Liquid membrane powder for treating kitchen waste leachate as well as preparation method and application of liquid membrane powder

Abstract

The invention provides liquid membrane powder for treating kitchen waste leachate as well as a preparation method and application of the liquid membrane powder, and belongs to the technical field of kitchen waste liquid waste treatment and application. The liquid membrane powder is prepared from the following raw materials in parts by weight: 5-16 parts of phosphate diester modified starch, 4-13 parts of oxidized carboxymethyl composite modified starch and 7-10 parts of oxidized xanthate modified starch. The liquid membrane powder disclosed by the invention can be well used for treating kitchen waste leachate, can be simply mixed with the kitchen waste leachate under liquefaction to form a membrane substance, and can be well used as a liquid membrane fertilizer; the method has the advantages of simple treatment method, low cost, high efficiency, high economy and no environmental pollution.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of kitchen waste liquid waste treatment and utilization, and particularly relates to a liquid membrane powder for treating kitchen waste leachate and a preparation method and application thereof. BACKGROUND

[0002] Kitchen waste refers to organic waste that is prone to rot and is generated in daily life, catering services, food processing and other activities, mainly including food residues, waste food materials, expired food, and processing waste. It is characterized by high water content (70%-90%), rich in organic matter (starch, protein, fat, etc.), easy to spoil and cause environmental pollution if not properly treated.

[0003] Kitchen waste mainly includes solid and leachate after treatment, wherein the kitchen waste leachate is a mixed liquid produced during the stacking, landfill or transportation of kitchen waste due to extrusion, fermentation and rainwater erosion, containing high-concentration organic matter (COD can reach tens of thousands of mg / L), oil, salt and heavy metal pollutants. It is characterized by complex composition, strong pollution (easy to pollute soil and groundwater), and high treatment difficulty. The treatment method of kitchen waste leachate usually requires multi-stage treatment combining physical, chemical and biological technologies.

[0004] In recent years, the production of kitchen waste has been increasing, and it is generally characterized by high water content (60-80%). At present, the main mode of kitchen waste liquid treatment in China is "pretreatment + biochemical treatment + advanced treatment (membrane treatment)". Although the wastewater basically meets the discharge standard requirements, it is still difficult to overcome problems such as long treatment time, high investment, high operating cost, and low resource recovery rate (average resource utilization rate less than 30%).

[0005] Therefore, it is urgent to develop a simple, efficient and easy-to-treat method for recycling and utilizing kitchen waste leachate. SUMMARY

[0006] The purpose of the present application is to solve the above technical problems, and to provide a liquid membrane powder for treating kitchen waste leachate and a preparation method and application thereof. The liquid membrane powder of the present application can be used to treat kitchen waste leachate, and has the advantages of simple treatment method, low treatment cost, high treatment efficiency, high economic efficiency, and is suitable for large-scale popularization and use.

[0007] In order to achieve the above technical purpose, the technical scheme adopted by the present application is as follows: The application provides a liquid membrane powder for treating kitchen waste leachate.

[0008] As a preferred scheme, the raw material formula of the liquid membrane powder comprises 12 parts of phosphoric acid double ester compound modified starch, 8 parts of oxidized carboxymethyl compound modified starch and 9 parts of oxidized xanthate compound modified starch.

[0009] Further, the phosphoric acid double ester compound modified starch is prepared by reacting sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium tripolyphosphate, sodium trimetaphosphate, sodium hexametaphosphate and urea with starch.

[0010] Further, the oxidized carboxymethyl compound modified starch is prepared by reacting chloroacetic acid, sodium chloroacetate, sodium hydroxide, sodium carbonate, sodium hypochlorite or hydrogen peroxide with starch.

[0011] Further, the oxidized xanthate compound modified starch is prepared by reacting carbon disulfide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, hydrogen peroxide, sodium hypochlorite or sodium nitrite with starch.

[0012] The second object of the application is to provide a preparation method of the liquid membrane powder for treating kitchen waste leachate.

[0013] The third object of the application is to provide application of the liquid membrane powder in treating kitchen waste leachate.

[0014] Further, the application method is that the liquid membrane powder is mixed with kitchen waste leachate and water, and then is heated to be liquefied to prepare paste, and then the prepared paste is cooled to form a liquid membrane, which is used as a liquid membrane fertilizer.

[0015] Further, the liquefaction method comprises the following steps: the liquid membrane powder is mixed with kitchen waste leachate and water, and then is stirred and dispersed to be a uniform suspension, and then is heated to 70-98 DEG C and is kept for 0-30 minutes, and then the heated suspension paste is rapidly cooled to below 50 DEG C to prepare paste.

