CN114073937A - Method for treating arsenic and cadmium composite polluted land by composite biochar - Google Patents
Method for treating arsenic and cadmium composite polluted land by composite biochar Download PDFInfo
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- CN114073937A CN114073937A CN202010828458.1A CN202010828458A CN114073937A CN 114073937 A CN114073937 A CN 114073937A CN 202010828458 A CN202010828458 A CN 202010828458A CN 114073937 A CN114073937 A CN 114073937A
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- biochar
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- arsenic
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- 229910052785 arsenic Inorganic materials 0.000 title claims abstract description 31
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 title claims abstract description 31
- 229910052793 cadmium Inorganic materials 0.000 title claims abstract description 31
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 title claims abstract description 30
- 239000002131 composite material Substances 0.000 title claims abstract description 25
- 238000000034 method Methods 0.000 title claims abstract description 25
- 239000002689 soil Substances 0.000 claims abstract description 79
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims abstract description 48
- 238000005067 remediation Methods 0.000 claims abstract description 35
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 29
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 26
- 238000002156 mixing Methods 0.000 claims abstract description 22
- 239000000203 mixture Substances 0.000 claims abstract description 17
- MAYVZUQEFSJDHA-UHFFFAOYSA-N 1,5-bis(methylsulfanyl)naphthalene Chemical compound C1=CC=C2C(SC)=CC=CC2=C1SC MAYVZUQEFSJDHA-UHFFFAOYSA-N 0.000 claims abstract description 16
- 238000003756 stirring Methods 0.000 claims abstract description 16
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 13
- 150000002910 rare earth metals Chemical class 0.000 claims abstract description 12
- 229920002472 Starch Polymers 0.000 claims abstract description 8
- 235000019698 starch Nutrition 0.000 claims abstract description 8
- 239000008107 starch Substances 0.000 claims abstract description 8
- ONCZQWJXONKSMM-UHFFFAOYSA-N dialuminum;disodium;oxygen(2-);silicon(4+);hydrate Chemical compound O.[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[Na+].[Na+].[Al+3].[Al+3].[Si+4].[Si+4].[Si+4].[Si+4] ONCZQWJXONKSMM-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229940080314 sodium bentonite Drugs 0.000 claims abstract description 7
- 229910000280 sodium bentonite Inorganic materials 0.000 claims abstract description 7
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims abstract description 6
- 239000001110 calcium chloride Substances 0.000 claims abstract description 6
- 229910001628 calcium chloride Inorganic materials 0.000 claims abstract description 6
- NCXUIEDQTCQZRK-UHFFFAOYSA-L disodium;decanedioate Chemical compound [Na+].[Na+].[O-]C(=O)CCCCCCCCC([O-])=O NCXUIEDQTCQZRK-UHFFFAOYSA-L 0.000 claims abstract description 6
- 238000000227 grinding Methods 0.000 claims abstract description 6
- 238000001035 drying Methods 0.000 claims description 30
- 239000002245 particle Substances 0.000 claims description 28
- 239000002244 precipitate Substances 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 238000005469 granulation Methods 0.000 claims description 5
- 230000003179 granulation Effects 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 5
- 238000004321 preservation Methods 0.000 claims description 5
- 239000006228 supernatant Substances 0.000 claims description 5
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 4
- 238000013329 compounding Methods 0.000 claims 3
- 230000000694 effects Effects 0.000 abstract description 6
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 abstract description 2
- 229910000360 iron(III) sulfate Inorganic materials 0.000 abstract description 2
- 230000002262 irrigation Effects 0.000 abstract 1
- 238000003973 irrigation Methods 0.000 abstract 1
- 229910001385 heavy metal Inorganic materials 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 5
- 241000196324 Embryophyta Species 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 229910052692 Dysprosium Inorganic materials 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- WLZRMCYVCSSEQC-UHFFFAOYSA-N cadmium(2+) Chemical compound [Cd+2] WLZRMCYVCSSEQC-UHFFFAOYSA-N 0.000 description 3
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 230000005012 migration Effects 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- 240000007594 Oryza sativa Species 0.000 description 1
- 235000007164 Oryza sativa Nutrition 0.000 description 1
- 239000002154 agricultural waste Substances 0.000 description 1
- 230000000844 anti-bacterial effect Effects 0.000 description 1
- 229940000489 arsenate Drugs 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 235000009566 rice Nutrition 0.000 description 1
- 239000002681 soil colloid Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
- B01J20/0207—Compounds of Sc, Y or Lanthanides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
- B01J20/24—Naturally occurring macromolecular compounds, e.g. humic acids or their derivatives
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C2101/00—In situ
