Acid-base neutralizer reproduced from wax gourd waste and preparation method thereof

Abstract

The invention discloses an acid-base neutralizer reproduced from wax gourd waste, which is prepared from the following raw materials in percentage by mass: 10% of potassium polyacrylate polymer, 10% of hydrolytic polymaleic anhydride, 15% of sesbania gum, 40% of humic acid, 25% of CMC (Carboxymethyl Cellulose) gum and the balance of acidified melon water serving as a solvent, the acidified melon water is obtained by acidifying wax gourd waste and diluting the acidified wax gourd waste by 100-300 times. The invention relates to the technical field of environmental engineering and resource recycling, in particular to an acid-base neutralizer reproduced from wax gourd waste and a preparation method thereof, and due to the adoption of the technical scheme, the acid-base neutralizer has the following advantages that the limitation of a traditional acid-base neutralizer, the application bottleneck of a natural base material and the pain point of waste recycling are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental engineering and resource recycling, and in particular to an acid-base neutralizer produced by recycling wax gourd waste and a preparation method thereof. Background Art

[0002] Limitations of traditional acid-base neutralizers: Although chemical neutralizers (such as lime and sodium hydroxide) can quickly adjust the pH value, they have problems such as high resource consumption, high sludge production, and easy accumulation of calcium and magnesium ions or sodium ion pollution. Long-term use can lead to soil compaction or excessive water hardness. The synthesis process of single polymer neutralizers (such as polyacrylic acid) relies on petrochemical raw materials, which is costly and has poor biodegradability, and is prone to long-term environmental residues.

[0003] Application bottlenecks of natural-based materials: Although natural polymers such as chitosan and starch are environmentally friendly, their neutralization efficiency is low and their performance significantly decreases under extreme pH or high temperature conditions, which limits their industrial application.

[0004] Pain points of waste resource utilization: my country's annual winter melon production exceeds 15 million tons, and waste such as melon peel and pulp generated during the processing accounts for 30%-40%. The current main treatment methods are landfill or incineration, which not only causes waste of resources (including natural organic acids, polysaccharides and other usable ingredients), but also leads to environmental pollution (COD emission intensity reaches more than 5000mg / L). Summary of the Invention

[0005] In view of this, the embodiments of the present invention hope to provide an acid-base neutralizer produced by using wax gourd waste and a preparation method thereof, so as to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial option.

[0006] The purpose of the present invention can be achieved by the following technical measures: an acid-base neutralizer produced by recycling wax gourd waste, the acid-base neutralizer is composed of the following raw materials in percentage by mass:

[0007] Potassium polyacrylate polymer 10%, hydrolyzed polymaleic anhydride 10%, Tianqing gum 15%, humic acid 40%, CMC glue 25%

[0008] The solvent is acidified melon water, which is obtained by diluting winter melon waste by 100-300 times after acidification.

[0009] The purpose of the present invention can also be achieved by the following technical measures:

[0010] The wax gourd waste is the peel and pulp produced by wax gourd processing;

[0011] The acidification treatment comprises the following steps: chopping the wax gourd waste, adding 1-3% citric acid or acetic acid, adjusting the pH to 3-5, stirring at room temperature for 24 hours, and then filtering.

[0012] The purpose of the present invention can also be achieved by the following technical measures:

[0013] The neutralizer is a granular solid with a particle size of 100-300 μm, a water content of less than 5%, a viscosity of ≥1000 mPa·s within a pH range of 4-10, and a biodegradation rate of ≥90% within 6 months.

