CN115109593A - Synthetic method and application of plant biomass xanthate - Google Patents

Abstract

The invention discloses a method for synthesizing plant biomass xanthate, comprising the following steps: taking crop straw powder into a reactor, adding potassium hydroxide, stirring evenly, spraying water, stirring evenly, compacting and placing, to obtain Alkalize the material; slowly add the alkalized material to the yellowing agent while stirring, and stir to obtain a suspension; add a paste-like magnesium sulfate solution to the suspension, stir to form a yellow precipitate, continue stirring, stand, and suction filtration, The crude biomass xanthate magnesium salt is obtained; after the crude biomass xanthate magnesium salt is separated from the organic solvent, washed with water and centrifuged to obtain the biomass magnesium potassium xanthate. The invention also discloses the application of biomass magnesium potassium xanthate as seed coating agent or root dipping agent to passivate heavy metals in soil. The invention provides a method for synthesizing plant biomass xanthate and application thereof, which has the advantages of simple process and little environmental pollution, and the obtained plant biomass xanthate can achieve the effect of precipitating heavy metals with less dosage and high efficiency.

Description

A kind of synthetic method and application of plant biomass xanthate

technical field

The invention relates to the field of agriculture and forestry, in particular to a method for synthesizing plant biomass xanthate and its application.

Background technique

Human activities make heavy metals accumulate in the soil, resulting in the decline of soil quality, excessive heavy metals in crops and deteriorating ecological environment. At present, soil heavy metal pollution remediation can be divided into two directions: one is to remove heavy metals from soil to directly eliminate their harm; the other is to fix heavy metals in soil and reduce their harm by controlling their migration. Based on the above two principles, the current treatment of heavy metals in soil can be roughly divided into technologies such as physical remediation, chemical remediation and bioremediation. Among them, chemical remediation is to control the migration of heavy metals in soil through the direct action of chemical reagents on the soil or through the adsorption and passivation of environmentally friendly minerals. However, both methods require sufficient contact between reagents or minerals and soil to play a more effective role. It is difficult to implement on the soil of large-scale planting of crops and the amount of materials is large, which is often difficult to use continuously.

In the past long practice, xanthate was used to precipitate heavy metal elements known as xanthate. The replacement of -R on xanthate by cellulose is cellulose xanthate, which can be prepared by mixing cellulose with lye and carbon disulfide to prepare cellulose xanthate. Cellulose xanthate magnesium salt has both chemical stability and ion exchange properties. After the cellulose xanthate magnesium salt is exchanged with transition metal ions, the cellulose xanthate precipitate that generates heavy metals has very low solubility and low solubility. The high stability constant can make heavy metal ions inactive.

Substituting plant biomass for cellulose also yields biomass xanthates, which have good properties for precipitating heavy metals. However, although the existing method for synthesizing biomass xanthate from aqueous solution can obtain the required heavy metal precipitant, this method will cause serious water pollution, which will limit the widespread use of biomass xanthate.

SUMMARY OF THE INVENTION

In view of the shortcomings of serious water pollution in the current method for synthesizing biomass xanthate from aqueous solutions, the present invention provides a method for synthesizing plant biomass xanthate and application thereof, with simple process and little environmental pollution, and the obtained plant biomass yellow Orthoate can achieve the effect of precipitation of heavy metals with low dosage and high efficiency.

To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

A synthetic method of plant biomass xanthate, comprising the steps:

Alkalization of crop straw powder: take the crop straw powder in the reactor, add potassium hydroxide, stir evenly, spray water, stir evenly, compact and place, and conduct alkalization reaction to obtain alkalized material;

Yellowing of the alkalized material: slowly add the alkalized material to the yellowing agent while stirring, and fully stir under ventilation conditions to obtain a suspension;

Suspension transformation reaction: add paste magnesium sulfate solution to the suspension, stir to generate yellow precipitate, continue stirring, stand, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate;

Separation and purification: after separating the crude biomass magnesium xanthate containing potassium sulfate from the organic solvent, washing with a little water and centrifuging to obtain the biomass potassium magnesium xanthate.

