Kitchen waste deodorization treatment agent and deodorization process

Abstract

The application discloses a kind of kitchen waste deodorization with treating agent and deodorization process, belong to garbage disposal technical field.The kitchen waste deodorization with treating agent includes ZIF-8@TiO2 / Fe2O3 and coated sodium persulfate material, with titanium dioxide, iron oxide and sodium persulfate as active component, ZIF-8 and diatomite in coated sodium persulfate material as adsorption material, by adsorption enrichment kitchen waste treatment odor in odor material, active component cooperation under the action of photocatalysis produces free radical, realize the photocatalytic oxidation degradation of odor material.The kitchen waste deodorization with treating agent is combined with tea polyphenol loaded biochar to design deodorization process, by the coupling of photocatalytic oxidation and chemical adsorption, efficiently degrade and remove NH3, H2S and VOCs, with dual protection of degradation and adsorption, realize multistage processing, suitable for the complex component processing of kitchen waste odor.

Description

Technical Field

[0001] This invention belongs to the field of waste treatment technology, specifically relating to a deodorizing agent and deodorization process for kitchen waste. Background Technology

[0002] Food waste mainly includes restaurant waste and kitchen waste. Restaurant waste refers to leftover food from restaurants and eateries, as well as waste from the processing of fruits, vegetables, meat, oil, and pastries in the kitchen. Kitchen waste refers to easily perishable organic waste such as fruits, vegetables, leftover food, and fruit peels discarded in daily household life. If food waste is not disposed of in a timely manner, it will produce foul-smelling gases, which will have a significant impact on people's health and the environment.

[0003] In recent years, with the rapid development of the catering industry in major cities across my country, the catering industry has become an important part of my country's economy and society. At the same time, the amount of food waste generated has also increased year by year. Due to the high organic content of food waste, a large amount of malodorous gases are generated during the treatment process, causing secondary pollution to the environment. Malodorous gases are one of the environmental hazards.

[0004] The odor-causing substances produced during food waste treatment are mainly composed of carbon, nitrogen, and sulfur. Only a few of these odor-causing substances are inorganic compounds, such as ammonia (NH3) and hydrogen sulfide (H2S); most are organic compounds, such as low-molecular-weight fatty acids, amines, aldehydes, ketones, ethers, halogenated hydrocarbons, and aliphatic, aromatic, and heterocyclic nitrogen or sulfide compounds. It is worth noting that these substances all contain reactive groups and are prone to chemical reactions, especially oxidation.

[0005] Traditional treatment methods, such as anaerobic fermentation and aerobic composting, can degrade organic matter and reduce odor, but their processing cycles are long (approximately 15 days) and they are difficult to completely control odor emissions. Commonly used deodorization methods include biological deodorization, UV photocatalytic deodorization, and activated carbon adsorption. To improve deodorization efficiency, deodorization processes often combine multiple methods, such as acid washing, alkaline washing, photocatalytic oxidation, and biofilters. These processes are complex, and currently, the photocatalytic oxidation agents used for deodorization are mostly porous materials loaded with titanium dioxide, which has low actual catalytic degradation efficiency and fails to meet the standards for odor removal. Therefore, more efficient, economical, and environmentally friendly deodorization treatment of kitchen waste is needed through agent innovation and process improvement. Summary of the Invention

[0006] This invention provides a treatment agent and deodorization process for kitchen waste, which can solve the problems of complex processes and poor deodorization effect in the existing kitchen waste deodorization process.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A deodorizing agent for kitchen waste, comprising the following raw materials by weight:

[0009] 60-80 parts ZIF-8@TiO2 / Fe2O3 and 20-40 parts coated sodium persulfate material;

[0010] The ZIF-8@TiO2 / Fe2O3 is a ZIF-8 nanoparticle carrier with TiO2 and Fe2O3 deposited on the surface.

[0011] The coated sodium persulfate material is obtained by coating sodium persulfate with diatomaceous earth and polycaprolactone.

[0012] The ZIF-8@TiO2 / Fe2O3 treatment agent in this study differs from traditional photocatalytic oxidation treatment agents. It uses ZIF-8 nanoparticles as a carrier, and ZIF-8 nanoparticles are a metal-organic framework material with an SOD-type topology, composed of Zn... 2+ The ions and 2-methylimidazolium ligands are linked by coordination bonds. It possesses a large specific surface area and high porosity, enabling efficient loading of titanium dioxide and Fe2O3. ZIF-8@TiO2 / Fe2O3 utilizes its porous structure to adsorb and enrich odor substances, then leverages the photocatalytic effect of titanium dioxide to degrade these substances. The Fe2O3 can activate sodium persulfate to generate reactive sulfur radicals (SO42-). - ·) and ·OH degrade recalcitrant organic compounds (such as halogenated hydrocarbons) through electron transfer.

