CN114437732B - Compound leaching agent for arsenic-polluted soil and method for repairing arsenic-polluted soil - Google Patents
Compound leaching agent for arsenic-polluted soil and method for repairing arsenic-polluted soil Download PDFInfo
- Publication number
- CN114437732B CN114437732B CN202210073052.6A CN202210073052A CN114437732B CN 114437732 B CN114437732 B CN 114437732B CN 202210073052 A CN202210073052 A CN 202210073052A CN 114437732 B CN114437732 B CN 114437732B
- Authority
- CN
- China
- Prior art keywords
- arsenic
- soil
- leaching
- polluted soil
- tartaric acid
- 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
- 239000002689 soil Substances 0.000 title claims abstract description 145
- 238000002386 leaching Methods 0.000 title claims abstract description 74
- 238000000034 method Methods 0.000 title claims abstract description 39
- 150000001875 compounds Chemical class 0.000 title claims abstract description 29
- 239000003795 chemical substances by application Substances 0.000 title abstract description 28
- 229910052785 arsenic Inorganic materials 0.000 claims abstract description 87
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 claims abstract description 87
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 claims abstract description 29
- JVBXVOWTABLYPX-UHFFFAOYSA-L sodium dithionite Chemical compound [Na+].[Na+].[O-]S(=O)S([O-])=O JVBXVOWTABLYPX-UHFFFAOYSA-L 0.000 claims abstract description 29
- 239000003480 eluent Substances 0.000 claims abstract description 27
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 claims abstract description 18
- 230000010355 oscillation Effects 0.000 claims abstract description 18
- 235000002906 tartaric acid Nutrition 0.000 claims abstract description 18
- 239000011975 tartaric acid Substances 0.000 claims abstract description 18
- 239000007788 liquid Substances 0.000 claims description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 24
- 238000002156 mixing Methods 0.000 claims description 13
- 238000000926 separation method Methods 0.000 claims description 13
- 239000002699 waste material Substances 0.000 claims description 11
- 239000002131 composite material Substances 0.000 claims description 3
- 238000005067 remediation Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 13
- 238000013329 compounding Methods 0.000 abstract description 2
- 239000000243 solution Substances 0.000 description 26
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 24
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 16
- 229910052742 iron Inorganic materials 0.000 description 11
- 230000008439 repair process Effects 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 229910001385 heavy metal Inorganic materials 0.000 description 7
- 235000013980 iron oxide Nutrition 0.000 description 7
- KCZFLPPCFOHPNI-UHFFFAOYSA-N alumane;iron Chemical compound [AlH3].[Fe] KCZFLPPCFOHPNI-UHFFFAOYSA-N 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 5
- 229910052787 antimony Inorganic materials 0.000 description 5
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 5
- 229910052797 bismuth Inorganic materials 0.000 description 5
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 5
- 238000004090 dissolution Methods 0.000 description 5
- 238000004993 emission spectroscopy Methods 0.000 description 5
- 230000007613 environmental effect Effects 0.000 description 5
- 238000000605 extraction Methods 0.000 description 5
- 238000002795 fluorescence method Methods 0.000 description 5
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 5
- 229910052753 mercury Inorganic materials 0.000 description 5
- 238000000120 microwave digestion Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 239000013049 sediment Substances 0.000 description 5
- 229910052711 selenium Inorganic materials 0.000 description 5
- 239000011669 selenium Substances 0.000 description 5
- 238000007605 air drying Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 229910052500 inorganic mineral Inorganic materials 0.000 description 4
- 238000011835 investigation Methods 0.000 description 4
- 239000011707 mineral Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000007873 sieving Methods 0.000 description 4
- 238000005303 weighing Methods 0.000 description 4
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- JAQXDZTWVWLKGC-UHFFFAOYSA-N [O-2].[Al+3].[Fe+2] Chemical compound [O-2].[Al+3].[Fe+2] JAQXDZTWVWLKGC-UHFFFAOYSA-N 0.000 description 3
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 3
- 238000003900 soil pollution Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 241001465754 Metazoa Species 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- VETKVGYBAMGARK-UHFFFAOYSA-N arsanylidyneiron Chemical compound [As]#[Fe] VETKVGYBAMGARK-UHFFFAOYSA-N 0.000 description 2
- 238000010170 biological method Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- 238000011065 in-situ storage Methods 0.000 description 2
- 229910001608 iron mineral Inorganic materials 0.000 description 2
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical group [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 2
- 229910001710 laterite Inorganic materials 0.000 description 2
- 239000011504 laterite Substances 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 238000000053 physical method Methods 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- ZNCPFRVNHGOPAG-UHFFFAOYSA-L sodium oxalate Chemical compound [Na+].[Na+].[O-]C(=O)C([O-])=O ZNCPFRVNHGOPAG-UHFFFAOYSA-L 0.000 description 2
