CN116986738B - Chromium-polluted underground water in-situ chemical and biological combined restoration method - Google Patents
Chromium-polluted underground water in-situ chemical and biological combined restoration method Download PDFInfo
- Publication number
- CN116986738B CN116986738B CN202311250219.2A CN202311250219A CN116986738B CN 116986738 B CN116986738 B CN 116986738B CN 202311250219 A CN202311250219 A CN 202311250219A CN 116986738 B CN116986738 B CN 116986738B
- Authority
- CN
- China
- Prior art keywords
- underground water
- chromium
- hexavalent chromium
- restoration
- well
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 title claims abstract description 21
- 239000000126 substance Substances 0.000 title claims abstract description 17
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 13
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 claims abstract description 38
- 239000003673 groundwater Substances 0.000 claims abstract description 33
- 239000003463 adsorbent Substances 0.000 claims abstract description 32
- 239000007788 liquid Substances 0.000 claims abstract description 29
- 230000008439 repair process Effects 0.000 claims abstract description 27
- 241000894006 Bacteria Species 0.000 claims abstract description 17
- 241000193755 Bacillus cereus Species 0.000 claims abstract description 13
- 241000589614 Pseudomonas stutzeri Species 0.000 claims abstract description 13
- 241000193830 Bacillus <bacterium> Species 0.000 claims abstract description 12
- 238000012544 monitoring process Methods 0.000 claims abstract description 12
- KDXKERNSBIXSRK-UHFFFAOYSA-N Lysine Natural products NCCCCC(N)C(O)=O KDXKERNSBIXSRK-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000004472 Lysine Substances 0.000 claims abstract description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 4
- 239000001301 oxygen Substances 0.000 claims abstract description 4
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 36
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 35
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims description 35
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims description 35
- 229960000892 attapulgite Drugs 0.000 claims description 34
- 229910052625 palygorskite Inorganic materials 0.000 claims description 34
- 125000002057 carboxymethyl group Chemical group [H]OC(=O)C([H])([H])[*] 0.000 claims description 25
- 238000002360 preparation method Methods 0.000 claims description 17
- 239000000843 powder Substances 0.000 claims description 16
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 15
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 15
- 238000003756 stirring Methods 0.000 claims description 14
- 230000001580 bacterial effect Effects 0.000 claims description 12
- 238000001035 drying Methods 0.000 claims description 11
- 230000009467 reduction Effects 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 9
- 239000007864 aqueous solution Substances 0.000 claims description 8
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 7
- 244000068988 Glycine max Species 0.000 claims description 6
- 235000010469 Glycine max Nutrition 0.000 claims description 6
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 claims description 6
- 239000011148 porous material Substances 0.000 claims description 6
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 4
- 238000000227 grinding Methods 0.000 claims description 4
- 230000007935 neutral effect Effects 0.000 claims description 4
- 229910017604 nitric acid Inorganic materials 0.000 claims description 4
- 238000007873 sieving Methods 0.000 claims description 4
- 238000005406 washing Methods 0.000 claims description 4
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims description 3
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 3
- 229910001870 ammonium persulfate Inorganic materials 0.000 claims description 3
- 238000004140 cleaning Methods 0.000 claims description 3
- -1 methylene bisacryloyl Chemical group 0.000 claims description 3
- 238000005067 remediation Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 19
- 230000000052 comparative effect Effects 0.000 description 27
- HFZWRUODUSTPEG-UHFFFAOYSA-N 2,4-dichlorophenol Chemical compound OC1=CC=C(Cl)C=C1Cl HFZWRUODUSTPEG-UHFFFAOYSA-N 0.000 description 12
- 238000006722 reduction reaction Methods 0.000 description 11
- 239000003209 petroleum derivative Substances 0.000 description 7
- 230000015556 catabolic process Effects 0.000 description 6
- 238000006731 degradation reaction Methods 0.000 description 6
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 5
- 229910052804 chromium Inorganic materials 0.000 description 5
- 239000011651 chromium Substances 0.000 description 5
- 239000004927 clay Substances 0.000 description 5
- 230000002195 synergetic effect Effects 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 239000003638 chemical reducing agent Substances 0.000 description 4
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- 230000035876 healing Effects 0.000 description 3
- 230000036541 health Effects 0.000 description 3
- 230000002035 prolonged effect Effects 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 239000011593 sulfur Substances 0.000 description 3
- 241000193752 Bacillus circulans Species 0.000 description 2
- 241000058353 Paenibacillus terrae Species 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 2