[0013] The coated sodium persulfate material uses diatomaceous earth and polycaprolactone (PCL) as coating materials. The biodegradability and film-forming properties of PCL form a slow-release coating layer, which is mixed with diatomaceous earth. Diatomaceous earth is porous and lightweight, with high porosity and specific surface area, and is inexpensive. The rigid framework of diatomaceous earth and the hydrophobicity of PCL work together to protect sodium persulfate from the influence of humidity, reducing premature decomposition and forming a slow-release coating material. The sodium persulfate in it can be slowly released and works with Fe2O3 in ZIF-8@TiO2 / Fe2O3 to degrade volatile organic compounds.

[0014] Furthermore, the preparation steps of the ZIF-8@TiO2 / Fe2O3 are as follows:

[0015] Step 1: Select a surface area of ​​1500-1650 m² 2 / g of ZIF-8 nanoparticles were placed in a reaction vessel, anhydrous ethanol was added and mixed evenly, titanium trichloride solution was added, stirred and mixed, the pH was adjusted to 6-7 with ammonia water, and the reaction was carried out at 120-130℃ for 8-12h. After filtration and drying, ZIF-8@TiO2 was obtained.

[0016] Step 2: Dissolve ferric nitrate in water, add urea and polyvinylpyrrolidone, stir until completely dissolved to obtain a precursor solution, add ZIF-8@TiO2 to the precursor solution, sonicate for 1-2 h, stir at room temperature for 8-10 h, transfer to a reaction vessel and react at 120-130℃ for 6-8 h, Fe(OH)3 precursor is generated in situ on the ZIF-8 surface, centrifuge and wash, calcine at 240-260℃ for 2-3 h under an inert atmosphere, then calcine at 330-360℃ for 3-4 h to obtain ZIF-8@TiO2 / Fe2O3.

[0017] TiO2 was grown in situ on the surface of ZIF-8 nanoparticles using a hydrothermal method. The high porosity of the ZIF-8 nanoparticles provided abundant active and adsorption sites for the subsequent loading of TiO2 and Fe2O3. Stepwise calcination was performed in the final stage of loading to avoid the risk of structural collapse caused by direct high temperature, enhance the bonding between the supported material and the ZIF-8 nanoparticles, and broaden the light absorption range of Fe2O3, further improving catalytic efficiency.

[0018] Furthermore, the TiCl3 content of the titanium trichloride solution is 15wt%, and the mass ratio of ZIF-8 nanoparticles to titanium in the titanium trichloride solution is 10:1-3.

[0019] Furthermore, the Fe in the ferric nitrate 3+ The molar ratio of urea to urea is 1:3-3.5;

[0020] The ZIF-8@TiO2 and Fe in ferric nitrate 3+ The mass ratio is 5-7:1.

[0021] Further, the polyvinylpyrrolidone is added at 0.5-1% of the precursor solution mass. Polyvinylpyrrolidone is a high molecular weight surfactant that promotes dispersion and facilitates uniform loading of iron oxide onto ZIF-8@TiO2.

[0022] Furthermore, the preparation steps of the coated sodium persulfate material are as follows:

[0023] After weighing polycaprolactone and heating it until completely melted, add diatomaceous earth and stir evenly. Then add sodium persulfate powder and stir evenly. Pour the mixture into a mold while it is still hot, let it cool to room temperature and then demold to obtain the coated sodium persulfate material.

[0024] Furthermore, the mass ratio of polycaprolactone to diatomaceous earth is 5:1-2.

[0025] Furthermore, the mass of the sodium persulfate powder is 60-80% of the sum of the masses of polycaprolactone and diatomaceous earth.

[0026] The present invention also provides a deodorization process, which uses the deodorizing agent for kitchen waste as described above for deodorization. The steps of the deodorization process are as follows:

[0027] Step 1: Collect the odor generated during the food waste treatment process and filter the odor to remove particulate matter;

[0028] Step 2: The filtered odorous gas is sent by a blower into a photocatalytic reactor filled with a deodorizing agent for kitchen waste. The reaction is carried out under light irradiation with a light source of wavelength 450-550nm for 2-3 hours.

