CN105964684B - Heavy pollution site Cd in-situ and ex-situ coupling detoxification method - Google Patents

Heavy pollution site Cd in-situ and ex-situ coupling detoxification method Download PDF

Info

Publication number
CN105964684B
CN105964684B CN201610370395.3A CN201610370395A CN105964684B CN 105964684 B CN105964684 B CN 105964684B CN 201610370395 A CN201610370395 A CN 201610370395A CN 105964684 B CN105964684 B CN 105964684B
Authority
CN
China
Prior art keywords
situ
soil
solution
content
sludge
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
Application number
CN201610370395.3A
Other languages
Chinese (zh)
Other versions
CN105964684A (en
Inventor
张大磊
李瑞栋
王欣玉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Qingdao University of Technology
Original Assignee
Qingdao University of Technology
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Qingdao University of Technology filed Critical Qingdao University of Technology
Priority to CN201610370395.3A priority Critical patent/CN105964684B/en
Publication of CN105964684A publication Critical patent/CN105964684A/en
Application granted granted Critical
Publication of CN105964684B publication Critical patent/CN105964684B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B09DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09CRECLAMATION OF CONTAMINATED SOIL
    • B09C1/00Reclamation of contaminated soil
    • B09C1/10Reclamation of contaminated soil microbiologically, biologically or by using enzymes
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B09DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09CRECLAMATION OF CONTAMINATED SOIL
    • B09C1/00Reclamation of contaminated soil
    • B09C1/08Reclamation of contaminated soil chemically
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B09DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
    • B09CRECLAMATION OF CONTAMINATED SOIL
    • B09C2101/00In situ

Abstract

The invention adopts an in-situ and ex-situ coupling detoxification method for Cd in a heavily polluted site, sludge, a carbon source and sulfate are prepared into a medicament to be applied to Cd-containing soil, and then a special construction and maintenance mode is adopted to enable a reduction ecological microbial inoculum to gradually permeate underground to reduce Cd in deep polluted soil. The method can be used for repairing the Cd-containing field with high pollution depth at low cost and high efficiency, and simultaneously treating wastes with processes of wastes against one another and treating sludge.

