CN110665960A - Chemical leaching remediation process for chromium-contaminated soil - Google Patents
Chemical leaching remediation process for chromium-contaminated soil Download PDFInfo
- Publication number
- CN110665960A CN110665960A CN201911125982.6A CN201911125982A CN110665960A CN 110665960 A CN110665960 A CN 110665960A CN 201911125982 A CN201911125982 A CN 201911125982A CN 110665960 A CN110665960 A CN 110665960A
- Authority
- CN
- China
- Prior art keywords
- soil
- chromium
- chemical leaching
- remediation process
- water
- 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.)
- Pending
Links
Images
Classifications
-
- 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
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The invention discloses a chemical leaching remediation process for chromium-contaminated soil, which comprises the following steps: s1, soil dispersion: excavating polluted plot soil, and processing the plot soil into soil particles through a crusher for later use; s2, oxidizing organic matters: placing the soil particles into a stirrer, adding water, and then adding a mixture of the soil particles and water in a weight ratio of 1: fully stirring 100 dispersant sodium acrylate and oxidant hydrogen peroxide, and oxidizing soil to obtain oxidized soil; s3, chemical leaching: putting the oxidized soil into a leaching container, adding a citric acid solution into the oxidized soil in an amount of 1L/Kg while stirring, and leaching circularly for 10min at the same time to obtain leached soil; and S4, adding the biomass charcoal into the chemically washed soil according to the parts by weight, and adding water to fully stir and mix the mixture to obtain the restored soil. The whole repairing process can avoid causing unnecessary secondary pollution while reducing the content of Cr (VI) in the soil. Meanwhile, the whole method is simple and convenient to implement and short in repair period.
Description
Technical Field
The invention belongs to the technical field of soil pollution remediation methods, and particularly relates to a chemical leaching remediation process for chromium-polluted soil.
Background
Chromium is widely existed in nature, and minerals formed in a natural state are mainly chromite. There are two main sources of environmental chromium: natural and man-made sources. The main way of natural chromium source is rock weathering, which is mainly chromite FeCr in nature2O4The form exists. Is prepared from chromium oxide through reduction with aluminium or from chromium ammonia alum or chromic acid through electrolysis. As the most important metal in modern technology, chrome nickel steels alloyed in different percentages vary widely, especially in the field of metal alloys. However, environmental pollution caused by chromium is becoming serious.
The artificial source of the chromium pollution source is the discharge of three wastes (waste gas, waste water and waste residue) containing chromium in industrial and agricultural production, the artificial source is the main cause of chromium pollution of soil, and the industrial activities of digging and processing of chromium ore, chromium salt production, electroplating, printing and dyeing, leather making and the like can cause the chromium pollution of the soil. Chromium is usually present in field soils in both cr (iii) and cr (vi) forms. Cr (VI) is mostly soluble in water, mainly in HCrO4-And CrO4 2-The two forms exist, the chemical activity is high, the toxicity and the mobility are strong, and the threat to underground water is large. Relevant researches show that Cr (VI) and Cr (III) carried by water and infiltrated into soil have different adsorption characteristics in the soil and different migration speeds. After Cr (III) enters the soil, more than 90 percent of Cr (III) is rapidly adsorbed and fixed by the soil, can be doped into mineral lattices or adsorbed on the surface of the mineral, causes little free Cr (III), has lower activity and is used for against plantsThe toxicity of the product is relatively small. Therefore, Cr (III) is easy to be trapped by soil, Cr (VI) is easy to migrate in soil, and when leachate with high chromium concentration is stored or discharged in a pit, the leachate can quickly reach saturation on the upper layer of the soil and then is adsorbed and moved into underground water, so that the underground water is damaged.