- 239000000440 bentonite Substances 0.000 description 2
- 229910000278 bentonite Inorganic materials 0.000 description 2
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 235000013305 food Nutrition 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- VGVRPFIJEJYOFN-UHFFFAOYSA-N 2,3,4,6-tetrachlorophenol Chemical class OC1=C(Cl)C=C(Cl)C(Cl)=C1Cl VGVRPFIJEJYOFN-UHFFFAOYSA-N 0.000 description 1
- 244000241257 Cucumis melo Species 0.000 description 1
- 235000009847 Cucumis melo var cantalupensis Nutrition 0.000 description 1
- 241001468261 Lysinibacillus macroides Species 0.000 description 1
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 231100000693 bioaccumulation Toxicity 0.000 description 1
- 238000009388 chemical precipitation Methods 0.000 description 1
- 230000002508 compound effect Effects 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 238000003895 groundwater pollution Methods 0.000 description 1
- 231100000086 high toxicity Toxicity 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical group [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 1
- 229920001027 sodium carboxymethylcellulose Polymers 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 231100000167 toxic agent Toxicity 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 239000003053 toxin Substances 0.000 description 1
- 231100000765 toxin Toxicity 0.000 description 1
- 108700012359 toxins Proteins 0.000 description 1
- 238000003911 water pollution Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/34—Biological treatment of water, waste water, or sewage characterised by the microorganisms used
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/002—Reclamation of contaminated soil involving in-situ ground water treatment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/70—Treatment of water, waste water, or sewage by reduction
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/20—Heavy metals or heavy metal compounds
- C02F2101/22—Chromium or chromium compounds, e.g. chromates
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/06—Contaminated groundwater or leachate
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Microbiology (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Biodiversity & Conservation Biology (AREA)
- Soil Sciences (AREA)
- Processing Of Solid Wastes (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
The invention provides an in-situ chemical and biological combined restoration method for chromium-polluted groundwater, which belongs to the technical field of restoration of polluted groundwater and comprises the following steps: (1) Arranging underground water restoration well groups, and arranging underground water monitoring wells in the middle of the restoration wells; (2) Injecting an adsorbent into each repair well until the hexavalent chromium concentration in the underground water monitoring well is reduced to below 1.5 mg/L; (3) Pressurizing and injecting hexavalent chromium reducing bacteria liquid into each repairing well, and continuously injecting compressed air, wherein the hexavalent chromium reducing bacteria liquid comprises pseudomonas stutzeri, slender lysine bacillus and bacillus cereus; (4) And (3) aerating each repair well to ensure that the concentration of dissolved oxygen in the underground water monitoring well is maintained to be more than 2 mg/L until hexavalent chromium in the underground water reaches the standard. The repairing method disclosed by the invention is simple and feasible to operate, low in repairing cost, environment-friendly and pollution-free, can be applied to large-scale chromium-polluted groundwater repairing, and is high in repairing effect stability.
Description
Technical Field
The invention belongs to the technical field of polluted groundwater remediation, and particularly relates to an in-situ chemical-biological combined remediation method for chromium-polluted groundwater.
Background
Groundwater is one of the most precious natural resources on earth, groundwater pollution has serious influence on human health and environment, and while economy continues to develop, groundwater is threatened by various pollution. Hexavalent chromium is a toxic substance that poses a potential threat to the environment and human health. Landfill sites are one source of chromium contaminated groundwater, where chromium-containing waste, including chromium-containing waste and slag, may bleed over time and contaminate surrounding groundwater. The common chromium-polluted groundwater treatment method comprises the following steps: chemical precipitation, electrochemical method, biological repair, etc., wherein the chemical reduction technology is used more, the chemical reduction technology uses a sulfur-based reducing agent, the repair time is kept short, and the long-term stability of the repair effect is difficult to ensure.
Disclosure of Invention
The invention aims to provide an in-situ chemical and biological combined restoration method for chromium-polluted underground water, which is simple and feasible in operation, low in restoration cost, environment-friendly and pollution-free, can be applied to large-scale restoration of chromium-polluted underground water, and has high restoration effect stability and wide application prospect.