[0014] The purpose of the present invention can also be achieved by the following technical measures: an acid-base neutralizer produced by recycling wax gourd waste, the preparation method of the acid-base neutralizer comprising:

[0015] (1) Preparation of acidified melon water: chop the wax gourd waste, add 1-3% citric acid or acetic acid, add water at a mass volume ratio of 1:5-1:10, adjust the pH to 3-5, stir at room temperature for 24 hours, and filter to obtain the acidified melon water;

[0016] (2) Mixing and stirring: adding potassium polyacrylate polymer, hydrolyzed polymaleic anhydride, tianqing gum, humic acid, and CMC gum to the acidified melon water in proportion, stirring at 100-300 r / min for 30-60 minutes to form a uniform mixed solution;

[0017] (3) Spray film forming: The mixed liquid is sprayed through a spray dryer with an inlet air temperature of 120-150°C and an outlet air temperature of 60-80°C to obtain a granular neutralizer;

[0018] The purpose of the present invention can also be achieved by the following technical measures:

[0019] In the step (1), ultrasonic wave-assisted acidification treatment is adopted, with ultrasonic wave power of 200-400W, frequency of 40-60kHz, and treatment time of 1-2 hours to improve the acidification efficiency.

[0020] The purpose of the present invention can also be achieved by the following technical measures:

[0021] In the step (2), a planetary mixer is used to first add tianqing gum and CMC gum and stir for 30 minutes, and then sequentially add potassium polyacrylate polymer, hydrolyzed polymaleic anhydride and humic acid and continue stirring for 30 minutes.

[0022] The purpose of the present invention can also be achieved by the following technical measures:

[0023] When used for soil improvement, the dosage of the neutralizer is 200-500 kg / hectare, and the neutralizer is fully contacted with the treated object by stirring or tilling.

[0024] The purpose of the present invention can also be achieved by the following technical measures:

[0025] The soil improvement includes acidic red soil (pH 4-5) or saline-alkali land (pH 8-9). After the neutralizer is applied, the tillage depth is 15-30 cm, and the soil pH can be adjusted to 6.0-8.0 within 30-60 days.

[0026] The purpose of the present invention can also be achieved by the following technical measures:

[0027] The humic acid and potassium polyacrylate polymer are cross-linked by hydrolyzing polymaleic anhydride to form a three-dimensional network structure. 2+ , Pb 2+ The adsorption capacity of heavy metal ions is ≥8.87mg / g and 12.5mg / g respectively

[0028] The purpose of the present invention can also be achieved by the following technical measures:

[0029] The potassium polyacrylate polymer and hydrolyzed polymaleic anhydride form a three-dimensional network structure through free radical crosslinking reaction. The network pore size is 50-200nm and the neutralization capacity is ≥3.2mmol / g, which is more than 50% higher than that of traditional lime neutralizers.

[0030] The embodiment of the present invention adopts the above technical solution, which has the following advantages:

[0031] 1. Aiming at the limitations of traditional acid-base neutralizers: using winter melon waste to acidify winter melon water instead of chemical solvents, a low-cost production path of "waste → functional ingredient → neutralizer" is constructed. This not only avoids the resource consumption and ion pollution problems of lime / sodium hydroxide (sludge production is reduced by 50%, and there is no risk of calcium, magnesium and sodium enrichment), but also achieves a 90% biodegradation rate of the neutralizer through the compounding of natural gums (tianqing gum, CMC gum) and humic acid (accounting for 65%), solving the problem of single polymer materials relying on petrochemical raw materials and difficult-to-degrade environmental residues.

[0032] 2. Addressing the application bottleneck of natural-based materials: By cross-linking potassium polyacrylate and hydrolyzed polymaleic anhydride to form a three-dimensional network structure (neutralization capacity 3.2mmol / g, 100% higher than that of natural materials), and compounding Tianqing gum and CMC glue to enhance stability, the neutralizer of the present invention has a viscosity retention rate of over 95% under extreme pH (4-10) and high temperature (80°C) conditions, and its neutralization efficiency is more than 3 times higher than that of natural materials such as chitosan and starch, breaking through its performance limitations in industrial applications.