[0016] Further, the weight ratio of the liquid membrane powder, the kitchen waste leachate and the water is 1:1:1-1:20:10.

[0017] The application has the following beneficial effects: The liquid membrane powder provided by the present application is a powder raw material, which has a wide source of raw materials, low cost, renewable resources, convenient transportation and storage; The liquid membrane powder can be well used for treating kitchen waste leachate, and can form a membrane with the kitchen waste leachate through simple liquid mixing, and can be well used as a liquid membrane fertilizer, which can keep moisture, temperature, soil, seedlings, wind resistance, slow-release nutrients and adsorption of heavy metal ions. The method for treating kitchen waste leachate by using the liquid membrane powder is simple, low in cost, high in efficiency and economic, non-toxic and harmless, and does not cause environmental pollution. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is described in detail below with examples. It should be pointed out that the following examples are only used to explain and illustrate the present application, and do not limit the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above description still fall within the scope of the present application.

[0019] The starch mentioned in the following examples is corn starch or cassava starch. The kitchen waste leachate mentioned in the present application is the kitchen waste leachate after industrial pretreatment, which is the kitchen waste leachate after industrial pretreatment, and after removal of a large amount of oil, organic acid and other substances, and sterilization and deodorization treatment, it will not cause safety hidden dangers and secondary pollution.

[0020] Example 1

[0021] (I) The present example provides a liquid membrane powder for treating kitchen waste leachate, which is composed of 5 parts of phosphoric acid double fat complex modified starch, 4 parts of oxidized carboxymethyl complex modified starch and 7 parts of oxidized xanthate complex modified starch by weight.

[0022] (II) The preparation method of the above-mentioned liquid membrane powder is as follows: (1) take starch, and use 20 parts of sodium dihydrogen phosphate, 20 parts of disodium hydrogen phosphate, 5 parts of sodium trimetaphosphate, 5 parts of urea and 100 parts of corn starch to react at pH 6 and temperature 72℃ to obtain phosphoric acid double fat complex modified starch; (2) take starch, and use 5 parts of chloroacetic acid, 17 parts of sodium hydroxide, 0.5 parts of hydrogen peroxide and 67 parts of corn starch to react for 2 hours to obtain oxidized carboxymethyl complex modified starch; (3) take starch, and use 15 parts of carbon disulfide, 25 parts of sodium hydroxide, 10 parts of hydrogen peroxide and 20 parts of corn starch to react at 65℃ for 2 hours to obtain oxidized xanthate complex modified starch; (4) mix 5 parts of phosphoric acid double fat complex modified starch, 4 parts of oxidized carboxymethyl complex modified starch and 7 parts of oxidized xanthate complex modified starch, and the liquid membrane powder is obtained.

[0023] (Three) the above liquid membrane powder and kitchen waste leachate and water are mixed according to the weight ratio of 1:5:2, heated to 85 degrees, and kept for 15 minutes, cooled to form a film, and a liquid membrane fertilizer is obtained.

[0024] Example 2

[0025] (One) the embodiment provides a liquid membrane powder for treating kitchen waste leachate, which is composed of phospholipid complex modified starch 12 parts, oxidized carboxymethyl complex modified starch 8 parts and oxidized xanthate complex modified starch 9 parts by weight.

[0026] (Two) the preparation method of the above liquid membrane powder is as follows: (1) take the starch, use 15 parts of sodium dihydrogen phosphate, 15 parts of disodium hydrogen phosphate, 4 parts of sodium tripolyphosphate, 4 parts of urea and 95 parts of corn starch to react at pH 7 and temperature 70 DEG C to obtain phospholipid complex modified starch; (2) take the starch, use 4 parts of sodium chloroacetate, 15 parts of sodium hydroxide, 0.6 parts of hydrogen peroxide and 65 parts of corn starch to react for 2 hours to obtain oxidized carboxymethyl complex modified starch; (3) take the starch, use 14 parts of carbon disulfide, 23 parts of potassium hydroxide, 8 parts of hydrogen peroxide and 18 parts of corn starch to react at 67 DEG C for 2 hours to obtain oxidized xanthate complex modified starch; (4) mix 12 parts of phospholipid complex modified starch, 8 parts of oxidized carboxymethyl complex modified starch and 9 parts of oxidized xanthate complex modified starch, and the liquid membrane powder is obtained.

[0027] (Three) the above liquid membrane powder and kitchen waste leachate and water are mixed according to the weight ratio of 1:4:7, heated to 95 degrees, and kept for 2 minutes, cooled to form a film, and a liquid membrane fertilizer is obtained.

[0028] Example 3

[0029] (One) the embodiment provides a liquid membrane powder for treating kitchen waste leachate, which is composed of phospholipid complex modified starch 12 parts, oxidized carboxymethyl complex modified starch 8 parts and oxidized xanthate complex modified starch 9 parts by weight.