In order to achieve the above object, the present invention provides the following technical solutions:
an in-situ chemical and biological joint repair method for chromium-contaminated groundwater, comprising the steps of:
(1) Arranging underground water restoration well groups, and arranging underground water monitoring wells in the middle of the restoration wells;
(2) Injecting an adsorbent into each repair well until the hexavalent chromium concentration in the underground water monitoring well is reduced to below 1.5 mg/L; the preparation method of the adsorbent comprises the following steps: pyrolyzing soybean hulls at 500-550 ℃ for 4-6 hours, crushing, and sieving with a 80-mesh sieve to obtain powder; under the nitrogen atmosphere, the powder and 6-8 g/L FeCl 3 ·6H 2 The O aqueous solution is prepared according to the solid-to-liquid ratio of 1: mixing 35-45, stirring for 20-30 h, continuously adding modified carboxymethyl cellulose, polyvinyl alcohol and modified attapulgite, continuously stirring for 10-15 h, vacuum filtering, and drying for 15-25 h at 70-80 ℃ in an oven to obtain an adsorbent;
(3) Pressurizing and injecting hexavalent chromium reducing bacteria liquid into each repair well, and continuously injecting compressed air for 20-30 minutes; the hexavalent chromium reducing bacteria liquid comprises pseudomonas stutzeri, slender lysine bacillus and bacillus cereus;
(4) And (3) aerating each repair well to ensure that the concentration of dissolved oxygen in the underground water monitoring well is maintained to be more than 2 mg/L until hexavalent chromium in the underground water reaches the standard.
Further, the preparation method of the modified carboxymethyl cellulose comprises the following steps: under nitrogen atmosphere, the mass ratio is 10:3:1:0.1:0.5:100, mixing carboxymethyl cellulose, methacrylic acid, acrylamide, ammonium persulfate, methylene bisacryloyl and water, uniformly stirring, reacting for 4.5 hours at 82 ℃, cleaning, and drying to obtain the modified carboxymethyl cellulose.
Further, the preparation method of the modified attapulgite comprises the following steps: the ratio of the attapulgite to the 25-35 v/v% nitric acid aqueous solution is 1 g/30-40 mL, and after mixing, stirring and reacting for 30-40 min at 25-40 ℃, centrifuging, washing to be neutral, drying and grinding.
Further, the specific surface area of the modified attapulgite is 19-21 m 2 Per gram, the average pore volume is 0.095-0.104 cm 3 And/g, wherein the average pore diameter is 21.5-22 nm.
Further, the mass ratio of the modified carboxymethyl cellulose to the polyvinyl alcohol to the modified attapulgite to the powder is 1-3: 2-4: 1: 3-6; further selecting the mass ratio of the modified carboxymethyl cellulose, the polyvinyl alcohol and the modified attapulgite to the powder as 2:3:1:5.
the sulfur reducing agent is easy to cause secondary pollution due to the use of a large amount of sulfur-containing substances, and has poor repair stability. The invention provides a novel adsorbent, which is prepared by selecting soybean hulls which are common in inner Mongolia regions and have low cost, wherein nano iron-based material substances are loaded on the modified biochar; the modified carboxymethyl cellulose, the polyvinyl alcohol and the modified attapulgite are adopted to carry out compounding to generate a mutual promotion relationship, so that the combination of carboxyl and hydroxyl can be efficiently realized, the adsorbent is not easy to agglomerate, and the obtained modified substance is added into a reaction system by modifying the attapulgite and the carboxymethyl cellulose, so that the repair stability of chromium-polluted underground water can be prolonged, the biological synergistic repair effect can be enhanced, and the repair period of the adsorbent can be prolonged. 2, 4-dichlorophenol belongs to common chlorophenols pollutants, has the characteristics of difficult degradation and high toxicity, and the existence and release of the 2, 4-dichlorophenol in water pollution have potential harm to the environment and human health. 2, 4-dichlorophenol is difficult to degrade in water and has a certain bioaccumulation, which means that it gradually accumulates in the organism and gradually rises to the high level of the food chain, which causes toxins to accumulate in the organism when the species in the food chain ingest the organism containing 2, 4-dichlorophenol, thus causing a wider range of ecological problems. The inventors also found that when the mass ratio of the modified carboxymethyl cellulose, the polyvinyl alcohol, the modified attapulgite to the powder is 1-3: 2-4: 1: 3-6, the degradation rate of 2, 4-dichlorophenol in the groundwater can be improved; the adsorbent prepared under the proportional condition is used in the system, so that the compound effect is generated, a mutually coordinated promotion relationship is generated for biological combined repair, and the adsorbent has a good degradation effect on 2, 4-dichlorophenol.
