Organic complexing agent composition for reducing salt and alkali as well as preparation method and application of organic complexing agent composition

Abstract

The invention relates to the technical field of preparation of soil conditioners, in particular to an organic complexing agent composition for reducing salt and alkali as well as a preparation method and application of the organic complexing agent composition. The organic complexing agent composition for reducing salt and alkali comprises a pH value regulator and a salt ion and metal ion capturing agent, the salt ion and metal ion capturing agent comprises an outer film layer A and an organic complex component located in the outer film layer A, and the outer film layer A is prepared from polyvinyl alcohol resin; the pH value regulator comprises an outer membrane layer B and a pH value regulating component positioned in the outer membrane layer B; and the outer film layer B is at least one of film-grade polylactic resin or starch composite modified polylactic resin. As a saline-alkali soil conditioner, the saline-alkali soil conditioner provided by the invention can regulate the pH value of soil, effectively remove residual harmful salt ions and heavy metal particles in the soil, and effectively repair the soil and restore the fertility of the soil.

Description

Technical Field

[0001] The present application relates to the technical field of soil conditioner preparation, and in particular to an organic complexing agent composition for reducing salt and alkali, and a preparation method and application thereof. Background Art

[0002] With the development of large-scale agriculture, pesticides are inevitably used to deal with natural disasters of plants. Large-scale use of pesticides will cause some pesticides to remain in the soil. Pesticides contain heavy metal elements such as cadmium, lead, mercury, arsenic, chromium, copper, zinc, nickel, etc., which will cause serious pollution and damage to soil and agricultural crops, and will damage soil microbial communities, leading to a decline in soil environmental quality, affecting the ecological balance of the soil and soil productivity. Soil remediation is urgent, and an efficient organic chelating agent combination is urgently needed to effectively eliminate pesticide residues, improve the physical and chemical properties of continuous cropping soils and the diversity of microbial communities, and restore soil productivity. Summary of the invention

[0003] In order to solve the above technical problems, the present application provides an organic complexing agent composition for reducing salt and alkali, and a preparation method and application thereof.

[0004] In the first aspect, the present application provides an organic complexing agent composition for reducing salt and alkali, which is achieved by the following technical solutions:

[0005] An organic complexing agent composition for reducing salt and alkali is composed of a pH value regulator and a salt ion and metal ion scavenger, wherein the metal ion scavenger comprises an outer film layer A and an organic complex component located inside the outer film layer A, wherein the outer film layer A is made of polyvinyl alcohol resin; the pH value regulator comprises an outer film layer B and a pH value regulating component located inside the outer film layer B; the outer film layer B is a film-grade polylactic acid resin or a starch composite modified polylactic acid resin; the organic complexing agent component comprises an aminocarboxylate organic complex and an organic phosphonate organic complex; the aminocarboxylate organic complex is trinitrilotriacetic acid tris(III) The organic phosphonate organic complex is at least one of diethylenetriaminepentamethylenephosphonic acid heptasodium salt, ethylenediaminetetramethylenephosphonic acid pentasodium salt, hexasodium hexamethylenediaminetetramethylenephosphonic acid hexasodium salt, and aminotrimethylenephosphonic acid sodium salt; the pH value adjusting component is at least one of citric acid, tartaric acid, malic acid, phosphoric acid, ethylenediaminetetramethylenephosphonic acid, hexasodium hexamethylenediaminetetramethylenephosphonic acid, and diethylenetriaminepentamethylenephosphonic acid.

[0006] The salt ion and metal ion scavenger in the organic complexing agent composition provided by the present invention are firstly slowly released and disintegrated, and the released organic complexing agent components effectively capture and eliminate salt ions and heavy metal particles in the soil under an alkaline environment, and the biodegradation time of the outer film layer B in the pH value regulator is controlled. After the metal ion scavenger effectively captures and eliminates salt ions and heavy metal particles, the pH value regulating component can be slowly released under the degradation of the outer film of the pH value regulator, and the pH value regulator also has the ability to capture salt ions and heavy metal particles. The pH value regulator and the metal ion scavenger are used in combination, which can not only adjust the pH value of the polluted saline-alkali land, but also can complex and remove harmful salt ions and heavy metal particles in the soil, thereby accelerating the soil restoration effect.

[0007] In addition, adding compound fertilizer and biochar into the outer film layer A can effectively improve soil fertility.

[0008] Preferably, the organic complexing agent composition further comprises a synergist, the synergist comprises an outer film layer C and a synergistic component located inside the outer film layer C, and the synergistic component comprises pure humic acid, ferrous sulfate, and compound fertilizer.

[0009] Preferably, the outer film layer C is made of film-grade polylactic acid resin.

[0010] Preferably, a pore opening agent is embedded in the outer film layer C, and the average particle size of the pore opening agent in the outer film layer C is 0.8-1.2 times the thickness of the outer film layer C; the content of the pore opening agent in the outer film layer C is 5-10wt%; the pore opening agent is made of water-absorbent resin, zeolite powder, and polyvinyl alcohol resin, and the content of polyvinyl alcohol resin in the pore opening agent is 50-55wt%; the content of the water-absorbent resin in the pore opening agent is 4-10wt%.