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- 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 method for treating arsenic and cadmium composite polluted land by composite biochar, which comprises the following operation steps: (1) grinding the biochar, mixing the ground biochar with heat-treated starch, adding the mixture into an ethanol solution, and reacting to obtain HTS-coated biochar; (2) mixing and stirring the HTS-coated biochar and the dysprosium chloride solution uniformly, and continuously adding a sodium hydroxide solution into the mixture to obtain rare earth modified HTS biochar; (3) uniformly mixing rare earth modified HTS biochar, sodium bentonite, disodium sebacate, polymeric ferric sulfate and calcium chloride, and granulating to obtain a soil remediation agent; (4) the soil remediation agent is scattered on the surface of the soil, then the soil remediation agent and the soil are uniformly stirred by a rotary cultivator, and irrigation is carried out, so that the soil remediation work is finished. The method for treating the arsenic and cadmium composite polluted land by the composite biochar can effectively reduce the activity and content of arsenic and cadmium in soil and can obviously reduce the content of arsenic and cadmium in agricultural products.
Description
Technical Field
The invention relates to the technical field of soil remediation and treatment, in particular to a method for treating arsenic and cadmium combined polluted land by using composite biochar.
Background
Soil heavy metal pollution caused by industrial and agricultural wastes is not only the pollution problem of single heavy metal, but also the compound pollution caused by the simultaneous exceeding of a plurality of heavy metal elements and the interaction, so that the toxicity to plants and the migration dynamics of heavy metal in soil are more serious and complicated than the single heavy metal pollution.
The heavy metal combined pollution is influenced by various factors such as the types and concentrations of coexisting metals, the types of plants and the like besides physicochemical properties such as soil pH, organic matters and the like. The pH change in the soil has great influence on the adsorption and fixation of heavy metals, and mainly influences the occurrence form and the bioavailability of the heavy metals in the soil. Changes in soil pH can significantly affect their bioavailability, and pH decreases can lead to H in the soil+The content is increased, negative charges in the soil colloid are reduced by competing for the adsorption sites of the soil, so that the migration capability of the heavy metal in the soil is enhanced, and the bioavailability of the heavy metal in the soil is greatly increased. However, the influence is completely different for metal elements such AS AS, and the metal elements are valence-variable elements As (including As)3+,As5+) The change of the pH value can influence the existing form of As in the soil, and the influence effect is completely opposite to that of heavy metals such As Cd, Cu and the like, namely the increase of the pH value of the soil can improve the biological effectiveness of As and greatly increase the absorption amount of crops to the arsenic; the reduction of pH promotes enhanced bioavailability of Cd and reduces bioavailability of As.
In the prior art, the land polluted by arsenic and cadmium singly is treated, and the treatment effect on the land polluted by arsenic and cadmium compositely is poor.
Disclosure of Invention
In order to solve the existing problems, the invention provides a method for treating arsenic and cadmium composite polluted land by composite biochar.
The invention is realized by the following technical scheme:
a method for treating arsenic and cadmium composite polluted land by composite biochar comprises the following operation steps:
(1) grinding the biochar to an average particle size of 60-80 meshes, uniformly mixing the biochar with heat-treated starch according to a mass ratio of 15:4-8, adding the mixture into an ethanol solution, uniformly stirring, keeping balance for 2-3 hours, centrifuging, removing supernatant, drying precipitates, and crushing to an average particle size of 200 meshes to obtain HTS-coated biochar;
(2) mixing and stirring the HTS-coated biochar and a dysprosium chloride solution uniformly, continuously adding a sodium hydroxide solution into the mixture, mixing and stirring uniformly, heating to 65-75 ℃, and carrying out heat preservation reaction for 2-3 hours to obtain rare earth modified HTS biochar;
(3) uniformly mixing 45-50 parts by weight of rare earth modified HTS biochar, 18-24 parts by weight of sodium bentonite, 4-6 parts by weight of disodium sebacate, 1-5 parts by weight of polyferric sulfate and 0.1-0.4 part by weight of calcium chloride, transferring the mixture into a disc through a feeding tank, preparing particles with the particle size of 2.5-4.0mm by using a disc granulation method, and drying to obtain a soil remediation agent;
(4) the soil repairing agent is added according to the proportion of 2200-2The soil remediation agent is uniformly applied to the surface of the soil, then the soil remediation agent and the soil are uniformly stirred by adopting a rotary cultivator, the water is irrigated until the water content of the soil is 75-80%, and the soil remediation work is finished.
Specifically, in the step (1), the mass fraction of the ethanol solution is 70-80%.
Specifically, in the step (1), 1.0 to 1.5 kg of ethanol solution is added per kg of biochar.
Specifically, in the step (1), the temperature for drying the precipitate is 55-60 ℃, and the drying is finished when the water content of the precipitate is below 10%.
Specifically, in the step (2), the mass fraction of the dysprosium chloride solution is 12-16%, the molar concentration of the sodium hydroxide solution is 0.1-0.3mol/L, and in the step (2), the mass ratio of the HTS-coated biochar to the dysprosium chloride solution to the sodium hydroxide solution is 1:2-4: 8-11.
Specifically, in the step (3), the drying temperature is 90-95 ℃, and the drying time is 8-10 min.
According to the technical scheme, the beneficial effects of the invention are as follows:
the method for treating the arsenic and cadmium composite polluted land by the composite biochar can effectively reduce the activity and content of arsenic and cadmium in the soil, remarkably reduce the content of arsenic and cadmium in agricultural products, effectively improve the environment of the soil and improve the yield of crops. In the step (1), the biochar is coated by the heat-treated starch, so that the strength of the soil remediation agent particles can be effectively improved, the soil remediation agent particles can be effectively prevented from being decomposed in soil, and the soil remediation effect of the soil remediation agent particles on the soil is further ensured; through the treatment in the step (2), rare earth element dysprosium can be effectively bonded on the surface of the biochar, the addition of the dysprosium can effectively prevent arsenic and cadmium from transferring upwards in plants, and the content of arsenic and cadmium in agricultural products can be effectively avoided; the HTS coated biochar prepared by the invention has high strength and huge specific surface area, can strongly adsorb arsenate radicals and cadmium ions in soil, further effectively reduce the content of active arsenic elements and cadmium elements in the soil, and on the other hand, sodium bentonite with high calcium content can form a competitive absorption relationship with the cadmium ions, and can effectively inhibit the absorption of crops to the cadmium ions.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
Example 1
A method for treating arsenic and cadmium composite polluted land by composite biochar comprises the following operation steps:
(1) grinding biochar to an average particle size of 60 meshes, uniformly mixing the biochar with heat-treated starch according to a mass ratio of 15:4, adding the mixture into an ethanol solution with a mass fraction of 70%, wherein 1.0 kg of ethanol solution is added to each kg of biochar, stirring uniformly, keeping balance for 2 hours, centrifuging, removing supernatant, drying the precipitate, crushing to an average particle size of 200 meshes to obtain HTS-coated biochar, drying the precipitate at a temperature of 55 ℃ until the water content of the precipitate is below 10%, and finishing drying;
(2) mixing and stirring the HTS-coated biochar and the dysprosium chloride solution uniformly, continuing to add a sodium hydroxide solution into the mixture, mixing and stirring uniformly, heating to 65 ℃, and carrying out heat preservation reaction for 2 hours to obtain rare earth modified HTS biochar, wherein the mass fraction of the dysprosium chloride solution is 12%, the molar concentration of the sodium hydroxide solution is 0.1mol/L, and in the step (2), the mass ratio of the HTS-coated biochar to the dysprosium chloride solution to the sodium hydroxide solution is 1:2: 8;
(3) uniformly mixing 45 parts of rare earth modified HTS biochar, 18 parts of sodium bentonite, 4 parts of disodium sebacate, 1 part of polyferric sulfate and 0.1 part of calcium chloride in parts by weight, transferring the mixture into a disc through a feeding tank, preparing particles with the particle size of 2.5mm by using a disc granulation method, and drying the particles to obtain the soil remediation agent, wherein the drying temperature is 90 ℃ and the drying time is 8 min;
(4) treating soil with repairing agent at 2200kg/hm2The soil remediation agent is uniformly applied to the surface of the soil, then the soil remediation agent and the soil are uniformly stirred by adopting a rotary cultivator, the water is irrigated until the water content of the soil is 75%, and the soil remediation work is finished.
Example 2
A method for treating arsenic and cadmium composite polluted land by composite biochar comprises the following operation steps:
(1) grinding biochar to an average particle size of 70 meshes, uniformly mixing the biochar with heat-treated starch according to a mass ratio of 15:6, adding the mixture into 75% of ethanol solution by mass fraction, adding 1.3 kg of ethanol solution into each kg of biochar, uniformly stirring, keeping balance for 2.5 hours, centrifuging, removing supernatant, drying the precipitate, crushing to an average particle size of 200 meshes to obtain HTS-coated biochar, drying the precipitate at a temperature of 55-60 ℃, and finishing drying when the water content of the precipitate is below 10%;
(2) mixing and stirring the HTS-coated biochar and a dysprosium chloride solution uniformly, continuing to add a sodium hydroxide solution into the mixture, mixing and stirring uniformly, heating to 70 ℃, and carrying out heat preservation reaction for 2.5 hours to obtain rare earth modified HTS biochar, wherein the mass fraction of the dysprosium chloride solution is 14%, the molar concentration of the sodium hydroxide solution is 0.2mol/L, and in the step (2), the mass ratio of the HTS-coated biochar to the dysprosium chloride solution to the sodium hydroxide solution is 1:3: 10;
(3) according to the weight parts, after 48 parts of rare earth modified HTS biochar, 22 parts of sodium bentonite, 5 parts of disodium sebacate, 3 parts of polymeric ferric sulfate and 0.3 part of calcium chloride are uniformly mixed, the mixture is transferred into a disc through a feeding tank, particles with the particle size of 2.8mm are prepared by a disc granulation method, and then the soil remediation agent is obtained after drying treatment, wherein the drying treatment temperature is 93 ℃, and the drying treatment time is 9 min;
(4) soil repairing agent according to 2300kg/hm2The soil remediation agent is uniformly applied to the surface of the soil, then the soil remediation agent and the soil are uniformly stirred by adopting a rotary cultivator, the water is irrigated until the water content of the soil is 78%, and the soil remediation work is finished.
Example 3
A method for treating arsenic and cadmium composite polluted land by composite biochar comprises the following operation steps:
(1) grinding biochar to an average particle size of 80 meshes, uniformly mixing the biochar with heat-treated starch according to a mass ratio of 15:8, adding the mixture into an ethanol solution with a mass fraction of 80%, wherein 1.5 kg of ethanol solution is added to each kg of biochar, stirring uniformly, keeping balance for 3 hours, centrifuging, removing supernatant, drying the precipitate, crushing to an average particle size of 200 meshes to obtain HTS-coated biochar, drying the precipitate at a temperature of 60 ℃ until the water content of the precipitate is below 10%, and finishing drying;
(2) mixing and stirring the HTS-coated biochar and the dysprosium chloride solution uniformly, continuing to add a sodium hydroxide solution into the mixture, mixing and stirring uniformly, heating to 75 ℃ and carrying out heat preservation reaction for 3 hours to obtain rare earth modified HTS biochar, wherein the mass fraction of the dysprosium chloride solution is 16%, the molar concentration of the sodium hydroxide solution is 0.3mol/L, and in the step (2), the mass ratio of the HTS-coated biochar to the dysprosium chloride solution to the sodium hydroxide solution is 1:4: 11;
(3) uniformly mixing 50 parts by weight of rare earth modified HTS biochar, 24 parts by weight of sodium bentonite, 6 parts by weight of disodium sebacate, 5 parts by weight of polyferric sulfate and 0.4 part by weight of calcium chloride, transferring the mixture into a disc through a feeding tank, preparing particles with the particle size of 4.0mm by using a disc granulation method, and drying the particles to obtain the soil remediation agent, wherein the drying temperature is 95 ℃ and the drying time is 10 min;
(4) adding soil repairing agent according to 2500kg/hm2The soil remediation agent is uniformly applied to the surface of the soil, then the soil remediation agent and the soil are uniformly stirred by adopting a rotary cultivator, and the water is irrigated until the water content of the soil is 80%, so that the soil remediation work is completed.
Comparative example 1
The general biochar is adopted in the step (2), and the rest of the operation steps are completely the same as the example 1.
Comparative example 2
The HTS-coated biochar obtained in step (1) was used directly in step (3), and the remaining procedure was exactly the same as in example 2.