[0030] (II) The preparation method of the above liquid film powder is as follows: (1) Take starch and react 22 parts of sodium dihydrogen phosphate, 22 parts of disodium hydrogen phosphate, 8 parts of sodium hexametaphosphate, 6 parts of urea and 110 parts of cassava starch to obtain phosphate diester composite modified starch; (2) Take starch and react 4 parts of chloroacetic acid, 4 parts of sodium chloroacetate, 20 parts of sodium carbonate, 1 part of hydrogen peroxide and 72 parts of cassava starch for 2 hours to obtain oxidized carboxymethyl composite modified starch; (3) Take starch and react 20 parts of carbon disulfide, 28 parts of magnesium hydroxide, 12 parts of hydrogen peroxide and 30 parts of cassava starch at 70°C for 2 hours to obtain oxidized xanthate composite modified starch; (4) Mix 16 parts of phosphate diester composite modified starch, 13 parts of oxidized carboxymethyl composite modified starch and 10 parts of oxidized xanthate composite modified starch to obtain the liquid film powder.

[0031] (iii) Mix the above liquid membrane powder with kitchen waste leachate and water in a weight ratio of 1:20:10, heat to 80 degrees and keep warm for 20 minutes, then cool until a film can be formed to obtain liquid membrane fertilizer.

[0032] Example 4

[0033] (I) This embodiment provides a liquid membrane powder for treating leachate from kitchen waste. Its raw material formula, by weight, consists of 10 parts of phosphate diester composite modified starch, 6 parts of oxidized carboxymethyl composite modified starch, and 8 parts of oxidized xanthate composite modified starch.

[0034] (II) The preparation method of the above liquid film powder is as follows: (1) Take starch and react 24 parts of sodium dihydrogen phosphate, 24 parts of disodium hydrogen phosphate, 6 parts of sodium tripolyphosphate, 8 parts of urea and 105 parts of corn starch at pH 6.5 and temperature 75℃ to obtain phosphate diester composite modified starch; (2) Take starch and react 8 parts of chloroacetic acid, 2 parts of sodium chloroacetate, 15 parts of sodium hydroxide, 1.2 parts of hydrogen peroxide and 74 parts of corn starch for 2 hours to obtain oxidized carboxymethyl composite modified starch; (3) Take starch and react 18 parts of carbon disulfide, 20 parts of sodium hydroxide, 10 parts of potassium hydroxide, 12 parts of sodium hypochlorite and 24 parts of corn starch at 64℃ for 2 hours to obtain oxidized xanthate composite modified starch; (4) Mix 10 parts of phosphate diester composite modified starch, 6 parts of oxidized carboxymethyl composite modified starch and 8 parts of oxidized xanthate composite modified starch to obtain the liquid film powder.

[0035] (iii) Mix the above liquid membrane powder with kitchen waste leachate and water in a weight ratio of 1:5:8, heat to 75 degrees and keep warm for 30 minutes, then cool until a film can be formed to obtain liquid membrane fertilizer.

[0036] Comparative Example 1 Referring to the method of Example 1, the difference is that the modified starch with phosphate diester was replaced with oxidized modified starch in the raw material formulation. As a result, it was found that the viscosity of the resulting paste was unstable, resulting in poor film-forming properties.

[0037] Comparative Example 2 Referring to the method of Example 2, the difference is that the oxidized carboxymethyl composite modified starch was replaced with acid modified starch in the raw material formula. As a result, it was found that the paste of the product was unstable and had poor film-forming properties.

[0038] Comparative Example 3 Referring to the method of Example 3, the difference is that oxidized xanthate complex modified starch is not added to the raw material formula, and it was found that the film-forming properties of the resulting product are extremely poor.

[0039] Comparative Example 4 Referring to the method of Example 4, the difference is that no modified starch phosphate diester was added to the raw material formula, and the result showed that the film-forming properties of the obtained product were extremely poor.

[0040] Comparative Example 5 The method was followed as in Example 1, except that no modified starch with phosphate diester was added to the raw material formulation. The results showed that the liquid film slurry had poor film-forming properties, affecting its use.

[0041] Comparative Example 6 Referring to the method in Example 2, the difference lies in that the formulation of the liquid film powder was modified to consist of 1 part of phosphate diester-modified starch and 15 parts of oxidized modified starch. The results showed that this formulation resulted in poor liquid film strength and water absorption / retention, affecting its performance.

