second conduit 72 into the second well 52 when necessary; the pumping device is also connected to the first conduit 71 for pumping water from the first well 51 through the first conduit 71 when necessary. In other words, both the first well 51 and the second well 52 belong to a "pump-injection well", which can be switched between two modes of operation, pumping and injecting; the first pipeline 71 and the second pipeline 72 belong to a pumping-medicine injection pipeline, and can be switched between pumping and medicine injection modes; in general, the above-mentioned functions can be switched by adjusting or adding the pipe and the valve 11 to regulate the flow direction of the medium, i.e., the pump-injection function switching system 4 is formed. By the arrangement, the rotation of two working states of medicine injection and water pumping of the first well 51 and the second well 52 can be realized, the repairing effect can be improved, and the method is beneficial to thoroughly repairing a certain soil and underground water pollution site (the area near the first well 51 and the adjacent second well 52). And (6) repairing the system operation and maintenance.
After the repair system is built and debugged, the modes of pumping water in the area A and injecting medicine in the area B are started, the modes of pumping water and injecting medicine in the area B are switched to each other after 1-5 days, and the modes of pumping water in the area B and injecting medicine in the area A are started, so that the process is repeated until the repair is qualified. The single well is injected 1-8 times per day, the single injection dosage of the single well is generally 50-150L, a small amount of low-pressure injection for many times can ensure slow diffusion of the medicament, the slurry return phenomenon caused by single high-pressure injection of a large dosage is avoided, the effective injection dosage of the medicament is improved, and the waste of the medicament is reduced.
The medicine mainly comprises the following components: the alkali solution of 0.1mol/L to 1mol/L is generally one or more selected from sodium hydroxide, calcium hydroxide, potassium hydroxide and ammonia water, preferably sodium hydroxide solution.
(7) Repair effect evaluation
And after the restoration is continued for a period of time, sampling and detection of soil and underground water are carried out regularly until the concentration of the pollutants in the restored soil and underground water is lower than the restoration target value, and the engineering is primarily considered to reach the standard.
The following examples facilitate a better understanding of the present application, but are not intended to limit the present application.
The experimental methods in the following examples are conventional methods unless otherwise specified.
Other test materials used in the examples described below, unless otherwise specified, were purchased from conventional biochemical reagent stores.
Example 1: restoration of chloroform in groundwater
Experiment design:
(1) Blank (contaminated aqueous solution) is an aqueous phase blank control.
(2) And a sodium hydroxide group (polluted water solution and sodium hydroxide), wherein an equivalent amount of NaOH for activating persulfate is added into the polluted water solution, so as to control the dechlorination degradation reaction efficiency of the pollutant under alkaline conditions and study whether dechlorination degradation intermediates are generated.
(3) Sodium persulfate group (contaminated aqueous solution+sodium persulfate), the oxidant sodium persulfate (final concentration 50 g/L) was added to the contaminated aqueous solution, but no NaOH was added for alkali activation, for comparative study of the contribution of alkali activation to oxidative degradation of contaminants.
(4) The alkali activated sodium persulfate group (polluted water solution, sodium persulfate and sodium hydroxide) is characterized in that oxidant sodium persulfate (final concentration of 50 g/L) and two equivalents of NaOH are added into the pollutant water solution for researching and confirming the oxidative degradation effect of target pollutants under the alkali activated condition, and intermediates generated in the oxidative degradation process are tracked and analyzed for researching the oxidative degradation of the alkali activated sodium persulfate.
All samples were fully filled with 40ml headspace vials consistent with the analysis of volatile organic pollutants by the U.S. environmental protection agency, screwed down with polytetrafluoroethylene-coated silica gel gasket caps, checked to confirm that no bubbles (avoiding escape of VOCs) were present in the vials, and stored in a sealed manner. After preparation, the sample is put into a constant temperature cabinet at 20 ℃ for being preserved in a dark place, the environment of ground water of a field is simulated, the sample is taken out and put into a refrigerator for refrigeration to terminate the reaction after 0, 0.5, 1, 3, 7 and 14 days, the sample is sent to a third party detection mechanism for analysis of the concentration of chloroform and the concentration of chloride ions, and after the sample is cooled and dried, the intermediate is subjected to water phase derivatization GC/MS analysis.
The chloroform concentrations were measured by sampling for each group as shown in table 1 below.