[0033] 3. Targeting the pain points of waste resource utilization: 30%-40% of the waste (peel and pulp) generated by winter melon processing is converted into an acidified melon water solvent containing natural organic acids and polysaccharides. Each ton of neutralizer can consume 2.5 tons of waste, which not only avoids COD pollution caused by landfill / incineration (reducing the discharge of high-concentration organic wastewater by 5000mg / L), but also realizes high-value utilization of waste through the "acidification extraction → functional compounding → film spraying molding" process, and builds a circular economy chain of agricultural processing and environmentally friendly materials.

[0034] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 The present invention is a flow chart of a specific embodiment of the method for preparing an acid-base neutralizer by reproducing wax gourd waste. DETAILED DESCRIPTION

[0037] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0038] It should be noted that the terms "first," "second," "symmetrical," "array," etc. are used only to distinguish descriptions from positional descriptions and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, limitations on features such as "first" and "symmetrical" may explicitly or implicitly include one or more of these features; similarly, when the number of certain features is not limited in the form of words such as "two" or "three," it should be noted that these features also explicitly or implicitly include one or more of the number of features.

[0039] In the present invention, unless otherwise expressly specified or limited, terms such as "installation," "connection," and "fixation" should be understood broadly; for example, they may refer to fixed connection, detachable connection, or integral molding; they may refer to mechanical connection, direct connection, welding, or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on the specification and drawings in conjunction with specific circumstances.

[0040] The embodiments of the present invention are described in detail below.

[0041] The present invention discloses an acid-base neutralizer produced by recycling wax gourd waste. The acid-base neutralizer is composed of the following raw materials in percentage by mass: 10% potassium polyacrylate polymer, 10% hydrolyzed polymaleic anhydride, 15% tianqing gum, 40% humic acid, and 25% CMC glue. The solvent is acidified melon water, which is obtained by diluting wax gourd waste 100-300 times after acidification. The wax gourd waste is the peel and pulp produced by wax gourd processing.

[0042] The acidification treatment comprises the following steps: chopping the wax gourd waste, adding 1-3% citric acid or acetic acid, adjusting the pH to 3-5, stirring at room temperature for 24 hours, and filtering. The neutralizing agent is a granular solid with a particle size of 100-300 μm, a moisture content of less than 5%, a viscosity of ≥1000 mPa·s within the pH range of 4-10, and a biodegradation rate of ≥90% within 6 months.

[0043] like Figure 1 As shown, Figure 1 The present invention provides an acid-base neutralizer produced by recycling wax gourd waste. The preparation method of the acid-base neutralizer comprises:

[0044] (1) Preparation of acidified melon water: chop the wax gourd waste, add 1-3% citric acid or acetic acid, add water at a mass volume ratio of 1:5-1:10, adjust the pH to 3-5, stir at room temperature for 24 hours, and filter to obtain the acidified melon water;

[0045] (2) Mixing and stirring: adding potassium polyacrylate polymer, hydrolyzed polymaleic anhydride, tianqing gum, humic acid, and CMC gum to the acidified melon water in proportion, stirring at 100-300 r / min for 30-60 minutes to form a uniform mixed solution;

[0046] (3) Spray film forming: The mixed liquid is sprayed through a spray dryer with an inlet air temperature of 120-150°C and an outlet air temperature of 60-80°C to obtain a granular neutralizer;

[0047] In step (1), ultrasonic-assisted acidification treatment is adopted, with an ultrasonic power of 200-400W, a frequency of 40-60kHz, and a treatment time of 1-2 hours to improve the acidification efficiency. In step (2), a planetary mixer is adopted to first add tianqing gum and CMC glue and stir for 30 minutes, and then potassium polyacrylate polymer, hydrolyzed polymaleic anhydride, and humic acid are added in sequence and stirred for another 30 minutes.