- 229940039790 sodium oxalate Drugs 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 206010028980 Neoplasm Diseases 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 238000005269 aluminizing Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 201000011510 cancer Diseases 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000011066 ex-situ storage Methods 0.000 description 1
- 230000003631 expected effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052752 metalloid Inorganic materials 0.000 description 1
- 230000000813 microbial effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000003607 modifier Substances 0.000 description 1
- 210000005036 nerve Anatomy 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 239000002574 poison Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 231100000167 toxic agent Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K17/00—Soil-conditioning materials or soil-stabilising materials
- C09K17/40—Soil-conditioning materials or soil-stabilising materials containing mixtures of inorganic and organic compounds
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Environmental & Geological Engineering (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The invention discloses a compound leaching agent for arsenic-polluted soil and a method for repairing the arsenic-polluted soil. The compound eluent consists of sodium dithionite and tartaric acid, arsenic-polluted soil and the compound eluent are uniformly mixed, and arsenic in the soil can be effectively removed by oscillation leaching. The invention utilizes the combination and the compounding of the sodium dithionite and the tartaric acid, can effectively reduce the content of arsenic in polluted soil, has the arsenic removal rate of more than 80 percent, has simple components of the leaching agent, obvious effect and low cost, and has good application prospect.
Description
Technical Field
The invention relates to the technical field of arsenic-polluted soil treatment and restoration, in particular to a compound leaching agent for arsenic-polluted soil and an arsenic-polluted soil restoration method.
Background
Arsenic is a toxic and carcinogenic metalloid element, one of five poisons for environmental pollution, listed as a first type of pollutant in environmental protection standards. The domestic arsenic pollution mainly comes from mining of arsenic-containing ores, waste in smelting process and industrial waste residues of arsenic production enterprises, and has the characteristics of wide pollution range, deep pollution degree, serious hazard and the like. According to the national soil pollution condition investigation publication issued by the national environmental protection department and the national resource department in 2014, the total overstandard rate of the national soil pollution is 16.1%, and the heavy metal pollution occupies a larger proportion, wherein the overstandard rate of the arsenic point is 2.7%. The investigation shows that the soil environment conditions of the whole country are not optimistic, the soil pollution problem of partial areas is serious, the soil environment quality of cultivated lands is candid, and the soil environment problem of industrial and mining abandoned lands is prominent. The red loam is mainly distributed in the lower hilly areas of the south of the Yangtze river in China, and comprises most of the two provinces of Jiangxi and Hunan, and southern areas of Guangdong and the like. Red soil is called as iron-aluminum soil mainly because the formation of main red soil is a desilication iron-rich aluminizing process, and in the soil, the iron-aluminum content is high, and elements such as silicon, calcium, magnesium, sodium and the like are low. According to investigation, arsenic pollution accounts for a relatively large proportion in heavy metal pollution of soil in southern China, and the arsenic enters the soil to form oxides with relatively good stability with iron and aluminum in red loam. The soil with high iron, aluminum and arsenic pollution in the south of China becomes a soil type with wide typical range distribution and special arsenic pollution. Arsenic exists mainly in five forms in the soil, and in the laterite with high iron and aluminum content, arsenic exists mainly in two forms of amorphous and poorly crystalline hydrous oxides of iron and aluminum and well-crystallized hydrous oxides of iron and aluminum. Arsenic and iron aluminum in the two forms form iron aluminum oxide with better stability, so the difficulty for repairing the arsenic-polluted soil is higher. In addition, arsenic accumulated in this type of contaminated soil is difficult to eliminate by dilution and self-cleaning, nor is it decomposed by soil microorganisms; in contrast, organisms can enrich arsenic, so that arsenic is often accumulated gradually in soil environment, even arsenic can be converted into more toxic compounds in soil, and the arsenic is accumulated in human bodies through food chains in harmful concentration, so that the health of the human bodies is seriously endangered, bones and nerves can be damaged to different degrees after the human bodies ingest the heavy metals, and the probability of cancer is increased. Therefore, the method has important significance for repairing the arsenic-polluted soil in the south red loam.