[0011] Pure mineral potassium humate has a good affinity with the eight major ions in the soil. Through molecular reactions, it generates organic potassium humate, organic calcium humate, organic sodium humate, organic magnesium humate, and organic humate roots. It complexes heavy metal ions and combines with nitrogen and phosphorus nutrients in the soil to generate organic humic acid nitrogen and humic acid phosphorus, which have the effects of nitrogen fixation, phosphorus dissolution, and potassium activation.

[0012] Ferrous sulfate can effectively adjust the soil pH, supplement soil iron, and prevent the occurrence of physiological chlorosis of plant leaves. Humic acid bacteria agent and large-element organic water-soluble fertilizer can quickly restore soil fertility.

[0013] Preferably, the pH adjusting component is composed of tartaric acid and ethylenediaminetetramethylenephosphonic acid in a mass ratio of 10:(5-20).

[0014] The acidic organic complex formed by compounding the above components is mainly used to adjust the pH value of the polluted saline-alkali land, and can also assist in enhancing the efficiency of complexing and removing salt ions and heavy metal particles in the saline-alkali land.

[0015] Preferably, the aminocarboxylate organic complex is composed of tetrasodium EDTA, pentasodium diethylenetriamine pentacarboxylate, and [N-(2-maleimidoethyl)]diethylenetriamine pentaacetic acid monoamide in a mass ratio of 10:(1-5):(1-5).

[0016] Preferably, the organic phosphonate organic complex is diethylenetriaminepentamethylenephosphonic acid heptasodium salt.

[0017] Preferably, the organic phosphonate organic complex is composed of diethylenetriaminepentamethylenephosphonic acid heptasodium salt and hexamethylenediaminetetramethylenephosphonic acid hexasodium salt in a mass ratio of 100:(50-200).

[0018] By adopting the above technical solution, the overall efficiency of complexing to remove salt ions and heavy metal particles can be guaranteed.

[0019] Preferably, the organic complexing agent component is composed of an aminocarboxylate organic complex and an organic phosphonate organic complex in a mass ratio of (60-80):(10-40).

[0020] Preferably, the organic complexing agent component is composed of an aminocarboxylate organic complex and an organic phosphonate organic complex in a mass ratio of 75:25; the mass ratio of the pH regulator and the salt ion and metal ion capture agent is (12-15):10.

[0021] By adopting the above technical solution, the organic complexing agent composition is endowed with good alkali and salt reducing performance.

[0022] Preferably, a pore opening agent is embedded in the outer film layer A, and the average particle size of the pore opening agent in the outer film layer A is 0.8-1.2 times the thickness of the outer film layer A; the content of the pore opening agent in the outer film layer A is 10-15wt%; the pore opening agent is made of water-absorbent resin, zeolite powder, and polyvinyl alcohol resin, and the content of polyvinyl alcohol resin in the pore opening agent is 50-55wt%; the content of the water-absorbent resin in the pore opening agent is 4-10wt%; a pore opening agent is also embedded in the outer film layer B, and the average particle size of the pore opening agent in the outer film layer B is 0.8-1.2 times the thickness of the outer film layer B; the content of the pore opening agent in the outer film layer B is 0.5-4wt%.

[0023] By adopting the above technical scheme, the water-absorbing resin in the pore-opening agent absorbs water and expands, which can accelerate the rupture of the outer film layer, and the organic complexing agent components in the outer film layer A flow out, and the pH value regulating components in the outer film layer B flow out, which plays a role in preliminary soil repair and reduces the volatility of pH value. As the water-soluble erosion and hydrolysis of the outer film layer A increases, the outflow of the organic complexing agent components increases, which plays a role in continuous soil modification, effectively removing harmful salt ions and heavy metal particles. Finally, the outer film layer A is completely degraded, and the organic complexing agent components are fully released, which can effectively and durably repair the contaminated soil, and the organic The utilization rate of the complexing agent components is quite high, and the use economy is good; in about 30-40 days, the outer film layer B quickly releases the pH adjusting components as it biodegrades. At this time, most of the organic complexing agent components have been released, and the complexing treatment of harmful salt ions and metal particles has been completed. The remaining organic complexing agent components have a certain alkalinity and the saline-alkali soil is also alkaline. As the pH adjusting components are released, the pH value of the soil can be effectively lowered. At the same time, the pH adjusting components also have the function of complexing harmful salt ions and heavy metal ions, which plays a role in adjusting the pH value while assisting in complexing and removing harmful salt ions and heavy metal ions.

[0024] The sustained-release mechanism of the enhancer is the same as that of the pH regulator. It can assist in reducing alkalinity while supplementing trace elements and organic matter in the soil, effectively improving soil fertility.