[0029] Step 3: The gas after the reaction enters the adsorption tower, which is filled with biochar loaded with tea polyphenols. The gas after adsorption meets the emission standards.

[0030] The odor generated from food waste treatment typically contains ammonia, hydrogen sulfide, and other volatile organic compounds (VOCs). Conventional processes remove ammonia and hydrogen sulfide through absorption with acids or alkalis, but this consumes a large amount of these substances. In the above deodorization process, the odor is directly introduced into a photocatalytic reactor, where the deodorizing agent of this invention performs simultaneous photocatalytic degradation and adsorption. On one hand, the porous structure of the material in the deodorizing agent adsorbs and enriches ammonia, hydrogen sulfide, and other VOCs. TiO2 photocatalytically degrades VOCs, and Fe2O3 activates the sodium persulfate material, releasing sodium persulfate to generate free radicals, further promoting degradation.

[0031] Under light, TiO2 / Fe2O3 generates electrons (e - )-hole (h + Yes, h + H2O or OH adsorbed on the oxidized surface - Generates hydroxyl radicals (·OH), e - Through Fe³ + / Fe² + Cyclic inhibition of recombination enhances oxidation efficiency. Light and electrons on the Fe2O3 surface activate sodium persulfate, generating the highly oxidizing SO4. - NH3 is attacked by ·OH in synergy with SO42-, and NH3 is attacked by ·OH / SO42-. - • Oxidized to NO3 - Alternatively, N2 and H2S are oxidized to SO4. 2- Alternatively, elemental sulfur (S) and volatile organic compounds (hydrocarbons, sulfur / nitrogen-containing organic compounds) are mineralized by free radicals into CO2, H2O, and inorganic salts, eliminating odors.

[0032] After the photocatalytic and adsorption treatment in step 2, the biochar loaded with tea polyphenols in step 3 uses the porous structure of biochar to adsorb residual small molecule gases (such as unoxidized NH3 and H2S). In addition, tea polyphenols have a bactericidal effect, which can inhibit the growth of toxic bacteria in the odor. The phenolic hydroxyl groups in tea polyphenols react with NH3 to form ammonium salts, which further deodorizes the odor.

[0033] Furthermore, the preparation steps of the biochar loaded with tea polyphenols are as follows:

[0034] Under a nitrogen atmosphere, shrimp shells are calcined and carbonized at 600-650℃ for 2-5 hours to obtain porous biochar. The porous biochar is then impregnated in a tea polyphenol ethanol solution, ultrasonically treated for 2-4 hours, and dried to obtain tea polyphenol-loaded biochar.

[0035] Furthermore, the specific surface area of ​​the porous biochar is 800-900 m². 2 / g.

[0036] Furthermore, the concentration of tea polyphenols in the tea polyphenol ethanol solution is 10-20 wt%.

[0037] Furthermore, the mass ratio of the porous biochar to tea polyphenols is 3-4:1.

[0038] The beneficial effects of this invention are:

[0039] (1) The deodorizing agent for kitchen waste provided by the present invention includes ZIF-8@TiO2 / Fe2O3 and coated sodium persulfate material, with titanium dioxide, iron oxide and sodium persulfate as active components, and diatomaceous earth in ZIF-8 and coated sodium persulfate material as adsorbent material. By adsorbing and enriching odor substances (ammonia, hydrogen sulfide and volatile organic compounds) in the odor of kitchen waste, the active components work together to generate free radicals under photocatalysis, thereby realizing the photocatalytic oxidation degradation of odor substances.

[0040] (2) The ZIF-8@TiO2 / Fe2O3 and coated sodium persulfate material in the deodorizing agent for kitchen waste provided by the present invention have a synergistic effect. Fe2O3 can broaden the light absorption range and synergistically improve the photocatalytic degradation effect with titanium dioxide. The electron-hole pairs and hydroxyl radicals generated by the photocatalysis of titanium dioxide react with the sulfur radicals (SO4) generated by the activation of sodium persulfate by Fe2O3. - ·) work together to efficiently photocatalytically oxidize and degrade odor substances in odorous gases.

