Nitrogen-rich binder for side slope spray seeding matrix and preparation method of nitrogen-rich binder

Abstract

The invention discloses a nitrogen-rich binder for a side slope spray seeding matrix and a preparation method thereof. The preparation method comprises the following steps: drying and crushing marsh spoil to obtain marsh spoil dry powder; the method comprises the following steps: adding dry marsh spoil powder, an alkaline regulator and a chelating agent into water, uniformly stirring, oscillating, extracting, filtering, evaporating, concentrating, and freeze-drying to obtain a crude extraction product a; dissolving the crude extraction product a with water, dialyzing, and freeze-drying to obtain a crude extraction product b; washing the crude extraction product b with an acid mixed solution and water in sequence, and freeze-drying to obtain a crude extraction product c; and dissolving the crude extraction product c and 4-(4, 6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride in water, adding dopamine hydrochloride, carrying out a reaction in a nitrogen environment, and carrying out freeze drying to obtain the nitrogen-rich binder. The novel environment-friendly material capable of being used for side slope prevention and control is prepared from the marsh spoil, has the same bonding effect as other existing side slope spray-seeding matrix binders, also has high-content nitrogen elements, can provide fertility for soil and is beneficial to seed germination.

Description

Technical Field

[0001] The invention relates to the technical field of slope management, and in particular to a nitrogen-rich binder for a slope spraying matrix and a preparation method thereof. Background Art

[0002] The road construction process will produce a large number of exposed slopes, such as tall and steep rock slopes or soil slopes lacking fertilizer and water. The structure of vegetation and soil layers on these slopes is destroyed, and the geology is unstable. Affected by the seasonal drought and strong ultraviolet rays in the project area, the damaged slopes face problems such as long natural vegetation recovery period, difficulty in local ecological recovery, and poor long-term ecological restoration. The concentrated rain season is prone to induce natural disasters such as landslides and mudslides, and the safety of life and property of residents along the road cannot be guaranteed. Therefore, the management of the slopes encountered in the project is the key to ensuring the safety and smoothness of the route and preventing secondary disasters and accidents. Ecological slope protection has become a hot spot for slope protection projects at home and abroad. However, due to the high cost of polymer materials, they are not suitable for large-scale application in engineering. At the same time, some polymer materials are environmentally toxic and are not suitable for spraying substrates for slope ecological restoration. Therefore, based on the concept of "environmentally friendly and ecological slope consolidation", the development of economical, fast, long-term and environmentally friendly new slope protection materials is a scientific and technological problem that needs to be solved urgently.

[0003] In view of this, this application is hereby filed. Summary of the invention

[0004] The present invention provides a nitrogen-rich binder for slope spraying matrix and a preparation method thereof, and utilizes marsh abandoned soil to prepare an environmentally friendly new material that can be used for slope prevention and treatment. The binder not only has the same bonding effect as other existing slope spraying matrix binders, but also has a high content of nitrogen, which can provide fertility for the soil and is beneficial to the germination of seeds.

[0005] The present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a nitrogen-rich binder for slope spraying matrix, comprising marsh spoil, a chelating agent, an alkaline regulator, 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride, dopamine hydrochloride and water.

[0007] In a specific embodiment, the nitrogen-rich binder comprises the following components in parts by weight:

[0008] 100 parts of marsh waste soil, 2-5 parts of chelating agent, 3-6 parts of alkaline regulator, 0.3-0.7 parts of 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride, 0.3-0.7 parts of dopamine hydrochloride and 800-1200 parts of water.

[0009] In a specific embodiment, the chelating agent is one or more of sodium hexametaphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium citrate, preferably sodium hexametaphosphate.

[0010] In a specific embodiment, the alkaline regulator is sodium hydroxide or potassium hydroxide.