The engineering restoration and treatment of the cadmium polluted soil mainly comprises the following approaches: 1) a dilution method, wherein the chromium in the soil is diluted by doping clean soil, so that the concentration of the chromium is reduced; 2) changing the existing form of chromium, physically isolating pollutants or converting pollutants into chemically inactive forms through a solid form, changing the existing form of chromium in soil, reducing hexavalent chromium into trivalent chromium, reducing the migration capacity and bioavailability of the trivalent chromium in the environment, and further reducing the harm of chromium pollutants; 3) chromium is removed from the soil, i.e. heavy metals are separated from the soil by some means. The treatment and repair methods are the most complicated, the Cr (VI) in the soil is not completely repaired, the content is still high, and secondary pollution is caused after the repair.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a chemical leaching remediation process for chromium-contaminated soil, and solves the problems that the remediation is not thorough and secondary pollution is caused in the prior art.
The purpose of the invention can be realized by the following technical scheme:
a chemical leaching remediation process for chromium-contaminated soil comprises the following steps:
s1, soil dispersion: excavating polluted plot soil, and processing the plot soil into soil particles through a crusher for later use;
s2, oxidizing organic matters: placing the soil particles into a stirrer, adding water, and then adding a mixture of the soil particles and water in a weight ratio of 1: fully stirring 100 dispersant sodium acrylate and oxidant hydrogen peroxide, and oxidizing soil to obtain oxidized soil;
s3, chemical leaching: putting the oxidized soil into a leaching container, adding a citric acid solution into the oxidized soil in an amount of 1L/Kg while stirring, and leaching circularly for 10min at the same time to obtain leached soil;
s4, reduction treatment: adding the biomass charcoal into the chemically leached and washed soil according to the parts by weight, and adding water to fully stir and mix the mixture to obtain the restored soil.
Further, the diameter of the crushed soil particles in the S1 is 1-15 mm.
Further, the dosage ratio of the soil particles to the water in the S2 is 1: 1.
further, the concentration of the dispersant polyacrylic acid in the S2 is 0.1-0.2mol/L, and the concentration of hydrogen peroxide is 0.03 mol/L.
Further, the concentration of the citric acid in the S3 is 0.1 mol/L.
Further, the leacheate obtained after the soil is leached in the S3 is recovered
Further, the using amount ratio of the biomass charcoal in the S4 is 10 g/Kg.
Further, the dosage ratio of the washed soil to the water in the S4 is 4: 1.
the invention has the beneficial effects that:
1. according to the soil chemical leaching remediation method provided by the invention, the mineral crystal lattices on the surface of the soil are damaged by the complexation reaction or ion exchange effect generated between the chemical reagent and the soil, the strong-mobility complexation or chelate is formed by the functional group and the heavy metal, and the heavy metal absorbed by the solid phase of the soil is exchanged and desorbed into a solution system, so that the heavy metal is dissolved out of the solid phase of the soil, and the reduction of the Cr (VI) content in the soil is realized.
2. According to the soil chemical leaching remediation method provided by the invention, leaching wastewater after leaching can be recycled, so that unnecessary secondary pollution is avoided. Meanwhile, the whole method is simple and convenient to implement and short in repair period.
Drawings
In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
FIG. 1 is a schematic overall flow diagram of an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, an embodiment of the present invention provides a chemical leaching remediation process for chromium-contaminated soil, including the following steps:
s1, soil dispersion: and excavating the polluted plot soil, and processing the plot soil into soil particles by a crusher, wherein the diameter of the crushed soil particles is between 1 and 15mm, and the soil particles are reserved.
S2, oxidizing organic matters: putting the soil particles into a stirrer, adding water with the dosage of 1:1, mixing the water with the soil particles, and then adding the mixture into the stirrer in a weight ratio of 1: fully stirring 100 dispersant sodium acrylate and oxidant hydrogen peroxide to fully oxidize organic matters and Cr (III) in soil particles to obtain oxidized soil, wherein: the concentration of the dispersant polyacrylic acid is 0.1-0.2mol/L, and the concentration of the hydrogen peroxide is 0.03 mol/L. Polyacrylic acid is a high-molecular polymer, has good water solubility, is non-toxic and non-corrosive, can improve the physical properties of soil, increase the number of large aggregates in the soil, improve the water conductivity and water content of the soil, slow down the loss of the soil and ensure that the soil is fully contacted with leacheate; the hydrogen peroxide has high oxidizability, can fully oxidize organic matters in the soil, further promote the form of heavy metals to be converted into exchangeable forms, and is beneficial to washing out chromium; in addition, hydrogen peroxide can oxidize partial Cr (III) into Cr (VI), so that the migration of chromium in soil is improved, and the chromium is easier to wash out.