Further, the ratio of the adsorbent to hexavalent chromium reduction bacteria liquid is 60-90 g/230-450 mL.
Further, the density of active bacterial cells in the hexavalent chromium reduction bacterial liquid is 10 7 ~10 10 And each mL.
Further, the cell density ratio of the pseudomonas stutzeri, the slender lysine bacillus and the bacillus cereus in the hexavalent chromium reduction bacterial liquid is 2-6: 1-3: 1.
according to the invention, the adsorbent and hexavalent chromium reducing bacteria liquid are mixed at a ratio of 60-90 g/230-450 mL for joint repair, so that the chromium removal rate is highest. When the hexavalent chromium reducing bacteria liquid comprises pseudomonas stutzeri, bacillus tenuiform and bacillus cereus, the stability of repairing the groundwater of the landfill is high. It is hypothesized that the groundwater environment of the landfill is favorable for the synergistic effect of the bacteria in the system, thereby promoting the reduction of hexavalent chromium. The inventor also unexpectedly discovers that the cell density ratio of pseudomonas stutzeri, bacillus tenuiform and bacillus cereus in the hexavalent chromium reduction bacterial liquid is 2-6: 1-3: 1, the petroleum hydrocarbon content in the groundwater of the landfill site can be reduced.
Further, the pH of the chromium-polluted groundwater is 8-10.
Further, the chromium-contaminated groundwater is groundwater of a landfill site.
The inventor detects in the field that the pH of the underground water of the landfill in most areas of inner Mongolia is alkaline, and the repairing method has a good repairing effect in the underground water with the pH of 8-10. When the water is used in groundwater with lower pH, the pH can be properly adjusted to obtain better effect.
Further, the carboxymethyl cellulose has a Mw of 90000 (wherein the molar mass of sodium carboxymethyl cellulose is generally expressed as Mw). Purchased from aladine.
The strain used in the invention: pseudomonas stutzeri (Pseudomonas stutzeri), american type culture Collection, accession number: ATCC17588.
Bacillus elongate lysine (Lysinibacillus macroides), shanghai deposit Biotechnology center, accession number: SHBCC D17917.
Bacillus cereus (cantaloupe), cantonese province microorganism strain collection accession number: GDMCC 1.541.
Compared with the prior art, the invention has the advantages that:
1. the invention aims to provide an in-situ chemical and biological combined restoration method for chromium-polluted underground water, which is simple and feasible in operation, low in restoration cost, environment-friendly and pollution-free, can be applied to large-scale restoration of chromium-polluted underground water, and has high restoration effect stability and wide application prospect.
2. The invention provides a novel adsorbent, which is prepared by selecting common soybean hulls with low cost in inner Mongolia regions to prepare modified biochar and loading nano iron-based material substances, adopts the relationship of mutual promotion of modified carboxymethyl cellulose, polyvinyl alcohol and modified attapulgite for compounding, can efficiently realize the combination of carboxyl and hydroxyl, ensures that the adsorbent is not easy to agglomerate, and can prolong the restoration stability of chromium-polluted groundwater by adding the obtained modified substances into a reaction system and simultaneously strengthen the biological synergistic restoration effect and prolong the restoration period of the adsorbent.
3. When the mass ratio of the modified carboxymethyl cellulose to the polyvinyl alcohol to the modified attapulgite to the powder is 1-3: 2-4: 1: 3-6, the degradation rate of 2, 4-dichlorophenol in the groundwater can be improved.
4. According to the method, the adsorbent and hexavalent chromium reducing bacteria liquid are subjected to joint repair according to the ratio of 60-90 g/230-450 mL, and the chromium removal rate is highest. When the hexavalent chromium reducing bacteria liquid comprises pseudomonas stutzeri, bacillus tenuifolia and bacillus cereus, the repairing time is prolonged. The groundwater environment of the landfill is beneficial to the synergistic effect of the bacteria, so that the reduction of hexavalent chromium is promoted. The inventor also unexpectedly discovers that the cell density ratio of pseudomonas stutzeri, bacillus tenuiform and bacillus cereus in the hexavalent chromium reduction bacterial liquid is 2-6: 1-3: 1, the petroleum hydrocarbon content in the groundwater of the landfill site is also reduced.