Description

Heavy pollution site Cd in-situ and ex-situ coupling detoxification method
Technical Field
The invention provides a novel method for treating Cd-polluted soil, which is characterized in that sludge, a carbon source and sulfate are prepared into a medicament to be applied to Cd-containing soil, and then a special maintenance mode is adopted, so that Cd can be efficiently reduced, and secondary pollution of sulfate is avoided, and the method belongs to the field of environmental protection.
Background
Because mine exploitation and metallurgical wastewater are discharged randomly, a large amount of soil is polluted by Cd. Current methods for treating cadmium-containing soils have drawbacks. The high-temperature melting method has high cost and large energy consumption. The biological method has long reaction period and is easy to cause secondary pollution of external biological agents. The curing method has unstable effect, and the curing agent is easy to cause secondary pollution to soil. Patent No. 201510056406.6 describes a method for solidifying soil containing heavy metals, but this method uses a large amount of materials and is relatively expensive, and on the other hand, the solidification effect is unstable, for example, calcium oxide added is liable to carbonation under natural conditions, so that the alkaline solidification effect is reduced.
Disclosure of Invention
Aiming at the defects of the prior art, the invention adopts a Cd in-situ and ex-situ coupling detoxification method for a heavy polluted site, prepares sludge, a carbon source and sulfate into a medicament and applies the medicament to Cd-containing soil, and then adopts a special construction and maintenance mode to ensure that a reduction ecological microbial inoculum gradually permeates underground to reduce Cd in deep polluted soil. The method can be used for repairing the Cd-containing field with high pollution depth at low cost and high efficiency, and simultaneously treating wastes with processes of wastes against one another and treating sludge. Which comprises the following steps:
(1) mixing sodium sulfate, sludge or carbon source solution according to a certain proportion, enabling the dry sludge content of the mixed solution to be 0.1-20%, the solid content to be 0.5-25%, the organic carbon content to be 0.5-25%, and the mass ratio of sulfate (recorded as SO 4)/organic carbon to be (0-1): 1, and reacting the mixed solution for 0-5 days to obtain the Cd soil remediation agent;
(2) excavating soil with the surface layer of 1-10m of the Cd-containing field, then paving a geomembrane with meshes at the bottom of the excavated field, and paving impermeable materials around the excavated field to build a semi-closed storage yard;
(3) crushing the soil in the step (2) to be less than 10mm, paving the crushed soil on a semi-closed storage yard, and then spraying and mixing the medicament in the step (1), wherein the mixing ratio is that the mass ratio of the Cd-containing soil to the medicament is 1 (0.1-0.8);
(4) during the stockpiling period, the water content of the soil is kept within the range of 5-60% within 5-100 days in the initial stage, so that biochemical reaction can be carried out, and sulfate reducing bacteria are propagated in a large amount in the field; spraying the soil remediation agent or the carbon source solution in the step (1) to the site every 1-200 days, wherein the ratio of the accumulated organic carbon in the agent or the carbon source solution sprayed for several times to the total Cd content in the whole site is not lower than 0.5: 1; the average rainfall of the field per year is required to be more than 200mm, and if the average rainfall is not enough, the ground is supplemented by adopting a surface water spraying mode, so that the medicine can continuously seep to the lower layer.
In the above steps, the sludge is anaerobic sludge generated by a sewage treatment anaerobic process, and part of facultative sludge can be added. The carbon source solution can be a solution containing alcohol, sugar, protein or starch, can also be a solution containing industrial organic waste or kitchen waste, and can also be industrial and municipal organic wastewater, and the sodium sulfate can be replaced by other sulfates. The water sprayed on the surface can be replaced by organic solution, and the organic carbon content of the organic solution is 10-1000 mg/L. The material of the geomembrane paved with meshes in the step (2) can be a material which is difficult to biodegrade or a biodegradable material; the equivalent diameter of the small holes in the mesh geomembrane is 1-100 mm.
The method promotes the large-scale formation of the site to use sulfate reducing bacteria as a main flora through the addition of special ecological agents and the special site maintenance, the flora can firstly utilize a carbon source to effectively reduce Cd, simultaneously, the sulfate is fully utilized to convert the Cd into sulfide, and the Cd is effectively reduced and simultaneously converted into more stable sulfide Cd precipitate.
Compared with the traditional Cd-containing soil treatment method, the method has the following advantages:
1. sulfate reducing bacteria in the sludge microbial inoculum reduce sulfate to generate sulfide, so that Cd can be more effectively fixed;
2. the cultured sulfate reducing flora is indigenous flora, has strong natural tolerance, is easy to propagate on site in a large scale, can permanently and effectively fix Cd, and does not cause ecological problems;
3. the reduced Cd and a sulfate reducing bacteria metabolite sulfide form a Cd sulfide precipitate, so that the Cd in the soil is more stable and is obviously superior to other biochemical processes;
4. the method uses the sludge and the organic waste as main raw materials, so that the cost is greatly reduced;
5. the method adopts in-situ remediation for the deep soil, avoids excavation of the deep soil and greatly reduces the cost.
The specific implementation example is as follows:
example 1:
(1) mixing sodium sulfate, sludge or carbon source solution according to a certain proportion to ensure that the dry sludge content of the mixed solution is 0.1-5%, the solid content is 0.5-5%, the organic carbon content is 0.5-5%, and the mass ratio of sulfate (recorded as SO 4)/organic carbon is 0.7: 1, and reacting the mixed solution for 2 days to obtain the Cd soil remediation agent;
(2) excavating 10m soil on the surface layer of the Cd-containing field, then paving a geomembrane with meshes at the bottom of the excavated field, and paving impermeable materials around the excavated field to build a semi-closed storage yard;
(3) crushing the soil in the step (2) to be less than 5mm, then mixing the crushed soil with the medicament in the step (1) in a mass ratio of the Cd-containing soil to the medicament of 1:0.5, and then placing the mixture in a semi-closed storage yard in the step (2) for closed storage;
(4) during the stockpiling period, the water content of the soil is kept within the range of 5-60% within 20 days in the initial stage, so that biochemical reaction can be carried out, and a large amount of sulfate reducing bacteria are propagated in the field; sprinkling the soil remediation agent or the carbon source solution in the step (1) to the site every 2 days for the initial 100 days, wherein the number of days at intervals in the later period exceeds 20 days, and the ratio of the accumulated organic carbon in the agent or the carbon source solution sprayed for a plurality of times to the total Cd content of the whole site is not lower than 0.5: 1; the average rainfall of the field is 500mm each year by natural rainfall and artificial spraying. After the engineering is carried out for 2 years, the Cd content of the soil with the depth of more than 20 meters is lower than 2mg/kg, and the Cd content of underground water is lower than 0.1 mg/L.
Example 2:
(1) mixing sodium sulfate, sludge or carbon source solution according to a certain proportion, enabling the dry sludge content of the mixed solution to be 5-15%, the solid content to be 5-15%, the organic carbon content to be 5-15%, and the mass ratio of sulfate (recorded as SO 4)/organic carbon to be 0.5:1, and reacting the mixed solution for 1 day to obtain the Cd soil remediation agent;
(2) excavating soil with the surface layer of 5m of the Cd-containing field, then paving a geomembrane with meshes at the bottom of the excavated field, and paving impermeable materials around the excavated field to build a semi-closed storage yard;
(3) crushing the soil in the step (2) to be less than 5mm, then mixing the crushed soil with the medicament in the step (1) in a mass ratio of the Cd-containing soil to the medicament of 1:0.5, and then placing the mixture in a semi-closed storage yard in the step (2) for closed storage;
(4) during the stockpiling period, the water content of the soil is kept within the range of 5-60% within 20 days in the initial stage, so that biochemical reaction can be carried out, and a large amount of sulfate reducing bacteria are propagated in the field; sprinkling the soil remediation agent or the carbon source solution in the step (1) to the site every 2 days for the initial 100 days, wherein the number of days at intervals in the later period exceeds 20 days, and the ratio of the accumulated organic carbon in the agent or the carbon source solution sprayed for a plurality of times to the total Cd content of the whole site is not lower than 0.5: 1; the average rainfall of the field is 500mm each year by natural rainfall and artificial spraying. After the engineering is carried out for 1 year, the Cd content of the soil with the depth of more than 40 meters is less than 2mg/kg, and the Cd content of underground water is less than 0.1 mg/L.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims (5)