[0011] The present invention resourcefully utilizes marsh waste soil. Using marsh waste soil as a raw material, it prepares an environmentally friendly new material that can be used for slope prevention and control. It not only has the same bonding effect as existing other slope spraying matrix binders but also has a high nitrogen content, which can provide fertility for the soil and is beneficial to the germination of seeds. The marsh waste soil used in the binder of the present invention is rich in natural polymer compounds with various functional groups, such as carboxyl groups, phenolic hydroxyl groups, and alcoholic hydroxyl groups, which can form coordination bonds with metal cations in the soil to bridge soil particles; water serves as a reaction medium, acting as the medium phase for the dissolution of sodium hydroxide and the graft modification of dopamine hydrochloride; the chelating agent sodium hexametaphosphate, as an inorganic dispersant, can chelate with high-valent metal ions in the marsh waste soil through phosphate anions, inhibiting the aggregation of soil particles, thereby facilitating the full extraction of polymer compounds in the marsh waste soil; the alkaline regulator is a pH regulator, providing the alkaline environment required for extraction and preventing the precipitation of polymer compounds in the marsh waste soil in an acidic environment; 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride serves as a crosslinking catalyst, which can release active triazine groups under alkaline conditions and catalyze the condensation reaction between the carboxyl groups on the polymer compounds in the extraction solution of the marsh waste soil and the amino groups in dopamine hydrochloride; dopamine hydrochloride serves as a bionic bonding precursor, reacting with the carboxyl groups on the natural polymer compounds in the waste soil under the action of a catalyst to graft catechol groups, and achieving the bonding function through the formation of coordination bonds between the catechol groups and the soil particle surface.

[0012] Among them, the marsh waste soil mentioned in the present invention refers to the engineering waste generated during highway engineering due to the line passing through marsh areas and through construction activities such as foundation treatment and subgrade excavation, mainly including clay minerals (content about 40 - 65%), humus (15 - 30%), plant residues (5 - 15%), moisture (initial moisture content ≥ 45%), and microbial communities, etc.

[0013] Second, the present invention provides a preparation method for a nitrogen-rich binder for slope spraying matrix, including the following steps:

[0014] (1) Dry and crush the marsh waste soil to obtain marsh waste soil dry powder;

[0015] (2) Add the marsh waste soil dry powder, alkaline regulator, and chelating agent to water, stir well, perform oscillating extraction, and after filtration, evaporate and concentrate the crude extraction solution and then freeze-dry it to obtain a crude extraction product a;

[0016] (3) Dissolve the crude extract a in water, dialyze it, and then freeze-dry to obtain the crude extract b;

[0017] (4) Wash the crude extract b successively with an acid solution mixture and water, and then freeze-dry to obtain the crude extract c;

[0018] (5) Dissolve the crude extract c and 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride in water together, then add dopamine hydrochloride and react for 6 h under a nitrogen atmosphere, and then freeze-dry to obtain the nitrogen-rich binder.

[0019] In a specific embodiment, in step (2), add the marsh waste soil dry powder, alkaline regulator, and chelating agent to water, stir well, extract in a shaker for 4 h, evaporate and concentrate the crude extract after screening out the precipitate to 1 / 3 of the original volume to obtain a liquid concentrated binder, and then freeze-dry the liquid concentrated binder to obtain the crude extract a; the amplitude of the shaker is 20-60 mm, and the rotation speed is 100-300 rpm; the temperature for evaporating and concentrating the crude extract is 65 °C.

[0020] In a specific embodiment, in step (3), after dissolving the crude extract a in pure water, dialyze it with a 300000 Mw dialysis bag for 5 days, and then freeze-dry to obtain the crude product b.

[0021] In a specific embodiment, in step (4), wash the crude product b 3 times with a mixed solution of 0.3 mM hydrofluoric acid and 0.1 mM hydrochloric acid, and then wash it 3 times with pure water and freeze-dry to obtain the crude extract c.

[0022] In a third aspect, the present invention provides a slope spraying matrix containing a nitrogen-rich binder, which includes a spraying matrix and the nitrogen-rich binder.

[0023] In a specific embodiment, the addition ratio of the nitrogen-rich binder is 1-2.5% of the total amount of the spraying matrix.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] 1. The nitrogen-rich binder and preparation method for a slope spraying matrix provided by the embodiment of the present invention utilize marsh waste soil to prepare an environmentally friendly new material that can be used for slope prevention and control. It not only has the same bonding effect as other existing slope spraying matrix binders, but also has a high content of nitrogen elements, which can provide fertility for the soil and is beneficial to the germination of seeds;

[0026] 2. The nitrogen-rich binder for slope spraying matrix provided by the embodiments of the present invention and its preparation method utilize marsh waste soil in a resourceful way, which is beneficial to the protection of the ecological environment. At the same time, the preparation process is simple, the raw material sources are extensive, and it is environmentally friendly, suitable for large-scale application, and can reduce the cost of slope restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0028] Figure 1 It shows the influence of different addition ratios of nitrogen-rich binders provided by the embodiments of the present invention on soil fertility. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in combination with the embodiments and the drawings. The illustrative embodiments and their descriptions of the present invention are only used to explain the present invention and do not limit the present invention.