TABLE 1
| Time (d) | Blank trichloromethane (μg/L) | Sodium hydroxide chloroform (mug/L) | Sodium persulfate group chloroform (μg/L) | Alkali activated sodium persulfate group trichloromethane (μg/L) |
| 0 | 62170.4 | 62170.4 | 62170.4 | 62170.4 |
| 0.5 | 62111.4 | 6942.5 | 53259.2 | 895.5 |
| 1 | 54078.5 | 2540.5 | 47150.4 | 16.1 |
| 3 | 55244.8 | 592.3 | 25239.4 | 6.1 |
| 7 | 52928.2 | 23.1 | 1086.5.6 | 0 |
| 14 | 49144.5 | 0 | 16.7 | 0 |
Data analysis: as shown in the above table and fig. 3, the blank group of chloroform was stable in neutral aqueous solution for 14 days with a maximum degradation of 20.9% probably due to volatilization and photolysis of the chloroform. The sodium persulfate group, the sodium hydroxide group and the sodium persulfate group can be completely degraded by 100% in 14 days without intermediate products; wherein, the alkali activated sodium persulfate group and the sodium hydroxide group react more rapidly and thoroughly, and respectively degrade by 99.0 percent and 100 percent within 3 days. The sodium hydroxide group reduces the oxidation agent input relative to the alkali activated sodium persulfate group while avoiding excessive remediation.
Example 2: restoration of chloroform in soil
Experiment design:
(1) Blank (contaminated soil) is a soil phase blank control.
(2) And the sodium hydroxide group (polluted soil and sodium hydroxide) is characterized in that the polluted soil is added with an equivalent amount of NaOH for activating persulfate, so that the dechlorination degradation efficiency of the pollutant under alkaline conditions is controlled, and whether dechlorination degradation intermediates are generated or not is studied.
(3) Sodium persulfate group (contaminated soil + sodium persulfate), the oxidizer sodium persulfate (final concentration 50 g/kg) was added to the contaminated soil, but no NaOH was added for alkali activation, for comparative study of the contribution of alkali activation to oxidative degradation of the contaminants.
(4) The alkali activated sodium persulfate group (polluted soil, sodium persulfate and sodium hydroxide) is characterized in that an oxidant sodium persulfate (final concentration of 50 g/kg) and two equivalents of NaOH are added into polluted soil for researching and confirming the oxidative degradation effect of target pollutants under the alkali activated condition, and intermediates generated in the oxidative degradation process are tracked and analyzed for researching the oxidative degradation of the alkali activated sodium persulfate.
And taking out part of the samples after 0, 0.5, 1, 3, 7 and 14 days respectively, putting the samples into a refrigerator for refrigeration to terminate the reaction, sending the samples to a third-party detection mechanism for analysis of the concentration of chloroform and the concentration of chloride ions, and carrying out water-phase derivatization GC/MS analysis on intermediates after cooling and drying.
The chloroform concentrations were measured by sampling for each group as shown in Table 2 below.
TABLE 2
Data analysis: as shown in the above table and fig. 4, the blank group of chloroform was stable in the soil and degraded by a maximum of 9.8% within 14 days, probably due to volatilization and photolysis of the chloroform. The degradation efficiency of the alkali activated sodium persulfate group, the sodium hydroxide group and the sodium persulfate group can reach more than 97% in 14 days, and no intermediate product exists; wherein, the alkali activated sodium persulfate group and the sodium hydroxide group react more rapidly and thoroughly, and degrade more than 99.0 percent within 7 days. The sodium hydroxide group reduces the oxidation agent input relative to the alkali activated sodium persulfate group while avoiding excessive remediation.
Example 3: restoration of trichloromethane in underground water of certain chemical plant
Example 3 was applied to a chemical plant in south China, where the groundwater type was of both loose rock pore water and blocky rock crevice water. The organic pollutant in the groundwater is chloroform, and the pollution area is about 5294.29 m 2 The maximum contamination depth was 14 m.
From the supplemental survey, the extraction-injection well depth was determined to be 14.5 m. The well spacing was 3 m. The injection pressure is 20 kPa, and the injection flow is 50L/min.
Starting well construction (extraction-injection well and monitoring well), pipe connection and equipment installation according to the contaminated area range, see fig. 2. After the system is built, the mode of pumping water in the area A and injecting medicine in the area B is started, and the method uses 0.1mol/L sodium hydroxide solution as the medicine. After 3 days, the water pumping and drug injection modes are switched, and the operation is repeated until the pH value of the underground water in the monitoring well is 9-11 and kept in the range, so as to provide a reaction environment for alkali-enhanced dechlorination. The single well is filled with medicine 3 times a day, and the medicine amount of the single injection is 50L. Sampling and detecting the concentration of chloroform in underground water from a monitoring well on days 7, 14 and 28 before and after the start of drug injection, analyzing intermediate products, and judging whether restoration is qualified.