The current method for remedying arsenic-polluted soil mainly comprises a physical method, a chemical method and a biological method. The physical method mainly adopts a certain engineering technology and means to repair the polluted soil, and comprises methods such as a soil-alien method, a soil-changing method and the like. The chemical method mainly comprises an in-situ passivation method, an in-situ leaching method and an ex-situ leaching method, and mainly aims to directionally change the existence form of arsenic in soil by adding certain chemical reagents or modifiers, reduce the bioavailability of the arsenic by the actions of separation, adsorption, conversion and the like, or promote the dissolution or accelerated migration of pollutants in the soil by leaching agents so that the arsenic in the soil migrates into the leacheate and flows out along with the leaching agents. Biological methods mainly comprise animal repair, plant repair and microbial repair, and are methods for removing arsenic from soil, improving soil quality and restoring soil functions by using natural or genetically engineered microorganisms or plants and specific animals.
Compared with other technologies, the soil ectopic leaching technology is one of the main technologies for researching the repair of the arsenic pollution of the soil at present due to the characteristics of short repair period, high removal efficiency, stable effect and the like. The key point of leaching and restoring the arsenic-polluted soil is to find an economic and efficient leaching agent, and different leaching agents are also selected according to the existence form of arsenic in the soil and the type characteristics of the soil. In the remediation of arsenic contaminated soil, it is necessary to repair various forms of arsenic, particularly the form with the highest content, so that a greater degree of arsenic removal from the soil can be achieved.
For the restoration of arsenic-contaminated soil in which arsenic-contaminated soil is mainly bound to iron-aluminum oxide, korean patent publication No. KR2015073289 (a) discloses a restoration method for iron-aluminum-rich arsenic-contaminated soil, which discloses that arsenic bound to iron or aluminum amorphous oxide is extracted by contact with arsenic-contaminated soil under acidic conditions using sodium oxalate as a eluent. The method mainly extracts most of arsenic in amorphous iron aluminum oxide in the soil through sodium oxalate, but has great limitation on extraction of other forms with high arsenic content in the soil.
The Chinese patent publication No. CN111957731A discloses a sulfur-induced stabilization treatment method for iron-rich arsenic-polluted soil, which utilizes sodium sulfide solution to induce and accelerate the conversion of amorphous iron oxide in the soil into steady-state iron minerals, so that arsenic initially adsorbed on the surface of the iron oxide enters into a steady-state iron mineral structure, thereby improving the stability of arsenic in the soil and reducing the migration and toxicity of arsenic in the arsenic-polluted soil. According to the method, the original unstable arsenic is transferred into stable iron ores through stabilizing treatment of the iron-rich arsenic polluted soil, but the method does not remove the total arsenic content in the soil from the root, the stability of the arsenic-iron-containing minerals is reduced along with the change of time and environment, and the arsenic in the arsenic-iron-containing minerals is released again to cause secondary pollution of the arsenic, so that the environmental risk is increased.
According to investigation, in the current typical iron-aluminum-rich arsenic-polluted soil leaching restoration cases for the south red loam, most leaching agents are poor in effect in restoring polluted soil, and the expected effect cannot be achieved. Therefore, development of a compound leaching agent for repairing the southern red loam arsenic-polluted soil and an application method thereof are very necessary.
