Catalyst composition for ozone treatment of livestock / domestic sewage and application thereof

Abstract

The invention discloses a catalyst composition for ozone treatment of livestock / domestic sewage and application of the catalyst composition. The catalyst composition comprises the following components in percentage by mass: 5-50% of organic acid, 1-10% of at least one of aldehydes, alcohols, esters or ketones and the balance of deionized water. According to the sewage treatment method, the composition is mixed with living / livestock sewage / livestock sewage according to the proportion of 1: 500-5000, then the action mechanism of solubilization and catalytic oxidation reaction is achieved through the ozone aeration technology or the ozone nanometer microbubble technology, ammonia nitrogen, hydrogen sulfide and organic matter in the sewage are rapidly and effectively removed, and COD is reduced. And the purposes of reducing cost and improving efficiency are achieved for sewage treatment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of water treatment, and particularly relates to a catalyst composition for livestock / living sewage ozone treatment and application thereof. BACKGROUND

[0002] The oxidation process of ozone in water is a process in which mass transfer and chemical reaction are carried out simultaneously, and therefore, the reaction and mass transfer inevitably influence and restrict each other. The mass transfer efficiency of ozone is related to the turbulence degree of liquid in the reactor, the decomposition kinetics of ozone in water, and the number and size of generated bubbles. Under the same gas-liquid flow rate conditions, the smaller the diameter of the bubble is, the greater the phase interface area per unit volume of liquid phase has, that is, the greater the contact area of ozone and water is, and the greater the utilization rate of ozone is. Therefore, the use of nano micro-bubbles can not only improve the mass transfer speed of ozone in water, thereby improving the utilization rate of ozone, but also strengthen the oxidation capacity of ozone.

[0003] The physical and chemical characteristics of ozone nano micro-bubbles mainly show the following aspects: 1) high specific surface area and dissolution efficiency: nano-bubbles (diameter <1 μm) have extremely high specific surface area, which greatly increases the contact opportunity of ozone and pollutants. At the same time, the nano micro-bubbles have a long residence time in water, which can prolong the action time of ozone; 2) interface charge effect: the surface of nano-bubbles is usually negatively charged, which can enrich positively charged pollutants (such as some organic molecules or heavy metals) through electrostatic adsorption, and improve the local reaction concentration; 3) cavitation effect: when the nano-bubbles break, energy is released, which generates a local high-temperature and high-pressure environment, promotes the decomposition of ozone to generate highly active hydroxyl radicals (·OH), and the oxidation capacity (oxidation potential 2.8 V) of the hydroxyl radicals is far higher than that of ozone itself (2.07 V).

[0004] In the field of livestock wastewater and biological wastewater treatment, there are the following main problems in technology and economy: 1) High concentrations of organic matter, nitrogen and sulfur: Livestock wastewater (such as livestock and poultry breeding wastewater) contains a large amount of feces, urine and feed residues, resulting in high concentrations of chemical oxygen demand (COD), ammonia nitrogen (NH3-N) and hydrogen sulfide (H2S), far exceeding domestic wastewater. Traditional processes are difficult to degrade efficiently, requiring multiple stages of treatment (such as anaerobic + aerobic + advanced treatment), but the combined process is complex and has poor operational stability; 2) Poor resistance to impact load: Water quantity and quality fluctuate greatly (such as seasonal flushing wastewater), making the treatment system susceptible to impact, and anaerobic reactors may collapse due to temperature and pH fluctuations, with significant increases in energy consumption for aerobic treatment; 3) Difficulties in biogas slurry treatment and utilization: Biogas slurry produced by anaerobic treatment contains high concentrations of nitrogen, phosphorus and salt, and direct discharge will pollute water bodies, but deep treatment (such as membrane separation, advanced oxidation) is costly, and ecological treatment (constructed wetlands, oxidation ponds) is limited by land and climate; 4) Insufficient technical applicability: Small farms are limited by funds and technology, and often use simple treatment methods (such as natural sedimentation, oxidation ponds), but the efficiency is low and secondary pollution is easy to occur; large-scale farms can use combined processes, but management is complex and there is a lack of professional operators; 5) High construction and operation costs: High initial investment, anaerobic reactors, aerobic aeration systems and advanced treatment equipment (such as membrane components) require high capital investment, making it difficult for large and medium-sized farms to bear; high operating costs, electricity (aerobic treatment), chemicals (chemical phosphorus removal) and sludge disposal costs (dewatering, transportation) continue to consume, and deep treatment technologies (such as reverse osmosis) further exacerbate cost pressures; limited resource utilization benefits, biogas power generation is limited by low conversion efficiency, difficulty in grid connection and other factors, and economic returns are insufficient; the transportation cost of biogas slurry as liquid fertilizer is high, and the market acceptance is low, making it difficult to generate stable income.