S3, chemical leaching: the citric acid solution with the concentration of 0.1mol/L is prepared and used as an eluent, the citric acid solution is used as the eluent, heavy metals in the polluted soil can be rapidly removed, and compared with other chemical eluents, the effect is better and the leaching time is shorter. Putting the oxidized soil into a leaching container, adding the leacheate into the oxidized soil in an amount of 1L/Kg while stirring, simultaneously circularly leaching for 10min to uniformly mix the leacheate to obtain the leached soil, simultaneously recovering the leacheate after leaching, and performing reduction treatment to reduce secondary pollution to the environment, wherein chromium in the leacheate obtained by oxidation leaching can be recycled.
S4, reduction treatment: adding 10g/Kg of biomass charcoal into the chemically leached soil, adding 1/4 parts of water by weight, and fully stirring and mixing the materials, wherein the reduction performance is high, and the main purpose is to reduce Cr (VI) into Cr (III), and the reducing agent is low in price and better in effect compared with other reducing agents, so that the restored soil is obtained.
In summary, the chemical leaching remediation process for chromium-contaminated soil provided by the invention has the advantages of short remediation period and simple process, firstly, the dispersant and the oxidant are artificially added and mixed with the soil, then, the complexing reaction or ion exchange effect is generated between the chemical reagent and the soil, the mineral crystal lattices on the soil surface are destroyed, the functional groups and the heavy metals form a complex or chelate with strong mobility, the heavy metals absorbed by the soil solid phase are exchanged and desorbed into a solution system, and the heavy metals are dissolved out of the soil solid phase. Meanwhile, the added citric acid solution is used for acid dissolution to accelerate the dissolution rate of chromium ions, and leaching wastewater generated in the process can be recycled, so that unnecessary secondary pollution is avoided.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.
Claims (8)
1. The chemical leaching remediation process for the chromium-contaminated soil is characterized by comprising the following steps of:
s1, soil dispersion: excavating polluted plot soil, and processing the plot soil into soil particles through a crusher for later use;
s2, oxidizing organic matters: placing the soil particles into a stirrer, adding water, and then adding a mixture of the soil particles and water in a weight ratio of 1: fully stirring 100 dispersant sodium acrylate and oxidant hydrogen peroxide, and oxidizing soil to obtain oxidized soil;
s3, chemical leaching: putting the oxidized soil into a leaching container, adding a citric acid solution into the oxidized soil in an amount of 1L/Kg while stirring, and leaching circularly for 10min at the same time to obtain leached soil;
s4, reduction treatment: adding the biomass charcoal into the chemically leached and washed soil according to the parts by weight, and adding water to fully stir and mix the mixture to obtain the restored soil.
2. The chemical leaching remediation process of chromium-contaminated soil according to claim 1, wherein the crushed soil particles in S1 are between 1-15mm in diameter.
3. The chemical leaching remediation process of chromium-contaminated soil according to claim 1, wherein the dosage ratio of soil particles to water in S2 is 1: 1.
4. the chemical leaching remediation process of chromium-contaminated soil according to claim 1, wherein the concentration of the dispersant polyacrylic acid in S2 is 0.1-0.2mol/L, and the concentration of hydrogen peroxide is 0.03 mol/L.
5. The chemical leaching remediation process of chromium-contaminated soil according to claim 1, wherein the concentration of citric acid in S3 is 0.1 mol/L.
6. The chemical leaching remediation process of chromium-contaminated soil according to claim 1, wherein the leacheate obtained after the soil is leached in S3 is recycled.
7. The chemical leaching remediation process of chromium-contaminated soil according to claim 1, wherein the amount ratio of biomass charcoal in S4 is 10 g/Kg.