[0048] An acid-base neutralizer produced by recycling wax gourd waste, and an application method of the acid-base neutralizer comprising:

[0049] When used for soil improvement, the dosage of the neutralizer is 200-500kg / hectare. The neutralizer is fully contacted with the treated object by stirring or plowing. The soil improvement includes acidic red soil (pH 4-5) or saline-alkali land (pH 8-9). The plowing depth after the neutralizer is applied is 15-30cm. The soil pH can be adjusted to 6.0-8.0 within 30-60 days. Humic acid and potassium polyacrylate polymer are cross-linked by hydrolysis of polymaleic anhydride to form a three-dimensional network structure, which has a great effect on Cu 2+ , Pb 2+ The adsorption capacity of heavy metal ions is ≥8.87 mg / g and 12.5 mg / g respectively. Potassium polyacrylate polymer and hydrolyzed polymaleic anhydride form a three-dimensional network structure through free radical cross-linking reaction. The network pore size is 50-200 nm, and the neutralization capacity is ≥3.2 mmol / g, which is more than 50% higher than that of traditional lime neutralizers.

[0050] The following are several specific embodiments of the present invention:

[0051] Example 1: Preparation and application of neutralizer for saline-alkali land improvement

[0052] Raw material preparation (for preparing 15 kg of neutralizing agent): 15 kg of wax gourd waste, 0.3 kg of acetic acid (accounting for 2% of the waste mass); 1.5 kg of potassium polyacrylate polymer, 1.5 kg of hydrolyzed polymaleic anhydride, 2.25 kg of tianqing gum, 6 kg of humic acid, 3.75 kg of CMC glue; 150 L of deionized water (for dilution of acidified wax gourd water).

[0053] Preparation process: 1. Preparation of acidified melon water: After chopping wax gourd waste, add 0.3 kg acetic acid and 75 L water (mass-to-volume ratio 1:5), adjust the pH to 4.0, and ultrasonically treat (power 300 W, frequency 40 kHz) for 1.5 hours. Filter to obtain 85 L of acidified melon water (total sugar content 2.5%, organic acid content 2.1%);

[0054] 2. Mixing and stirring: Use a planetary mixer to first mix Tianqing gum, CMC glue and 40L of acidified melon water, and stir at low speed for 30 minutes; add the remaining raw materials and the remaining acidified melon water, and stir at medium speed for 70 minutes to form a mixed solution with a viscosity of 1200mPa·s.

[0055] 3. Spray film forming: The spray dryer has an inlet air temperature of 135°C and an outlet air temperature of 72°C. The obtained particles have a particle size of 150-200 μm, a moisture content of 4.0%, and a particle density of 1.2 g / cm 3 Facilitates deep soil penetration.

[0056] Application test: Improved object: pH8.8, conductivity (EC) 4.0mS / cm saline-alkali land (Na + Content 150mmol / kg, severe soil compaction);

[0057] Application method: Broadcast application at a rate of 500 kg / ha, combined with 300 kg / ha of gypsum (adjust Na + -Ca 2+ exchange), tillage depth 30cm, irrigation quota 200m 3 / hectare to promote salt leaching.

[0058] Monitoring indicators and results: Soil physical and chemical properties: After 60 days, pH dropped to 7.5, EC dropped to 1.8mS / cm, Na + The content dropped to 80mmol / kg, and the soil bulk density increased from 1.5g / cm 3 Down to 1.3g / cm 3 , porosity increased by 12%;

[0059] Microbial activity: Soil urease activity increased by 40% (from 0.35 mg / g·24h to 0.49 mg / g·24h), and the total bacterial count increased by 25%, promoting organic matter decomposition and nutrient recycling;

[0060] Crop growth performance: Planting the salt-tolerant wheat variety "Dekang 961" increased the germination rate from 35% to 75%, the chlorophyll content of flag leaves during the filling period increased by 20%, the protein content of grains increased by 5%, and the yield reduction rate dropped from 40% to 10%.

[0061] Example 2: Preparation and application of neutralizing agent for acidic electroplating wastewater treatment

[0062] Raw material preparation (for preparing 10 kg of neutralizing agent): 10 kg of wax gourd waste (rind and pulp), 0.2 kg of citric acid (2% of the waste mass); 1 kg of potassium polyacrylate polymer, 1 kg of hydrolyzed polymaleic anhydride, 1.5 kg of tianqing gum, 4 kg of humic acid, 2.5 kg of CMC glue; 100 L of deionized water (for dilution of acidified wax gourd water).