1. An in-situ and ex-situ coupling detoxification method for Cd in a heavily polluted site is characterized by comprising the following steps:
(1) mixing sodium sulfate, sludge and a carbon source solution according to a certain proportion, enabling the content of dry sludge of the mixed solution to be 0.1-20%, the solid content to be 0.5-25%, the content of organic carbon to be 0.5-25%, and the mass ratio of SO 4/organic carbon to be 1: 1, and reacting the mixed solution for 0-5 days to obtain a Cd soil remediation agent;
(2) excavating soil with the surface layer of 1-10m of the Cd-containing field, then paving a geomembrane with meshes at the bottom of the excavated field, and paving impermeable materials around the excavated field to build a semi-closed storage yard;
(3) crushing the soil in the step (2) to be less than 10mm, paving the crushed soil on a semi-closed storage yard, spraying and mixing the medicament in the step (1) according to the mass ratio of the Cd-containing soil to the medicament of 1 (0.1-0.8), and then placing the mixture on the semi-closed storage yard in the step (2) for closed storage;
(4) during the stockpiling period, keeping the water content of the soil within the range of 5-60% within 5-100 days in the initial stage, simultaneously sprinkling the soil remediation agent or the carbon source solution in the step (1) to the site every 1-200 days, and the requirement of the ratio of accumulated organic carbon in the agent or the carbon source solution to the total Cd content of the whole site for several times is not lower than 0.5: 1; the average rainfall of the field per year is required to be more than 200mm, and if the average rainfall is not enough, the ground is supplemented by adopting a surface water spraying mode, so that the medicine can continuously seep to the lower layer.
2. The in-situ and ex-situ coupling detoxification method for Cd in a heavily polluted site as claimed in claim 1, wherein the sludge is anaerobic sludge generated by anaerobic process of sewage treatment, and optionally some facultative sludge.
3. The in-situ and ex-situ coupling detoxification method of Cd in a heavily polluted site as claimed in claim 1, wherein the carbon source solution can be a solution containing alcohol, sugar, protein or starch, a solution of organic solid waste, industrial and municipal organic wastewater, and the sodium sulfate can be replaced by other sulfate.
4. The in-situ and ex-situ coupling detoxification method for Cd in a heavily polluted site as claimed in claim 1, wherein the water sprayed on the surface of the heavily polluted site can be replaced by an organic solution, and the organic carbon content of the organic solution is 10-1000 mg/L.
5. The in-situ and ex-situ coupling detoxification method for Cd in a heavily polluted site as claimed in claim 1, wherein the geomembrane with meshes laid in the step (2) is made of a material which is difficult to biodegrade or a biodegradable material; the equivalent diameter of the small holes in the mesh geomembrane is 1-100 mm.
CN201610370395.3A 2016-05-30 2016-05-30 Heavy pollution site Cd in-situ and ex-situ coupling detoxification method Active CN105964684B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201610370395.3A CN105964684B (en) 2016-05-30 2016-05-30 Heavy pollution site Cd in-situ and ex-situ coupling detoxification method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201610370395.3A CN105964684B (en) 2016-05-30 2016-05-30 Heavy pollution site Cd in-situ and ex-situ coupling detoxification method

Publications (2)

Publication Number Publication Date
CN105964684A CN105964684A (en) 2016-09-28
CN105964684B true CN105964684B (en) 2021-04-27

Family

ID=57010709

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201610370395.3A Active CN105964684B (en) 2016-05-30 2016-05-30 Heavy pollution site Cd in-situ and ex-situ coupling detoxification method

Country Status (1)

Country Link
CN (1) CN105964684B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102500612A (en) * 2011-10-28 2012-06-20 中南大学 Chemical leaching restoring method for soil polluted by heavy metals
CN102598911A (en) * 2012-03-29 2012-07-25 常熟市佳盛农业科技发展有限公司 Method for remedying heavy metal polluted mining soil
CN104759466A (en) * 2014-01-08 2015-07-08 湖北科技学院 Soil heavy metal ex-situ remediation method based on molecular combination
CN105032912A (en) * 2015-07-17 2015-11-11 中国科学院武汉岩土力学研究所 In-situ repair method for shallow-buried heavy metal pollution site

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003103866A1 (en) * 2002-06-07 2003-12-18 日本板硝子株式会社 Contamination diffusion preventing structure in contaminated area
CN103981097B (en) * 2013-12-05 2016-04-20 青岛理工大学 One utilizes mud to prepare the method for Cr (VI) contaminated site reparation flora
CN105598144B (en) * 2016-03-22 2019-01-18 安徽工程大学 A kind of restorative procedure of contaminated soil

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102500612A (en) * 2011-10-28 2012-06-20 中南大学 Chemical leaching restoring method for soil polluted by heavy metals
CN102598911A (en) * 2012-03-29 2012-07-25 常熟市佳盛农业科技发展有限公司 Method for remedying heavy metal polluted mining soil
CN104759466A (en) * 2014-01-08 2015-07-08 湖北科技学院 Soil heavy metal ex-situ remediation method based on molecular combination
CN105032912A (en) * 2015-07-17 2015-11-11 中国科学院武汉岩土力学研究所 In-situ repair method for shallow-buried heavy metal pollution site

Also Published As

Publication number Publication date
CN105964684A (en) 2016-09-28

Similar Documents

Publication Publication Date Title
Rani et al. Overview of Subsurface Constructed Wetlands Application in Tropical Climates.
CN107446584B (en) Hexavalent chromium site in-situ and ex-situ coupling detoxification method based on biogas residues
CN106040736B (en) Heavy pollution site Sb in-situ and ex-situ coupling detoxification method based on biogas residues
CN106040735B (en) Heavily-polluted site Cu in-situ and ex-situ coupling detoxification method
CN105945052B (en) Pb in-situ and ectopic coupling detoxification method for heavily polluted site
CN101164924A (en) Countryside sewage treatment equipment and application
CN105935695A (en) Novel contaminated site Hg in-situ detoxifying method based on biogas residues
CN105964684B (en) Heavy pollution site Cd in-situ and ex-situ coupling detoxification method
CN105935693B (en) Sb in-situ and ectopic coupling detoxification method for heavily polluted site
CN106001087B (en) Hg in-situ and ectopic coupling detoxification method for heavily polluted site
CN105945056B (en) Heavy pollution site Cd in-situ and ex-situ coupling detoxification method based on biogas residues
CN106001088B (en) Heavily-polluted site Pb in-situ and ex-situ coupling detoxification method based on biogas residues
CN106001085B (en) Zn in-situ and ectopic coupling detoxification method for heavily polluted site
CN105945065B (en) Heavily-polluted site Cu in-situ and ex-situ coupling detoxification method based on biogas residues
CN105935691A (en) Novel contaminated site Cd in-situ detoxication method
CN105945054A (en) Heavily-polluted site Zn in-situ and ex-situ coupling detoxification method based on biogas residues
CN102476900A (en) Sewage and sludge treatment method
Parmar et al. Bio cementation: a novel technique and approach towards sustainable material
CN105935687A (en) Novel pollution site Pb in-situ detoxification method
CN105935685A (en) Novel pollution site Zn in-situ detoxification method
CN105945053A (en) Novel contaminated site Pb in-situ detoxification method based on biogas residues
KR100753852B1 (en) Food dirt, the pro-environment block where a microorganism was used and this production technique
CN105935696A (en) Novel pollution site Cd in-situ detoxification method based on biogas residues
KR20090104218A (en) Anti-fungus concrete and method for producing the same
CN105945055A (en) Heavily-polluted site Hg in-situ and ex-situ coupling detoxification method based on biogas residues

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant