CN113155558B - Method for extracting, separating and purifying microplastic in soil - Google Patents
Method for extracting, separating and purifying microplastic in soil Download PDFInfo
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- 239000002689 soil Substances 0.000 title claims abstract description 150
- 229920000426 Microplastic Polymers 0.000 title claims abstract description 73
- 238000000034 method Methods 0.000 title claims abstract description 32
- 239000004576 sand Substances 0.000 claims abstract description 32
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 30
- 239000004927 clay Substances 0.000 claims abstract description 30
- 239000002245 particle Substances 0.000 claims abstract description 18
- 239000000725 suspension Substances 0.000 claims abstract description 18
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical class [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 claims abstract description 13
- 239000012535 impurity Substances 0.000 claims abstract description 11
- 238000006243 chemical reaction Methods 0.000 claims abstract description 4
- 239000000243 solution Substances 0.000 claims description 26
- 229920003023 plastic Polymers 0.000 claims description 23
- 239000004033 plastic Substances 0.000 claims description 23
- 238000001914 filtration Methods 0.000 claims description 15
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 14
- 238000000746 purification Methods 0.000 claims description 12
- 239000012528 membrane Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 230000032798 delamination Effects 0.000 claims description 9
- 238000011010 flushing procedure Methods 0.000 claims description 6
- 238000004445 quantitative analysis Methods 0.000 claims description 5
- 239000007864 aqueous solution Substances 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 239000006228 supernatant Substances 0.000 claims description 4
- 239000008367 deionised water Substances 0.000 claims description 3
- 229910021641 deionized water Inorganic materials 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 3
- 239000011148 porous material Substances 0.000 claims description 3
- 238000007873 sieving Methods 0.000 claims description 3
- 150000004649 carbonic acid derivatives Chemical class 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- 238000000926 separation method Methods 0.000 abstract description 21
- 238000000605 extraction Methods 0.000 abstract description 18
- 239000002688 soil aggregate Substances 0.000 abstract description 11
- 238000004458 analytical method Methods 0.000 abstract description 4
- 239000000126 substance Substances 0.000 abstract description 4
- 229910052500 inorganic mineral Inorganic materials 0.000 abstract description 3
- 235000010755 mineral Nutrition 0.000 abstract description 3
- 239000011707 mineral Substances 0.000 abstract description 3
- 239000004016 soil organic matter Substances 0.000 abstract description 3
- 238000005345 coagulation Methods 0.000 abstract description 2
- 230000015271 coagulation Effects 0.000 abstract description 2
- 238000004090 dissolution Methods 0.000 abstract description 2
- 239000005416 organic matter Substances 0.000 description 18
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 9
- 239000003153 chemical reaction reagent Substances 0.000 description 7
- 239000012615 aggregate Substances 0.000 description 6
- 238000011160 research Methods 0.000 description 6
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- 239000012028 Fenton's reagent Substances 0.000 description 3
- 239000002734 clay mineral Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000011592 zinc chloride Substances 0.000 description 3
- 235000005074 zinc chloride Nutrition 0.000 description 3
- 241000196324 Embryophyta Species 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical class [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- 241001523486 Poncirus Species 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000003556 assay Methods 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000013043 chemical agent Substances 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229910001448 ferrous ion Inorganic materials 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000008202 granule composition Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- MGZTXXNFBIUONY-UHFFFAOYSA-N hydrogen peroxide;iron(2+);sulfuric acid Chemical compound [Fe+2].OO.OS(O)(=O)=O MGZTXXNFBIUONY-UHFFFAOYSA-N 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 235000013324 preserved food Nutrition 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000013049 sediment Substances 0.000 description 1
- 229910052604 silicate mineral Inorganic materials 0.000 description 1
- 239000003802 soil pollutant Substances 0.000 description 1
- 238000003900 soil pollution Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 238000009210 therapy by ultrasound Methods 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/34—Purifying; Cleaning
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3563—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing solids; Preparation of samples therefor
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/62—Plastics recycling; Rubber recycling
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Abstract
The invention relates to a method for extracting, separating and purifying microplastic in soil, belonging to the technical field of soil chemical analysis. The method is according to the soil texture: classifying the analyzed soil samples by using the differences of sand, loam and clay, and adopting different extraction and separation methods for different soil types; to promote the dissolution of some mineral components in the soil, reduce the coagulation of soil particles, and add hydrochloric acid into the saturated zinc chloride suspension; the soil suspension is subjected to ultrasonic and vibration, so that the soil aggregate structure is broken, and the separation of the microplastic and impurity components is promoted. And standing and layering the suspension, separating, and removing soil organic matter interference by using a Fenton reaction.
Description
Technical Field
The invention relates to a method for extracting, separating and purifying microplastic in soil, belonging to the technical field of soil chemical analysis.
Background
Soil is a natural resource which is vital for guaranteeing the sustainable development of agriculture in China, and is an important object for ecology and environmental protection. However, with the rapid development of industrialization in China, the problems of soil pollution and soil quality reduction are becoming serious. Among the numerous soil pollutants, microplastic with a diameter smaller than 5mm becomes a novel pollutant, and the pollution problem brought by the novel pollutant is more and more concerned. The micro plastics in the soil mainly enter through a great amount of use of agricultural films, recycling of plastic-containing wastes and other ways, and continuously accumulate in the soil, so that the soil property, the soil function and the soil biodiversity are affected. Therefore, the method has great significance in strengthening the treatment and research of the microplastic pollution in the soil.
The primary problem in researching and controlling the pollution of the soil microplastic is to extract and separate the microplastic from a complex soil matrix, however, the microplastic in the soil has wide sources and large residual quantity, and the commercial microplastic may have a certain difference from the microplastic in the soil environment, so that it is difficult to separate and identify a sufficient amount of microplastic from the actual soil for evaluating the ecological environment effect. Although there are reports on pollution of microplastic in soil at present, the extraction and separation methods of the adopted soil microplastic are not uniform and the methods are different; the extraction and separation methods are mostly extraction methods for referencing water and microplastic in sediment, such as Zhou Qian, and the like, in the text of the separation of microplastic and surface microscopic features thereof in coastal tidal flat soil, on the basis of the study of people before summarizing, quantitative soil samples are weighed, firstly, saturated sodium chloride solution is used for floatation to obtain preliminary separation samples, then saturated sodium chloride solution is used for floatation separation, a vacuum suction filtration device is used for filtering, salt is washed, microplastic is placed in a glass culture dish, and the glass culture dish is dried in air and is tested.
Soil is classified according to the ratio of soil texture and granule composition, and is generally classified into the following three categories:
(1) Sand soil: the single sand grains can be seen or perceived, and the sand grains are caught in the hand when dry and fall off after being loosened slightly; while the wet materials can be kneaded into clusters, but the powder can be dispersed when being touched; the cosmid content was less than 15%.
(2) Loam: when the dried food is dry, the food is held by hands to form clusters, and the clusters can not be scattered when being held by hands carefully; when the wet state is met, the wet state is not generally touched to be dispersed after being held into clusters; the content of the cosmid is 15-25%.
(3) Clay: dry and hard soil blocks are often hard, have adhesiveness and are extremely plastic, and can be twisted into long plastic soil strips by hands; the cosmid content was greater than 25%.
Research shows that when the existing soil microplastic extraction and separation method is used for extracting microplastic in soil with different textures, the microplastic extraction efficiency and recovery rate are found to be unstable, the extraction efficiency of sand samples is high, the clay and loam efficiency is low, and the extraction is insufficient.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide a method for extracting, separating and purifying microplastic in soil. According to the method, according to the difference of soil textures (sand, loam and clay), the analyzed soil samples are classified, and different extraction and separation methods are adopted for different soil types of samples; to promote the dissolution of some mineral components in the soil, reduce the coagulation of soil particles, and add hydrochloric acid into the saturated zinc chloride suspension; the soil suspension is subjected to ultrasonic and vibration, the soil aggregate structure is broken, and the separation of the micro plastics and impurity components is promoted. And standing and layering the suspension, separating, and removing soil organic matter interference by using a Fenton reaction.
In order to achieve the purpose of the invention, the following technical scheme is provided.
A method for extracting, separating and purifying microplastic in soil comprises the following steps:
step one, pretreatment of soil samples
Classifying soil samples according to textures, and dividing the soil samples into sandy soil, loam soil and clay; removing large-particle impurities such as crushed stone, plant rhizome and the like in the sample, sieving, and removing impurities such as plastics with the particle diameter of 5.0mm and the like with the sieve pore diameter of more than 5mm to obtain a pretreated soil sample.
Step two, extracting and separating soil microplastic
(1) The pretreated soil sample was dissolved in saturated zinc chloride (ZnCl) 2 ) In the aqueous solution, a soil suspension solution was prepared, and hydrochloric acid was added while stirring.
Wherein the mass fraction of the hydrochloric acid is 36-38%.
H in the hydrochloric acid + CO in soil samples after pretreatment 3 2- The molar ratio of (2) is more than or equal to 3:1; the CO 3 2- Derived from carbonates in the soil sample after pretreatment.
(2) Mixing evenly by ultrasonic and shaking, standing for layering, and filtering supernatant after layering; repeating the steps for more than 3 times to obtain the sample of the extracted soil micro-plastic.
The ultrasonic power is 600W, the frequency is 40KHz, wherein the ultrasonic time of the sand is 3-6 min, the ultrasonic time of the clay is 10-15 min, and the ultrasonic time of the loam is 20-30 min.
Preferably, when standing and layering, the standing and layering time of the sand is more than 2.0h; the standing delamination time of clay is more than 12.0 h; the standing delamination time of loam is more than 12.0h.
Step three, purification of microplastic
Adding FeSO into the sample from which the soil micro-plastic is extracted 4 Solution and H with mass fraction of 27.5% -50% 2 O 2 Solution H 2 O 2 With Fe 2+ The molar ratio of the catalyst to the catalyst is greater than or equal to 10:1, and the reaction is carried out for more than 2 hours at the temperature of 40-80 ℃ to remove organic matters in the sample; filtering, repeatedly flushing the filtering device with water for more than three times, and filtering the flushing liquid to ensure that all target objects are gathered on the filter membrane; and taking down the filter membrane, drying, and obtaining the purified micro-plastic sample on the filter membrane for subsequent micro-plastic identification and quantitative analysis.
Wherein H in hydrogen peroxide solution 2 O 2 The mass ratio of the organic matters to the organic matters is 5-10:1.
The water is water with the purity higher than that of deionized water.
Advantageous effects
1. The invention provides an extraction, separation and purification method of microplastic in soil, which is found by research that as the soil is divided into three different soil types of sandy soil, clay and loam according to the texture, the three soil types have huge differences in physicochemical properties; the sand has high sand grain content, small clay grain content and low organic matter content; the clay is opposite to the sand, has less sand grains, is formed by weathering silicate minerals, has sticky texture, slow organic matter decomposition and rich humic substances; the soil particles in loam have moderate content of sticky particles and sand grains, the particle size is 0.2-0.02 mm, and the soil aggregate structure is most abundant; therefore, the single microplastic extraction and separation method in the prior art is not suitable for all soil types with different textures; according to the method, soil samples are firstly preprocessed and divided into sandy soil, clay and loam, and in the subsequent processing, the soil samples are processed in a targeted mode according to the characteristics of the three soil types.
2. The invention provides a method for extracting, separating and purifying microplastic in soil, which is found by research that carbonate particles contained in the soil have small particle size and extremely strong adsorptivity; for example, in the northern calcareous soil, a large amount of calcium carbonate is contained, and the calcium carbonate has the function of agglomerating soil particles; if the substances in the soil are not removed, the soil suspension is not easy to stabilize and is in a flocculation state, the micro-plastics coated in the soil suspension are difficult to separate from the soil suspension, and the aperture of the filter membrane is easy to block, so that the difficulty of filtration is increased; therefore, in the method, the influence of carbonate particles is removed by dropwise adding hydrochloric acid into the saturated zinc chloride suspension, and the separation efficiency is improved.
3. The invention provides an extraction separation and purification method of microplastic in soil, which is found by research, the establishment of the extraction separation method of the microplastic in the soil in the prior art ignores the existence of soil aggregates and the influence of the aggregates and inorganic colloid on the microplastic in the soil; soil aggregate is a basic unit of a soil structure, and aggregate structure is a basic structure thereof; in the process of forming the soil aggregate structure, soil adhesive particles are very easy to combine with small-particle-diameter microplastic, organic matters and the like, so that the soil aggregate structure becomes a part of the aggregate structure; the separation method in the prior art can not fully separate the microplastic wrapped in the soil aggregate, and the obtained result can not reflect the real pollution condition of the soil microplastic; therefore, the breaking of soil aggregates, i.e. the breaking of the aggregate structure of the soil, is a prerequisite for the adequate extraction of the soil microplastic; in the method, the aggregate structure of the soil is fully crushed through ultrasonic and vibration, so that the micro-plastics coated in the soil are separated, and the dissociation of impurities such as mineral salt adsorbed on the surface of the micro-plastics is promoted;
further, because the clay content in the sand is low, the sand grain content is high, and the soil particles with an aggregate structure in the sand are low; however, the clay has the property opposite to that of sand, and contains more clay particles; therefore, during extraction and separation, the ultrasonic oscillation time of the sand sample is short, and the standing delamination treatment is short; while clay treatment requires relatively long ultrasonic vibration and standing delamination time relative to sand; different treatment methods are adopted for soil samples with different textures, so that time is saved, working efficiency is improved, reagents are saved, and resource waste is reduced.
4. The invention provides an extraction, separation and purification method of microplastic in soil, which is found by research that the soil contains rich organic matters, the organic matters are easy to be mutually wrapped with the microplastic, and the density of some organic matters is similar to that of the microplastic, so that a sample subjected to preliminary separation contains a large amount of impurities such as soil organic matters, a little clay mineral, mineral oil and the like, and the impurities not only influence the separation of the microplastic, but also influence the identification and quantitative analysis of the microplastic; thus, in the method of the present invention, fenton's reagent is added to a sample from which the soil micro-plastic is extracted, and the organic matter is dissolved in hydrogen peroxide (H 2 O 2 ) Ferrous ion (Fe) 2+ ) The mixed solution is rapidly oxidized; through the purification treatment, a large amount of soil organic matters, clay minerals and other impurities adsorbed on the microplastic are removed, so that the microplastic is further purified, and a foundation is laid for accurate identification and quantitative analysis of the microplastic;
further, the sand has low organic matter content; however, the clay has the property opposite to that of sand, and contains rich organic matters; thus, less Fenton reagent is required for the sand in the purification treatment, while relatively more Fenton reagent is required for the clay; different treatment methods are adopted for soil samples with different textures, so that time is saved, working efficiency is improved, reagents are saved, and resource waste is reduced.
Detailed Description
The present invention will be described in detail with reference to specific examples, but is not limited to the patent of the invention.
In the following examples:
the main instruments and reagents used are as follows:
(1) Reagent(s)
Zinc chloride (ZnCl) 2 ): analytically pure, purchased from the company, heng chemical agents, inc.
Hydrochloric acid: 36-38% of quality grade pure, purchased from national pharmaceutical group chemical reagent company;
hydrogen peroxide (H) 2 O 2 ): the mass fraction was 30%, analytically pure, purchased from Tianjin chemical reagent Co., ltd;
ferrous sulfate (FeSO) 4 ): analytically pure, purchased from national pharmaceutical groups chemical reagent company, inc.
(2) Experimental instrument
The Hyperion 2000 micro Fourier transform Infrared spectrometer, manufacturer: bruker, germany;
OLYM-PUS SZ61 type microscope, manufacturer: olympus Corporation, japan;
FA2204 electronic balance, manufacturer: shanghai force instruments and technology limited company, china;
DH-101 electrothermal blowing dry box, manufacturer: middle ring experiment electric furnace limited company in Tianjin, china;
KQ-600DV desk-top numerical control ultrasonic cleaner, producer: kunshan, ultrosophy instruments Inc.;
DB-2EFS graphite electric heating plate, manufacturer: shanghai Poncirus instruments science and technology Co., ltd., china.
Determination of carbonate in soil samples after pretreatment:
see LY/T1251-1999 forest soil water soluble salt analysis.
Determining organic matters in the pretreated soil sample:
see NY/T85-1988 soil organic matter assay.
The method for identifying and quantitatively analyzing the microplastic comprises the following steps:
the purified microplastic samples prepared in the examples were observed using a bulk microscope, and the shape, color, size and number were recorded, followed by a wavenumber of 4000cm -1 ～400cm -1 The scanning times are 32 times, and the resolution is 4cm -1 And (3) further performing differential analysis on the sample on the filter membrane by adopting a micro infrared spectrometer, analyzing microplastic, and determining the number of microplastic.
Quantitative calculation of the abundance of Microplastic (MPs) in soil: according to the formula: a=n/m×1000, and calculating the content of the microplastic in the soil, wherein a is the abundance of the microplastic in the soil, N is the number of the microplastic, and M is the pretreated soil sample.
Example 1
Step one, pretreatment of soil samples
Classifying soil samples according to textures, and dividing the soil samples into sandy soil, loam soil and clay; removing large-particle impurities such as crushed stone, plant rhizome and the like in the sample, sieving, and removing impurities such as plastics with the particle diameter of 5.0mm and the like with the sieve pore diameter of more than 5mm to obtain a pretreated soil sample.
The carbonate and organic matters in the pretreated soil sample are measured, and the result is as follows:
carbonate:
carbonate in the sand is 0.065g/100g, thus CO 3 2- 0.004g/100g;
carbonate in loam is 0.131g/100g, thus CO therein 3 2- 0.008g/100g;
the carbonate content of the clay is 0.128g/100g, thus the CO content thereof 3 2- 0.0078g/100g.
Organic matter:
100g of sand contains 0.50g of organic matters,
100g loam contains 2.82g organic matter,
100g of clay contains 3.63g of organic matters.
Step two, extracting and separating soil microplastic
(1) 50.0g of the pretreated soil sample was placed in a 500mL beaker and saturated ZnCl was added 2 200mL of the aqueous solution was dissolved to prepare a soil suspension, and hydrochloric acid was added thereto with stirring, and the addition amounts of hydrochloric acid are shown in Table 1.
(2) Ultrasonic and shaking for 2min, standing for layering, and filtering supernatant; repeating the step for 3 times to obtain a sample of the extracted soil micro-plastic.
The ultrasonic power is 600W, the frequency is 40KHz, wherein the ultrasonic time of the sand is 3min, the ultrasonic time of the clay is 10min, and the ultrasonic time of the loam is 20min.
Standing and layering time of sand is 2.0h; the standing delamination time of clay is 12.0h, and the standing delamination time of loam is 12.0h.
Step three, purification of microplastic
Into the sample from which the soil microplastic was extracted:
sand soil: adding 2mol/L FeSO 4 4mL of solution and 30% by mass of H 2 O 2 Solution 10mL, H 2 O 2 With Fe 2+ The molar ratio of (2) is equal to 10:1, H in the hydrogen peroxide solution 2 O 2 The mass ratio of the organic matter to the organic matter is 10:1;
clay: adding 2mol/L FeSO 4 26mL of solution and 30% by mass of H 2 O 2 60mL of solution, H 2 O 2 With Fe 2 + The molar ratio of (2) is equal to 10:1, H in the hydrogen peroxide solution 2 O 2 The mass ratio of the organic matter to the organic matter is 10:1;
loam: adding 2mol/L FeSO 4 16mL of solution and 30% by mass of H 2 O 2 40mL of solution, H 2 O 2 With Fe 2 + The molar ratio of (2) is equal to 10:1, H in the hydrogen peroxide solution 2 O 2 The mass ratio of the organic matter to the organic matter is 10:1.
Reacting for 2 hours at 60 ℃ to remove organic matters in the sample; filtering, namely repeatedly flushing the filtering device with deionized water for three times, and filtering the flushing liquid together to enable all target objects to be gathered on the filter membrane; the filter membrane is taken down by toothless stainless steel tweezers and put into a culture dish, after drying, the filter membrane is the purified micro plastic sample, the micro plastic identification and quantitative analysis are carried out, and the abundance of Micro Plastic (MPs) in soil is calculated, and the result is shown in Table 1.
TABLE 1 addition of hydrochloric acid to soil suspensions of different textures and results
Example 2
Step one, pretreatment of soil samples
Step one as in example 1.
Step two, extracting and separating soil microplastic
(1) 50.0g of the pretreated soil sample was placed in a 500mL beaker and saturated ZnCl was added 2 200mL of the aqueous solution was dissolved to prepare a soil suspension, hydrochloric acid was added while stirring, and the addition amount of hydrochloric acid was as follows:
0.5mL of the sandy soil sample, 1.0mL of the loam soil sample, and 1.0mL of the clay sample were added.
The procedure (1) is otherwise the same as in example 1.
(2) Ultrasonic and shaking for 2min, standing for layering, and filtering supernatant; repeating the step for 3 times to obtain a sample of the extracted soil micro-plastic.
The ultrasonic power was 600W and the frequency was 40KHz, wherein the ultrasonic time of the sand, clay and loam was as shown in table 2.
Standing and layering time of sand is 2.0h; the standing delamination time of clay is 12.0h, and the standing delamination time of loam is 12.0h.
Step three, purification of microplastic
The results are shown in Table 2 as in step three of example 1.
TABLE 2 ultrasound time and results for soil suspensions of different textures
Example 3
Step one, pretreatment of soil samples
Step one as in example 1.
Step two, extracting and separating soil microplastic
(1) Step two (1) as in example 2;
(2) Step two (1) is the same as in example 1.
Step three, purification of microplastic
Into the sample from which the soil microplastic was extracted:
sand soil: adding 2mol/L FeSO 4 2mL of solution and 30% by mass of H 2 O 2 Solution 5mL (as shown in Table 3), H 2 O 2 With Fe 2+ The molar ratio of (2) is 10:1, H in hydrogen peroxide solution 2 O 2 The mass ratio of the organic matters to the organic matters is 5:1;
adding 2mol/L FeSO 4 3mL of solution and 30% by mass of H 2 O 2 10mL of solution (as shown in Table 3), H 2 O 2 With Fe 2+ The molar ratio of (2) is 15:1, H in hydrogen peroxide solution 2 O 2 The mass ratio of the organic matter to the organic matter is 10:1;
clay: adding 2mol/L FeSO 4 13mL of solution and 30% by mass of H 2 O 2 30mL of solution (as shown in Table 3), H 2 O 2 With Fe 2+ The molar ratio of (2) is 10:1, H in hydrogen peroxide solution 2 O 2 The mass ratio of the organic matters to the organic matters is 5:1;
adding 2mol/L FeSO 4 18mL of solution and 30% by mass of H 2 O 2 60mL of solution (as shown in Table 3), H 2 O 2 With Fe 2+ The molar ratio of (2) is 15:1, H in hydrogen peroxide solution 2 O 2 The mass ratio of the organic matter to the organic matter is 10:1;
loam: adding 2mol/L FeSO 4 8mL of solution and 30% by mass of H 2 O 2 Solution 20mL (as shown in Table 3), H 2 O 2 With Fe 2+ The molar ratio of (2) is 10:1, H in hydrogen peroxide solution 2 O 2 The mass ratio of the organic matters to the organic matters is 5:1;
adding 2mol/L FeSO 4 12mL of solution and 30% by mass of H 2 O 2 40mL of solution (as shown in Table 3), H 2 O 2 With Fe 2+ The molar ratio of (2) is 15:1, H in hydrogen peroxide solution 2 O 2 The mass ratio of the organic matter to the organic matter is 10:1.
The rest of the procedure is the same as in example 1, step three, and the results are shown in Table 3.
TABLE 3 oxidizing purification effect of soil suspensions of different textures
By the above examples, the person skilled in the art can know that, compared with the existing soil microplastic extraction method, the method of the present invention proposes: (1) The soil microplastic extraction should select different treatment methods according to different soil textures, so that not only is the time saved and the working efficiency improved, but also the reagent is saved and the resource waste is reduced. (2) Adding acid into the suspension and carrying out ultrasonic treatment on the soil mixed solution, so that flocculent precipitate and a soil aggregate structure caused by carbonate in the soil are broken, and the micro-plastics wrapped by the flocculent precipitate and the soil aggregate structure are released, so that the micro-plastics are extracted more completely; (3) The micro-plastic sample subjected to primary separation is subjected to purification treatment, so that the influence of organic matters and clay mineral particles is eliminated, and the efficiency and accuracy of micro-plastic identification are improved.
Claims (3)
1. A method for extracting, separating and purifying microplastic in soil is characterized in that: the method comprises the following steps:
step one, pretreatment of soil samples
Classifying soil samples according to textures, and dividing the soil samples into sandy soil, loam soil and clay; removing large-particle impurities, and sieving to obtain a pretreated soil sample, wherein the sieve pore diameter is 5.0 mm;
step two, extracting and separating soil microplastic
(1) Dissolving the pretreated soil sample in saturated zinc chloride aqueous solution to prepare soil suspension solution, and adding hydrochloric acid while stirring; the mass fraction of the hydrochloric acid is 36-38%;
h in hydrochloric acid + CO in soil samples after pretreatment 3 2- The molar ratio of (2) is more than or equal to 3:1;
(2) Mixing evenly by ultrasonic and shaking, standing for layering, and filtering supernatant after layering; repeating the steps for more than 3 times to obtain a sample of the extracted soil micro-plastic;
the ultrasonic power is 600W, the frequency is 40KHz, the ultrasonic time of the sand is 3-6 min, the ultrasonic time of the clay is 10-15 min, and the ultrasonic time of the loam is 20-30 min;
when standing and layering, the standing and layering time of sand is more than 2.0h; the standing delamination time of clay is more than 12.0 h; standing and layering time of loam is more than 12.0 h;
step three, purification of microplastic
Adding FeSO into the sample from which the soil micro-plastic is extracted 4 Solution and H with mass fraction of 27.5% -50% 2 O 2 Solution H 2 O 2 With Fe 2+ The mol ratio of (2) is more than or equal to 10:1, and the reaction is carried out for more than 2 hours at the temperature of 40-80 ℃; filtering, repeatedly flushing the filtering device with water for more than three times, and filtering the flushing liquid to ensure that all target objects are gathered on the filter membrane; taking down and drying the filter membrane, wherein the filter membrane is the purified micro-plastic sample for subsequent micro-plastic identification and quantitative analysis;
h in hydrogen peroxide solution 2 O 2 The mass ratio of the organic matters to the organic matters is 5-10:1.
2. The method for extracting, separating and purifying microplastic in soil according to claim 1, wherein the method comprises the following steps: in the second step (1), the CO 3 2- Derived from carbonates in the soil sample after pretreatment.
3. The method for extracting, separating and purifying microplastic in soil according to claim 1 or 2, wherein the method comprises the following steps: in the third step, the water is water with the purity higher than that of deionized water.
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| CN113640084B (en) * | 2021-08-20 | 2023-05-02 | 北京大学 | Detection method of farmland soil micro-plastics |
| CN113618966B (en) * | 2021-08-30 | 2022-12-27 | 陕西师范大学 | Method for separating micro plastic and biochar |
| CN113720844A (en) * | 2021-10-11 | 2021-11-30 | 中国科学院西北生态环境资源研究院 | Quantitative analysis method for soil micro-plastics in biological soil crust layer |
| CN114062071B (en) * | 2021-10-14 | 2023-04-07 | 中国农业科学院农业环境与可持续发展研究所 | Method for quickly separating and detecting plastic from soil |
| CN114308401B (en) * | 2022-01-05 | 2023-12-15 | 澳门大学 | Micro-plastic flotation device and method |
| CN115582945A (en) * | 2022-09-26 | 2023-01-10 | 中国水利水电科学研究院 | Device and method for pretreating middle and small-particle-size micro-plastics in soil or sediment |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110186863A (en) * | 2019-05-08 | 2019-08-30 | 浙江工业大学 | The detection method of the micro- plastic degradation situation in mulch source in a kind of pair of soil |
| CN110987578A (en) * | 2019-10-28 | 2020-04-10 | 天津理工大学 | Screening and extracting method for micro-plastics in vegetation cover soil |
| CN111426545A (en) * | 2020-03-25 | 2020-07-17 | 中国环境科学研究院 | Method for quickly separating micro-plastic in soil |
| CN111420794A (en) * | 2020-03-31 | 2020-07-17 | 陕西科技大学 | Device and method for separating and extracting micro-plastic in soil |
| CN111721600A (en) * | 2020-06-24 | 2020-09-29 | 南京师范大学 | Method for extracting and separating dissolved organic matters in soil and dissolved organic matters extracted and separated by method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT201800003337A1 (en) * | 2018-03-07 | 2019-09-07 | Margherita Anna Letizia Ferrante | Method for the extraction and determination of microplastics in samples with organic and inorganic matrices |
-
2021
- 2021-02-05 CN CN202110162041.0A patent/CN113155558B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110186863A (en) * | 2019-05-08 | 2019-08-30 | 浙江工业大学 | The detection method of the micro- plastic degradation situation in mulch source in a kind of pair of soil |
| CN110987578A (en) * | 2019-10-28 | 2020-04-10 | 天津理工大学 | Screening and extracting method for micro-plastics in vegetation cover soil |
| CN111426545A (en) * | 2020-03-25 | 2020-07-17 | 中国环境科学研究院 | Method for quickly separating micro-plastic in soil |
| CN111420794A (en) * | 2020-03-31 | 2020-07-17 | 陕西科技大学 | Device and method for separating and extracting micro-plastic in soil |
| CN111721600A (en) * | 2020-06-24 | 2020-09-29 | 南京师范大学 | Method for extracting and separating dissolved organic matters in soil and dissolved organic matters extracted and separated by method |
Non-Patent Citations (5)
| Title |
|---|
| How does sonication affect the mineral and organic constituents of soil aggregates?—A review;Michael Kaiser;《Journal of Plant Nutrition and Soil Science》;20140903;第177卷(第4期);第480-481页 * |
| Validation of a Method for Extracting Microplastics from Complex, Organic-Rich, Environmental Matrices;Rachel R. Hurley;《ENVIRONMENTAL SCIENCE & TECHNOLOGY》;20181228;第52卷(第13期);第7409-7417页 * |
| 土壤微塑料污染及生态环境效应研究进展;雷雨辰 等;《化学研究》;20210125;第32卷(第1期);第85-86页 * |
| 汤庆峰 等.环境样品中微塑料分析技术研究进展.《分析测试学报》.2019,第38卷(第8期),第1009-1019页. * |
| 陈苍鹏.土壤.《初中地理模型与实验活动》.2018,第213-219页. * |
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