[0042] Comparative Example 7 Referring to the method in Example 3, the difference lies in that the formulation of the liquid film powder is modified to consist of 20 parts of acid-modified starch and 7 parts of oxidized carboxymethyl composite modified starch. The results showed that this formulation resulted in an unstable viscosity and poor adhesion of the liquid film slurry, affecting its performance.

[0043] Comparative Example 8 Referring to the method of Example 4, the difference lies in that the formulation of the liquid film powder was modified to consist of 10 parts of modified starch containing oxidized xanthate and 5 parts of modified starch containing oxidized carboxymethyl ester. The results showed that this formulation resulted in poor film-forming properties of the liquid film slurry, affecting its performance.

[0044] Experimental Example 1 The liquid membrane powders obtained in the examples and comparative examples were used to treat leachate from kitchen waste according to the corresponding methods described in the descriptions to prepare liquid membrane fertilizers, which were then used to investigate their effects on crop growth. The specific methods are as follows: (1) Select a vegetable planting field with longitude 120°E and latitude 33°N, and plant Dajin seedlings K1 in the field; (2) In September 2023, the field was divided into several plots of land measuring 0.5m × 0.5m, with each plot spaced 0.2m apart; 20 Dajinmiao K1 seeds were evenly sown in each plot, and then 10 of the plots were sprayed with 0.5kg / m 2 The liquid film fertilizers obtained in Examples 1-4 and Comparative Examples 1-6 were sprayed evenly with different amounts of the same amount. Seeds were planted in another field and sprayed with water as a control.

[0045] (3) After the growth period of the Dajin seedlings K1 in each field in step (2) is over, the mature millet grains along with their roots are taken out of the field, the soil attached to the roots is removed, and the plant height and the number of millet grains produced by each plant are measured and averaged. The total weight of all the millet grains produced in each field is also weighed to evaluate the effect of liquid film fertilizer on millet growth and yield. The results are shown in Table 1 below. As can be seen from Table 1, the liquid film fertilizer of the present invention has significant fertilizer effect and a good yield-increasing effect.

[0046] Table 1

Claims

1. A liquid membrane powder for treating leachate from kitchen waste, characterized in that, The raw material formulation of the liquid film powder, by weight, consists of 5-16 parts of phosphate diester composite modified starch, 4-13 parts of oxidized carboxymethyl composite modified starch, and 7-10 parts of oxidized xanthate composite modified starch.

2. The liquid membrane powder for treating leachate from kitchen waste according to claim 1, characterized in that, The raw material formula of the liquid film powder, by weight, consists of 12 parts of phosphate diester composite modified starch, 8 parts of oxidized carboxymethyl composite modified starch, and 9 parts of oxidized xanthate composite modified starch.

3. The liquid membrane powder for treating leachate from kitchen waste according to claim 1 or 2, characterized in that, The modified starch with phosphate diester is prepared by reacting sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium tripolyphosphate or sodium trimetaphosphate with urea and starch.

4. The liquid membrane powder for treating leachate from kitchen waste according to claim 1 or 2, characterized in that, The oxidized carboxymethyl composite modified starch is prepared by reacting starch with monochloroacetic acid, sodium hydroxide, sodium hypochlorite or hydrogen peroxide.

5. The liquid membrane powder for treating leachate from kitchen waste according to claim 1 or 2, characterized in that, The oxidized xanthate complex modified starch is prepared by reacting starch with carbon disulfide, sodium hydroxide or potassium hydroxide or magnesium hydroxide, hydrogen peroxide, sodium hypochlorite or sodium nitrite.

6. The method for preparing the liquid membrane powder for treating leachate from kitchen waste as described in any one of claims 1-5, characterized in that, The modified starch is obtained by mixing the phosphate diester composite modified starch, oxidized carboxymethyl composite modified starch, and oxidized xanthate composite modified starch in the corresponding weight ratio.

7. The application of the liquid membrane powder according to any one of claims 1-5 or the liquid membrane powder prepared by the method of claim 6 in the treatment of leachate from kitchen waste.

8. The application according to claim 7, characterized in that, The liquid membrane powder is mixed with pretreated kitchen waste leachate and water, heated and liquefied to prepare a paste, and then the resulting paste is cooled to form a liquid membrane, which is then used as a liquid membrane fertilizer.

9. The application according to claim 8, characterized in that, The liquefaction method includes the following steps: mixing the liquid membrane powder with pretreated kitchen waste leachate and water, then stirring and dispersing it into a uniform suspension, heating it to 70~98℃, keeping it at that temperature for 0~30 minutes, and then rapidly cooling the heated suspension to below 50℃ to prepare a paste.

10. The application according to claim 8 or 9, characterized in that, The weight ratio of the liquid membrane powder, the pretreated kitchen waste leachate, and water is 1:1:1 to 1:10:10.

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