[0030] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that: these specific details do not have to be adopted to implement the present invention. In other embodiments, well-known structural materials or methods are not specifically described to avoid confusing the present invention.

[0031] Throughout the specification, the reference to "one embodiment", "embodiment", "one example" or "example" means that the specific features, structures or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment", "embodiment", "one example" or "example" appearing throughout the specification do not necessarily refer to the same embodiment or example. In addition, the specific features, structures or characteristics can be combined in any appropriate combination and / or sub-combination in one or more embodiments or examples. In addition, those of ordinary skill in the art should understand that the drawings provided here are for illustrative purposes only, and the drawings are not necessarily drawn to scale. The term "and / or" used here includes any and all combinations of one or more of the related listed items.

[0032] In the description of the present invention, the orientation or positional relationship indicated by terms such as "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the protection scope of the present invention.

[0033] Ecological slope protection has become a hot topic in slope protection projects at home and abroad. However, due to the high cost of polymer materials, they are not suitable for large-scale applications in engineering. At the same time, some polymer materials have environmental toxicity and are not suitable for use as the spraying matrix for slope ecological restoration. To solve the above problems:

[0034] In a first aspect, the present invention provides a nitrogen-rich binder for slope spraying matrix, which includes marsh waste soil, chelating agent, alkaline regulator, 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride, dopamine hydrochloride and water.

[0035] In a specific embodiment, the nitrogen-rich binder includes the following components in parts by mass:

[0036] 100 parts of marsh waste soil, 2 - 5 parts of chelating agent, 3 - 6 parts of alkaline regulator, 0.3 - 0.7 parts of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride, 0.3 - 0.7 parts of dopamine hydrochloride and 800 - 1200 parts of water.

[0037] In a specific embodiment, the chelating agent is one or more of sodium hexametaphosphate, sodium pyrophosphate, sodium tripolyphosphate and sodium citrate, and preferably sodium hexametaphosphate.

[0038] In a specific embodiment, the alkaline regulator is sodium hydroxide or potassium hydroxide.

[0039] The present invention makes resource utilization of marsh waste soil. Using marsh waste soil as raw material, it prepares an environmentally friendly new material that can be used for slope prevention and control. It not only has the same bonding effect as other existing slope spraying matrix binders, but also has a high content of nitrogen element, which can provide fertility for the soil and is beneficial to the germination of seeds. The marsh waste soil used in the binder of the present invention is rich in natural high molecular polymers and has various functional groups, such as carboxyl groups, phenolic hydroxyl groups, and alcoholic hydroxyl groups, which can form coordination bonds with metal cations in the soil to bridge soil particles; water is used as the reaction medium and as the medium phase for the dissolution of sodium hydroxide and the graft modification of dopamine hydrochloride; the chelating agent sodium hexametaphosphate, as an inorganic dispersant, can chelate with the high-valent metal ions in the marsh waste soil through phosphate anions to inhibit the aggregation of soil particles, thereby contributing to the full extraction of high molecular polymers in the marsh waste soil; the alkaline regulator is a pH regulator, providing the alkaline environment required for extraction and preventing the precipitation of high molecular polymers in the marsh waste soil in an acidic environment; 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride is used as a crosslinking catalyst, which can release active triazine groups under alkaline conditions and catalyze the condensation reaction between the carboxyl groups on the high molecular polymers in the extraction solution of marsh waste soil and the amino groups in dopamine hydrochloride; dopamine hydrochloride is used as a biomimetic bonding precursor, and under the action of a catalyst, it reacts with the carboxyl groups on the natural high molecular polymers in the waste soil to graft catechol groups, and realizes the bonding function through the formation of coordination bonds between the catechol groups and the soil particle surface.