[0005] Chinese patent discloses a system for preparing instant deodorizing agent and organic fertilizer rapid additive from biomass such as sand willow (CN113289567A). The system is prepared from biomass materials through high-temperature reaction, mainly relies on biochar to adsorb odors in the air, and cannot adsorb ammonia and hydrogen sulfide gas in sewage. The patent does not involve specific chemical composition and mechanism. A biological deodorizing absorbent and its preparation method (CN105561737A) provides a biological deodorizing absorbent and its preparation method. The composition of the biological deodorizing absorbent is as follows: water 81-90%, organic acid 3.2-10%, phenolic 0.1-0.23%, ketone 4-8%, aldehyde 0.2-0.7%, alcohol 0.1-0.15%, and ester 0.1-0.3%. Its use is air deodorizing agent. The main principle is to use organic acid to adsorb ammonia in the air to form ammonium acetate. Other phenolic, ketone, aldehyde, alcohol and ester increase the solubility of hydrogen sulfide and sulfur dioxide to achieve the effect of adsorption. Although this method can achieve the purpose of removing odors in the air, the reaction products and adsorption products will settle on the ground, causing secondary pollution. Therefore, this invention cannot remove ammonia and sulfur dioxide in sewage.

[0006] In order to solve the problems of low efficiency, backward technology, high operation cost and other aspects in sewage treatment, the application develops a catalytic composition suitable for ozone oxidation of organic matter, which not only improves the solubility and transmission effect of ozone in sewage, but also speeds up the oxidation process, achieves effective and low operation cost effect. At the same time, the composition of the application is combined with ozone nanometer microbubble technology, through the synergy of physical enrichment, chemical catalysis and free radical chain reaction, the oxidation efficiency is significantly improved. This technology provides an innovative solution for green water treatment, agricultural environmental protection and industrial wastewater treatment. SUMMARY

[0007] In view of the problems in the prior art, the application provides a catalyst composition for livestock / living sewage ozone treatment and its application. The catalyst composition of the application not only can increase the solubility of ozone in sewage, but also can catalyze the catalytic oxidation effect of ozone and ammonia nitrogen, hydrogen sulfide, organic matter and other substances; and has the advantages of low price, simple and environment-friendly production process, etc., and can be applied to living / livestock sewage treatment in multiple scenes.

[0008] The application provides the following technical solutions: A catalyst composition for livestock / living sewage ozone treatment, the catalyst composition comprises 5-50% organic acid, and 1-10% of at least one of aldehyde, alcohol, ester or ketone, and the rest is deionized water.

[0009] Further, the organic acid is preferably one or both of acetic acid or propionic acid; the aldehyde is preferably furfural; the alcohol is preferably 2-methyl-1-penten-3-ol; the ester is preferably gamma-butyrolactone; and the ketone is preferably 3-methyl-2-hydroxy-2-cyclopenten-1-one.

[0010] The application also provides the use of the above-mentioned catalyst composition in livestock / living sewage ozone treatment.

[0011] Further, the use comprises adding the catalyst composition to sewage, combining ozone purification technology, and effectively purifying the sewage; and the mass ratio of the catalyst composition to the sewage is 1:500-5000.

[0012] Further, the ozone purification technology comprises ozone aeration technology or ozone nanometer micro-bubble technology.

[0013] Further, the oxygen supply amount of the ozone aeration is 1-3 L / min, and the aeration time is 1-10 h.

[0014] The application is a catalyst composition for livestock / living sewage ozone treatment, which comprises organic acid, and at least one of aldehyde, alcohol, ester or ketone, and the rest is deionized water. The effect is to increase the concentration of O2 or O3 gas in the sewage, utilize the oxidation reaction to completely remove ammonia and hydrogen sulfide in the sewage, rather than adsorbing or transferring pollutants, and the catalyst composition can reduce the reaction activation energy and accelerate the reaction. The chemical principle and mechanism of the application are as follows: 1. Reaction of hydrogen sulfide (H2S) and ozone (O3) Main reaction (generation of elemental sulfur): H2S + O3→ S + H2O + O2 Side reaction: 3H2S + 4O3→ 3H2SO4 2. Reaction of ammonium ion (NH4 + ) The reaction product, sulfuric acid, adsorbs ammonia to form ammonium sulfate, and continues to react with ozone as follows: (NH4)2SO4 + 8O3→ 2HNO3 + H2SO4 + H2O + 7O2 The application has the following beneficial effects: The catalyst composition of the application not only improves the solubility and transfer effect of ozone in sewage, but also accelerates the oxidation process, achieves effective and low operation cost. At the same time, the catalyst composition of the application is combined with ozone nanometer micro-bubble technology, through the synergy of physical enrichment, chemical catalysis and free radical chain reaction, the oxidation efficiency is significantly improved. This technology provides an innovative solution for green water treatment, agricultural environmental protection and industrial wastewater treatment. DETAILED DESCRIPTION

[0015] In order to make the technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0016] Example 1

[0017] 50g of propionic acid, 10g of furfural, 10g of 2-methyl-1-penten-3-ol, 10g of γ-butyrolactone, 10g of 3-methyl-2-hydroxy-2-cyclopenten-1-one, and 860g of ion-free water were mixed and stirred uniformly to obtain a catalyst composition. 10g of the composition was added to 25kg of domestic sewage / livestock sewage, and an ozone generating device (oxygen flow controlled at 1.5L / min) was aerated for 2h / 6h.

[0018] Example 2

[0019] 50g of propionic acid, 10g of furfural, 10g of 2-methyl-1-penten-3-ol, 10g of γ-butyrolactone, 10g of 3-methyl-2-hydroxy-2-cyclopenten-1-one, and 860g of ion-free water were mixed and stirred uniformly to obtain a catalyst composition. 10g of the composition was added to 25kg of domestic sewage / livestock sewage, and an ozone generating device (oxygen flow controlled at 1.5L / min) was aerated for 2h / 6h.

[0020] Example 3

[0021] 50g of propionic acid, 50g of acetic acid, 10g of furfural, 10g of 2-methyl-1-penten-3-ol, 10g of γ-butyrolactone, 10g of 3-methyl-2-hydroxy-2-cyclopenten-1-one, and 860g of ion-free water were mixed and stirred uniformly to obtain a catalyst composition. 10g of the composition was added to 25kg of domestic sewage / livestock sewage, and an ozone generating device (oxygen flow controlled at 1.5L / min) was aerated for 2h / 6h.

[0022] Example 4

[0023] 100g of propionic acid, 100g of acetic acid, 10g of furfural, 10g of 2-methyl-1-penten-3-ol, 10g of 3-methyl-2-hydroxy-2-cyclopenten-1-one, and 770g of ion-free water were mixed and stirred uniformly to obtain a catalyst composition. 20g of the composition was added to 25kg of domestic sewage / livestock sewage, and an ozone generating device (oxygen flow controlled at 1.5L / min) was aerated for 2h / 6h.

[0024] Example 5

[0025] Mix 150 g of propionic acid, 150 g of acetic acid, 10 g of furfural, 10 g of 2-methyl-1-pentene-3-ol, and 680 g of ion-free water to obtain a catalyst composition, take 25 g of the composition, and add it to 25 kg of domestic sewage / livestock sewage, and aerate it using an ozone generating device (oxygen flow controlled at 1.5 L / min) for 2 h / 6 h.

[0026] Example 6

[0027] Mix 150 g of propionic acid, 150 g of acetic acid, 10 g of 2-methyl-1-pentene-3-ol, and 680 g of ion-free water to obtain a catalyst composition, take 25 g of the composition, and add it to 25 kg of domestic sewage / livestock sewage, and aerate it using an ozone generating device (oxygen flow controlled at 1.5 L / min) for 2 h / 6 h.

[0028] Example 7

[0029] Mix 150 g of propionic acid, 150 g of acetic acid, 10 g of 2-methyl-1-pentene-3-ol, and 680 g of ion-free water to obtain a catalyst composition, take 25 g of the composition, and add it to 25 kg of domestic sewage / livestock sewage, and aerate it using an ozone generating device (oxygen flow controlled at 1.5 L / min) for 2 h / 6 h.

[0030] Example 8

[0031] Mix 150 g of propionic acid, 150 g of acetic acid, 10 g of 2-methyl-1-pentene-3-ol, and 680 g of ion-free water to obtain a catalyst composition, take 25 g of the composition, and add it to 25 kg of domestic sewage / livestock sewage, and aerate it using an ozone generating device (oxygen flow controlled at 1.5 L / min) for 2 h / 6 h.

[0032] The treatment effects of the domestic / livestock sewage of the above examples 1-8 were detected, including the determination of COD, ammonia nitrogen, and hydrogen sulfide values, and the specific determination methods were as follows: The determination of chemical oxygen demand (COD) was carried out according to the potassium dichromate method (HJ 828-2017); The determination of ammonia nitrogen (NH3-N) was carried out according to the salicylic acid spectrophotometric method (HJ 536-2009); The determination of hydrogen sulfide (H2S) was carried out according to the acidification-blowing absorption method (HJ1226-2021).

[0033] The detection results are shown in Tables 1 and 2, wherein the control group is not added with the catalyst composition.

[0034] Table 1 Comparison of the effects of Examples 1-8 on the purification of domestic sewage (mg / L)

[0035] Note: Different letters indicate significant differences between different treatments (Duncan's multiple comparison test, n = 3, P≤0.05); removal effect (%) = (average of initial sewage value - average of final sewage value after treatment) / average of initial sewage value * 100 Table 2 Comparison of the effects of Examples 1-8 on the purification of livestock wastewater (mg / L)

[0036] Note: Different letters indicate significant differences between different treatments (Duncan's multiple comparison test, n = 3, P≤0.05); removal effect (%) = (average of initial sewage value - average of final sewage value after treatment) / average of initial sewage value * 100 From Table 1, the control group CK is the group without adding catalyst composition when using ozone aeration technology alone, and the ozone solubility increases slightly, and the 2h removal rates of COD and ammonia nitrogen are 20% and 48% respectively, which has a small pollution removal effect. Examples 1-8 are the use of ozone aeration technology alone or combined with nano microbubble technology when adding 1 / 500-5000 catalyst composition in the treatment of domestic sewage, the O3 solubility and transfer efficiency reach 1.1-3.5 mg / L, which is significantly higher than 0.6 mg / L of CK by 83-483%; with the increase of composition concentration, the solubility increases significantly. The 2h removal rates of COD and ammonia nitrogen of Examples 1-8 are 60-91% and 63-88% respectively, showing a trend of better pollution removal effect with increasing concentration.

[0037] From the results of Table 2, compared with CK, the ozone solubility was significantly increased by a small margin when the ozone aeration technology was used alone without the composition, and the 2h removal rates of COD, NH3-N and H2S were 12%, 40% and 25%, respectively, which had a relatively small pollution removal effect. In Examples 1-8, the O3 solubility and transfer efficiency reached 0.7-2.4 mg / L when the composition was added at a concentration of 1 / 500-5000 while the ozone aeration technology was used alone or in combination with the nano microbubble technology, which was significantly higher than 0.5 mg / L of CK by 40-380%; the solubility was significantly increased as the concentration of the composition increased. The 2h removal rates of COD, NH3-N and H2S in Examples 1-8 were 59-99%, 62-97% and 37-96%, respectively, which were significantly increased compared with the removal rates of COD, NH3-N and H2S of 12%, 40% and 25%, respectively, when the ozone nano microbubble technology was used alone, and the pollution removal effect of the three pollutants COD, NH3-N and H2S was increased by 3.9-8.2 times, 1.5-2.4 times and 1.5-3.8 times, respectively, and the pollution removal effect was significantly better as the concentration of the composition increased.

[0038] The above-described examples are only a preferred scheme of the present application, and do not limit the present application in any form, and other variants and modifications are possible without exceeding the technical scheme recited in the claims.

Claims

1. A catalyst composition for livestock / living sewage ozone treatment, characterized by, The catalyst composition comprises 5-50% organic acid, 1-10% at least one of aldehyde, alcohol, ester or ketone, and the rest is deionized water by mass percentage; the organic acid is one or both of acetic acid or propionic acid; the aldehyde is furfural; the alcohol is 2-methyl-1-pentene-3-ol; the ester is γ-butyrolactone; and the ketone is 3-methyl-2-hydroxy-2-cyclopenten-1-one.

2. Use of the catalyst composition of claim 1 in livestock / living sewage ozone treatment.

3. Use according to claim 2, characterized in that, The catalyst composition comprises: The catalyst composition is added to sewage, and combined with an ozone purification method to effectively purify the sewage; the mass ratio of the catalyst composition to the sewage is 1:500-5000.

4. Use according to claim 3, characterized in that, The ozone purification method comprises an ozone aeration method or an ozone nanometer micro-bubble method.

5. Use according to claim 3, characterized in that, The oxygen flow rate of the ozone aeration is 1-3 L / min, and the aeration time is 1-10 h.

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