The same 5 test plots contaminated with arsenic and cadmium were treated by the methods of the examples and comparative examples, respectively, the control group was a test plot that was not subjected to any soil remediation treatment, and then rice was planted on each group of soil, the remaining field management methods were completely the same except for the methods of soil remediation, and the test results are shown in table 1:
TABLE 1 test method for antibacterial activity of pearl cotton
As can be seen from the data of example 1, comparative example 1 and the control group in Table 1, the strength of the soil remediation agent particles can be effectively improved by coating the biochar with the heat-treated starch, the soil remediation agent particles can be effectively prevented from being decomposed in the soil, and the soil remediation effect of the soil remediation agent particles on the soil can be further ensured; as can be seen from the data of the example 2, the comparative example 2 and the control group, the addition of the dysprosium element can effectively prevent the arsenic and the cadmium from transferring upwards in plants and can effectively avoid the content of the arsenic and the cadmium in agricultural products.
The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. 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.
Claims (6)
1. The method for treating the land polluted by the arsenic and the cadmium by the composite biochar is characterized by comprising the following operation steps of:
(1) grinding the biochar to an average particle size of 60-80 meshes, uniformly mixing the biochar with heat-treated starch according to a mass ratio of 15:4-8, adding the mixture into an ethanol solution, uniformly stirring, keeping balance for 2-3 hours, centrifuging, removing supernatant, drying precipitates, and crushing to an average particle size of 200 meshes to obtain HTS-coated biochar;
(2) mixing and stirring the HTS-coated biochar and a dysprosium chloride solution uniformly, continuously adding a sodium hydroxide solution into the mixture, mixing and stirring uniformly, heating to 65-75 ℃, and carrying out heat preservation reaction for 2-3 hours to obtain rare earth modified HTS biochar;
(3) uniformly mixing 45-50 parts by weight of rare earth modified HTS biochar, 18-24 parts by weight of sodium bentonite, 4-6 parts by weight of disodium sebacate, 1-5 parts by weight of polyferric sulfate and 0.1-0.4 part by weight of calcium chloride, transferring the mixture into a disc through a feeding tank, preparing particles with the particle size of 2.5-4.0mm by using a disc granulation method, and drying to obtain a soil remediation agent;
(4) the soil repairing agent is added according to the proportion of 2200-2The soil remediation agent is uniformly applied to the surface of the soil, then the soil remediation agent and the soil are uniformly stirred by adopting a rotary cultivator, the water is irrigated until the water content of the soil is 75-80%, and the soil remediation work is finished.
2. The method for treating the land polluted by the arsenic and the cadmium by compounding with the biochar as claimed in claim 1, wherein the ethanol solution accounts for 70-80% of the total mass of the land polluted by the arsenic and the cadmium by compounding with the biochar in the step (1).
3. The method for treating the land polluted by the arsenic and the cadmium compositely by the composite biochar as claimed in claim 1, wherein in the step (1), 1.0-1.5 kg of ethanol solution is added per kg of biochar.
4. The method for treating the land polluted by the arsenic and the cadmium by compounding with the biochar as claimed in claim 1, wherein in the step (1), the temperature for drying the precipitate is 55-60 ℃, and the drying is finished when the water content of the precipitate is below 10%.
5. The method for treating the arsenic and cadmium combined polluted land by the composite biochar as claimed in claim 1, wherein in the step (2), the mass fraction of the dysprosium chloride solution is 12-16%, the molar concentration of the sodium hydroxide solution is 0.1-0.3mol/L, and in the step (2), the mass ratio of the HTS-coated biochar to the dysprosium chloride solution to the sodium hydroxide solution is 1:2-4: 8-11.
6. The method for treating the land polluted by the arsenic and the cadmium compositely by the composite biochar as claimed in claim 1, wherein in the step (3), the drying treatment temperature is 90-95 ℃, and the drying treatment time is 8-10 min.
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| CN114891515A (en) * | 2022-04-15 | 2022-08-12 | 西南石油大学 | Rare earth tailing doped biomass-based carrier soil heavy metal passivation material and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114891515A (en) * | 2022-04-15 | 2022-08-12 | 西南石油大学 | Rare earth tailing doped biomass-based carrier soil heavy metal passivation material and preparation method thereof |
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Application publication date: 20220222 |