[0040] Second, the present invention provides a preparation method of a nitrogen-rich binder for a slope spraying matrix, which includes the following steps:

[0041] (1) Dry and crush the marsh waste soil to obtain marsh waste soil dry powder;

[0042] (2) Add the marsh waste soil dry powder, alkaline regulator, and chelating agent into water, stir well, shake and extract, and after filtration, evaporate and concentrate the crude extract and then freeze-dry it to obtain the crude extract product a;

[0043] (3) Dissolve the crude extract product a in water, dialyze it, and then freeze-dry it to obtain the crude extract product b;

[0044] (4) Wash the crude extract product b successively with an acid solution mixture and water, and then freeze-dry it to obtain the crude extract product c;

[0045] (5) Dissolve the crude extract product c and 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride in water together, then add dopamine hydrochloride and react for 6 h under a nitrogen environment, and then freeze-dry it to obtain the nitrogen-rich binder.

[0046] In a specific embodiment, in step (2), the marsh waste soil dry powder, the alkaline regulator, and the chelating agent are added to water and stirred evenly, and extracted by shaking in a shaker for 4 h. The crude extract after screening out the precipitate is evaporated and concentrated to 1 / 3 of the original volume to obtain a liquid concentrated binder, and then the liquid concentrated binder is freeze-dried to obtain a crude extract product a; the amplitude of the shaker is 20-60 mm, and the rotation speed is 100-300 rpm; the temperature for evaporating and concentrating the crude extract is 65 °C.

[0047] In a specific embodiment, in step (3), the crude extract product a is dissolved in pure water, dialyzed with a 300000 Mw dialysis bag for 5 days, and then freeze-dried to obtain a crude product b.

[0048] In a specific embodiment, in step (4), the crude product b is washed 3 times with a mixed solution of 0.3 mM hydrofluoric acid and 0.1 mM hydrochloric acid, and then washed 3 times with pure water and freeze-dried to obtain a crude extract product c.

[0049] In a third aspect, the present invention provides a slope spraying matrix containing a nitrogen-rich binder, including a spraying matrix and the nitrogen-rich binder.

[0050] In a specific embodiment, the addition ratio of the nitrogen-rich binder is 1-2.5% of the total amount of the spraying matrix.

[0051] Example 1

[0052] The embodiment of the present invention provides a preparation method for resource utilization of marsh waste soil to prepare a nitrogen-rich binder for a slope spraying matrix, including the following steps:

[0053] (1) The marsh waste soil is fully dried at 70 °C until constant weight, and the dried marsh waste soil is crushed by a pulverizer and sieved through a 0.5 mm sieve to obtain marsh waste soil dry powder;

[0054] (2) The marsh waste soil dry powder, sodium hydroxide, and sodium hexametaphosphate are added to water and stirred evenly, and extracted by shaking in a shaker for 4 h. Then, the crude extract of the binder after screening is evaporated and concentrated to 1 / 3 of the original volume to obtain a liquid concentrated binder, and then the liquid concentrated binder is freeze-dried to obtain a crude extract product a;

[0055] (3) The crude extract product a is dissolved in water, dialyzed with a 300000 Mw dialysis bag for 5 days and then freeze-dried to obtain a crude extract product b;

[0056] (4) The crude extract product b is washed 3 times with a mixed solution of 0.3 mM hydrofluoric acid and 0.1 mM hydrochloric acid, and then washed 3 times with pure water and freeze-dried to obtain a crude extract product c;

[0057] (5) The crude product c and 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride are co-dissolved in pure water, and then dopamine hydrochloride is added. After reacting for 6 h under a nitrogen atmosphere, it is freeze-dried to obtain a nitrogen-rich binder;

[0058] Among them, there are 100 parts of marsh waste soil, 3 parts of sodium hexametaphosphate, 4 parts of sodium hydroxide, 0.5 part of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride, 0.5 part of dopamine hydrochloride, and 1000 parts of water.

[0059] Example 2

[0060] The embodiment of the present invention provides a preparation method for resource utilization of marsh waste soil to prepare a nitrogen-rich binder for slope spraying matrix, including the following steps:

[0061] (1) The marsh waste soil is fully dried to constant weight at 70 °C. The dried marsh waste soil is crushed by a pulverizer and sieved through a 0.5 mm sieve to obtain dry powder of marsh waste soil;

[0062] (2) The dry powder of marsh waste soil, sodium hydroxide, and sodium hexametaphosphate are added to water and stirred evenly. It is oscillated and extracted in a shaker for 4 h, and then the crude extract of the binder after sieving is evaporated and concentrated to 1 / 3 of the original volume to obtain a liquid concentrated binder. Then the liquid concentrated binder is freeze-dried to obtain a crude product a;

[0063] (3) After the crude product a is dissolved in water, it is dialyzed with a 300000 Mw dialysis bag for 5 days and then freeze-dried to obtain a crude product b;

[0064] (4) The crude product b is washed 3 times with a mixed solution of 0.3 mM hydrofluoric acid and 0.1 mM hydrochloric acid, and then washed 3 times with pure water and freeze-dried to obtain a crude product c;

[0065] (5) The crude product c and 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride are co-dissolved in pure water, and then dopamine hydrochloride is added. After reacting for 6 h under a nitrogen atmosphere, it is freeze-dried to obtain a nitrogen-rich binder;

[0066] Among them, there are 100 parts of marsh waste soil, 2 parts of sodium hexametaphosphate, 3 parts of sodium hydroxide, 0.3 part of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride, 0.3 part of dopamine hydrochloride, and 800 parts of water.

[0067] Example 3

[0068] The embodiment of the present invention provides a preparation method for resource utilization of marsh waste soil to prepare a nitrogen-rich binder for slope spraying matrix, including the following steps:

[0069] (1) The swamp waste soil is fully dried at 70 °C until constant weight. After drying, the swamp waste soil is crushed by a pulverizer and sieved through a 0.5 mm sieve to obtain dry powder of swamp waste soil;

[0070] (2) The dry powder of swamp waste soil, sodium hydroxide, and sodium hexametaphosphate are added to water and stirred evenly. It is extracted by shaking in a shaker for 4 h. Then, the crude extract of the binder after sieving is evaporated and concentrated to 1 / 3 of the original volume to obtain a liquid concentrated binder. After that, the liquid concentrated binder is freeze-dried to obtain a crude product a;

[0071] (3) After the crude product a is dissolved in water, it is dialyzed with a 300000 Mw dialysis bag for 5 days and then freeze-dried to obtain a crude product b;

[0072] (4) The crude product b is washed 3 times with a mixed solution of 0.3 mM hydrofluoric acid and 0.1 mM hydrochloric acid, and then washed 3 times with pure water and freeze-dried to obtain a crude product c;

[0073] (5) The crude product c and 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride are co-dissolved in pure water, and then dopamine hydrochloride is added and reacted in a nitrogen environment for 6 h and then freeze-dried to obtain a nitrogen-rich binder;

[0074] Among them, there are 100 parts of swamp waste soil, 5 parts of sodium hexametaphosphate, 6 parts of sodium hydroxide, 0.7 part of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride, 0.7 part of dopamine hydrochloride, and 1200 parts of water.

[0075] Comparative Example 1

[0076] The embodiment of the present invention provides a preparation method of a binder, including the following steps:

[0077] (1) The swamp waste soil is fully dried at 70 °C until constant weight. After drying, the swamp waste soil is crushed by a pulverizer and sieved through a 0.5 mm sieve to obtain dry powder of swamp waste soil;

[0078] (2) The dry powder of swamp waste soil, sodium hydroxide, and sodium hexametaphosphate are added to water and stirred evenly. It is extracted by shaking in a shaker for 4 h. Then, the crude extract of the binder after sieving is evaporated and concentrated to 1 / 3 of the original volume to obtain a liquid concentrated binder. After that, the liquid concentrated binder is freeze-dried to obtain a crude product a;

[0079] Among them, there are 100 parts of swamp waste soil, 3 parts of sodium hexametaphosphate, 4 parts of sodium hydroxide, and 1000 parts of water.

[0080] Different from Example 1, this comparative example lacks the participation of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride and dopamine hydrochloride in the preparation of the binder, that is, the step of catechol group grafting modification is missing.

[0081] Comparative Example 2

[0082] An embodiment of the present invention provides a method for preparing a binder, which includes the following steps:

[0083] (1) The swamp waste soil is fully dried to a constant weight at 70°C, and the dried swamp waste soil is crushed by a pulverizer and passed through a 0.5-mm sieve to obtain dry powder of swamp waste soil;

[0084] (2) The dry powder of swamp waste soil and sodium hexametaphosphate are added to water and stirred evenly, shaken and extracted in a shaker for 4 h, and then the crude extract of the binder after screening is evaporated and concentrated to 1 / 3 of the original volume to obtain a liquid concentrated binder, and then the liquid concentrated binder is freeze-dried to obtain a crude product a;

[0085] Among them, there are 100 parts of swamp waste soil, 3 parts of sodium hexametaphosphate and 1000 parts of water.

[0086] Different from Example 1, this comparative example lacks sodium hydroxide, 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride, and dopamine hydrochloride participating in the preparation of the binder, that is, it lacks the steps of alkaline extraction environment and catechol group grafting modification.

[0087] Comparative Example 3

[0088] An embodiment of the present invention provides a method for preparing a nitrogen-rich binder for slope spraying matrix by resource utilization of swamp waste soil, which includes the following steps:

[0089] (1) The swamp waste soil is fully dried to a constant weight at 70°C, and the dried swamp waste soil is crushed by a pulverizer and passed through a 0.5-mm sieve to obtain dry powder of swamp waste soil;

[0090] (2) The dry powder of swamp waste soil and sodium hydroxide are added to water and stirred evenly, shaken and extracted in a shaker for 4 h, and then the crude extract of the binder after screening is evaporated and concentrated to 1 / 3 of the original volume to obtain a liquid concentrated binder, and then the liquid concentrated binder is freeze-dried to obtain a crude product a;

[0091] (3) After dissolving the crude product a in water, it is dialyzed with a 300,000 Mw dialysis bag for 5 days and then freeze-dried to obtain a crude product b;

[0092] (4) The crude product b is washed 3 times with a mixed solution of 0.3 mM hydrofluoric acid and 0.1 mM hydrochloric acid, and then washed 3 times with pure water and freeze-dried to obtain a crude product c;

[0093] (5) The crude product c and 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride are co-dissolved in pure water, and then dopamine hydrochloride is added and reacted in a nitrogen environment for 6 h and then freeze-dried to obtain a nitrogen-rich binder;

[0094] Among them, there are 100 parts of marsh waste soil, 4 parts of sodium hydroxide, 0.5 part of 4-(4,6-dimethoxytriazin-2-yl)-4-methylmorpholine hydrochloride, 0.5 part of dopamine hydrochloride, and 1000 parts of water.

[0095] Different from Example 1, this comparative example lacks the participation of sodium hexametaphosphate in the preparation of the binder, that is, the step of chelating with high-valent metal ions to inhibit soil particle aggregation is missing.

[0096] Performance test

[0097] 1. Detect the nitrogen nutrient content of the binders prepared in Examples 1-3 and Comparative Examples 1-3, and the results are shown in Table 1 below.

[0098] Table 1 Nitrogen nutrient situation of slope spraying matrix binder

[0099]

[0100] It can be seen from the above results that the ammonia nitrogen content of the binders extracted in Examples 1-3 of the present invention is as high as 487 mg / kg, and the total carbon content of humus can reach 3.67 g / kg.

[0101] According to relevant literature data, the nitrogen content range of common soil improvement products on the market, including peat soil, livestock and poultry manure, and biomass soil improvers, is relatively wide. Among them, the available nitrogen content of peat soil is 200-400 mg / kg, the available nitrogen content of livestock and poultry manure is 100-200 mg / kg, and the total nitrogen content of fermented biomass soil improver is about 7-25 g / kg (i.e., 7000-25000 mg / kg). The binder prepared from natural marsh waste soil generated in the project of the present invention has a higher ammonia nitrogen content (477 mg / kg) than natural peat soil and livestock and poultry manure, and is a nitrogen-rich binder.

[0102] Both Comparative Example 1 and Example 1 are extracted in an alkaline environment. Compared with Example 1, Comparative Example 1 lacks the graft modification of catechol groups, so the nutrient indexes have no obvious difference from those of Example 1. Comparative Example 2 is extracted in a neutral environment and sodium hydroxide is not added during the extraction process, resulting in a very insufficient extraction reaction and a large nutrient gap. Comparative Example 3 lacks the chelation of sodium hexametaphosphate with high-valent metal ions to inhibit soil particle aggregation, so the extraction reaction is slightly worse and the nutrient content is lower.