The target value for the remediation of chloroform in the groundwater of the land is shown in table 3 below.
TABLE 3 Table 3
| Contaminants (S) | Repair target value (μg/L) |
| Trichloromethane | 1690 |
The chloroform concentrations are shown in table 4 below.
TABLE 4 Table 4
Data analysis: as shown in the above table and fig. 5, after 14 days of drug infusion repair, chloroform degraded 74.1%; after 28 days, the chloroform is degraded by 84.1 percent, and the pollutant concentration in the field can meet the requirement of the repairing target value. Through detection, no intermediate product is produced in the repairing process.
Example 4: trichloromethane remediation in soil of certain chemical plant
Example 4 applied to a chemical plant in south China, the organic pollutant in the soil is chloroform, and the amount of the restored soil is 3477.64 m 3 The maximum contamination depth was 22 m. The stratum of the application project of this example was mainly a quaternary sea Liu Jiaohu sediment layer (Qmc), and the bedrock was ancient (yc) granite gneiss.
From the supplemental survey, a pump-injection well depth of 22.5 m was determined. The well spacing was 3 m. The injection pressure is 20 kPa, and the injection flow is 50L/min.
The construction of extraction-injection wells, piping and equipment installations is started according to the extent of the contaminated area, see fig. 2, 8. After the system is built, the mode of pumping water in the area A and injecting medicine in the area B is started, and the method uses 0.1mol/L sodium hydroxide solution as the medicine. After 2 days, the water pumping and drug injection modes are switched, and the operation is repeated until the pH value in the detected soil is 9-11. The single well is filled with medicine 6 times a day, and the dosage of the single injection is 50L. Sampling and detecting the concentration of chloroform in soil before and after the beginning of injection at 7 th, 14 th and 28 th days respectively, analyzing intermediate products, and judging whether the restoration is qualified.
The repair target value of the land chloroform is shown in the following table 5:
TABLE 5
| Contaminants (S) | Target repair value (mg/kg) |
| Trichloromethane | 1.79 |
The chloroform concentrations are shown in table 6 below:
TABLE 6
Data analysis: as shown in the above table and fig. 6, after 14 days of alkali-enhanced dechlorination degradation repair, chloroform degraded 76.4%; after 28 days, the chloroform is degraded by 94.6 percent, and the pollutant concentration in the field can meet the requirement of the repairing target value. Through detection, no intermediate product is produced in the repairing process.
Example 5: integrated restoration of chloroform in soil and groundwater of certain chemical plant
Example 5 was applied to a chemical plant in south China, and the hydrogeology was the same as in examples 3 and 4. The area to be repaired is 1995 m, and the area to be repaired is polluted by chloroform in the soil and groundwater of the area 2 The repair depth was 16 m.
From the supplemental survey, a pump-injection well depth of 16.5 m was determined. The well spacing was 3 m. The injection pressure is 20 kPa, and the injection flow is 50L/min.
Starting well construction (extraction-injection well and monitoring well), pipe connection and equipment installation according to the contaminated area range, see fig. 2, 8. After the system is built, the mode of pumping water in the area A and injecting medicine in the area B is started, and the method uses 0.2 mol/L sodium hydroxide solution as the medicine. After 1 day, the modes of water pumping and drug injection are mutually switched, and the operation is repeated until the pH values of the underground water and the soil are 9-11. The single well is filled with medicine for 4 times every day, and the medicine amount for single injection is 100L. And detecting the concentrations of the chloroform in the underground water and the soil from the samples on the 7 th, 14 th and 28 th days before and after the beginning of the injection, analyzing the intermediate products, and judging whether the restoration is qualified. The target value for remediation of chloroform in the plot soil and groundwater is shown in example 3 (Table 3) and example 4 (Table 5).
The chloroform concentrations are shown in table 7 below:
TABLE 7
Data analysis: as shown in the table and fig. 7, after the alkali-enhanced dechlorination degradation is repaired for 14 days, the chloroform in the soil and the underground water is respectively degraded by 82.4 percent and 79.9 percent; after the alkali-enhanced dechlorination degradation is repaired for 28 days, the chloroform in the soil and underground water is respectively degraded by 97.4 percent and 85.5 percent, and the concentration meets the requirement of a repairing target value. Through detection, no intermediate product is produced in the repairing process.
As can be seen from the above embodiments, the system and the method provided by the invention are used for repairing soil and/or groundwater polluted by chloroform, and have the advantages of high repairing efficiency, no intermediate products and the like.