[0041] (3) The deodorization process provided by the present invention achieves efficient degradation and removal of NH3, H2S and VOCs through the coupling of photocatalytic oxidation and chemical adsorption (synergistic effect of tea polyphenols). It has the dual guarantee of degradation and adsorption, realizes multi-stage treatment, and is suitable for the treatment of complex components of kitchen waste odor. Detailed Implementation

[0042] 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.

[0043] Example 1

[0044] This embodiment provides a deodorizing agent for kitchen waste, which, by weight, comprises the following raw materials:

[0045] 60 parts of ZIF-8@TiO2 / Fe2O3 and 40 parts of coated sodium persulfate material.

[0046] The preparation steps of ZIF-8@TiO2 / Fe2O3 are as follows:

[0047] Step 1: Select a surface area of ​​1500-1650 m² 2 / g ZIF-8 nanoparticles were placed in a reaction vessel, 1L of anhydrous ethanol was added and mixed evenly, and a titanium trichloride solution with a TiCl3 content of 15wt% was added. The mass ratio of titanium in the ZIF-8 nanoparticles and the titanium trichloride solution was controlled to be 10:1. The mixture was stirred and mixed, and the pH was adjusted to 6-7 with ammonia water. The reaction was carried out at 120℃ for 12h, and the mixture was filtered and dried to obtain ZIF-8@TiO2.

[0048] Step 2: Dissolve ferric nitrate in water at a concentration of 0.1 mol / L, add urea and polyvinylpyrrolidone, and the Fe in the ferric nitrate... 3+ The molar ratio of polyvinylpyrrolidone to urea is 1:3. After stirring and complete dissolution, a precursor solution is obtained. The mass of polyvinylpyrrolidone is 0.5% of the precursor solution mass. ZIF-8@TiO2 is added to the precursor solution. The Fe in ZIF-8@TiO2 and ferric nitrate... 3+ The mass ratio was 7:1. The mixture was ultrasonically treated for 2 hours, stirred at room temperature for 10 hours, transferred to a reaction vessel and reacted at 130℃ for 8 hours. The precipitate was collected by centrifugation, washed with deionized water and anhydrous ethanol, calcined at 260℃ for 2 hours under an inert atmosphere, and then calcined at 330℃ for 4 hours to obtain ZIF-8@TiO2 / Fe2O3.

[0049] The preparation steps of the coated sodium persulfate material are as follows:

[0050] Weigh out polycaprolactone and heat it to 70°C until it is completely melted. Add diatomaceous earth and stir evenly. The mass ratio of polycaprolactone to diatomaceous earth is 5:2. Then add sodium persulfate powder. The mass of sodium persulfate powder is 60% of the total mass of polycaprolactone and diatomaceous earth. Stir evenly and pour it into a mold while hot. After cooling and solidifying at room temperature, demold and remove the material to obtain the coated sodium persulfate material.

[0051] The above-mentioned deodorizing agent for kitchen waste is used to deodorize the odor generated during kitchen waste treatment. The specific process steps are as follows:

[0052] Step 1: Collect the odor generated during the food waste treatment process and filter the odor to remove particulate matter;

[0053] Step 2: The filtered odorous gas is blown into a photocatalytic reactor filled with a food waste deodorizing agent by a blower. The reactor is irradiated with light at a wavelength of 450-550nm for 3 hours. The dosage of the food waste deodorizing agent used to treat the odor is 3.20g / m³. 3 .

[0054] Step 3: The reacted gas enters the adsorption tower, which is filled with biochar loaded with tea polyphenols. The amount of biochar loaded with tea polyphenols used to treat the gas is 1.0 g / m³. 3 The adsorbed gas meets the emission standards, and the deodorization effect is shown in Table 1.

[0055] The preparation of the tea polyphenol-loaded biochar is as follows:

[0056] Shrimp shells were calcined and carbonized at 650℃ for 4 hours under a nitrogen atmosphere to obtain a specific surface area of ​​800-900 m². 2 / g porous biochar was impregnated in a tea polyphenol ethanol solution (tea polyphenol concentration of 10wt%), with a mass ratio of porous biochar to tea polyphenol of 4:1. After ultrasonic treatment for 2h, the biochar was dried to obtain tea polyphenol-loaded biochar.

[0057] Table 1

[0058]

[0059] Example 2

[0060] The only difference from Example 1 is that in the preparation of ZIF-8@TiO2 / Fe2O3, the ZIF-8@TiO2 and Fe in ferric nitrate are different. 3+ The mass ratio was adjusted from 7:1 to 6:1, and other steps and conditions were the same as in Example 1. The deodorization effect is shown in Table 2.

[0061] Table 2

[0062]

[0063] Example 3

[0064] The only difference from Example 1 is that in the preparation of ZIF-8@TiO2 / Fe2O3, the ZIF-8@TiO2 and Fe in ferric nitrate are different. 3+ The mass ratio was adjusted from 7:1 to 5:1, and other steps and conditions were the same as in Example 1. The deodorization effect is shown in Table 3.

[0065] Table 3

[0066]

[0067] Example 4

[0068] The only difference from Example 2 is that the mass ratio of ZIF-8 nanoparticles to titanium in the titanium trichloride solution in the preparation of ZIF-8@TiO2 / Fe2O3 was adjusted from 10:1 to 10:2. Other steps and conditions are the same as in Example 2. The deodorization effect is shown in Table 4.

[0069] Table 4

[0070]

[0071] Example 5

[0072] The only difference from Example 2 is that the mass ratio of ZIF-8 nanoparticles to titanium in the titanium trichloride solution in the preparation of ZIF-8@TiO2 / Fe2O3 was adjusted from 10:1 to 10:3. Other steps and conditions are the same as in Example 2. The deodorization effect is shown in Table 5.

[0073] Table 5

[0074]

[0075] Example 6

[0076] The only difference from Example 4 is that the mass of sodium persulfate powder in the preparation of the coated sodium persulfate material was adjusted from 60% to 70% of the sum of the masses of polycaprolactone and diatomaceous earth. The other steps and conditions were the same as in Example 4, and the deodorization effect is shown in Table 6.

[0077] Table 6

[0078]

[0079] Example 7

[0080] The only difference from Example 4 is that the mass of sodium persulfate powder in the preparation of the coated sodium persulfate material was adjusted from 60% to 80% of the sum of the masses of polycaprolactone and diatomaceous earth. The other steps and conditions were the same as in Example 4, and the deodorization effect is shown in Table 7.

[0081] Table 7

[0082]

[0083] Example 8

[0084] The only difference from Example 6 is that the proportion of ZIF-8@TiO2 / Fe2O3 in the deodorizing agent for kitchen waste is increased. Specifically, the ZIF-8@TiO2 / Fe2O3 is increased from 60 parts to 70 parts, and the coated sodium persulfate material is reduced from 40 parts to 30 parts. The other steps and conditions are the same as in Example 6, and the deodorization effect is shown in Table 8.

[0085] Table 8

[0086]

[0087] Example 9

[0088] The only difference from Example 6 is that the proportion of ZIF-8@TiO2 / Fe2O3 in the deodorizing agent for kitchen waste is increased. Specifically, the ZIF-8@TiO2 / Fe2O3 is increased from 60 parts to 80 parts, and the coated sodium persulfate material is reduced from 40 parts to 20 parts. The other steps and conditions are the same as in Example 6, and the deodorization effect is shown in Table 9.

[0089] Table 9

[0090]

[0091] Comparative Example 1

[0092] The only difference between this comparative example and Example 1 is that ZIF-8@TiO2 / Fe2O3 is replaced with ZIF-8@TiO2, and no iron oxide loading is added.

[0093] This comparative example provides a deodorizing agent for kitchen waste, which, by mass parts, includes the following raw materials:

[0094] 60 parts ZIF-8@TiO2 and 40 parts coated sodium persulfate material.

[0095] The preparation steps of ZIF-8@TiO2 are as follows:

[0096] Select a specific surface area of ​​1500-1650 m² 2 / g ZIF-8 nanoparticles were placed in a reaction vessel, 1L of anhydrous ethanol was added and mixed evenly, and a titanium trichloride solution with a TiCl3 content of 15wt% was added. The mass ratio of titanium in the ZIF-8 nanoparticles and the titanium trichloride solution was controlled to be 10:1. The mixture was stirred and mixed, and the pH was adjusted to 6-7 with ammonia water. The reaction was carried out at 120℃ for 12h, and the mixture was filtered and dried to obtain ZIF-8@TiO2.

[0097] The preparation steps of the coated sodium persulfate material are as follows:

[0098] Weigh out polycaprolactone and heat it to 70°C until it is completely melted. Add diatomaceous earth and stir evenly. The mass ratio of polycaprolactone to diatomaceous earth is 5:2. Then add sodium persulfate powder. The mass of sodium persulfate powder is 60% of the total mass of polycaprolactone and diatomaceous earth. Stir evenly and pour it into a mold while hot. After cooling and solidifying at room temperature, demold and remove the material to obtain the coated sodium persulfate material.

[0099] The above-mentioned deodorizing agent for kitchen waste is used to deodorize the odor generated during kitchen waste treatment. The specific process steps are as follows:

[0100] Step 1: Collect the odor generated during the food waste treatment process and filter the odor to remove particulate matter;

[0101] Step 2: The filtered odorous gas is blown into a photocatalytic reactor filled with a food waste deodorizing agent by a blower. The reactor is irradiated with light at a wavelength of 450-550nm for 3 hours. The dosage of the food waste deodorizing agent used to treat the odor is 3.20g / m³. 3 .

[0102] Step 3: The reacted gas enters the adsorption tower, which is filled with biochar loaded with tea polyphenols. The amount of biochar loaded with tea polyphenols used to treat the gas is 1.0 g / m³. 3 The adsorbed gas meets the emission standards, and the deodorization effect is shown in Table 10.

[0103] The preparation of the tea polyphenol-loaded biochar is as follows:

[0104] Shrimp shells were calcined and carbonized at 650℃ for 4 hours under a nitrogen atmosphere to obtain a specific surface area of ​​800-900 m². 2 / g porous biochar was impregnated in a tea polyphenol ethanol solution (tea polyphenol concentration of 10wt%), with a mass ratio of porous biochar to tea polyphenol of 4:1. After ultrasonic treatment for 2h, the biochar was dried to obtain tea polyphenol-loaded biochar.

[0105] Table 10

[0106]

[0107] Comparative Example 2

[0108] The only difference between this comparative example and Example 1 is that the deodorizing agent for kitchen waste contains only ZIF-8@TiO2 / Fe2O3.

[0109] This comparative example provides a deodorizing agent for kitchen waste, which is ZIF-8@TiO2 / Fe2O3.

[0110] The preparation steps of ZIF-8@TiO2 / Fe2O3 are as follows:

[0111] Step 1: Select a surface area of ​​1500-1650 m² 2 / g ZIF-8 nanoparticles were placed in a reaction vessel, 1L of anhydrous ethanol was added and mixed evenly, and a titanium trichloride solution with a TiCl3 content of 15wt% was added. The mass ratio of titanium in the ZIF-8 nanoparticles and the titanium trichloride solution was controlled to be 10:1. The mixture was stirred and mixed, and the pH was adjusted to 6-7 with ammonia water. The reaction was carried out at 120℃ for 12h, and the mixture was filtered and dried to obtain ZIF-8@TiO2.

[0112] Step 2: Dissolve ferric nitrate in water at a concentration of 0.1 mol / L, add urea and polyvinylpyrrolidone, and the Fe in the ferric nitrate... 3+ The molar ratio of polyvinylpyrrolidone to urea is 1:3. After stirring and complete dissolution, a precursor solution is obtained. The mass of polyvinylpyrrolidone is 0.5% of the precursor solution mass. ZIF-8@TiO2 is added to the precursor solution. The Fe in ZIF-8@TiO2 and ferric nitrate... 3+ The mass ratio was 7:1. The mixture was ultrasonically treated for 2 hours, stirred at room temperature for 10 hours, transferred to a reaction vessel and reacted at 130℃ for 8 hours. The precipitate was collected by centrifugation, washed with deionized water and anhydrous ethanol, calcined at 260℃ for 2 hours under an inert atmosphere, and then calcined at 330℃ for 4 hours to obtain ZIF-8@TiO2 / Fe2O3.

[0113] The above-mentioned deodorizing agent for kitchen waste is used to deodorize the odor generated during kitchen waste treatment. The specific process steps are as follows:

[0114] Step 1: Collect the odor generated during the food waste treatment process and filter the odor to remove particulate matter;

[0115] Step 2: The filtered odorous gas is blown into a photocatalytic reactor filled with a food waste deodorizing agent by a blower. The reactor is irradiated with light at a wavelength of 450-550nm for 3 hours. The dosage of the food waste deodorizing agent used to treat the odor is 3.20g / m³. 3 .

[0116] Step 3: The reacted gas enters the adsorption tower, which is filled with biochar loaded with tea polyphenols. The amount of biochar loaded with tea polyphenols used to treat the gas is 1.0 g / m³. 3 The adsorbed gas meets the emission standards, and the deodorization effect is shown in Table 11.

[0117] The preparation of the tea polyphenol-loaded biochar is as follows:

[0118] Shrimp shells were calcined and carbonized at 650℃ for 4 hours under a nitrogen atmosphere to obtain a specific surface area of ​​800-900 m². 2 / g porous biochar was impregnated in a tea polyphenol ethanol solution (tea polyphenol concentration of 10wt%), with a mass ratio of porous biochar to tea polyphenol of 4:1. After ultrasonic treatment for 2h, the biochar was dried to obtain tea polyphenol-loaded biochar.

[0119] The deodorization effect is shown in Table 11.

[0120] Table 11

[0121]

[0122] Comparative Example 3

[0123] The only difference between this comparative example and Example 1 is that biochar was used instead of biochar loaded with tea polyphenols.

[0124] This comparative example provides a deodorizing agent for kitchen waste, which, by mass parts, includes the following raw materials:

[0125] 60 parts of ZIF-8@TiO2 / Fe2O3 and 40 parts of coated sodium persulfate material.

[0126] The preparation steps of ZIF-8@TiO2 / Fe2O3 are as follows:

[0127] Step 1: Select a surface area of ​​1500-1650 m² 2 / g ZIF-8 nanoparticles were placed in a reaction vessel, 1L of anhydrous ethanol was added and mixed evenly, and a titanium trichloride solution with a TiCl3 content of 15wt% was added. The mass ratio of titanium in the ZIF-8 nanoparticles and the titanium trichloride solution was controlled to be 10:1. The mixture was stirred and mixed, and the pH was adjusted to 6-7 with ammonia water. The reaction was carried out at 120℃ for 12h, and the mixture was filtered and dried to obtain ZIF-8@TiO2.

[0128] Step 2: Dissolve ferric nitrate in water at a concentration of 0.1 mol / L, add urea and polyvinylpyrrolidone, and the Fe in the ferric nitrate... 3+ The molar ratio of polyvinylpyrrolidone to urea is 1:3. After stirring and complete dissolution, a precursor solution is obtained. The mass of polyvinylpyrrolidone is 0.5% of the precursor solution mass. ZIF-8@TiO2 is added to the precursor solution. The Fe in ZIF-8@TiO2 and ferric nitrate... 3+ The mass ratio was 7:1. The mixture was ultrasonically treated for 2 hours, stirred at room temperature for 10 hours, transferred to a reaction vessel and reacted at 130℃ for 8 hours. The precipitate was collected by centrifugation, washed with deionized water and anhydrous ethanol, calcined at 260℃ for 2 hours under an inert atmosphere, and then calcined at 330℃ for 4 hours to obtain ZIF-8@TiO2 / Fe2O3.

[0129] The preparation steps of the coated sodium persulfate material are as follows:

[0130] Weigh out polycaprolactone and heat it to 70°C until it is completely melted. Add diatomaceous earth and stir evenly. The mass ratio of polycaprolactone to diatomaceous earth is 5:2. Then add sodium persulfate powder. The mass of sodium persulfate powder is 60% of the total mass of polycaprolactone and diatomaceous earth. Stir evenly and pour it into a mold while hot. After cooling and solidifying at room temperature, demold and remove the material to obtain the coated sodium persulfate material.

[0131] The above-mentioned deodorizing agent for kitchen waste is used to deodorize the odor generated during kitchen waste treatment. The specific process steps are as follows:

[0132] Step 1: Collect the odor generated during the food waste treatment process and filter the odor to remove particulate matter;

[0133] Step 2: The filtered odorous gas is blown into a photocatalytic reactor filled with a food waste deodorizing agent by a blower. The reactor is irradiated with light at a wavelength of 450-550nm for 3 hours. The dosage of the food waste deodorizing agent used to treat the odor is 3.20g / m³. 3 .

[0134] Step 3: The reacted gas enters the adsorption tower, which is filled with biochar. The biochar dosage for treating the gas is 1.0 g / m³. 3 The adsorbed gas meets the emission standards, and the deodorization effect is shown in Table 1.

[0135] The preparation of biochar is as follows:

[0136] Shrimp shells were calcined and carbonized at 650℃ for 4 hours under a nitrogen atmosphere to obtain a specific surface area of ​​800-900 m². 2 / g porous biochar.

[0137] The deodorization effect is shown in Table 12.