[0103] 2. Add the binders prepared in Example 1 and Comparative Examples 1-3 to the spraying matrix for planting tests, which are specifically as follows:

[0104] (1) Test materials

[0105] The formula of the hydroseeding substrate used in the planting experiment is as follows: 330 - 420 parts of planting soil, 1 - 3 parts of straw fiber, 0.03 - 0.05 parts of water-retaining agent, 0.5 - 2 parts of pH regulator, 30 - 40 parts of mixed seeds, and 150 - 200 parts of water; wherein the mixed seeds are composed of plant seeds in the following weight parts: 10 - 12 parts of Cosmos bipinnatus seeds, and 20 - 28 parts of Festuca elata seeds; the addition amount of the binder is added according to the mass percentage of the total weight of the above materials, and the addition ratios are 0%, 1%, 2.5%, and 5% respectively. Observe the germination of Cosmos bipinnatus and Festuca elata at 3d and 9d in Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 under different addition ratios.

[0106] (2) Measurement results

[0107] From Figure 1 , Table 2, and Table 3, it can be seen that the nitrogen-rich binder for slope hydroseeding substrate prepared according to the present invention can provide certain fertility for the soil, so as to significantly improve the germination rate of seeds. Among them, when the addition amount of the binder in Example 1 is 1 - 2.5%, it has a good seed germination rate. When the addition amount is 2.5%, the seed germination rate is 50% (9d) and 90% (9d), and the seed germination effect is the best. While a higher addition ratio (5%) may cause soil compaction, resulting in a decline in the germination rate. At the same time, since the nutrient content of the binder in Example 1 and Comparative Example 1 is higher than that in Comparative Example 2 and Comparative Example 3, the overall germination rate is relatively high. By comparison, the germination rate of Comparative Example 3 is slightly lower, and the germination rate of Comparative Example 2 is poor. Cosmos bipinnatus and Festuca elata are commonly used plants for slope hydroseeding and revegetation. Their roots are developed, with deep roots, dense rhizomes, and a wide coverage area, which can effectively prevent soil erosion. After using the nitrogen-rich binder extracted by the technology of the present invention, enhancing its germination rate is beneficial to improving the soil and water conservation ability of the slope.

[0108] Table 2 3d germination rate (%)

[0109] Addition ratio % Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 0 35 35 30 30 1 40 40 25 35 2.5 50 40 25 30 5 40 35 20 30

[0110] Table 3 9d germination rate (%)

[0111] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 0 60 60 60 60 1 85 75 65 70 2.5 90 75 65 65 5 75 70 60 70

[0112] 3. Measure the bonding performance of the binders prepared in Example 1 and Comparative Examples 1 - 3, specifically as follows:

[0113] (1) Tested soil

[0114] Soil sample 1 is from the slope to be repaired outside the mixing station of Kangding - Xinlong Expressway in Kangding City, soil sample 2 is from the No. 1 waste dump and the lower - layer rock mass in Section ZCB1 - 1 of Huilu Expressway in Huidong County, Xichang City, and soil sample 3 is from the sludge in the sedimentation tank beside Jituo Tunnel of Kangding - Xinlong Expressway in Kangding City.

[0115] (2) Test method

[0116] Test the cohesion improvement effects of Test Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 on three types of test soils with different initial cohesions at an addition amount of 2.5%. Relevant data were measured using a strain-controlled direct shear apparatus. The specimen preparation and specimen size were in accordance with the specified size (diameter / height: 61.6 mm / 20 mm) and method in the "Standard for Geotechnical Test Methods" (GB / T 50123-1999), and the sampling method was in accordance with on-site sampling in the "Standard for Geotechnical Test Methods" (GB / T 50123-1999). The direct shear test was carried out by applying four levels of vertical normal pressures of 50, 100, 150, and 200 kPa to a group of specimens respectively, and rapid shearing was carried out at a strain rate of 1.2 mm / min.

[0117] (3) Data analysis

[0118] Monitor the shear stress-displacement change curves at different times to obtain the shear strength τ under each level of pressure, then plot the τ-P curve, and further calculate the interface cohesion and internal friction angle of the soil mass.