[0063] Preparation process: 1. Preparation of acidified melon water: chop wax gourd waste into particles <5 mm, add 0.2 kg citric acid and 50 L water (mass-to-volume ratio 1:5), adjust the pH to 4.0, stir at room temperature for 24 hours, and filter through a 100-mesh filter to obtain 55 L of acidified melon water (total sugar content 2.1%, organic acid content 1.8%);

[0064] 2. Mixing and stirring: Add Tianqing gum and CMC gum to 20L of acidified melon water and stir at 200r / min for 30 minutes until they are completely swollen; add potassium polyacrylate polymer, hydrolyzed polymaleic anhydride, and humic acid in sequence, and add the remaining 35L of acidified melon water, and continue stirring for 45 minutes to form a uniform brown colloidal liquid;

[0065] 3. Spray film forming: The spray dryer has an inlet air temperature of 130°C, an outlet air temperature of 70°C, and a feed rate of 4 mL / min. The obtained particles have a particle size of 150-250 μm and a moisture content of 4.2%.

[0066] Application test: Processing object: containing Cr 6+ (50mg / L) acidic wastewater (pH2.0, COD1200mg / L); dosage: 0.8g / L (i.e. 0.8kg neutralizer for 1 ton of wastewater); treatment effect: pH rises to 7.0 after stirring for 10 minutes, Cr 6+ It is reduced and adsorbed, and the total chromium concentration is reduced to 0.3 mg / L (GB21900-2008 emission standard ≤ 1.5 mg / L);

[0067] The COD removal rate is 88%, and the sludge production is 0.32 kg / ton of water (65% less than the lime method).

[0068] Example 3: Preparation and application of neutralizer for acidic red soil improvement

[0069] Raw material preparation (preparation of 20 kg neutralizer): 20 kg of wax gourd waste, 0.3 kg of acetic acid (accounting for 1.5% of the waste mass); 2 kg of potassium polyacrylate polymer, 2 kg of hydrolyzed polymaleic anhydride, 3 kg of tianqing gum, 8 kg of humic acid, 5 kg of CMC glue; 200 L of deionized water (for dilution of acidified wax gourd water).

[0070] Preparation process: 1. Preparation of acidified melon water: After chopping wax gourd waste, add 0.3 kg of acetic acid and 100 L of water (mass-to-volume ratio 1:5), adjust the pH to 3.5, and ultrasonically treat (power 200 W, frequency 40 kHz) for 1 hour. Filter to obtain 110 L of acidified melon water (total sugar content 2.3%, organic acid content 2.0%);

[0071] 2. Mixing and stirring: Use a planetary mixer to first mix Tianqing gum, CMC gum and 50L of acidified melon water, and stir at low speed for 30 minutes; add the remaining raw materials and the remaining acidified melon water, and stir at medium speed for 60 minutes to form a uniform mixture.

[0072] 3. Spray film forming: The spray dryer has an inlet air temperature of 140°C and an outlet air temperature of 75°C, and produces particles with a particle size of 200-300 μm and a moisture content of 3.8%.

[0073] Application test: Improvement object: acidic red soil with a pH of 4.5 (CEC 10 cmol / kg, organic matter content 1.2%); application method: broadcast application at a rate of 300 kg / hectare, plowing depth of 20 cm, combined with 1500 kg / hectare of decomposed organic fertilizer; monitoring results: after 30 days, the soil pH rose to 6.8, and the CEC increased to 13 cmol / kg (an increase of 30%); the planting emergence rate increased from 50% to 85%, the yield per plant at maturity increased by 25%, and the heavy metal (Pb, Cd) contents of the fruits were all lower than the GB2762-2022 standards.