[0025] In the second aspect, the present application provides a method for preparing a salt-reducing and alkali-reducing organic complexing agent composition, which is achieved by the following technical scheme:

[0026] A method for preparing a salt-reducing and alkali-reducing organic complexing agent composition comprises the following steps:

[0027] The preparation of the pH value regulator is as follows: the pH value regulating component is used as the core material, the film-grade polylactic acid resin or the starch composite modified polylactic acid resin is used as the packaging film B, and the pH value regulator with a particle size of 1-5 mm is obtained by using a laundry bead packaging machine;

[0028] The preparation of the metal ion scavenger is as follows: an organic complex component is uniformly prepared by mixing an accurately measured aminocarboxylate organic complex and an organic phosphonate organic complex, and a packaging film A is prepared by melt extrusion, casting, and biphasic stretching of a polyvinyl alcohol resin, the organic complex component is used as a core material, and the packaging film A is used as a packaging film material, and a metal ion scavenger with a particle size of 1-5 mm is prepared by a laundry bead packaging machine;

[0029] The preparation of the synergist is as follows: accurately measured mineral source potassium humate, ferrous sulfate, and humic acid bacteria agent macroelement formula fertilizer are uniformly mixed to obtain a synergist component, and polyvinyl alcohol resin is melt-extruded, cast, and biphasically stretched to obtain a packaging film C, the synergist component is used as a core material, and the packaging film C is used as a packaging film material, and a laundry bead packaging machine is used to obtain a synergist with a particle size of 1-5 mm;

[0030] The pH value regulator and the metal ion scavenger are mixed to obtain the salt-reducing and alkali-reducing organic complexing agent composition; or the pH value regulator, the synergist and the metal ion scavenger are mixed to obtain the salt-reducing and alkali-reducing organic complexing agent composition.

[0031] The preparation method of the invention is simple, has low equipment cost and mature technology, and is easy to realize industrial production.

[0032] On the third aspect, an organic chelating agent composition for reducing salt and alkali is used in the field of soil improvement, specifically in repairing saline-alkali soil contaminated by heavy metal particles. It can adjust the pH value of the soil and effectively remove the heavy metal particles remaining in the soil, effectively repairing the soil and restoring its fertility.

[0033] In summary, this application has the following advantages:

[0034] 1. The present invention can adjust the pH value of saline-alkali soil, effectively remove the heavy metal particles remaining in the soil, repair the soil environment and fertility, and effectively improve the soil fertility by adding compound fertilizer and biochar.

[0035] 2. The preparation method of the present invention is simple, the equipment cost is low and the process is mature, which is convenient for industrial production.

[0036] Instruction Manual

[0037] Figure 1 The present invention is a bar graph of the pH parameters of the soil at 0d, 1d, 3d, 7d, 14d, 21d, 28d, 42d, 49d, 56d and 63d in an alkaline soil simulation remediation experiment using the organic complexing agent composition of Examples 1-4 and Control Examples 1-2 as a soil remediation agent.

[0038] Figure 2 The present invention is a bar graph of the pH parameters of the soil at 0d, 1d, 3d, 7d, 14d, 21d, 28d, 42d, 49d, 56d and 63d in an alkaline soil simulation remediation experiment using the organic complexing agent composition of Example 1 and Examples 5-9 as a soil remediation agent.

[0039] Figure 3 This is a bar graph of heavy metal particle content parameters after 63 days in an alkaline soil simulation remediation experiment using the organic complexing agent compositions of Examples 1-9 and Control Groups 1-2 as soil remediation agents. DETAILED DESCRIPTION

[0040] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples and comparative examples.

[0041] Example

[0042] The invention discloses an organic complexing agent composition for reducing salt and alkali, which is composed of a pH value regulator and a metal ion capture agent.

[0043] Preferably, the mass ratio of the pH regulator to the metal ion capture agent is (12-15):10.

[0044] The metal ion capture agent comprises an outer film layer A and an organic complex component located inside the outer film layer A, wherein the outer film layer A is made of a water-soluble and degradable polyvinyl alcohol resin. Preferably, the outer film layer A is made of polyvinyl alcohol resin and a pore-opening agent. The pore-opening agent accounts for 10-15wt% of the mass of the outer film layer, and the average particle size of the pore-opening agent is 0.8-1.2 times the thickness of the outer film layer A.

[0045] The pore opening agent is made of water-absorbing resin, zeolite powder and polyvinyl alcohol resin. The content of polyvinyl alcohol resin in the pore opening agent is 50-55wt%, and the content of water-absorbing resin in the pore opening agent is 4-10wt%.

[0046] The amount of pore opener added affects the primary release rate of organic complex components. If the amount of pore opener added is too low, the primary release rate of organic complex components will be low, resulting in unclear initial soil remediation and extending the overall soil cycle. If the amount of pore opener added is too large, it will not only affect the processing performance and product yield, but also the primary release rate of organic complex components will be too fast, resulting in a decrease in the overall use of organic complex components, affecting the overall soil remediation economy of the product.

[0047] The organic complexing agent component consists of aminocarboxylate organic complex and organic phosphonate organic complex.

[0048] Preferably, the organic complexing agent component is composed of an aminocarboxylate organic complex and an organic phosphonate organic complex in a mass ratio of (60-80):(20-40). Further preferably, the organic complexing agent component is composed of an aminocarboxylate organic complex and an organic phosphonate organic complex in a mass ratio of 75:25.

[0049] The aminocarboxylate organic complex is at least one of trisodium nitrilotriacetate, disodium EDTA, tetrasodium EDTA, ethylenediaminetetraacetic acid TEA salt, pentasodium diethylenetriamine pentacarboxylate, and [N-(2-maleimidoethyl)]diethylenetriaminepentaacetic acid monoamide.

[0050] Preferably, the aminocarboxylate organic complex is composed of tetrasodium EDTA, pentasodium diethylenetriamine pentacarboxylate, and [N-(2-maleimidoethyl)]diethylenetriamine pentaacetic acid monoamide in a mass ratio of 10:(1-5):(1-5).

[0051] The organic phosphonate organic complex is at least one of diethylenetriaminepentamethylenephosphonic acid heptasodium salt, ethylenediaminetetramethylenephosphonic acid pentasodium salt, hexamethylenediaminetetramethylenephosphonic acid hexasodium salt, and aminotrimethylenephosphonic acid sodium salt.

[0052] Preferably, the organic phosphonate organic complex is diethylenetriaminepentamethylenephosphonic acid heptasodium salt.

[0053] More preferably, the organic phosphonate organic complex is composed of diethylenetriaminepentamethylenephosphonic acid heptasodium salt and hexamethylenediaminetetramethylenephosphonic acid hexasodium salt in a mass ratio of 100:(50-200).

[0054] The pH regulator includes an outer film layer B and a pH regulating component located inside the outer film layer B, wherein the outer film layer B is a film-grade polylactic acid resin or a starch composite modified polylactic acid resin. Preferably, a pore opening agent is also embedded in the outer film layer B, and the average particle size of the pore opening agent in the outer film layer B is 0.8-1.2 times the thickness of the outer film layer B, and the content of the pore opening agent in the outer film layer B is 0.5-4wt%. A small amount of pH regulator is slowly released in the early stage of soil remediation, which can stabilize the pH value and help improve the heavy metal capture efficiency.

[0055] The pH value adjusting component is at least one of citric acid, tartaric acid, malic acid, phosphoric acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, and diethylenetriaminepenta(methylenephosphonic acid). Preferably, the pH value adjusting component is tartaric acid and ethylenediaminetetramethylenephosphonic acid in a mass ratio of 100:(50-200).

[0056] In order to supplement soil fertility and adjust the living environment of soil microbial flora, the organic complexing agent composition also includes a synergist, and the synergist includes an outer film layer C and a synergistic component located inside the outer film layer C.

[0057] The outer film layer C is made of film-grade polylactic acid resin.

[0058] Preferably, the outer film layer C is made of film-grade polylactic acid resin and a pore opening agent. The average particle size of the pore opening agent in the outer film layer C is 0.8-1.2 times the thickness of the outer film layer C. The content of the pore opening agent in the outer film layer C is 5-10wt%. The pore opening agent is made of a water-absorbent resin, zeolite powder, and polyvinyl alcohol resin. The content of the polyvinyl alcohol resin in the pore opening agent is 50-55wt%, and the content of the water-absorbent resin in the pore opening agent is 4-10wt%.

[0059] The synergistic components include humic acid (CAS No.: 1415-93-6), ferrous sulfate, and compound fertilizer (water-soluble nitrogen, phosphorus and potassium compound fertilizer, provided by Shandong Huayunda New Materials Co., Ltd.).

[0060] The mass ratio of humic acid, ferrous sulfate and compound fertilizer in the synergistic component is (30-60):(10-20):(30-60). Preferably, the mass ratio of humic acid, ferrous sulfate and compound fertilizer in the synergistic component is 40:10:50.

[0061] A method for preparing a salt-reducing and alkali-reducing organic complexing agent composition comprises the following steps:

[0062] The preparation of the pH value regulator is as follows: the pH value regulating component is used as the core material, the film-grade polylactic acid resin or the starch composite modified polylactic acid resin is used as the packaging film B, and the pH value regulator with a particle size of 1-5 mm is obtained by using a laundry bead packaging machine;

[0063] The preparation of the metal ion scavenger is as follows: an organic complex component is uniformly prepared by mixing an accurately measured aminocarboxylate organic complex and an organic phosphonate organic complex, and a packaging film A is prepared by melt extrusion, casting, and biphasic stretching of a polyvinyl alcohol resin, the organic complex component is used as a core material, and the packaging film A is used as a packaging film material, and a metal ion scavenger with a particle size of 1-5 mm is prepared by a laundry bead packaging machine;

[0064] The preparation of the synergist is as follows: accurately measured mineral source potassium humate, ferrous sulfate, humic acid bacteria agent, and large-element organic water-soluble fertilizer are uniformly mixed to obtain a synergist component, and polyvinyl alcohol resin is melt-extruded, cast, and biphasically stretched to obtain a packaging film C, the synergist component is used as a core material, and the packaging film C is used as a packaging film material, and a laundry bead packaging machine is used to obtain a synergist with a particle size of 1-5 mm;

[0065] The pH value regulator and the metal ion scavenger are mixed to obtain the salt-reducing and alkali-reducing organic complexing agent composition; or the pH value regulator, the synergist and the metal ion scavenger are mixed to obtain the salt-reducing and alkali-reducing organic complexing agent composition.

[0066] When in use, the saline-alkali land contaminated by heavy metal particles is plowed to a thickness of 25-30 cm, and then the organic chelating agent composition for reducing salt and alkali is spread on the surface of the plowed saline-alkali land, and then plowed again to a thickness of 25-30 cm, and water sprayed / sprinkled every 3-5 days. The soil remediation can be completed after about 60 days.

[0067] Example 1: An organic complexing agent composition for reducing salt and alkali is composed of 12 parts of a pH regulator and 10 parts of a metal ion capture agent.

[0068] The metal ion scavenger includes an outer film layer A and an organic complex component located inside the outer film layer A. The outer film layer A of the metal ion scavenger is made of 92 parts by mass of polyvinyl alcohol resin and 8 parts by mass of a pore-opening agent through melt extrusion, casting, and biaxial stretching pore-opening treatment, with an average thickness of 50 microns. The particle size distribution of the pore-opening agent is between 40 and 60 microns, and the average particle size D pq The pore opening agent is made of 5 parts by mass of water-absorbent resin (Sumitomo SA60N polymer water-absorbent resin SAP), 45 parts by mass of 2000-mesh zeolite powder (4A white zeolite powder 2000-mesh provided by Lingshou County Shifeng Mining Processing Plant), and 50 parts by mass of polyvinyl alcohol resin (Kuraray Japan Poval PVA-117S fine powder grade polyvinyl alcohol).

[0069] The organic complex component is composed of an aminocarboxylate organic complex and an organic phosphonate organic complex in a mass ratio of 80:20. The aminocarboxylate organic complex is composed of tetrasodium EDTA, pentasodium diethylenetriamine pentacarboxylate, and [N-(2-maleimidoethyl)] diethylenetriamine pentaacetic acid monoamide in a mass ratio of 10:2:4. The organic phosphonate organic complex is diethylenetriamine penta-methylenephosphonic acid heptasodium salt.

[0070] The pH value regulator includes an outer film layer B and a pH value regulating component located inside the outer film layer B. The pH value regulating component is composed of tartaric acid and ethylenediaminetetramethylenephosphonic acid in a mass ratio of 2:1. The outer film layer B is made of 97.5 parts by mass of film-grade polylactic acid resin (blown film PLA film-grade polylactic acid resin, brand SH-606C, brand Shenghao Plastic) and 2.5 parts by mass of a pore opening agent through melt extrusion, casting, and biaxial stretching pore opening treatment, with a thickness of 50±5 microns. The particle size distribution of the pore opening agent is between 40-60 microns, with an average particle size D pq The pore opening agent is made of 5 parts by mass of water-absorbent resin (Sumitomo SA60N polymer water-absorbent resin SAP), 45 parts by mass of 2000-mesh zeolite powder (4A white zeolite powder 2000-mesh provided by Lingshou County Shifeng Mining Processing Plant), and 50 parts by mass of polyvinyl alcohol resin (Kuraray Japan Poval PVA-117S fine powder grade polyvinyl alcohol).

[0071] A method for preparing a salt-reducing and alkali-reducing organic complexing agent composition comprises the following steps:

[0072] The pH value adjusting agent is prepared as follows. First, the pore opening agent is prepared. The specific preparation method is as follows: 5 parts by weight of water-absorbing resin, 45 parts by weight of 2000-mesh zeolite powder, and 50 parts by weight of polyvinyl alcohol resin are placed at 205° C. and kneaded for 180 seconds, and then added into a twin-screw extruder for melt extrusion. The melt extrudate is stretched, oil-cooled, granulated, dried, ball-milled, and sieved to obtain an average particle size Dpq A pore-opening agent with a particle size of 50 microns is prepared, and then 95 parts by mass of a film-grade polylactic acid resin and 5 parts of a pore-opening agent with an average particle size of 40-60 microns are placed in a high-speed dispersion kettle and mixed evenly. The resulting mixture is put into a twin-screw extruder and melt-extruded at 170°C. The resulting melt extrudate is subjected to a casting treatment to obtain a film material with an average thickness of 110 microns, and then subjected to a biaxial stretching treatment, with a transverse stretching ratio of 1.6 and a longitudinal stretching ratio of 1.4. The biaxial stretching pore-opening treatment obtains a packaging film B with an average thickness of 50 microns. 10 parts of tartaric acid and 5 parts of ethylenediaminetetramethylenephosphonic acid are mixed evenly to obtain a pH adjusting component, and the pH adjusting component is used as a core material. The packaging film B with an average thickness of 50 microns prepared above is a packaging film material, and a pH adjusting agent with an average particle size of about 4 mm is obtained by using a laundry beads packaging machine.

[0073] The preparation of the metal ion scavenger is as follows. First, the pore opening agent is prepared. The specific preparation method is as follows: 5 parts by weight of a water-absorbent resin, 45 parts by weight of a 2000-mesh zeolite powder, and 50 parts by weight of a polyvinyl alcohol resin are placed in a twin-screw extruder for melt extrusion at 200°C, and then stretched, oil-cooled, granulated, dried, and ball-milled to obtain a pore opening agent with an average particle size of 40-60 microns. Then, 90 parts by weight of a film-grade polylactic acid resin and 10 parts of a pore opening agent with an average particle size of 40-60 microns are placed in a high-speed dispersion kettle and mixed evenly. The resulting mixture is added to a molten metal ion scavenger. The extruder is fed into a twin-screw extruder and melt-extruded at 180-205°C. The obtained molten extrudate is subjected to casting treatment to obtain a PVA film material of 145-150 microns, which is then subjected to biaxial stretching treatment with a transverse stretching ratio of 1.8 and a longitudinal stretching ratio of 1.6. The biaxial stretching opening treatment obtains a packaging film A with a thickness of 50-55 μm. Accurately measured aminocarboxylate organic complexes and organic phosphonate organic complexes are uniformly mixed to obtain an organic complex component. The organic complex component is used as the core material, and packaging film B is the packaging film material. A laundry beads packaging machine is used to obtain a metal ion capture agent with a particle size of 3-4 mm.

[0074] 12 parts of pH value regulator and 10 parts of metal ion capture agent are mixed to obtain a finished organic complexing agent composition.

[0075] The difference between Example 2 and Example 1 is that an organic complexing agent composition for reducing salt and alkali is composed of 13 parts of pH regulator and 10 parts of metal ion capture agent.

[0076] The difference between Example 3 and Example 1 is that an organic complexing agent composition for reducing salt and alkali is composed of 14 parts of pH regulator and 10 parts of metal ion capture agent.

[0077] The difference between Example 4 and Example 1 is that an organic complexing agent composition for reducing salt and alkali is composed of 15 parts of pH regulator and 10 parts of metal ion capture agent.

[0078] The difference between the control group 1 and the example 1 is that an organic complexing agent composition for reducing salt and alkali is composed of 11 parts of pH value adjusting agent and 10 parts of metal ion scavenger.

[0079] The difference between the control group 2 and the example 1 is that an organic complexing agent composition for reducing salt and alkali is composed of 16 parts of pH value adjusting agent and 10 parts of metal ion scavenger.

[0080] The simulated restoration experiment of saline-alkali soil is shown in Table 1 and Figure 1 It can be seen that the mass ratio of pH regulator to metal ion scavenger is (12-15):10, which can effectively reduce the alkalinity, and the pH is 6.8-7.4. The comparison between the groups shows that the mass ratio of pH regulator to metal ion scavenger is controlled to be (13-14):10.

[0081] The difference between Example 5 and Example 2 is that the pH value adjusting component is composed of citric acid and ethylenediaminetetramethylenephosphonic acid in a mass ratio of 2:1.

[0082] The difference between Example 6 and Example 2 is that the pH adjusting component is composed of malic acid and ethylenediaminetetramethylenephosphonic acid in a mass ratio of 2:1.

[0083] The difference between Example 7 and Example 2 is that the pH value adjusting component is composed of phosphoric acid and ethylenediaminetetramethylenephosphonic acid in a mass ratio of 2:1.

[0084] The difference between Example 8 and Example 2 is that the pH adjusting component is composed of tartaric acid and hexamethylenediaminetetramethylenephosphonic acid in a mass ratio of 2:1.

[0085] The difference between Example 9 and Example 2 is that the pH adjusting component is composed of tartaric acid and diethylenetriaminepenta(methylenephosphonic acid) in a mass ratio of 2:1.

[0086] The difference between Example 10 and Example 1 is that the organic complexing agent composition is composed of 2 parts of a synergist, 12 parts of a pH regulator and 10 parts of a metal ion scavenger.

[0087] The synergist includes an outer film layer C and a synergistic component located inside the outer film layer C. The outer film layer C is made of 94 parts of film-grade polylactic acid resin and 6 parts of a pore-opening agent through melt extrusion, casting, and biaxial stretching pore-opening treatment, and has a thickness of 50±5 microns. The pore-opening agent used in the outer film layer C is the same as the pore-opening agent used in the outer film layer A in Example 1. The mass ratio of humic acid, ferrous sulfate (purity 99.9%), and compound fertilizer in the synergistic component is 40:10:50.

[0088] The preparation of the synergist is as follows: accurately measured pure mineral potassium humate, ferrous sulfate, and humic acid bacteria agent macroelement formula fertilizer are mixed uniformly in a mass ratio of 40:10:50 to obtain a synergist component, and polyvinyl alcohol resin is melt-extruded, cast, and biphasically stretched to obtain a packaging film C; at the same time, 94 parts by mass of film-grade polylactic acid resin and 6 parts of a pore-opening agent with an average particle size of 40-60 microns are placed in a high-speed dispersion kettle and mixed uniformly, and the obtained mixture is put into a twin-screw extruder and melt-extruded at 165-175°C. The obtained melt extrudate is cast to obtain a film material of 110-115 microns, and then biaxially stretched, with a transverse stretching ratio of 1.6 and a longitudinal stretching ratio of 1.4. The biaxially stretched pore-opening treatment obtains a packaging film C with a thickness of 45-55 microns. The synergist component is used as a core material, and the packaging film C is used as a packaging film material. A laundry bead packaging machine is used to obtain a synergist with a particle size of 3-4 mm. The finished organic complexing agent composition can be obtained by uniformly mixing 2 parts of the synergist, 12 parts of the pH value regulator and 10 parts of the metal ion capture agent.

[0089] The experimental parameters of saline-alkali soil simulation remediation are shown in Tables 2 and Figure 2 And in combination with Examples 1, 5-9, it can be known that the pH regulating component composed of tartaric acid and ethylenediaminetetramethylenephosphonic acid in a mass ratio of 2:1 can effectively regulate the pH value of saline-alkali soil, play a good alkali reduction effect, and is conducive to the recovery of the soil microbial environment. Performance test: Experimental method for simulated restoration of saline-alkali soil: 20 cm of crushed stone with a particle size of 3-5 mm, 20 cm of crushed stone with a particle size of 0.5-1.5 mm, and 30 cm thick heavy metal-contaminated saline-alkali soil are laid in a C45 cement-cast experimental trough (3.0 m long, 3.0 m wide, and 80 cm thick). The heavy metal-contaminated saline-alkali soil is first plowed once, and then the organic complexing agent composition in the above Examples 1-9 and Control Group 1-2 is sown on the heavy metal-contaminated saline-alkali soil and plowed again. The sowing amount of the organic complexing agent composition is 240 g / m 2 , and then spray tap water 5L / m every 5 days 2, respectively measure the pH value of the soil at 0d, 1d, 3d, 7d, 14d, 21d, 28d, 42d, 49d, 56d, and 63d, and record the parameters and make a table. Among them, Table 1 is a table of soil pH parameters at 0d, 1d, 3d, 7d, 14d, 21d, 28d, 42d, 49d, 56d, and 63d in an alkaline soil simulation remediation experiment using the organic complexing agent composition of Examples 1-4 and Control Examples 1-2 as soil remediation agents. Table 2 is a table of soil pH parameters at 0d, 1d, 3d, 7d, 14d, 21d, 28d, 42d, 49d, 56d, and 63d in an alkaline soil simulation remediation experiment using the organic complexing agent composition of Examples 2 and 5-9 as soil remediation agents. Table 3 is a table of heavy metal particle content parameters after 63 days using the organic complexing agent composition of Examples 1-9 and Control Groups 1-2 as soil remediation agents in an alkaline soil simulation remediation experiment. Table 4 is a table of soil pH parameters and heavy metal particle content parameters at 0d, 1d, 3d, 7d, 14d, 21d, 28d, 42d, 49d, 56d, and 63d in an alkaline soil simulation remediation experiment using the organic complexing agent composition of Example 10 as a soil remediation agent.

[0090] Table 1: pH values ​​of soil at different times using the organic complexing agent compositions of Examples 1-4 and Comparative Examples 1-2 as soil remediation agents

[0091] Example 1 Example 2 Example 3 Example 4 Control group 1 Control group 2 0h 8.15 8.17 8.13 8.21 8.18 8.17 1d 8.49 8.43 8.39 8.37 8.54 8.36 3d 8.74 8.69 8.65 8.63 8.82 8.64 7d 8.92 8.84 8.76 8.69 8.98 8.65 14d 9.05 8.97 8.92 8.89 9.12 8.82 21d 9.01 9.02 8.96 8.94 9.08 8.89 28d 8.94 8.85 8.76 8.72 9.04 8.68 42d 8.36 8.19 8.05 7.97 8.63 7.93 49d 7.81 7.66 7.59 7.54 8.17 7.38 56d 7.49 7.34 7.26 7.19 7.81 7.03 63d 7.24 7.12 6.97 6.87 7.52 6.67

[0092] Table 2: pH values ​​of soil at different times using the organic complexing agent compositions of Example 2 and Examples 5-9 as soil remediation agents

[0093] Example 2 Example 5 Example 6 Example 7 Example 8 Example 9 0h 8.17 8.19 8.14 8.15 8.16 8.13 1d 8.43 8.49 8.51 8.38 8.45 8.39 3d 8.69 8.75 8.78 8.62 8.71 8.65 7d 8.84 8.91 8.95 8.78 8.85 8.81 14d 8.97 9.03 9.06 8.93 9.01 8.95 21d 9.02 9.07 9.11 8.98 9.04 9.01 28d 8.85 8.91 8.94 8.81 8.86 8.82 42d 8.19 8.25 8.29 8.03 8.21 8.16 49d 7.66 7.72 7.81 7.56 7.68 7.59 56d 7.34 7.38 7.44 7.23 7.36 7.28 63d 7.12 7.19 7.25 7.04 7.15 7.07

[0094] Table 3: Heavy metal particle content parameters after 63 days using the organic complexing agent composition of Examples 1-9 and Control Groups 1-2 as soil remediation agents

[0095] Cadmium mg / kg Lead mg / kg Mercury mg / kg Initial soil 2.56 25.61 3.48 Example 1 0.47 8.37 0.82 Example 2 0.46 8.17 0.80 Example 3 0.44 7.88 0.76 Example 4 0.44 7.63 0.72 Example 5 0.47 8.21 0.82 Example 6 0.47 8.25 0.84 Example 7 0.45 8.15 0.80 Example 8 0.46 8.21 0.81 Example 9 0.44 8.18 0.78 Control group 1 0.49 8.58 0.84 Control group 2 0.42 7.45 0.70

[0096] Table 4: pH parameters and heavy metal particle content parameters of soil at different times using the organic complexing agent composition of Example 10 as a soil remediation agent

[0097]

[0098]

[0099] In summary, the present application, as a saline-alkali soil conditioner, can adjust the pH value of the soil, and effectively remove harmful salt ions and heavy metal particles remaining in the soil, effectively repair the soil and restore soil fertility.

[0100] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An organic complexing agent composition for reducing salt and alkali, characterized in that: The organic complexing agent composition comprises a pH value regulator and a salt ion and metal ion capture agent, wherein the salt ion and metal ion capture agent comprises an outer film layer A and an organic complex component located inside the outer film layer A, and the outer film layer A is made of polyvinyl alcohol resin; The pH value adjusting agent includes an outer film layer B and a pH value adjusting component located inside the outer film layer B; The outer film layer B is a film-grade polylactic acid resin or a starch-composite modified polylactic acid resin; The organic complexing agent component includes aminocarboxylate organic complex and organic phosphonate organic complex; The aminocarboxylate organic complex is at least one of trisodium nitrilotriacetate, disodium EDTA, tetrasodium EDTA, ethylenediaminetetraacetic acid TEA salt, pentasodium diethylenetriamine pentacarboxylate, and [N-(2-maleimidoethyl)]diethylenetriaminepentaacetic acid monoamide; The organic phosphonate organic complex is at least one of diethylenetriaminepentamethylenephosphonic acid heptasodium salt, ethylenediaminetetramethylenephosphonic acid pentasodium salt, hexamethylenediaminetetramethylenephosphonic acid hexasodium salt, and aminotrimethylenephosphonic acid sodium salt; The pH value adjusting component is at least one of citric acid, tartaric acid, malic acid, phosphoric acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, and diethylenetriaminepenta(methylenephosphonic acid).

2. The salt-reducing and alkali-reducing organic complexing agent composition according to claim 1, characterized in that: The pH value adjusting component is composed of tartaric acid and ethylenediaminetetramethylenephosphonic acid in a mass ratio of 10:(5-20).

3. The organic complexing agent composition for reducing salt and alkali according to claim 1, characterized in that: The aminocarboxylate organic complex is composed of tetrasodium EDTA, pentasodium diethylenetriamine pentacarboxylate, and [N-(2-maleimidoethyl)] diethylenetriamine pentaacetic acid monoamide in a mass ratio of 10:(1-5):(1-5).

4. The organic complexing agent composition for reducing salt and alkali according to claim 1, characterized in that: The organic complexing agent composition also includes a synergist, which includes an outer film layer C and a synergistic component located inside the outer film layer C, and the synergistic component includes humic acid, ferrous sulfate, and compound fertilizer.

5. The organic complexing agent composition for reducing salt and alkali according to claim 1, characterized in that: The organic phosphonate organic complex is composed of diethylenetriaminepentamethylenephosphonic acid heptasodium salt and hexamethylenediaminetetramethylenephosphonic acid hexasodium salt in a mass ratio of 100:(50-200).

6. The organic complexing agent composition for reducing salt and alkali according to claim 1, characterized in that: The organic complexing agent component is composed of an aminocarboxylate organic complex and an organic phosphonate organic complex in a mass ratio of (60-80):(20-40).

7. The organic complexing agent composition for reducing salt and alkali according to claim 6, characterized in that: The organic complexing agent component is composed of an acidic organic complex, an aminocarboxylate organic complex, and an organic phosphonate organic complex in a mass ratio of 75:25; the mass ratio of the pH value regulator to the salt ion and metal ion capture agent is (12-15):

10.

8. The organic complexing agent composition for reducing salt and alkali according to claim 7, characterized in that: The outer film layer A is embedded with a pore opening agent, and the average particle size of the pore opening agent in the outer film layer A is 0.8-1.2 times the thickness of the outer film layer A; the content of the pore opening agent in the outer film layer A is 10-15wt%; the pore opening agent is made of water-absorbent resin, zeolite powder, and polyvinyl alcohol resin, and the content of polyvinyl alcohol resin in the pore opening agent is 50-55wt%; the content of the water-absorbent resin in the pore opening agent is 4-10wt%; the outer film layer B is also embedded with a pore opening agent, and the average particle size of the pore opening agent in the outer film layer B is 0.8-1.2 times the thickness of the outer film layer B; the content of the pore opening agent in the outer film layer B is 0.5-4wt%.

9. A method for preparing the salt-reducing and alkali-reducing organic complexing agent composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: The preparation of the pH value regulator is as follows: the pH value regulating component is used as the core material, the film-grade polylactic acid resin or the starch composite modified polylactic acid resin is used as the packaging film B, and the pH value regulator with a particle size of 1-5 mm is obtained by using a laundry bead packaging machine; The preparation of the metal ion scavenger is as follows: an organic complex component is uniformly prepared by mixing an accurately measured aminocarboxylate organic complex and an organic phosphonate organic complex, and a packaging film A is prepared by melt extrusion, casting, and biphasic stretching of a polyvinyl alcohol resin, the organic complex component is used as a core material, and the packaging film A is used as a packaging film material, and a metal ion scavenger with a particle size of 1-5 mm is prepared by a laundry bead packaging machine; The preparation of the synergist is as follows: accurately measured mineral source potassium humate, ferrous sulfate, humic acid bacteria agent, and large-element organic water-soluble fertilizer are uniformly mixed to obtain a synergist component, and polyvinyl alcohol resin is melt-extruded, cast, and biphasically stretched to obtain a packaging film C, the synergist component is used as a core material, and the packaging film C is used as a packaging film material, and a laundry bead packaging machine is used to obtain a synergist with a particle size of 1-5 mm; The pH value regulator and the metal ion scavenger are mixed to obtain the salt-reducing and alkali-reducing organic complexing agent composition; or the pH value regulator, the synergist and the metal ion scavenger are mixed to obtain the salt-reducing and alkali-reducing organic complexing agent composition.

10. An organic complexing agent composition for reducing salt and alkali according to any one of claims 1 to 8, applied in the field of soil improvement, characterized in that: It is specifically used to repair saline-alkali soil contaminated by salt ions and heavy metal particles.

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