[0119] (4) Measurement results

[0120] As can be seen from Table 4, after adding 2.5% of the binder in Example 1, the cohesions of the three soil samples increased by 133.33%, 49.99%, and 75.40% respectively. After adding 2.5% of the binder in Comparative Example 1, the cohesion improvement effect was significantly lower than that in Example 1. After adding the binder in Comparative Example 2, the cohesion basically did not increase. After adding Comparative Example 3, the cohesion increased but the effect was not as good as that in Example 1. This shows that suppressing the agglomeration of the extraction raw materials, the alkaline extraction environment, and the graft modification of catechol groups are crucial for improving the bonding ability of the natural polymers extracted from marsh waste soil to the soil. Based on the extraction method of Example 1, the slope ecological base material binder prepared can significantly enhance the structural stability of the soil, achieve the effect of ecological slope protection, and reduce soil erosion on the slope surface.

[0121] Table 4 Improvement of soil cohesion after adding binder

[0122]

[0123]

[0124] The above specific implementation manners have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above is only the specific implementation manners of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A nitrogen-rich binder for slope spraying matrix, characterized in that: The invention comprises marsh spoil, a chelating agent, an alkaline regulator, 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride, dopamine hydrochloride and water.

2. A nitrogen-rich binder for slope spraying matrix according to claim 1, characterized in that: Includes the following mass components: 100 parts of marsh waste soil, 2-5 parts of chelating agent, 3-6 parts of alkaline regulator, 0.3-0.7 parts of 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride, 0.3-0.7 parts of dopamine hydrochloride and 800-1200 parts of water.

3. A nitrogen-rich binder for slope spraying matrix according to claim 1, characterized in that: The chelating agent is one or more of sodium hexametaphosphate, sodium pyrophosphate, sodium tripolyphosphate and sodium citrate.

4. A nitrogen-rich binder for slope spraying matrix according to claim 1, characterized in that: The alkaline regulator is sodium hydroxide or potassium hydroxide.

5. The method for preparing a nitrogen-rich binder for slope spraying matrix according to claim 1, characterized in that: The steps include: (1) drying and crushing the marsh spoil to obtain marsh spoil dry powder; (2) adding the marsh waste soil dry powder, alkaline regulator and chelating agent into water, stirring well, extracting by shaking, filtering, evaporating and concentrating the crude extract, and freeze-drying to obtain the crude extract product a; (3) dissolving the crude product a in water, dialyzing and freeze-drying to obtain the crude product b; (4) washing the crude product b with an acid mixture solution and water in sequence, and freeze-drying to obtain a crude product c; (5) The crude product c and 4-(4,6-dimethoxytriazine-2-yl)-4-methylmorpholine hydrochloride are dissolved in water, dopamine hydrochloride is added, reacted under nitrogen environment, and freeze-dried to obtain a nitrogen-rich binder.

6. The method for preparing a nitrogen-rich binder for slope spraying matrix according to claim 5, characterized in that: In step (2), the swamp waste soil dry powder, alkaline regulator and chelating agent are added to water and stirred evenly, and the mixture is shaken and extracted in a shaker for 4 hours. The crude extract after screening out the precipitate is evaporated and concentrated to 1 / 3 of the original volume to obtain a liquid concentrated binder, and the liquid concentrated binder is then freeze-dried to obtain a crude extract product a; the shaker amplitude is 20 to 60 mm, and the rotation speed is 100 to 300 rpm; the temperature for evaporation and concentration of the crude extract is 65°C.

7. The method for preparing a nitrogen-rich binder for slope spraying matrix according to claim 5, characterized in that: In step (3), the crude product a is dissolved in pure water, dialyzed for 5 days using a 300,000 Mw dialysis bag, and then freeze-dried to obtain a crude product b.

8. The method for preparing a nitrogen-rich binder for slope spraying matrix according to claim 5, characterized in that: In step (4), the crude product b is washed three times with a mixed solution of 0.3 mM hydrofluoric acid and 0.1 mM hydrochloric acid, and then washed three times with pure water and freeze-dried to obtain a crude product c.

9. A slope spraying matrix containing a nitrogen-rich binder, characterized in that: It comprises a spraying matrix and the nitrogen-rich binder according to any one of claims 1 to 4.

10. The slope spraying matrix containing nitrogen-rich binder according to claim 9, characterized in that: The addition ratio of nitrogen-rich binder is 1 to 2.5% of the total amount of the spraying matrix.

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