[0138] Table 12

[0139]

[0140] As can be seen from the deodorization effect, the deodorizing agent for kitchen waste provided by this invention, combined with the deodorization process, treats the odor in kitchen waste treatment. It can utilize the combined effects of adsorption and photocatalytic oxidation degradation to achieve multi-stage treatment of complex components, efficiently remove odor substances, and achieve gas emission standards through a simple process.

[0141] 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 process, method, article, or apparatus.

[0142] 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 deodorizing agent for kitchen waste, characterized in that, By weight, it includes the following raw materials: 60-80 parts ZIF-8@TiO2 / Fe2O3 and 20-40 parts coated sodium persulfate material; The ZIF-8@TiO2 / Fe2O3 is a ZIF-8 nanoparticle carrier with TiO2 and Fe2O3 deposited on the surface. The coated sodium persulfate material is obtained by coating sodium persulfate with diatomaceous earth and polycaprolactone as coating materials; The preparation steps of ZIF-8@TiO2 / Fe2O3 are as follows: Step 1: Select a surface area of ​​1500-1650 m² 2 / g of ZIF-8 nanoparticles were placed in a reaction vessel, anhydrous ethanol was added and mixed evenly, titanium trichloride solution was added, stirred and mixed, the pH was adjusted to 6-7 with ammonia water, and the reaction was carried out at 120-130℃ for 8-12h. After filtration and drying, ZIF-8@TiO2 was obtained. Step 2: Dissolve ferric nitrate in water, add urea and polyvinylpyrrolidone, stir until completely dissolved to obtain a precursor solution, add ZIF-8@TiO2 to the precursor solution, sonicate for 1-2 h, stir at room temperature for 8-10 h, transfer to a reaction vessel and react at 120-130℃ for 6-8 h, Fe(OH)3 precursor is generated in situ on the surface of ZIF-8, centrifuge and wash, calcine at 240-260℃ for 2-3 h under an inert atmosphere, raise the temperature to 330-360℃ and calcine for 3-4 h to obtain ZIF-8@TiO2 / Fe2O3; The TiCl3 content of the titanium trichloride solution is 15wt%, and the mass ratio of ZIF-8 nanoparticles to titanium in the titanium trichloride solution is 10:1-3. Fe in ferric nitrate 3+ The molar ratio of urea to urea is 1:3-3.5; The ZIF-8@TiO2 and Fe in ferric nitrate 3+ The mass ratio is 5-7:1; The preparation steps of the coated sodium persulfate material are as follows: After weighing polycaprolactone and heating it until completely melted, add diatomaceous earth and stir evenly. Then add sodium persulfate powder and stir evenly. Pour the mixture into a mold while it is still hot, let it cool to room temperature and then demold to obtain the coated sodium persulfate material.

2. The deodorizing agent for kitchen waste according to claim 1, characterized in that, The polyvinylpyrrolidone is added at 0.5-1% of the precursor solution mass.

3. The deodorizing agent for kitchen waste according to claim 1, characterized in that, The mass ratio of polycaprolactone to diatomaceous earth is 5:1-2; The mass of the sodium persulfate powder is 60-80% of the total mass of polycaprolactone and diatomaceous earth.

4. A deodorization process, characterized in that, The deodorization process using the deodorizing agent for kitchen waste as described in any one of claims 1-3 comprises the following steps: Step 1: Collect the odor generated during the food waste treatment process and filter the odor to remove particulate matter; Step 2: The filtered odorous gas is sent by a blower into a photocatalytic reactor filled with a deodorizing agent for kitchen waste. The reaction is carried out under light irradiation with a wavelength of 450-550nm for 2-3 hours. Step 3: The gas after the reaction enters the adsorption tower, which is filled with biochar loaded with tea polyphenols. The gas after adsorption meets the emission standards.

5. The deodorization process according to claim 4, characterized in that, The preparation steps of the biochar loaded with tea polyphenols are as follows: Under a nitrogen atmosphere, shrimp shells are calcined and carbonized at 600-650℃ for 2-5 hours to obtain porous biochar. The porous biochar is then impregnated in a tea polyphenol ethanol solution, ultrasonically treated for 2-4 hours, and dried to obtain tea polyphenol-loaded biochar.

6. The deodorization process according to claim 5, characterized in that, The porous biochar has a specific surface area of ​​800-900 m². 2 / g; The concentration of tea polyphenols in the ethanol solution is 10-20 wt%. The mass ratio of porous biochar to tea polyphenols is 3-4:1.

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