Disclosure of Invention
The invention aims to realize the restoration of arsenic-polluted soil, and provides a compound leaching agent for restoring the arsenic-polluted soil in the south red loam and an application method thereof. Firstly, sodium dithionite and tartaric acid are prepared into a single leaching agent solution, and then the two solutions are combined into a compound leaching agent according to different concentrations and volumes; the arsenic polluted soil is pretreated by air drying, impurity removal, grinding, sieving and the like, and is evenly mixed with a certain amount of compound leaching agent, and then is put into an oscillator for oscillation leaching experiments. According to the invention, two leaching agents of sodium dithionite with reducibility and tartaric acid with complexation are selected for compounding and combining, the sodium dithionite extracts arsenic in polluted soil through reduction and dissolution of ferric oxide related to the arsenic, and the tartaric acid is added to form a complex with the dissolved iron, so that the extraction of the reduced arsenic is greatly enhanced, the precipitation of a new ferric oxide phase is prevented, the dissolution of the ferric oxide is enhanced through a non-reduction dissolution way, in addition, the addition of the tartaric acid can have a removal effect on other forms of arsenic in the soil, and the leaching amount of arsenic in the laterite is further increased by the combination of the two leaching agents. Aiming at the remediation of the arsenic-polluted soil in the south red loam, the iron oxide form with stronger stability in the arsenic-polluted soil is extracted by adding the compound leaching agent, and the compound leaching agent has better effect on leaching and remediating the arsenic-polluted soil in the south red loam.
The invention provides a method for repairing arsenic-polluted soil, which is characterized by comprising the following steps:
1) Uniformly mixing the compound eluent with arsenic-polluted soil, and carrying out oscillation leaching; wherein the compound eluent is obtained by mixing sodium dithionite and tartaric acid solution;
2) Performing solid-liquid separation on the soil after the oscillation leaching, removing leaching waste liquid, adding clear water, and continuing the oscillation leaching;
3) And (3) carrying out solid-liquid separation on the soil washed by the clear water, and removing the clear water to obtain the repaired soil.
Preferably, the formulated eluent is composed of the following components in molar concentration: 0.1-0.3 mol/L sodium dithionite: 30% -80% of a volume part; and 0.05 to 0.6mol/L tartaric acid: 20% -70% of a total of the components.
Preferably, the solid-to-liquid ratio of the composite eluent to the polluted soil in the step 1) is 1g and 10-20 mL; preferably, the arsenic-contaminated soil is southern red loam. Further preferably, in the step 1), the oscillation leaching time is 6-8 hours;
in a specific embodiment, the oscillators in the step 1) and the step 2) are used for oscillating and leaching, and the rotating speed is 180-200 r/min;
preferably, in the step 2), the oscillation leaching time is 0.5-1 h;
in a specific embodiment, in the step 3), the solid-to-liquid ratio of the clean water to the leached arsenic-polluted soil is 1g, and the solid-to-liquid ratio is 5-10 mL;
the invention also provides a compound leaching agent for repairing arsenic-polluted soil, which is characterized by being prepared by mixing sodium dithionite and tartaric acid solution.
Preferably, the eluent in S1 consists of the following components in molar concentration: 0.1-0.3 mol/L sodium dithionite: 30% -80% of a volume part; and 0.05 to 0.6mol/L tartaric acid: 20% -70% of a total of the components.
The invention further provides application of the compound eluent in repairing arsenic-polluted soil, in particular to arsenic-polluted soil of southern red loam.
Compared with the prior art, the invention has the following beneficial effects: the arsenic strengthening extraction of amorphous and crystalline iron oxide is realized by combining sodium dithionite and tartaric acid to form the compound eluting agent.
Sodium dithionite has better dissolution effect on arsenic-containing crystalline iron oxide, but the research of the invention discovers that arsenic can be re-adsorbed by a newly formed iron oxide phase in soil, so that the extraction effect of the single sodium dithionite on the arsenic is not obvious; tartaric acid has a good extraction effect on arsenic combined with amorphous iron oxide. Simultaneously, sodium dithionite and tartaric acid are used, and arsenic combined in amorphous and crystalline iron oxides is effectively removed through induction synergistic effect, so that new minerals are reduced, the main form removal amount of arsenic in the red loam is increased, and the restoration effect of arsenic pollution in the south red loam is further improved.