5. The inventor detects the pH of underground water of the refuse landfill in a plurality of areas of inner Mongolia, and the statistics shows that the pH is alkaline, and the repairing method has good repairing effect in the underground water with the pH of 8-10. When the water is used in groundwater with lower pH, the pH can be properly adjusted to obtain better effect.
Description of the embodiments
The following description of the technical solutions in the embodiments of the present invention will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Examples
In the embodiment, certain groundwater in the inner Mongolia landfill is repaired, the pH value is 8.5, and the repairing method comprises the following steps:
(1) Arranging underground water restoration well groups, and arranging underground water monitoring wells in the middle of the restoration wells; for a specific structure, refer to patent CN 114653737A.
(2) Injecting an adsorbent into the repair well until the hexavalent chromium concentration in the underground water monitoring well is reduced to below 1.5 mg/L; the preparation method of the adsorbent comprises the following steps: pyrolyzing soybean hull at 520 deg.C for 5 hr, pulverizing, and sieving with 80 mesh sieve to obtain powder; the powder was mixed with 7g/L FeCl under nitrogen atmosphere 3 ·6H 2 The O aqueous solution is prepared according to the solid-to-liquid ratio of 1:40, stirring for 25h, continuously adding modified carboxymethyl cellulose, polyvinyl alcohol and modified attapulgite, continuously stirring for 12h, vacuum filtering, and drying at 75 ℃ for 20h in an oven to obtain the adsorbent.
(3) Pressurizing and injecting hexavalent chromium reducing bacteria liquid into each repairing well, and continuously injecting compressed air for 25 minutes; the hexavalent chromium reducing bacteria liquid comprises pseudomonas stutzeri, slender lysine bacillus and bacillus cereus.
(4) And (3) aerating each repair well to ensure that the concentration of dissolved oxygen in the underground water monitoring well is maintained to be more than 2 mg/L until hexavalent chromium in the underground water reaches the standard.
The preparation method of the modified carboxymethyl cellulose comprises the following steps: under nitrogen atmosphere, the mass ratio is 10:3:1:0.1:0.5:100, mixing carboxymethyl cellulose, methacrylic acid, acrylamide, ammonium persulfate, methylene bisacryloyl and water, uniformly stirring, reacting for 4.5 hours at 82 ℃, cleaning, and drying to obtain the modified carboxymethyl cellulose.
Polyvinyl alcohol, commercially available from merck, model 363170. Carboxymethyl cellulose is available from microphone under model C804618.
The preparation method of the modified attapulgite comprises the following steps: the ratio of the attapulgite to the 30v/v% nitric acid aqueous solution is 1g/35mL, and after mixing, stirring and reacting for 35min at 30 ℃, centrifuging, washing to be neutral, drying and grinding. The specific surface area of the prepared modified attapulgite is 21m 2 Per gram, average pore volume of 0.102cm 3 And/g, average pore diameter of 21.7nm.
The mass ratio of the modified carboxymethyl cellulose to the polyvinyl alcohol to the modified attapulgite to the powder is 2:3:1:5.
the ratio of the adsorbent to hexavalent chromium reducing bacteria liquid is 75g/366mL.
The density of active bacterial cells in the hexavalent chromium reduction bacterial liquid is 7 multiplied by 10 9 And each mL.
The cell density ratio of the pseudomonas stutzeri, the slender lysine bacillus and the bacillus cereus in the hexavalent chromium reducing bacterial liquid is 4:2:1.
the carboxymethyl cellulose has a Mw of 90000.
Comparative example 1
The difference between this comparative example and example 1 is: this comparative example was carried out on groundwater from a landfill B of inner mongolia, at a pH of 8.6. The adsorbent is ferrous sulfate.
Comparative example 2
The difference between this comparative example and example 1 is: this comparative example was performed to repair groundwater from a landfill C of the inner mongolia,the pH was 8.5. The preparation method of the adsorbent comprises the following steps: pyrolyzing soybean hull at 520 deg.C for 5 hr, pulverizing, and sieving with 80 mesh sieve to obtain powder; the powder was mixed with 7g/L FeCl under nitrogen atmosphere 3 ·6H 2 The O aqueous solution is prepared according to the solid-to-liquid ratio of 1:40, stirring for 25h, vacuum filtering, and drying at 75 ℃ for 20h in an oven to obtain the adsorbent.
Comparative example 3
The difference between this comparative example and example 1 is: this comparative example was performed to repair the groundwater from a landfill D at pH 8.7. The hexavalent chromium reduction bacterial liquid contains cells with density ratio of 1:1:1 Paenibacillus terrae, bacillus circulans and Bacillus cereus; paenibacillus terrae, accession number: cctcbasb 206026. Bacillus circulans accession number ATCC 61.
Comparative example 4
The difference between this comparative example and example 1 is: the preparation method of the adsorbent is not added with modified carboxymethyl cellulose.
Comparative example 5:
the difference between this comparative example and example 1 is: the preparation method of the adsorbent uses carboxymethyl cellulose to replace modified carboxymethyl cellulose.
Comparative example 6
The difference between this comparative example and example 1 is: in the preparation method of the adsorbent, bentonite is used for replacing modified attapulgite.
Comparative example 7
The difference between this comparative example and example 1 is: in the preparation method of the adsorbent, attapulgite is used for replacing modified attapulgite.
Comparative example 8
The difference between this comparative example and example 1 is: in the preparation method of the adsorbent, modified carboxymethyl cellulose is not used, and the omitted modified carboxymethyl cellulose is added to the modified attapulgite, namely, the mass ratio of polyvinyl alcohol, the modified attapulgite and the powder is 3:3:5.
comparative example 9
The difference between this comparative example and example 1 is: in the preparation method of the adsorbent, modified attapulgite is not used, and the omitted dosage of the modified attapulgite is added to modified carboxymethyl cellulose; namely, the mass ratio of the modified carboxymethyl cellulose to the polyvinyl alcohol to the powder is 3:3:5.
performance testing
The number of sampling points of the underground water of the landfill sites of the examples and the comparative examples is 10, and the sampling points are selected to be mutually isolated so as to reduce the mutual influence among the test points. Then, after the restoration, the average value of hexavalent chromium and total petroleum hydrocarbon before and after restoration was calculated, and the degradation rate of 2, 4-dichlorophenol before and after restoration (degradation rate= (concentration before restoration-concentration after restoration)/concentration before restoration×100%) was calculated, and the result is shown in table 1.
Table 1: results of Performance test
The result shows that the repairing method has good repairing effect on the underground water of the refuse landfill, and can realize the combined repairing of hexavalent chromium, total petroleum hydrocarbon and 2, 4-dichlorophenol.
As can be seen from the comparison of comparative example 4 and example 1, the addition of modified carboxymethyl cellulose according to the present invention can significantly enhance the healing effect; and the modified carboxymethyl cellulose has better repairing effect compared with carboxymethyl cellulose, and can better realize the combined repairing of hexavalent chromium, total petroleum hydrocarbon and 2, 4-dichlorophenol, wherein the content can be obtained by comparing the embodiment 1 with the comparative examples 4 and 5.
As can be seen from the comparison of comparative example 7 and example 1, the addition of the modified attapulgite clay according to the invention can enhance the healing effect to a higher extent, so that the combined healing of hexavalent chromium, total petroleum hydrocarbon and 2, 4-dichlorophenol is excellent. When other clay such as bentonite is used instead of the modified clay of the present invention, the obtained restoration effect is poor, which can be obtained by comparing example 1 with comparative example 6; from this, it is clear that the modified attapulgite clay of the present invention is in a mutually promoting relationship with the system of the present invention, and that the effect of the present invention cannot be produced by using other clay.
The modified attapulgite of the invention, the polyvinyl alcohol and the modified attapulgite have a mutual promotion effect on the combined restoration effect of hexavalent chromium, total petroleum hydrocarbon and 2, 4-dichlorophenol, the three are not simple superposition of effects, the three components are mutually influenced, and a synergistic restoration effect can be generated, and the content can be obtained from the comparison of the embodiment 1 and the comparative examples 8-9.
While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.
Claims (7)
1. The in-situ chemical and biological combined restoration method for chromium-polluted underground water is characterized by being aimed at restoration of the underground water of a landfill site with pH of 8-10, and comprises the following steps:
(1) Arranging underground water restoration well groups, and arranging underground water monitoring wells in the middle of the restoration wells;
(2) Injecting an adsorbent into each repair well until the hexavalent chromium concentration in the underground water monitoring well is reduced to below 1.5 mg/L; the preparation method of the adsorbent comprises the following steps: pyrolyzing soybean hulls at 500-550 ℃ for 4-6 hours, crushing, and sieving with a 80-mesh sieve to obtain powder; under the nitrogen atmosphere, the powder and 6-8 g/L FeCl 3 ·6H 2 The O aqueous solution is prepared according to the solid-to-liquid ratio of 1: mixing 35-45, stirring for 20-30 h, continuously adding modified carboxymethyl cellulose, polyvinyl alcohol and modified attapulgite, continuously stirring for 10-15 h, vacuum filtering, and drying for 15-25 h at 70-80 ℃ in an oven to obtain an adsorbent; the preparation method of the modified carboxymethyl cellulose comprises the following steps: under nitrogen atmosphere, the mass ratio is 10:3:1:0.1:0.5:100, mixing carboxymethyl cellulose, methacrylic acid, acrylamide, ammonium persulfate, methylene bisacryloyl and water, uniformly stirring, reacting for 4.5 hours at 82 ℃, cleaning, and drying to obtain modified carboxymethyl cellulose; the preparation method of the modified attapulgite comprises the following steps: the feed liquid ratio of the attapulgite to the 25-35 v/v% nitric acid aqueous solution is 1 g/30-40 mL, after mixing, stirring and reacting for 30-40 min at 25-40 ℃, centrifuging, washing to be neutral, drying and grinding; the mass ratio of the modified carboxymethyl cellulose to the polyvinyl alcohol to the modified attapulgite to the powder is 1-3: 2-4: 1: 3-6;
(3) Pressurizing and injecting hexavalent chromium reducing bacteria liquid into each repair well, and continuously injecting compressed air for 20-30 minutes; the cell density ratio of the pseudomonas stutzeri, the slender lysine bacillus and the bacillus cereus in the hexavalent chromium reduction bacterial liquid is 2-6: 1-3: 1, a step of;
(4) And (3) aerating each repair well to ensure that the concentration of dissolved oxygen in the underground water monitoring well is maintained to be more than 2 mg/L until hexavalent chromium in the underground water reaches the standard.
2. The method for in-situ chemical biological joint repair of chromium-contaminated groundwater according to claim 1, wherein the preparation method of the modified attapulgite is as follows: the ratio of the attapulgite to the 30v/v% nitric acid aqueous solution is 1g/35mL, and after mixing, stirring and reacting for 35min at 30 ℃, centrifuging, washing to be neutral, drying and grinding.
3. The method for the in-situ chemical biological combined repair of chromium-contaminated groundwater according to claim 2, wherein the specific surface area of the modified attapulgite is 19-21 m 2 Per gram, the average pore volume is 0.095-0.104 cm 3 And/g, wherein the average pore diameter is 21.5-22 nm.
4. The method for in-situ chemical biological combined remediation of chromium-contaminated groundwater according to claim 1, wherein the ratio of the adsorbent to hexavalent chromium-reducing bacteria liquid is 60-90 g/230-450 mL.
5. The method for the in-situ chemical biological joint repair of chromium-contaminated groundwater according to claim 4, wherein the density of active bacterial cells in the hexavalent chromium-reducing bacterial liquid is 10 7 ~10 10 And each mL.
6. The method for the in-situ chemical biological joint repair of chromium-contaminated groundwater according to claim 1, wherein the ratio of cell densities of pseudomonas stutzeri, bacillus tenuipes and bacillus cereus in the hexavalent chromium reducing bacteria liquid is 4:2:1.
7. the method of claim 1, wherein the Mw of the carboxymethyl cellulose is 90000.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311250219.2A CN116986738B (en) | 2023-09-26 | 2023-09-26 | Chromium-polluted underground water in-situ chemical and biological combined restoration method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311250219.2A CN116986738B (en) | 2023-09-26 | 2023-09-26 | Chromium-polluted underground water in-situ chemical and biological combined restoration method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116986738A CN116986738A (en) | 2023-11-03 |
| CN116986738B true CN116986738B (en) | 2023-12-26 |
Family
ID=88534120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311250219.2A Active CN116986738B (en) | 2023-09-26 | 2023-09-26 | Chromium-polluted underground water in-situ chemical and biological combined restoration method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116986738B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019118982A1 (en) * | 2017-12-15 | 2019-06-20 | Bio-Cat Microbials Llc | Microbe combinations for bioremediation and methods of using the same |
| CN114653737A (en) * | 2022-04-02 | 2022-06-24 | 北京博诚立新环境科技股份有限公司 | In-situ chemical reduction and enhanced biological combined remediation method for hexavalent chromium contaminated soil and underground water |
| CN115261372A (en) * | 2022-06-24 | 2022-11-01 | 浙江大学 | Solid microbial inoculum for repairing electroplating polluted site and method and application thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105945050A (en) * | 2016-05-30 | 2016-09-21 | 青岛理工大学 | Cr (VI) heavy polluted site in-situ detoxification method based on biogas residue |
-
2023
- 2023-09-26 CN CN202311250219.2A patent/CN116986738B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019118982A1 (en) * | 2017-12-15 | 2019-06-20 | Bio-Cat Microbials Llc | Microbe combinations for bioremediation and methods of using the same |
| CN114653737A (en) * | 2022-04-02 | 2022-06-24 | 北京博诚立新环境科技股份有限公司 | In-situ chemical reduction and enhanced biological combined remediation method for hexavalent chromium contaminated soil and underground water |
| CN115261372A (en) * | 2022-06-24 | 2022-11-01 | 浙江大学 | Solid microbial inoculum for repairing electroplating polluted site and method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116986738A (en) | 2023-11-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109570227B (en) | Method for restoring acidified arsenic-polluted soil by using charcoal-loaded nano zero-valent iron and bacteria | |
| CN105478460A (en) | Bioremediation method of oil-contaminated soil | |
| CN108971220B (en) | Preparation method of pyrite microorganism combined permeable reaction wall | |
| CN106147775A (en) | A kind of biochemistry combined soil heavy metal pollution fixed and repaired agent and application | |
| CN109734199A (en) | Immobilized microorganism structural body and preparation method thereof | |
| CN113731367A (en) | Modified nano zero-valent iron-bio-based composite functional material and preparation method and application thereof | |
| CN104694525A (en) | Immobilization method of salt-tolerant and cold-tolerant compound strain and application of immobilization method | |
| CN110280582B (en) | Method for restoring organochlorine contaminated soil by zero-valent iron reduction combined with indigenous microorganisms | |
| CN108178246A (en) | A kind of environment-friendly type light electrolysis haydite and preparation method thereof | |
| CN112126437B (en) | Composite modified biomass charcoal stabilizer and preparation method and application thereof | |
| WO2022199445A1 (en) | Composite biochar for preventing and treating heavy metal pollution and preparation method therefor | |
| CN113248093A (en) | Ecological composite bottom mud in-situ restoration agent and restoration process | |
| CN113943580A (en) | Soil remediation material with dual functions of adsorption and degradation, and preparation and application thereof | |
| CN111778037A (en) | Conditioner for repairing organic contaminated soil and preparation method thereof | |
| CN113020249A (en) | Method for repairing soil arsenic pollution in arid region by using SAP (super absorbent polymer) reinforced manganese oxidizing bacteria | |
| CN109402003B (en) | Microbial agent for sludge reduction, carrier thereof and preparation method of carrier | |
| CN115231680A (en) | Preparation method and application of biochar loaded nano zero-valent iron material | |
| CN110104922A (en) | A kind of sediment in-situ biological curing repairs medicament and preparation method thereof | |
| CN109277405B (en) | Method for remediating arsenic-contaminated soil by using nano zero-valent iron and bacteria | |
| CN108690623B (en) | Nickel-polluted soil remediation agent and preparation method and use method thereof | |
| CN108114978B (en) | A kind of method of the efficient rehabilitating soil of chemistry-microorganism | |
| CN116986738B (en) | Chromium-polluted underground water in-situ chemical and biological combined restoration method | |
| CN115430401B (en) | Sulfur-doped biochar with carbon fixation and pollution reduction effects as well as preparation method and application thereof | |
| CN109847696A (en) | A kind of efficient preparation method for carrying the useless bacteria residue activated carbon from activated sludge of manganese for removing aniline in water body | |
| CN115093088A (en) | Preparation method of sludge synergistic decrement attenuation treatment agent |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |