A solid waste green modifier for saline-alkali soil improvement and carbon sink function improvement and a preparation method thereof

Abstract

The application discloses a solid waste green modifier for saline-alkali soil improvement and carbon sink function improvement and a preparation method thereof, and relates to the technical field of saline-alkali soil improvement.The solid waste green modifier for saline-alkali soil improvement and carbon sink function improvement and the preparation method thereof are characterized by using seafood waste (oyster shells, scallop shells, lobster shells and the like) and agricultural solid waste carbonized material as main raw materials, realizing efficient consumption of two types of solid waste, and reducing environmental pollution and resource waste.

Description

Technical Field

[0001] This invention relates to the field of saline-alkali land improvement technology, specifically to a green soil amendment for saline-alkali land improvement and carbon sequestration enhancement, and its preparation method. Background Technology

[0002] Saline-alkali land, as an important reserve of arable land, is widely distributed globally. In my country, large amounts of saline-alkali soil exist in coastal, inland, and arid northwestern regions. These soils generally suffer from high pH levels, salt accumulation, low organic carbon content, soil compaction, and weak microbial activity, severely hindering agricultural production and ecological restoration. Simultaneously, with the expansion of marine industries and agricultural production, the generation of seafood waste such as oyster, scallop, and lobster shells, as well as agricultural solid waste such as straw and livestock manure, continues to increase. The large-scale accumulation of solid waste not only occupies land resources but also easily leads to environmental problems such as soil and water pollution. Furthermore, under the "dual carbon" goal, improving soil carbon sequestration capacity and achieving synergistic effects between solid waste resource utilization and ecological benefits has become an important research direction in the fields of agriculture and the environment, requiring the development of integrated technical solutions that combine saline-alkali land improvement, solid waste disposal, and carbon sequestration enhancement.

[0003] Existing saline-alkali land improvement technologies often suffer from limitations due to their singular function. Traditional chemical amendments focus only on pH adjustment or salt leaching, failing to simultaneously improve soil carbon pools and micro-ecological environments. While some organic amendments can increase soil organic matter, their solid waste utilization rate is low, and their carbon sequestration effect is limited. Furthermore, existing solid waste-based amendments generally suffer from poor component synergy, complex preparation processes, and high energy consumption. Improper control of microbial inoculation conditions can also lead to reduced activity, affecting the sustainability of the improvement effect. In addition, most technologies fail to form a closed-loop system of "solid waste resource utilization - saline-alkali land restoration - carbon sequestration value enhancement," thus failing to meet the demands of green agriculture for low-cost, multifunctional, and eco-friendly amendments. Therefore, developing a multi-component, synergistic, green process, and multi-benefit solid waste green amendment has significant practical significance and application value. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: a green amendment for solid waste used for saline-alkali land improvement and carbon sequestration enhancement, comprising the following components:

[0005] The mixture contains 30-50 parts by weight of seafood waste, 20-40 parts by weight of carbonized agricultural solid waste, 10-20 parts by weight of biochar, 5-15 parts by weight of humic acid, and 1-5 parts by weight of compound microbial agent. The improver simultaneously achieves pH adjustment, salt leaching, and soil organic carbon sequestration in saline-alkali land, and the synergistic effect of each component enhances the soil carbon sink capacity.

[0006] Using seafood waste (oyster, scallop, and lobster shells, etc.) and agricultural solid waste carbonized materials as the main raw materials, this method achieves efficient disposal of both types of solid waste, reducing environmental pollution and resource waste.

[0007] The seafood waste consists of at least two types of shells from oysters, scallops, and lobsters, and has been screened using an 80-120 mesh sieve; wherein the calcium oxide content is ≥30% and the silicon oxide content is ≥20%.

[0008] The three core objectives of simultaneously achieving pH regulation, salt leaching, and soil organic carbon sequestration in saline-alkali land are realized. The synergistic effect of each component enhances the soil carbon sequestration capacity and overcomes the limitations of single-function improvement of saline-alkali land.

[0009] The agricultural solid waste carbonized material is at least two of the following: corn stalk carbon, rice stalk carbon, and fermented carbonized products of livestock and poultry manure. The carbonization temperature is 400-600℃, and the fixed carbon content is ≥45%.

[0010] The compound microbial agent is composed of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and halophilic Bacillus in a colony count ratio of 1:1:2; the effective viable count is ≥2.0 × 10⁻⁶. 9 CFU / g.