The invention further screens out proper concentration, volume ratio and eluting process parameter range of the eluting agent by changing the volume ratio and molar concentration of the sodium dithionite and the tartaric acid and the eluting process parameter, and the compound eluting agent prepared under the condition effectively reduces the formation of secondary minerals, improves the removal rate of arsenic in soil and effectively reduces the content of arsenic in the soil.
The leaching method has the advantages of simple leaching process and short treatment time, further shortens the operation time and greatly reduces the treatment cost. The tartaric acid of the composite eluent belongs to biodegradable organic acid, has small influence on the physical and chemical properties and structure of soil, reduces secondary pollution to the soil, can compensate some nutrient components in the soil, and is suitable for popularization and use.
Detailed Description
In order to make the technical content, achieve the purpose and effect of the present invention better presented, a specific embodiment will be further described below. It will be apparent that the embodiments described below are only some, but not all, embodiments of the invention. 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. The test methods used in the examples are conventional methods unless otherwise specified; the materials, reagents and the like used, unless otherwise specified, are those commercially available.
Example 1
Collecting a certain actual polluted site in the south, naturally air-drying, removing impurities, and crushing and sieving with a 60-mesh sieve. The basic physicochemical properties and heavy metal content of the soil are shown in table 1.
TABLE 1 basic physicochemical Properties of soil and heavy Metal content
| Moisture content (%) | Soil type | As(mg/kg) | Fe(mg/kg) | Al(mg/kg) | Mn(mg/kg) |
| 10.55 | Red loam | 70 | 20042.65 | 26071.25 | 283.45 |
1. Weighing sodium dithionite, respectively dissolving tartaric acid in water of different containers, and uniformly mixing to obtain 0.1mol/L sodium dithionite solution and 0.6mol/L tartaric acid solution;
2. mixing 0.1mol/L sodium dithionite solution with 40% of the volume and 0.6mol/L tartaric acid solution with 60% of the volume to obtain the compound eluent;
3. under the condition of room temperature, the compound eluent and 3g of arsenic-polluted soil are uniformly mixed according to the solid-to-liquid ratio (g: ml) of 1:10, and the mixture is stirred in a shaker for 180 r.min -1 Oscillating and leaching for 6h;
4. carrying out liquid-solid separation on the soil after the oscillation leaching, collecting leaching waste liquid, adding clear water into a container according to the solid-liquid ratio (g: ml) of 1:5, and continuing to carry out the oscillation leaching in an oscillator for 0.5h;
5. and (3) carrying out liquid-solid separation on the soil washed by the clear water, and removing the clear water to obtain the repaired soil.
After the reaction is finished, determining the arsenic concentration in the leaching waste liquid by adopting an atomic fluorescence emission spectrometry; and (3) determining the content of residual arsenic in the soil after leaching according to a microwave digestion/atomic fluorescence method (HJ 832-2017) for determining mercury, arsenic, selenium, bismuth and antimony in the soil and sediment.
After the method is adopted for restoration, the arsenic content of the original arsenic polluted soil is reduced from 70mg/kg to 21.98mg/kg, the removal rate is up to 68.6%, and the content of the post-restoration polluted soil tombstone reaches the national secondary standard of the soil environment quality.
Example 2
1. Weighing sodium dithionite, respectively dissolving tartaric acid in water of different containers, and uniformly mixing to obtain 0.2mol/L sodium dithionite solution and 0.5mol/L tartaric acid solution;
2. mixing 50% of 0.2mol/L sodium dithionite solution and 50% of 0.05mol/L tartaric acid solution to obtain the compound eluent;
3. under the condition of room temperature, the compound eluent and 3g of arsenic-polluted soil with the same example 1 are uniformly mixed according to the solid-to-liquid ratio (g: ml) of 1:15, and the mixture is stirred in a shaker for 180 r.min -1 Oscillating and leaching for 8 hours;
4. solid-liquid separation is carried out on the soil after the oscillation leaching, leaching waste liquid is collected, clear water is added into a container according to the solid-liquid ratio (g: ml) of 1:10, and the oscillation leaching is carried out in an oscillator for 1h;
5. and (3) carrying out solid-liquid separation on the soil washed by the clear water, and removing the clear water to obtain the repaired soil.