According to one aspect of the present invention, the yellowing agent is a mixture of dimethyl sulfoxide and carbon disulfide, and the volume ratio of the dimethyl sulfoxide and carbon disulfide is 8-9:1.

According to one aspect of the present invention, the paste-like magnesium sulfate solution is a mixture of magnesium sulfate heptahydrate and water, and the mass ratio of the magnesium sulfate heptahydrate and water is 23-27:1.

According to one aspect of the present invention, the mass ratio of the crop straw powder to potassium hydroxide is 1.5-2:1.

According to an aspect of the present invention, after the mixing is uniform, it is compacted and placed for 2-5 hours.

According to one aspect of the present invention, the crop comprises one or a combination of sugarcane, corn, rice, rape, and wheat.

According to one aspect of the present invention, the sufficient stirring time under the ventilation condition is 4 hours.

According to one aspect of the present invention, the centrifugal separation further includes drying, and the drying includes drying in an oven at 40-50° C. for 24 hours.

According to one aspect of the present invention, the application of the biomass magnesium potassium xanthate as a seed coating agent or a root dip agent to passivate heavy metals in soil.

The advantages of the present invention are as follows: by using crop straw powder as raw material, potassium hydroxide and carbon disulfide as yellowing agent, magnesium sulfate as stabilizer, and organic solvent such as dimethyl sulfoxide as reaction medium, the material yellowing is carried out by temperature-controlled stirring. to obtain biomass magnesium potassium xanthate. The non-aqueous solution system is used to synthesize magnesium xanthate, which has little environmental pollution, its sulfhydryl structure has a strong function of precipitating heavy metals, and the plant biomass macromolecules it contains have good biocompatibility, which can be combined with other nutrients The seed coating agent is made into seed coating agent together. The seed coating agent intercepts the heavy metals in the soil and targets the crops themselves rather than the soil. Direct contact with the heavy metals makes them precipitate before entering the crops, so that the heavy metals in the soil can be prevented from entering the crops. In order to overcome the harm of heavy metals to crops and improve the safety of crops in the food chain, the dosage is small and efficient.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the schematic flow sheet of the synthetic method of a kind of plant biomass xanthate of the present invention;

Fig. 2 is the comparison diagram of biomass magnesium xanthate potassium salt output under different KOH additions in the synthetic method of a kind of plant biomass xanthate of the present invention;

Fig. 3 is a comparison diagram of the yield of magnesium and potassium xanthate of biomass with different placement times in the method for synthesizing plant biomass xanthate according to the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in Figure 1, a method for synthesizing plant biomass xanthate includes the following steps: alkalization of crop straw powder: taking the crop straw powder in a reactor, adding potassium hydroxide, stirring evenly, and spraying water, After stirring evenly, compact and place, and carry out an alkalization reaction to obtain an alkalized material; yellowing of the alkalized material: slowly add the alkalized material to the yellowing agent while stirring, and fully stir under ventilation conditions to obtain a suspension ; Suspension transformation reaction: add paste magnesium sulfate solution in the suspension, stir to generate yellow precipitate, continue to stir, stand, suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; separation and purification : After separating the crude biomass magnesium xanthate containing potassium sulfate from the organic solvent, washing with a little water and centrifuging to obtain the biomass potassium magnesium xanthate.

Xanthogen is a polar organic compound with a density of 1.3-1.7g/cm3, easily soluble in water and dissociated in water. The general formula of xanthogen is R-O-CS·SH. In acidic solutions, xanthic acid is easily decomposed and easily oxidized in alkaline solutions. At the same time, the aqueous solution of xanthogen acid is contacted with air to generate alcohol. Therefore, the synthetic xanthogen acid is more often used in the form of xanthate (R-O-CS·SM). When the cation in R-O-CS·SM is magnesium ion, the chemical substance tends to be stable; when the cation is transition metal ion, this salt is equivalent to the sulfide of transition metal ion and becomes an insoluble substance.

The biomass magnesium potassium salt of xanthate is a chemical substance that can form precipitates with heavy metals and has good biocompatibility. This chemical substance is used as a seed coating agent to wrap crop seeds or as a fixative for crop seedlings. Dip the roots and let them directly contact heavy metals to cause precipitation before entering the crops, which can prevent soil heavy metals from entering the crops, thereby overcoming the harm of heavy metals to crops and improving the safety of crops in the food chain. The prepared seed coating agent intercepts heavy metals in the soil and targets the crop itself rather than the soil, so the dosage is small and efficient.

In practical applications, the crops include sugarcane, corn, rice, rape, wheat and the like. The yellowing agent is a mixture of dimethyl sulfoxide and carbon disulfide, and the volume ratio of the dimethyl sulfoxide and carbon disulfide is 8-9:1. The paste-like magnesium sulfate solution is a mixture of magnesium sulfate heptahydrate and water, and the mass ratio of the magnesium sulfate heptahydrate and water is 23-27:1. The sufficient stirring time under the ventilation condition is 4 hours. Preferably, after the stirring is uniform, the mixture is compacted and placed for 2-5 hours. The centrifugal separation also includes drying, and the drying includes drying in an oven at 40-50° C. for 24 hours.

By using crop straw powder, such as sugar cane, corn, rice, rape, wheat, etc. as raw materials, potassium hydroxide and carbon disulfide as yellowing agents, magnesium sulfate as stabilizers, using organic solvents such as dimethyl sulfoxide as reaction medium, through The material is yellowed by temperature control and stirring to obtain biomass xanthate, and the obtained biomass xanthate is made into seed coating agent or root dip agent together with other additives.

The following are specific examples.

Example 1

A synthetic method of plant biomass xanthate, comprising the steps:

Weigh 1kg of bagasse in the stainless steel reactor; add 0.4kg of potassium hydroxide on the bagasse, stir as evenly as possible; spray 1.5kg of clear water on the bagasse to which potassium hydroxide has been added, turn the feed, and after the water is uniform Press and place for 2 hours to carry out the alkalinization reaction; take another reactor in the fume hood, add 5L of dimethyl sulfoxide and 0.6L of carbon disulfide, mix well to obtain a non-aqueous solution; in the above-mentioned non-aqueous solution, slowly add the When the alkalized material is placed, when the material is added, it is fully stirred for 4 hours under ventilation conditions, and the non-aqueous system is in a light yellow suspension state at this time; take 2.5kg of magnesium sulfate heptahydrate, add 0.1L of water and grind it into a paste Then add it to the above non-aqueous system, stir to form a yellow precipitate, continue to stir for 2h, stand for 0.5h, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; The magnesium salt is separated from the organic solvent, and the separated organic solvent is supplemented with dimethyl sulfoxide to 5L to dissolve the carbon disulfide again, and the obtained organic solution enters the next reaction cycle; the crude biomass magnesium salt of xanthate containing potassium sulfate is washed with a little water and centrifuged Separation to obtain biomass potassium magnesium xanthate, and the washing water is returned to the process of preparing paste magnesium sulfate.

In practical application, the organic solution obtained after separation enters the next reaction cycle, and the washing water is returned to the process of preparing paste magnesium sulfate, which further saves resources and reduces environmental pollution.

Example 2

A synthetic method of plant biomass xanthate, comprising the steps:

Weigh 1kg of bagasse in the stainless steel reactor; add 0.5kg of potassium hydroxide on the bagasse, stir as evenly as possible; spray 1.5kg of clear water on the bagasse to which potassium hydroxide has been added, turn the feed, and after the water is uniform Press and place for 2 hours to carry out the alkalinization reaction; take another reactor in the fume hood, add 5L of dimethyl sulfoxide and 0.6L of carbon disulfide, mix well to obtain a non-aqueous solution; in the above-mentioned non-aqueous solution, slowly add the When the alkalized material is placed, when the material is added, it is fully stirred for 4 hours under ventilation conditions, and the non-aqueous system is in a light yellow suspension state at this time; take 2.5kg of magnesium sulfate heptahydrate, add 0.1L of water and grind it into a paste Then add it to the above non-aqueous system, stir to form a yellow precipitate, continue to stir for 2h, stand for 0.5h, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; The magnesium salt is separated from the organic solvent, and the separated organic solvent is supplemented with dimethyl sulfoxide to 5L to dissolve the carbon disulfide again, and the obtained organic solution enters the next reaction cycle; the crude biomass magnesium salt of xanthate containing potassium sulfate is washed with a little water and centrifuged Separation to obtain biomass potassium magnesium xanthate, and the washing water is returned to the process of preparing paste magnesium sulfate.

Example 3

A synthetic method of plant biomass xanthate, comprising the steps:

Weigh 1kg of bagasse in the stainless steel reactor; add 0.6kg of potassium hydroxide on the bagasse, stir as evenly as possible; spray 1.5kg of clean water on the bagasse to which potassium hydroxide has been added, turn the feed, and after the water is uniform Press and place for 2 hours to carry out the alkalinization reaction; take another reactor in the fume hood, add 5L of dimethyl sulfoxide and 0.6L of carbon disulfide, mix well to obtain a non-aqueous solution; in the above-mentioned non-aqueous solution, slowly add the When the alkalized material is placed, when the material is added, it is fully stirred for 4 hours under ventilation conditions, and the non-aqueous system is in a light yellow suspension state at this time; take 2.5kg of magnesium sulfate heptahydrate, add 0.1L of water and grind it into a paste Then add it to the above non-aqueous system, stir to form a yellow precipitate, continue to stir for 2h, stand for 0.5h, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; The magnesium salt is separated from the organic solvent, and the separated organic solvent is supplemented with dimethyl sulfoxide to 5L to dissolve the carbon disulfide again, and the obtained organic solution enters the next reaction cycle; the crude biomass magnesium salt of xanthate containing potassium sulfate is washed with a little water and centrifuged Separation to obtain biomass potassium magnesium xanthate, and the washing water is returned to the process of preparing paste magnesium sulfate.

Example 4

A synthetic method of plant biomass xanthate, comprising the steps:

Weigh 1kg of bagasse in the stainless steel reactor; add 0.7kg of potassium hydroxide on the bagasse, stir as evenly as possible; spray 1.5kg of clean water on the bagasse to which potassium hydroxide has been added, turn the feed, and after the water is uniform Press and place for 2 hours to carry out the alkalinization reaction; take another reactor in the fume hood, add 5L of dimethyl sulfoxide and 0.6L of carbon disulfide, mix well to obtain a non-aqueous solution; in the above-mentioned non-aqueous solution, slowly add the When the alkalized material is placed, when the material is added, it is fully stirred for 4 hours under ventilation conditions, and the non-aqueous system is in a light yellow suspension state at this time; take 2.5kg of magnesium sulfate heptahydrate, add 0.1L of water and grind it into a paste Then add it to the above non-aqueous system, stir to form a yellow precipitate, continue to stir for 2h, stand for 0.5h, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; The magnesium salt is separated from the organic solvent, and the separated organic solvent is supplemented with dimethyl sulfoxide to 5L to dissolve the carbon disulfide again, and the obtained organic solution enters the next reaction cycle; the crude biomass magnesium salt of xanthate containing potassium sulfate is washed with a little water and centrifuged Separation to obtain biomass potassium magnesium xanthate, and the washing water is returned to the process of preparing paste magnesium sulfate.

Example 5

A synthetic method of plant biomass xanthate, comprising the steps:

Weigh 1kg of bagasse in the stainless steel reactor; add 0.6kg of potassium hydroxide on the bagasse, stir as evenly as possible; spray 1.5kg of clean water on the bagasse to which potassium hydroxide has been added, turn the feed, and after the water is uniform Press and place for 1 hour to carry out the alkalization reaction; take another reactor in the fume hood, add 5L of dimethyl sulfoxide and 0.6L of carbon disulfide, mix well to obtain a non-aqueous solution; in the above-mentioned non-aqueous solution, slowly add the When the alkalized material is placed, when the material is added, it is fully stirred for 4 hours under ventilation conditions, and the non-aqueous system is in a light yellow suspension state at this time; take 2.5kg of magnesium sulfate heptahydrate, add 0.1L of water and grind it into a paste Then add it to the above non-aqueous system, stir to form a yellow precipitate, continue to stir for 2h, stand for 0.5h, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; The magnesium salt is separated from the organic solvent, and the separated organic solvent is supplemented with dimethyl sulfoxide to 5L to dissolve the carbon disulfide again, and the obtained organic solution enters the next reaction cycle; the crude biomass magnesium salt of xanthate containing potassium sulfate is washed with a little water and centrifuged Separation to obtain biomass potassium magnesium xanthate, and the washing water is returned to the process of preparing paste magnesium sulfate.

Example 6

A synthetic method of plant biomass xanthate, comprising the steps:

Weigh 1kg of bagasse in the stainless steel reactor; add 0.6kg of potassium hydroxide on the bagasse, stir as evenly as possible; spray 1.5kg of clean water on the bagasse to which potassium hydroxide has been added, turn the feed, and after the water is uniform Compacted and placed for 3 hours to carry out the alkalinization reaction; take another reactor in the fume hood, add 5L of dimethyl sulfoxide and 0.6L of carbon disulfide, mix well to obtain a non-aqueous solution; in the above-mentioned non-aqueous solution, slowly add the When the alkalized material is placed, when the material is added, it is fully stirred for 4 hours under ventilation conditions, and the non-aqueous system is in a light yellow suspension state at this time; take 2.5kg of magnesium sulfate heptahydrate, add 0.1L of water and grind it into a paste Then add it to the above non-aqueous system, stir to form a yellow precipitate, continue to stir for 2h, stand for 0.5h, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; The magnesium salt is separated from the organic solvent, and the separated organic solvent is supplemented with dimethyl sulfoxide to 5L to dissolve the carbon disulfide again, and the obtained organic solution enters the next reaction cycle; the crude biomass magnesium salt of xanthate containing potassium sulfate is washed with a little water and centrifuged Separation to obtain biomass potassium magnesium xanthate, and the washing water is returned to the process of preparing paste magnesium sulfate.

Example 7

A synthetic method of plant biomass xanthate, comprising the steps:

Weigh 1kg of bagasse in the stainless steel reactor; add 0.6kg of potassium hydroxide on the bagasse, stir as evenly as possible; spray 1.5kg of clean water on the bagasse to which potassium hydroxide has been added, turn the feed, and after the water is uniform Press and place for 4 hours to carry out the alkalization reaction; take another reactor in the fume hood, add 5L of dimethyl sulfoxide and 0.6L of carbon disulfide, mix well to obtain a non-aqueous solution; in the above-mentioned non-aqueous solution, slowly add the When the alkalized material is placed, when the material is added, it is fully stirred for 4 hours under ventilation conditions, and the non-aqueous system is in a light yellow suspension state at this time; take 2.5kg of magnesium sulfate heptahydrate, add 0.1L of water and grind it into a paste Then add it to the above non-aqueous system, stir to form a yellow precipitate, continue to stir for 2h, stand for 0.5h, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; The magnesium salt is separated from the organic solvent, and the separated organic solvent is supplemented with dimethyl sulfoxide to 5L to dissolve the carbon disulfide again, and the obtained organic solution enters the next reaction cycle; the crude biomass magnesium salt of xanthate containing potassium sulfate is washed with a little water and centrifuged Separation to obtain biomass potassium magnesium xanthate, and the washing water is returned to the process of preparing paste magnesium sulfate.

Example 8

A synthetic method of plant biomass xanthate, comprising the steps:

Weigh 1kg of bagasse in the stainless steel reactor; add 0.6kg of potassium hydroxide on the bagasse, stir as evenly as possible; spray 1.5kg of clean water on the bagasse to which potassium hydroxide has been added, turn the feed, and after the water is uniform Compacted and placed for 5 hours to carry out the alkalization reaction; take another reactor in the fume hood, add 5L of dimethyl sulfoxide and 0.6L of carbon disulfide, mix well to obtain a non-aqueous solution; in the above-mentioned non-aqueous solution, slowly add the When the alkalized material is placed, when the material is added, it is fully stirred for 4 hours under ventilation conditions, and the non-aqueous system is in a light yellow suspension state at this time; take 2.5kg of magnesium sulfate heptahydrate, add 0.1L of water and grind it into a paste Then add it to the above non-aqueous system, stir to form a yellow precipitate, continue to stir for 2h, stand for 0.5h, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; The magnesium salt is separated from the organic solvent, and the separated organic solvent is supplemented with dimethyl sulfoxide to 5L to dissolve the carbon disulfide again, and the obtained organic solution enters the next reaction cycle; the crude biomass magnesium salt of xanthate containing potassium sulfate is washed with a little water and centrifuged Separation to obtain biomass potassium magnesium xanthate, and the washing water is returned to the process of preparing paste magnesium sulfate.

The products prepared in Example 1, Example 2, Example 3, and Example 4 were compared with the output of biomass magnesium potassium xanthate under different KOH additions, and the results were as shown in Figure 2 below:

It can be seen that the optimum potassium hydroxide dosage is 0.56kg.

The products prepared in Example 3, Example 5, Example 6, Example 7, and Example 8 were compared for the yield of yellowed products with different placement times, and the results were shown in Figure 3 below:

It can be seen that the optimal placement time is 3h.

The biomass magnesium potassium salt of xanthate prepared in Example 1 was sampled for isothermal adsorption experiments of heavy metal ions of Cu, Cd, Pb and Hg. Specifically: take 1.00 g of the biomass magnesium potassium xanthate material prepared in Example 1 (repeated 3 times for each sample) in a triangular flask, add 100 ml of a heavy metal ion solution of 1000-5000 mg/L, and the heavy metal ion solution contains Cd2+, Cu2+, Pb2+, Hg2+, shake well, plug tightly, shake at 25°C for 30min, filter, after the filtrate is diluted, measure the concentration of Cd2+, Cu2+, Pb2+ in the diluted solution by flame atomic absorption spectrometer, and measure the concentration of Cd2+, Cu2+, Pb2+ in the diluted solution by automatic mercury measuring instrument The Hg ion concentration was then converted into the concentration of heavy metal ions in the solution to calculate the respective adsorption amounts. Finally, the Langmuir isotherm adsorption equation was used to calculate the relevant physical quantities.

Calculation of adsorption capacity:

X=(C0–C)×100/(1.000×1000)

X—the amount of heavy metal ion adsorption (mg/g)

C0—Initial concentration of heavy metal ions (mg/L)

C—equilibrium concentration of heavy metal ions (mg/L)

Langmuir adsorption isotherm: X=KXmax C/(1+KC)

X—the amount of heavy metal ion adsorption (mg/g)

Xmax—the maximum adsorption capacity of heavy metal ions (mg/g)

K—Adsorption constant (L/g)

C—equilibrium concentration of heavy metal ions (mg/L)

Through the isotherm adsorption of biomass magnesium potassium xanthate to a series of heavy metal solutions, the respective adsorption amounts were calculated, and the adsorption series was fitted with the Langmuir adsorption isotherm to obtain the adsorption of biomass magnesium potassium xanthate to various heavy metal ions The constant and maximum adsorption capacity are shown in Table 1.

The Langmuir isotherm adsorption parameters and maximum adsorption capacity of plant biomass magnesium potassium xanthate for Cd2+, Cu2+, Pb2+, Hg2+ in Table 1:

In practical applications, the obtained biomass xanthate can be used with other additives to make pellet coating material, and the pellet coating material can be used as a crop coating agent to wrap crop seeds or as a root dip agent for the dip roots of crop seedlings. In practical applications, pelletized seeds are prepared according to the ratio of 3:1-1:0.5 of different crop seeds and pelletized materials. Specifically, the pill coating material is mainly composed of the plant biomass magnesium potassium xanthate and filler. After grinding, add water to moisten, mix and rotate with the corresponding proportion of seeds, and spray the adhesive at the same time to increase the mechanical strength of the pill coating. . During the rooting process of pill-coated seeds, the root system is protected by plant biomass magnesium and potassium xanthate, and the plant biomass magnesium and potassium xanthate directly contacts heavy metals to cause precipitation before entering crops, which can prevent soil heavy metals from entering crops. Therefore, it can overcome the harm of heavy metals to crops and improve the safety of crops in the food chain. The prepared seed coating agent intercepts heavy metals in the soil and targets the crop itself rather than the soil, so the dosage is small and efficient.

The advantages of the present invention are as follows: by using crop straw powder as raw material, potassium hydroxide and carbon disulfide as yellowing agent, magnesium sulfate as stabilizer, and organic solvent such as dimethyl sulfoxide as reaction medium, the material yellowing is carried out by temperature-controlled stirring. to obtain biomass xanthate. The obtained biomass xanthate and other additives are used to prepare a crop coating agent or root dip containing biomass xanthate that can effectively intercept soil heavy metal poisoning, and a non-aqueous solution system is used to synthesize biomass xanthate magnesium salt , its sulfhydryl structure has a strong function of precipitating heavy metals, and the plant biomass macromolecules it contains have good biocompatibility. Heavy metals are aimed at the crops themselves, not the soil. By directly contacting the heavy metals and causing them to precipitate before entering the crops, it is possible to prevent the heavy metals from the soil from entering the crops, thereby overcoming the harm of heavy metals to crops and improving the safety of crops in the food chain. , so the dosage is small and efficient.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, All should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (9)

1. a synthetic method of plant biomass xanthate, is characterized in that, comprises the steps: Alkalization of crop straw powder: take the crop straw powder in the reactor, add potassium hydroxide, stir evenly, spray water, stir evenly, compact and place, and conduct alkalization reaction to obtain alkalized material; Yellowing of the alkalized material: slowly add the alkalized material to the yellowing agent while stirring, and fully stir under ventilation conditions to obtain a suspension; Suspension transformation reaction: add paste magnesium sulfate solution to the suspension, stir to generate yellow precipitate, continue stirring, stand, and suction filtration to obtain the crude biomass xanthate magnesium salt containing potassium sulfate; Separation and purification: after separating the crude biomass magnesium xanthate containing potassium sulfate from the organic solvent, washing with a little water and centrifuging to obtain the biomass potassium magnesium xanthate. 2. the synthetic method of a kind of plant biomass xanthate according to claim 1, is characterized in that, described yellowing agent is the mixture of dimethyl sulfoxide and carbon disulfide, and the mixture of described dimethyl sulfoxide and carbon disulfide The volume ratio is 8-9:1. 3. the synthetic method of a kind of plant biomass xanthate according to claim 2, is characterized in that, described pasty magnesium sulfate solution is the mixture of magnesium sulfate heptahydrate and water, and described magnesium sulfate heptahydrate and The mass ratio of water is 23-27:1. 4 . The method for synthesizing plant biomass xanthate according to claim 1 , wherein the mass ratio of the crop straw powder to potassium hydroxide is 1.5-2:1. 5 . 5. the synthetic method of a kind of plant biomass xanthate according to claim 1, is characterized in that, after described turning evenly, compaction is placed for 2-5 hours. 6 . The method for synthesizing plant biomass xanthate according to claim 1 , wherein the crops comprise one or a combination of sugarcane, corn, rice, rape, and wheat. 7 . 7. the synthetic method of a kind of plant biomass xanthate according to claim 1, is characterized in that, under described ventilation condition, fully stirring time is 4 hours. 8. the synthetic method of a kind of plant biomass xanthate according to claim 1, is characterized in that, also comprises drying after described centrifugation, and described drying comprises being placed in 40-50 ℃ of oven drying for 24 hours . 9. the application of the biomass magnesium potassium salt of xanthate obtained according to any one of claims 1 to 8 as a seed coating agent or a root-dipping agent to passivate heavy metals in soil.

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