[0074] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various modifications and substitutions within the technical scope disclosed in the present invention, and such modifications and substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An acid-base neutralizer produced by recycling wax gourd waste, characterized in that: The acid-base neutralizer is composed of the following raw materials in percentage by mass: Potassium polyacrylate polymer 10% Hydrolyzed polymaleic anhydride 10% Tianqing gum 15% Humic acid 40% CMC glue 25% The solvent is acidified melon water, which is obtained by diluting winter melon waste by 100-300 times after acidification.

2. The acid-base neutralizer produced by recycling wax gourd waste according to claim 1, characterized in that: The wax gourd waste is the peel and pulp produced by wax gourd processing; The acidification treatment comprises the following steps: chopping the wax gourd waste, adding 1-3% citric acid or acetic acid, adjusting the pH to 3-5, stirring at room temperature for 24 hours, and then filtering.

3. The acid-base neutralizer produced by recycling wax gourd waste according to claim 1, characterized in that: The neutralizer is a granular solid with a particle size of 100-300 μm, a water content of less than 5%, a viscosity of ≥1000 mPa·s within a pH range of 4-10, and a biodegradation rate of ≥90% within 6 months.

4. A method for preparing an acid-base neutralizer according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Preparation of acidified melon water: chop the wax gourd waste, add 1-3% citric acid or acetic acid, add water at a mass volume ratio of 1:5-1:10, adjust the pH to 3-5, stir at room temperature for 24 hours, and filter to obtain the acidified melon water; (2) Mixing and stirring: adding potassium polyacrylate polymer, hydrolyzed polymaleic anhydride, tianqing gum, humic acid, and CMC gum to the acidified melon water in proportion, stirring at 100-300 r / min for 30-60 minutes to form a uniform mixed solution; (3) Spray film forming: The mixed liquid is sprayed through a spray dryer with an inlet air temperature of 120-150°C and an outlet air temperature of 60-80°C to obtain a granular neutralizer.

5. The method for preparing the acid-base neutralizer according to claim 4, wherein In the step (1), ultrasonic wave-assisted acidification treatment is adopted, with ultrasonic wave power of 200-400W, frequency of 40-60kHz, and treatment time of 1-2 hours to improve the acidification efficiency.

6. The method for preparing the acid-base neutralizer according to claim 4, wherein In the step (2), a planetary mixer is used to first add tianqing gum and CMC gum and stir for 30 minutes, and then sequentially add potassium polyacrylate polymer, hydrolyzed polymaleic anhydride and humic acid and continue stirring for 30 minutes.

7. A method for using the acid-base neutralizer according to any one of claims 1 to 3, characterized in that: When used for soil improvement, the dosage of the neutralizer is 200-500 kg / hectare, and the neutralizer is fully contacted with the treated object by stirring or tilling.

8. The method for using the acid-base neutralizer according to claim 7, wherein: The soil improvement includes acidic red soil (pH 4-5) or saline-alkali land (pH 8-9). After the neutralizer is applied, the tillage depth is 15-30 cm, and the soil pH can be adjusted to 6.0-8.0 within 30-60 days.

9. The acid-base neutralizer produced by recycling wax gourd waste according to claim 1, characterized in that: The humic acid and potassium polyacrylate polymer are cross-linked by hydrolyzing polymaleic anhydride to form a three-dimensional network structure, which has a great influence on the growth of Cu2+, Pb 2 The adsorption capacity of heavy metal ions such as β-catenin and β-catenin is ≥8.87 mg / g and 12.5 mg / g respectively.

10. The acid-base neutralizer produced by recycling wax gourd waste according to claim 1, characterized in that: The potassium polyacrylate polymer and hydrolyzed polymaleic anhydride form a three-dimensional network structure through free radical crosslinking reaction. The network pore size is 50-200nm and the neutralization capacity is ≥3.2mmol / g, which is more than 50% higher than that of traditional lime neutralizers.

Images