After the reaction is finished, determining the arsenic concentration in the leaching waste liquid by adopting an atomic fluorescence emission spectrometry; and (3) determining the content of residual arsenic in the soil after leaching according to a microwave digestion/atomic fluorescence method (HJ 832-2017) for determining mercury, arsenic, selenium, bismuth and antimony in the soil and sediment.
After the method is adopted for restoration, the arsenic content of the original arsenic polluted soil is reduced from 70mg/kg to 13.055mg/kg, the removal rate is up to 81.35%, and the content of the post-restoration polluted soil reaches the national first-level standard of the environmental quality of the soil.
Example 3
Collecting a certain actual polluted site in Guangzhou city, naturally air-drying, removing impurities, crushing, and sieving with a 60-mesh sieve. The basic physicochemical properties and heavy metal content of the soil are shown in Table 2.
TABLE 2 basic physicochemical Properties of soil and heavy Metal content
| Moisture content (%) | Soil type | As(mg/kg) | Fe(mg/kg) | Al(mg/kg) | Mn(mg/kg) |
| 8.8 | Red loam | 134 | 18874.5 | 29559.45 | 282.16 |
1. Weighing sodium dithionite, respectively dissolving tartaric acid in water of different containers, and uniformly mixing to obtain 0.2mol/L sodium dithionite solution and 0.05mol/L tartaric acid solution;
2. mixing 0.2mol/L sodium dithionite solution with 80% of the volume and 0.4mol/L tartaric acid solution with 20% of the volume to obtain a compound eluent;
3. under the condition of room temperature, the compound eluent and 3g of arsenic-polluted soil are uniformly mixed in a container according to the solid-to-liquid ratio (g: ml) of 1:10, and the mixture is stirred in an oscillator for 200r.min -1 Oscillating and leaching for 6h;
4. solid-liquid separation is carried out on the soil after the oscillation leaching, leaching waste liquid is collected, clear water is added into a container according to the solid-liquid ratio (g: ml) of 1:10, and the oscillation leaching is carried out in an oscillator for 1h;
5. and (3) carrying out solid-liquid separation on the soil washed by the clear water, and removing the clear water to obtain the repaired soil.
After the reaction is finished, determining the arsenic concentration in the leaching waste liquid by adopting an atomic fluorescence emission spectrometry; and (3) determining the content of residual arsenic in the soil after leaching according to a microwave digestion/atomic fluorescence method (HJ 832-2017) for determining mercury, arsenic, selenium, bismuth and antimony in the soil and sediment.
After the method is adopted for restoration, the arsenic content of the original arsenic polluted soil is reduced from 134mg/kg to 41.5mg/kg, the removal rate is up to 69.03 percent, and the content of the post-restoration polluted soil reaches the national secondary standard of the environmental quality of the soil.
Example 4
1. Weighing sodium dithionite, respectively dissolving tartaric acid in water of different containers, and uniformly mixing to obtain 0.3mol/L sodium dithionite solution and 0.2mol/L tartaric acid solution;
2. mixing 30 parts by volume of 0.3mol/L sodium dithionite solution and 70 parts by volume of 0.2mol/L tartaric acid solution to obtain the compound eluent;
3. under the condition of room temperature, the compound eluent and 3g of arsenic-polluted soil with the same example 3 are uniformly mixed according to the solid-to-liquid ratio (g: ml) of 1:20, and the mixture is stirred in a shaker for 200r.min -1 Oscillating and leaching for 8 hours;
4. adding clear water into the container according to the solid-to-liquid ratio (g: ml) of 1:10, and continuously oscillating and leaching in a horizontal oscillator for 1h;
5. and (3) carrying out solid-liquid centrifugal separation on the soil washed by the clear water, and removing the clear water to obtain the repaired soil.
After the reaction is finished, determining the arsenic concentration in the leaching waste liquid by adopting an atomic fluorescence emission spectrometry; and (3) determining the content of residual arsenic in the soil after leaching according to a microwave digestion/atomic fluorescence method (HJ 832-2017) for determining mercury, arsenic, selenium, bismuth and antimony in the soil and sediment.
After the method is adopted for restoration, the arsenic content of the original arsenic-polluted soil is reduced from 134mg/kg to 35.6mg/kg, the removal rate is up to 73.42%, and the arsenic content of the restored polluted soil reaches the national secondary standard of the soil environment quality.
Comparative example
Leaching effect of single leaching agent on arsenic-polluted soil:
comparative example 1: an arsenic contaminated soil eluent, which is a 0.2mol/L sodium dithionite solution.
Comparative example 2: an arsenic-contaminated soil eluent, which is a 0.05mol/L tartaric acid solution.
Comparative example 3: an arsenic contaminated soil eluent, which is 0.4mol/L oxalic acid solution.
Comparative example 4: an arsenic contaminated soil eluent, which is a 0.4mol/L phosphoric acid solution.
The arsenic-contaminated soil leaching agent is used for repairing arsenic-contaminated soil, and the specific operation is as follows:
collecting from a certain actual polluted site in Guangzhou city, naturally air-drying, removing impurities, crushing, sieving with a 60-mesh sieve, and measuring the arsenic content to be 134mg/kg. The specific steps for exploring the leaching effect under the condition of a single leaching agent are as follows: adding 30ml of single eluent into a container filled with 3g of arsenic-polluted soil according to a solid-to-liquid ratio (g: ml) of 1:10, and stirring at 200r.min in a shaker -1 After shaking for 6 hours, solid-liquid separation was performed, and the supernatant was collected for measurement. Wherein, the arsenic concentration in the leaching waste liquid is measured by adopting an atomic fluorescence emission spectrometry; in the soil after leachingAnd (3) determining the content of residual arsenic in the soil according to a microwave digestion/atomic fluorescence method (HJ 832-2017) for determining mercury, arsenic, selenium, bismuth and antimony in soil and sediment. After the repair by adopting the method, the arsenic removal rates in comparative examples 1-4 of the invention are respectively as follows: 7.99%, 6.83%, 21.31%, 24.78%.
In summary, as can be seen from examples 1 to 4 and comparative examples 1 to 4, compared with a single leaching agent, the compound leaching agent provided by the invention has a great improvement compared with the prior art in the effect of repairing the high iron-aluminum-containing arsenic pollution of the south red loam, and remarkably improves the arsenic removal rate of polluted soil.
The above examples are only for illustrating the technical solution of the present invention, but the embodiments of the present invention are not limited by the above examples; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principles of the invention should be made in the form of the equivalent substitutions without departing from the spirit and scope of the embodiments of the invention.
Claims (5)
1. A method for remediation of arsenic contaminated south red soil comprising the steps of:
1) Uniformly mixing the compound eluent with arsenic-polluted soil, and carrying out oscillation leaching; wherein the compound eluent is obtained by mixing sodium dithionite and tartaric acid solution; wherein, the eluent is composed of the following components: 0.1-0.3 mol/L sodium dithionite: 30% -80% of a volume part; and 0.05 to 0.6mol/L tartaric acid: 20% -70% of a volume part;
2) Performing solid-liquid separation on the soil after the oscillation leaching, removing leaching waste liquid, adding clear water, and continuing the oscillation leaching;
3) Carrying out solid-liquid separation on the soil washed by the clear water, and removing the clear water to obtain the repaired soil;
wherein, the solid-liquid ratio of the composite eluent to the polluted soil in the step 1) is 1g to 10-20 mL.
2. The method of claim 1, wherein the oscillation leaching time in step 1) is 6-8 hours.
3. The method according to claim 1, wherein the oscillators in step 1) and step 2) are used for rinsing at a rotational speed of 180-200 r/min.
4. The method of claim 1, wherein the oscillation rinse time in step 2) is 0.5 to 1 hour.
5. The method of claim 1, wherein the solid-to-liquid ratio of the clean water to the arsenic-contaminated soil after leaching in step 3) is 1 g/5-10 ml.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210073052.6A CN114437732B (en) | 2022-01-21 | 2022-01-21 | Compound leaching agent for arsenic-polluted soil and method for repairing arsenic-polluted soil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210073052.6A CN114437732B (en) | 2022-01-21 | 2022-01-21 | Compound leaching agent for arsenic-polluted soil and method for repairing arsenic-polluted soil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114437732A CN114437732A (en) | 2022-05-06 |
| CN114437732B true CN114437732B (en) | 2023-10-24 |
Family
ID=81366817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210073052.6A Active CN114437732B (en) | 2022-01-21 | 2022-01-21 | Compound leaching agent for arsenic-polluted soil and method for repairing arsenic-polluted soil |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114437732B (en) |
-
2022
- 2022-01-21 CN CN202210073052.6A patent/CN114437732B/en active Active
Non-Patent Citations (2)
| Title |
|---|
| Eun Jung Kim et al..Role of reducing agent in extraction of arsenic and heavy metals from soils by use of EDTA.Chemosphere.2016,第152卷第274-283页. * |
| 林海等.砷污染农田土壤的化学修复技术研究进展.环境污染与防治.2020,第42卷(第6期),第780-787页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114437732A (en) | 2022-05-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106282585B (en) | A kind of detoxification classification resource utilization method of domestic garbage incineration flyash | |
| CN103406333B (en) | A kind of Safe disposal method for high-concentration arsenic residue | |
| CN105598148A (en) | Method for repairing volatile organic matter and heavy metal chromium combined polluted soil | |
| CN104845629A (en) | Leaching agent and leaching method for repairing heavy metal contaminated soil | |
| CN106825018A (en) | A kind of composite chemical ELUTION METHOD of efficient restoration of soil polluted by heavy metal | |
| CN104289515A (en) | Heavy metal contaminated soil washing method | |
| CN104190701A (en) | Leaching method for remediation of arsenic polluted soil by using magnetic separation | |
| CN102107208A (en) | Method for restoring heavy metal polluted soil in mine field | |
| CN103555338A (en) | Method and eluting agent for joint treatment of lead-zinc pollution by surfactant and chelating agent | |
| CN105950153A (en) | Composite stabilizer for contaminated soil and method for treating contaminated soil by virtue of composite stabilizer | |
| CN103521512A (en) | Sepiolite-chitosan composite material capable of repairing soils containing lead and cadmium and preparation method thereof | |
| CN116474720A (en) | Preparation method and application of red mud-based enhanced magnetic straw biochar material | |
| CN109985899B (en) | Heavy metal contaminated soil treatment method | |
| CN113070332B (en) | Compound eluting agent for repairing polycyclic aromatic hydrocarbon contaminated soil and application thereof | |
| CN109807165A (en) | Heavy metal leaching and reducing method for cadmium-polluted soil | |
| CN101597185B (en) | Method for removing heavy metals from waste compost by united elution by ammonium sulfate and oxalic acid | |
| CN102327894A (en) | Method for removing lead from heavy metal soil leacheate | |
| CN113649410A (en) | Process for repairing heavy metal pollution of soil by using nano repairing material | |
| CN114437732B (en) | Compound leaching agent for arsenic-polluted soil and method for repairing arsenic-polluted soil | |
| CN102327893B (en) | Material for removing lead in heavy-metal soil leacheate as well as preparation method and application thereof | |
| CN112222180A (en) | Heavy metal lead contaminated soil remediation method based on choline chloride eutectic solvent | |
| CN102115299A (en) | Preparation method and usage of mineral stabilizer for controlling release of phosphor and heavy metals in dredged sediment | |
| CN110665960A (en) | Chemical leaching remediation process for chromium-contaminated soil | |
| CN114316994B (en) | Heavy metal restoration agent and preparation method and application thereof | |
| CN113814255A (en) | Antimony tailing harmless treatment technology based on inorganic flocculant |
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 |