[0011] Preferably, the humic acid is composed of fulvic acid, black humic acid, brown humic acid, humic substances, and mineral elements in a ratio of 25:45:15:10:5.

[0012] The modifier has a pH value of 5.5-7.5 and a specific surface area ≥150m². 2 / g, when applied to saline-alkali land, can reduce soil pH by 0.5-2.0 units and increase soil organic carbon content by 15%-30%.

[0013] A method for preparing a green amendment for solid waste used to improve saline-alkali land and enhance carbon sequestration function includes the following steps:

[0014] Step 1: Raw material pretreatment: Seafood waste is crushed and screened to 80-120 mesh, and agricultural solid waste is dried until the moisture content is ≤15% and then carbonized to obtain carbonized material;

[0015] Step 2: Mixing of basic materials: Weigh the pretreated seafood waste, agricultural solid waste carbonized material, biochar, and humic acid according to the weight percentage, put them into a mixer and stir for 15-30 minutes at a speed of 300-500 r / min to obtain the mixed base material;

[0016] Step 3, Modification and Activation: Place the mixed base material in an activation furnace and keep it at 300-600℃ for 1-3 hours. At the same time, CO2 gas is introduced for activation, with a gas flow rate of 0.5-1.5L / min.

[0017] Step 4, inoculation with microbial agent: Dilute the compound microbial agent with sterile water 5-10 times, then spray it evenly into the activated mixed substrate and stir for 20-40 minutes until it is evenly mixed.

[0018] Step 5, Molding and Drying: The inoculated material is fed into a granulator to form 2-5mm granules, and then dried at 60-80℃ for 2-4 hours until the moisture content is ≤10%, thus obtaining a green improver for solid waste.

[0019] Preferably, in step one, the heating rate of the agricultural solid waste carbonization treatment is 5-10℃ / min, and nitrogen is introduced during the carbonization process for inert protection, with a nitrogen flow rate of 1-2L / min.

[0020] Preferably, the heating rate of the activation furnace in step three is 10-15℃ / min, and after activation, it is naturally cooled to room temperature before subsequent processing.

[0021] Preferably, the ambient temperature during inoculation of the microbial agent in step four is controlled at 25-35℃, and the ambient humidity is maintained at 60%-70% during the stirring process.

[0022] Preferably, the drying in step five adopts a segmented drying method, first drying at 60℃ for 1-2 hours, then raising the temperature to 80℃ for 1-2 hours, and then sieving to remove powdery materials with a particle size of less than 1mm.

[0023] The process employs CO2 activation and segmented drying, with reasonable heating rate and temperature control, mild inoculation conditions, low energy consumption throughout, and no secondary pollution, meeting the needs of green agricultural development.

[0024] This invention provides a green amendment for solid waste used in saline-alkali land improvement and carbon sequestration enhancement, as well as its preparation method. It has the following beneficial effects:

[0025] (I) The solid waste green amendment for improving saline-alkali land and enhancing carbon sequestration function and its preparation method, by using seafood waste (oyster, scallop and lobster shells, etc.) and agricultural solid waste carbonized material as the main raw materials, achieves efficient disposal of the two types of solid waste, reducing environmental pollution and resource waste.

[0026] (II) The solid waste green amendment for improving saline-alkali land and enhancing carbon sequestration function and its preparation method achieve three core objectives simultaneously: pH adjustment, salt leaching and soil organic carbon sequestration. The components work synergistically to enhance soil carbon sequestration capacity and solve the limitation of single function in improving saline-alkali land.

[0027] (III) This green soil amendment made from solid waste, used for improving saline-alkali land and enhancing carbon sequestration function, and its preparation method, after quantitative application, can reduce soil pH by 0.5-2.0 units and increase organic carbon content by 15%-30%, while the product's specific surface area is ≥150m². 2 / g ensures stable and lasting improvement effects.

[0028] (iv) The solid waste green amendment for improving saline-alkali land and enhancing carbon sequestration function and its preparation method adopt CO2 activation, segmented drying and other processes, with reasonable heating rate and temperature control, mild inoculation conditions for microbial agents, low energy consumption throughout the process, and no secondary pollution in the product, which meets the needs of green agricultural development. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: This invention provides a technical solution: mild coastal chloride saline soil improvement;

[0031] Application scenarios;

[0032] The site was selected as a slightly saline-alkali coastal area in the Bohai Bay, with a soil pH of 8.2, a surface salt content of 0.35% (chloride type), and a soil organic carbon content of 6.2 g / kg. There are oyster, scallop, and lobster shell deposits in the surrounding area.

[0033] Implementation plan;

[0034] Raw material ratio: 40 parts by weight of seafood waste (oyster: scallop = 1:1), 30 parts by weight of agricultural solid waste carbonization material (corn straw charcoal: livestock and poultry manure fermentation carbonization product = 3:2), 15 parts by weight of biochar, 10 parts by weight of preferred formula humic acid, and 3 parts by weight of compound microbial agent.

[0035] Preparation process: Strictly follow the invention steps, the heating rate of agricultural solid waste carbonization is 8℃ / min, the CO2 activation gas flow rate is 1.0L / min, the inoculation temperature of the microbial agent is 28℃ and the humidity is 65%, and after segmented drying, 2-5mm particle products are screened.

[0036] Application method: 15 days before crop planting, apply evenly at a rate of 200 kg / mu, combined with shallow tilling to a depth of 20 cm and flood irrigation (80 m³ / mu). 3 / mu).

[0037] Implementation results;

[0038] Solid waste disposal: 80 kg of seafood waste and 60 kg of agricultural solid waste are disposed of per mu, with a total annual solid waste treatment volume of 1,200 tons per thousand mu, reducing the land occupied by solid waste storage by 3 mu per thousand mu.

[0039] Soil improvement: 60 days after application, the soil pH dropped to 7.3 and the salinity dropped to 0.21%, both meeting the standards for suitable cultivation of slightly saline-alkali land; the soil organic carbon content increased to 7.8 g / kg, an increase of 25.8%.

[0040] Carbon sequestration enhancement: Through organic carbon sequestration and CO2 activation processes, the annual carbon sequestration volume of the 1,000-mu improvement area reaches 15 tons, which is equivalent to reducing coal-fired carbon emissions by 55 tons.

[0041] Crop performance: The emergence rate of cotton seedlings increased from 68% to 85% in subsequent plantings, the yield per mu increased by 18%, and the fiber quality indicators improved by 5%-8%.

[0042] Example 2: The present invention provides a technical solution for the improvement of moderately inland soda saline soil;

[0043] Application scenarios;

[0044] The selected soil is a moderately soda-saline-alkali land in the Songnen Plain, with a soil pH of 9.1, an alkalinity of 22%, a surface salt content of 0.45% (soda type), a soil organic carbon content of 5.1 g / kg, a compacted soil structure, and extremely low microbial activity. The surrounding area has resources such as oysters, scallops, lobster shells, and rice straw.

[0045] Implementation plan;

[0046] Raw material ratio: 45 parts by weight of seafood waste (oyster: scallop = 2:3), 35 parts by weight of agricultural solid waste carbonization material (rice straw carbon + livestock and poultry manure fermentation carbonization product = 2:1), 10 parts by weight of biochar, 8 parts by weight of preferred formula humic acid, and 2 parts by weight of compound microbial agent.

[0047] Preparation process: Agricultural solid waste is carbonized under nitrogen protection (flow rate 1.5L / min), CO2 activation is carried out at a heating rate of 12℃ / min, the bacterial agent is diluted 8 times and then inoculated, and the total drying time is 3h in stages.

[0048] Application method: Use the "amort + straw mulch" model. Apply 250 kg / mu of amort, till to a depth of 25 cm, irrigate and leach, then cover with 10 cm of rice straw and plant salt-tolerant corn.

[0049] Implementation results;

[0050] Synergistic improvement: Calcium oxides (32%) and silicon oxides (23%) in seafood waste synergistically replace soil exchangeable Na+ with the active groups of humic acid.+ The organic acids secreted by the microbial agents neutralize OH-. - Within 90 days, the soil pH dropped to 7.8, the alkalinity dropped to 11%, and the salt leaching rate reached 62%.

[0051] Structural optimization: The modifier has a specific surface area of ​​185m². 2 / g, promotes the formation of soil aggregates, and the soil bulk density increases from 1.52g / cm³. 3 Reduced to 1.31 g / cm³ 3 The porosity was increased by 12%, solving the problem of compaction in soda saline soil.