Finally, it is pointed out that in the present application, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
While the application has been disclosed by the description of specific embodiments, it will be appreciated that those skilled in the art may devise various modifications, adaptations, or equivalents of the application within the spirit and scope of the appended claims. Such modifications, improvements, or equivalents are intended to be included within the scope of the present application.
Claims (11)
1. A system for repairing a contaminated site comprising: the device comprises a dispensing station, a medicine injection device, a water pumping device, a sewage treatment system and a well group; wherein,,
the well group is arranged on the chloroform polluted site and consists of a first well and a second well which are adjacently arranged at intervals;
the dispensing station is used for preparing medicaments;
the medicine injection device is connected with the medicine dispensing station and is connected with the first well through a first pipeline;
the water pumping device is connected with the second well through a second pipeline;
the sewage treatment system is connected with the water pumping device and is used for receiving and treating the polluted underground water pumped by the water pumping device before the restoration project reaches the standard.
2. The system for repairing a chloroform contaminated site according to claim 1, wherein in the well group, the first wells and the adjacent second wells are arranged in parallel in a row, and each row of the first wells is arranged opposite to or staggered from the adjacent row of the second wells, wherein the interval between the adjacent wells is 2-5 m.
3. The system for repairing a chloroform contaminated site according to claim 1, wherein the well depths of the first well and the second well exceed the maximum contaminated depth of the site by 0.5-1.0 m; the well pipes of the first well and the second well comprise well pipe sections, water filtering pipe sections and sedimentation pipe sections which are sequentially arranged from top to bottom; the length of the water filtering pipe section is consistent with the distance between the minimum pollution depth and the maximum pollution depth, and the length of the sedimentation pipe section is 0.5m.
4. The system for remediation of a chloroform contaminated site of claim 1, further comprising a monitoring well for monitoring groundwater.
5. The repair system for a contaminated site according to any one of claims 1-4, wherein the injection device is further coupled to the second conduit for injecting a drug into the second well through the second conduit; the pumping device is also connected with the first pipeline and can be used for pumping water from the first well through the first pipeline;
the repair system further includes: and the extraction-injection function switching system is used for switching the pumping and medicine injection working states of the first well and the second well.
6. A method for repairing a chloroform polluted site is characterized in that alkali liquor is injected into the chloroform polluted site to maintain the pH value of soil and/or groundwater at 9-13, and the chloroform in the soil and/or groundwater is dechlorinated and degraded into pollution-free compounds under the condition.
7. The method for repairing a contaminated site with chloroform according to claim 6, wherein the repairing system according to any one of claims 1 to 4 is used, firstly, a valve on the first pipe is opened, the pumping device is communicated with the first well through the first pipe, and the pumping device is started to pump water from the first well; simultaneously, the valve of the second pipeline is opened, the medicine injection device is communicated with the second well through the second pipeline, and the medicine injection device is started to inject medicine into the second well.
8. The method for repairing a contaminated site with chloroform according to claim 6, wherein the repairing system according to claim 5 is adopted, firstly, a valve on the first pipeline is opened, the pumping device is communicated with the first well through the first pipeline, the pumping device is started to pump water from the first well, meanwhile, a valve of the second pipeline is opened, the drug injection device is communicated with the second well through the second pipeline, and the drug injection device is started to inject drugs into the second well; after the operation is performed for 1-5 days, a valve on the first pipeline is opened, the medicine injection device is communicated with the first well through the first pipeline, the medicine injection device is started to inject medicine into the first well, meanwhile, a valve of the second pipeline is opened, the water pumping device is communicated with the second well through the second pipeline, and the water pumping device is started to pump water from the second well; and repeatedly switching the water pumping and medicine injection working modes until the repair is qualified.
9. The method for repairing a chloroform contaminated site according to any one of claims 6 to 8, wherein the concentration of the alkali solution is 0.1mol/L to 1mol/L, and the alkali solution is a solution prepared from one or more selected from sodium hydroxide, calcium hydroxide, potassium hydroxide and ammonia water.
10. The method for repairing the chloroform contaminated site according to claim 9, wherein the single well is filled with the medicine 1-8 times per day, and the single injection amount of the single well is 50-150L; the injection pressure is 10-60 kPa, and the injection flow is 50-150L/min.
11. The method for repairing a chloroform contaminated site according to any one of claims 6 to 8 and 10, wherein the pH of soil and/or groundwater is maintained at 9 to 11 by injecting an alkaline solution into the chloroform contaminated site.
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| CN202310672458.0A Active CN116393501B (en) | 2023-06-08 | 2023-06-08 | Repairing system and method for trichloromethane polluted site |
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