8. The chemical leaching remediation process of chromium-contaminated soil according to claim 1, wherein the dosage ratio of the leached soil to the water in S4 is 4: 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911125982.6A CN110665960A (en) | 2019-11-15 | 2019-11-15 | Chemical leaching remediation process for chromium-contaminated soil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911125982.6A CN110665960A (en) | 2019-11-15 | 2019-11-15 | Chemical leaching remediation process for chromium-contaminated soil |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110665960A true CN110665960A (en) | 2020-01-10 |
Family
ID=69087536
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911125982.6A Pending CN110665960A (en) | 2019-11-15 | 2019-11-15 | Chemical leaching remediation process for chromium-contaminated soil |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110665960A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112718832A (en) * | 2020-12-17 | 2021-04-30 | 徐州云乐环保设备科技有限公司 | Self-dispersion remediation method for heavy metal contaminated soil |
| CN113617816A (en) * | 2020-05-08 | 2021-11-09 | 无锡蓝湾资源再生科技有限公司 | Soil remediation method |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102247980A (en) * | 2011-07-04 | 2011-11-23 | 中国科学院过程工程研究所 | Remediation agent for leaching soil polluted by heavy metal chrome |
| CN102601106A (en) * | 2012-03-08 | 2012-07-25 | 中国科学院过程工程研究所 | Ectopic leaching restoring device and restoring method for chromic slag polluted soil |
| CN104492806A (en) * | 2014-12-09 | 2015-04-08 | 云南民族大学 | Preparation method of chromium-contaminated soil composite eluant |
| CN104959376A (en) * | 2015-05-20 | 2015-10-07 | 湖南永清环保研究院有限责任公司 | Restoration method of chromium-polluted soil |
| CN104959369A (en) * | 2015-05-20 | 2015-10-07 | 湖南永清环保研究院有限责任公司 | Method used for recycling chromium from chromium-polluted soil |
| CN105149334A (en) * | 2015-10-12 | 2015-12-16 | 山东师范大学 | Oxidation-chelation leaching combined remediation method for Cr-contaminated soil |
| CN106583436A (en) * | 2016-12-16 | 2017-04-26 | 亿利首建生态科技有限公司 | Leaching method for remediating hexavalent chromium contaminated soil |
| CN107790478A (en) * | 2017-07-28 | 2018-03-13 | 安徽国祯环境修复股份有限公司 | A kind of method that pollution of chromium soil resource utilizes |
| CN110105959A (en) * | 2019-04-16 | 2019-08-09 | 大连地拓环境科技有限公司 | A kind of soil polluted by magnesite dust situ purification method |
-
2019
- 2019-11-15 CN CN201911125982.6A patent/CN110665960A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102247980A (en) * | 2011-07-04 | 2011-11-23 | 中国科学院过程工程研究所 | Remediation agent for leaching soil polluted by heavy metal chrome |
| CN102601106A (en) * | 2012-03-08 | 2012-07-25 | 中国科学院过程工程研究所 | Ectopic leaching restoring device and restoring method for chromic slag polluted soil |
| CN104492806A (en) * | 2014-12-09 | 2015-04-08 | 云南民族大学 | Preparation method of chromium-contaminated soil composite eluant |
| CN104959376A (en) * | 2015-05-20 | 2015-10-07 | 湖南永清环保研究院有限责任公司 | Restoration method of chromium-polluted soil |
| CN104959369A (en) * | 2015-05-20 | 2015-10-07 | 湖南永清环保研究院有限责任公司 | Method used for recycling chromium from chromium-polluted soil |
| CN105149334A (en) * | 2015-10-12 | 2015-12-16 | 山东师范大学 | Oxidation-chelation leaching combined remediation method for Cr-contaminated soil |
| CN106583436A (en) * | 2016-12-16 | 2017-04-26 | 亿利首建生态科技有限公司 | Leaching method for remediating hexavalent chromium contaminated soil |
| CN107790478A (en) * | 2017-07-28 | 2018-03-13 | 安徽国祯环境修复股份有限公司 | A kind of method that pollution of chromium soil resource utilizes |
| CN110105959A (en) * | 2019-04-16 | 2019-08-09 | 大连地拓环境科技有限公司 | A kind of soil polluted by magnesite dust situ purification method |
Non-Patent Citations (6)
| Title |
|---|
| 丁文川等: "腐殖酸对生物炭去除水中Cr(Ⅵ)的影响机制研究 ", 《腐植酸》 * |