[0052] Long-lasting effects: After 18 months of continuous monitoring, the soil pH remained stable at 7.5-7.9, the salinity did not rebound, the abundance of microbial communities increased by 3 times, and the proportion of Proteobacteria and Bacteroidetes reached 65%, thus constructing a stable soil micro-ecology.

[0053] Long-term carbon sequestration: Soil organic carbon content has continued to increase to 6.9 g / kg, an increase of 35.3%, and the annual stable carbon sequestration volume in a thousand-acre area reaches 18 tons, with a carbon sequestration duration of more than 5 years. Example 3: The present invention provides a technical solution:

[0054] Ecological restoration of severely saline-alkali land (circular economy closed loop + carbon trading linkage)

[0055] Application scenarios

[0056] The selected area is severely alkaline soil in the inland northwest, with a soil pH of 9.8, alkalinity of 38%, surface salt content of 0.85%, and soil organic carbon content of 3.8 g / kg. It is unused wasteland and meets the conditions for carbon sequestration project development.

[0057] Implementation Plan

[0058] Raw material ratio: 50 parts by weight of seafood waste (oyster: scallop: lobster shell = 2:2:1), 30 parts by weight of agricultural solid waste carbonization material (wheat straw charcoal + livestock and poultry manure fermentation carbonization product = 3:1), 12 parts by weight of biochar, 5 parts by weight of preferred formula humic acid, and 3 parts by weight of compound microbial agent.

[0059] Preparation process: Optimize CO2 activation temperature to 500℃ and hold for 2 hours; maintain bacterial inoculation humidity at 70% to ensure an effective viable count ≥ 2.0 × 10⁻⁶. 9 CFU / g, after drying, remove powder with a particle size <1mm.

[0060] Application method: Apply in two stages. In the first stage (ecological restoration period), apply 300 kg / mu by broadcasting, combined with drip irrigation (irrigated in 3 times, with a total irrigation volume of 120m³). 3In the first stage (carbon sequestration period), alfalfa is planted; in the second stage (carbon sequestration consolidation period), an additional 150 kg / mu is added the following year, and jujube is intercropped.

[0061] Implementation effect

[0062] Significant improvement breakthrough: 120 days after application, the soil pH dropped to 8.3, the alkalinity dropped to 20%, and the salinity dropped to 0.42%, transforming the severely saline-alkali land into moderately usable land; one year later, the soil pH stabilized at 7.9, and the organic carbon content increased to 5.1 g / kg, an increase of 34.2%.

[0063] Circular economy effect: The thousand-acre restoration area consumes 150 tons of seafood waste and 90 tons of agricultural solid waste annually, with a solid waste resource utilization rate of 100%. The energy consumption of the preparation process is reduced by 30% compared with traditional modifiers, and there is no secondary pollution.

[0064] Carbon trading realized: After 3 years of improvement, the cumulative carbon sequestration in the 1,000-mu area will reach 65 tons. After carbon sequestration project certification, carbon trading revenue of about 32,500 yuan can be realized (calculated at a carbon sequestration price of 500 yuan / ton), forming a closed loop of "solid waste utilization - saline-alkali land restoration - carbon sequestration revenue increase".

[0065] Ecological benefits: The survival rate of alfalfa reached 92%, the survival rate of jujube afforestation reached 88%, the regional vegetation coverage increased from 5% to 65%, the local microclimate was improved, and wind and sand erosion was reduced.

[0066] Example 4: The present invention provides a technical solution: supporting improvement for the planting of specialty crops in saline-alkali land;

[0067] Application scenarios;

[0068] Select a transitional zone of slightly to moderately saline-alkali land in the Yellow River Delta, with soil pH 8.6 and salt content 0.4%, to plan the planting of Yellow River Estuary Rice (a geographical indication product), with rice straw resources available in the surrounding area.

[0069] Implementation plan;

[0070] Raw material ratio: 35 parts by weight of seafood waste (oyster, scallop and lobster shells = 2:3:1), 38 parts by weight of agricultural solid waste carbonization material (rice straw charcoal + rice husk charcoal = 4:1), 17 parts by weight of biochar, 8 parts by weight of preferred formula humic acid, and 2 parts by weight of compound microbial agent.

[0071] Application method: Apply 220 kg / mu 20 days before transplanting, mix thoroughly with rotary tillage, and use a water-saving irrigation mode (total irrigation volume 60m³). 3 / mu).

[0072] Implementation results;

[0073] Quality Upgrade: The content of minerals such as calcium and iron in rice has increased by 12%-15%, and the total phenol content and antioxidant capacity have increased by 20% compared with conventional planting. It meets the standards for characteristic functional agricultural products of saline-alkali land and has a market premium of up to 30%.

[0074] Soil optimization: After harvest, the soil pH stabilized at 7.6, the organic carbon content reached 8.5g / kg, an increase of 28%, the soil water and fertilizer retention capacity was improved by 40%, and the amount of subsequent fertilizer application was reduced by 15%.

[0075] Carbon sequestration benefits: The annual carbon sequestration of 1,000 mu of paddy fields reaches 16 tons. Combined with the premium of specialty agricultural products, the comprehensive income of 1,000 mu is 80,000 yuan higher than that of conventional planting.

[0076] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0077] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A green amendment for solid waste used to improve saline-alkali land and enhance its carbon sequestration function, characterized in that, It consists of the following components: 30-50 parts by weight of seafood waste, 20-40 parts by weight of carbonized agricultural solid waste, 10-20 parts by weight of biochar, 5-15 parts by weight of humic acid, and 1-5 parts by weight of compound microbial agent. The seafood waste consists of at least two of the following: oyster, scallop, and lobster shells, and is processed by 80-120 mesh screening. The compound microbial agent is composed of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and halophilic Bacillus in a colony count ratio of 1:1:

2.

2. The solid waste green amendment for improving saline-alkali land and enhancing carbon sequestration function according to claim 1, characterized in that: The humic acid is composed of fulvic acid, black humic acid, brown humic acid, humic elements, and mineral elements in a ratio of 25:45:15:10:

5.

3. A method for preparing a green amendment for solid waste used to improve saline-alkali land and enhance carbon sequestration function, characterized in that, Includes the following steps: Step 1: Raw material pretreatment: Seafood waste is crushed and screened to 80-120 mesh, and agricultural solid waste is dried until the moisture content is ≤15% and then carbonized to obtain carbonized material; Step 2: Mixing of basic materials: Weigh the pretreated seafood waste, agricultural solid waste carbonized material, biochar, and humic acid according to the weight percentage, put them into a mixer and stir for 15-30 minutes at a speed of 300-500 r / min to obtain the mixed base material; Step 3, Modification and Activation: Place the mixed base material in an activation furnace and keep it at 300-600℃ for 1-3 hours. At the same time, CO2 gas is introduced for activation, with a gas flow rate of 0.5-1.5L / min. Step 4, inoculation with microbial agent: Dilute the compound microbial agent with sterile water 5-10 times, then spray it evenly into the activated mixed substrate and stir for 20-40 minutes until it is evenly mixed. Step 5, Molding and Drying: The inoculated material is fed into a granulator to form 2-5mm granules, and then dried at 60-80℃ for 2-4 hours until the moisture content is ≤10%, thus obtaining a green improver for solid waste.

4. The method for preparing a green amendment for solid waste used to improve saline-alkali land and enhance carbon sequestration function according to claim 3, characterized in that, In step one, the heating rate of the agricultural solid waste carbonization treatment is 5-10℃ / min, and nitrogen gas is introduced during the carbonization process for inert protection, with a nitrogen flow rate of 1-2L / min.

5. The method for preparing a green amendment for solid waste used to improve saline-alkali land and enhance carbon sequestration function according to claim 3, characterized in that: In step three, the heating rate of the activation furnace is 10-15℃ / min. After activation, the furnace is allowed to cool naturally to room temperature before further processing.

6. The method for preparing a green amendment for solid waste used to improve saline-alkali land and enhance carbon sequestration function according to claim 3, characterized in that: In step four, the ambient temperature during inoculation with the microbial agent is controlled at 25-35℃, and the ambient humidity is maintained at 60%-70% during stirring.

7. A method for preparing a green amendment for solid waste used to improve saline-alkali land and enhance carbon sequestration function according to claim 3, characterized in that: In step five, the drying process is carried out in stages. First, the material is dried at 60°C for 1-2 hours, and then the temperature is raised to 80°C for 1-2 hours. After drying, the material is sieved to remove powdery materials with a particle size of less than 1 mm.