| 中国环境科学学会: "《中国环境科学学会学术年会论文2011》", 30 November 2011, 中国环境科学出版社 * |
| 李丹丹等: "柠檬酸土柱淋洗法去除污染土壤中Cr的研究 ", 《农业环境科学学报》 * |
| 李文斌等: "添加复合吸附剂对塿土吸附菲和Cr(Ⅵ)的影响", 《环境科学》 * |
| 纪柱: "铬污染土壤的修复 ", 《无机盐工业》 * |
| 黄玉媛等: "《精细化工配方常用原料手册》", 31 March 2998, 广东科技出版社 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113617816A (en) * | 2020-05-08 | 2021-11-09 | 无锡蓝湾资源再生科技有限公司 | Soil remediation method |
| CN112718832A (en) * | 2020-12-17 | 2021-04-30 | 徐州云乐环保设备科技有限公司 | Self-dispersion remediation method for heavy metal contaminated soil |
| CN112718832B (en) * | 2020-12-17 | 2022-07-29 | 中赣核生态修复工程(江西)有限公司 | Self-dispersion remediation method for heavy metal contaminated soil |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Yang et al. | Remediation of heavy metal contaminated soils by organic acid extraction and electrochemical adsorption | |
| CN105013810B (en) | A kind of reparation medicament and restorative procedure for chromium-polluted soil | |
| CN107138519B (en) | Ectopic chemical oxidation remediation method for soil polluted by cyanide | |
| CN102173547B (en) | Resource recycling process for nickel-containing sludge in electroplating enterprises | |
| Du et al. | Enhancement of ball-miling on pyrite/zero-valent iron for arsenic removal in water: A mechanistic study | |
| CN104556342B (en) | The reparation medicament of hexavalent chromium polluted soil and underground water and preparation method | |
| CN104845629A (en) | Leaching agent and leaching method for repairing heavy metal contaminated soil | |
| CN106282585A (en) | The detoxification classification resource utilization method of one way of life incineration of refuse flyash | |
| CN103170501B (en) | Preparation method of in-situ repair material for soil polluted by heavy metal chromium and application of material | |
| CN104624632A (en) | Remediation method for hexavalent chromium polluted soil and underground water | |
| CN104550223A (en) | Treatment method of Ni and Pb contaminated soil remediation | |
| CN110665960A (en) | Chemical leaching remediation process for chromium-contaminated soil | |
| CN109622581A (en) | A method of Heavy Metals in Soil Contaminated is removed using magnetic modification biological charcoal | |
| CN105149334A (en) | Oxidation-chelation leaching combined remediation method for Cr-contaminated soil | |
| Xiao et al. | Electrokinetic remediation of uranium (VI)-contaminated red soil using composite electrolyte of citric acid and ferric chloride | |
| CN108689671A (en) | Manganese in electrolytic manganese residues and ammonium sulfate handle recovery method | |
| CN110947751B (en) | Device and method for restoring cadmium-polluted soil through electric auxiliary leaching | |
| CN104774619A (en) | Immobilizing and stabilizing agent for arsenic-contaminated soil and application thereof | |
| CN106380049A (en) | Method for remediating heavy metal polluted sediment by use of modified zeolite molecular sieve and farmland soil improvement method | |
| Yang et al. | Effect of ferric ions on the anaerobic bio-dissolution of jarosites by Acidithiobacillus ferrooxidans | |
| CN109985899A (en) | A kind of soil remediation method of heavy metal pollution | |
| CN107262522B (en) | Electrolytic manganese contaminated site soil stabilization remediation agent and remediation method thereof | |
| Li et al. | Effective multi-metal removal from plant incineration ash via the combination of bioleaching and brine leaching | |
| Yang et al. | Enhanced Leaching of Mn from electrolytic manganese anode slime via an electric field | |
| CN104628073A (en) | Method for preparing nano-iron used in wastewater treatment |
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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200110 |
|
| RJ01 | Rejection of invention patent application after publication |