Formaldehyde purifying agent with adsorption and degradation functions

Abstract

The invention discloses a formaldehyde purifying agent with adsorption and degradation functions, and relates to the technical field of air purification, the formaldehyde purifying agent comprises an adsorbent and a photocatalyst, the adsorbent is composed of sludge activated carbon and adsorption resin; through combined use of the adsorbent and the photocatalyst, the prepared purifying agent has dual functions of adsorbing and degrading formaldehyde, through combined use of the sludge activated carbon and the adsorption resin, the adsorption capacity of the adsorbent to formaldehyde is improved, and meanwhile resource utilization of sludge can be promoted through large-scale use of the sludge activated carbon.

Description

Technical Field

[0001] The invention relates to the technical field of air purification, and in particular to a formaldehyde purifier with both adsorption and degradation functions. Background Art

[0002] Formaldehyde is a colorless gas that is not easily detected at low concentrations and can be easily masked by other odors, such as air fresheners. At higher concentrations, it has a strong pungent and suffocating odor that irritates the eyes and nose. Formaldehyde is a toxic gas that seriously endangers human health and is more likely to appear in furniture and decoration materials that do not meet quality standards. If patients are exposed to a high concentration of formaldehyde for a long time, they may experience dizziness, headaches, tears, nausea and vomiting, coughing, chest tightness, leukemia, etc., and in severe cases, death. Therefore, we should pay attention to staying away from formaldehyde in our lives, ventilate newly renovated houses frequently, and pay attention to monitoring the formaldehyde content.

[0003] Formaldehyde purifiers refer to products used to remove or reduce the formaldehyde content in the environment. At present, the commonly used formaldehyde purifiers are mainly activated carbon, which adsorbs formaldehyde in the pores of activated carbon through physical adsorption to achieve a purification effect. However, activated carbon only has an adsorption effect and cannot degrade formaldehyde. In addition, the adsorption capacity of activated carbon for formaldehyde is limited and cannot effectively reduce the formaldehyde concentration in the environment. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a formaldehyde purifier, which has the dual functions of adsorption and degradation through the combined use of an adsorbent and a photocatalyst; and the adsorption capacity of the adsorbent for formaldehyde is improved through the combined use of sludge activated carbon and an adsorption resin.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] One of the purposes of the present invention is to provide a formaldehyde purifier with both adsorption and degradation functions, comprising an adsorbent and a photocatalyst, wherein the adsorbent is composed of sludge activated carbon and an adsorption resin.

[0007] Furthermore, the photocatalyst includes but is not limited to one or more of nano titanium dioxide, nano zinc oxide, nano silicon dioxide, nano zirconium dioxide, nano molybdenum disulfide, and nano ferric oxide. Adding a photocatalyst can make the purifier not only have the function of absorbing formaldehyde, but also degrade formaldehyde, so as to better achieve the treatment of formaldehyde.

[0008] Furthermore, the mass ratio of the adsorbent to the photocatalyst is 100:(0.5-10). The mass ratio of the adsorbent to the photocatalyst is controlled so that the purifier has both excellent functions of adsorbing and degrading formaldehyde.

[0009] Furthermore, the mass ratio of the sludge activated carbon to the adsorption resin is (1-10): 1. In the present invention, the sludge activated carbon and the adsorption resin are used in combination to fully utilize the adsorption advantages of the sludge activated carbon and the adsorption resin to improve the adsorption capacity of the purifier for formaldehyde.

[0010] Furthermore, the sludge activated carbon is obtained by physical pyrolysis or chemical pyrolysis of sludge. The physical pyrolysis method is to convert sludge into activated carbon by high-temperature treatment. Common methods include high-temperature combustion and high-temperature steam treatment. The chemical pyrolysis method introduces chemical substances for treatment on the basis of physical pyrolysis. Common methods include alkali fusion method and acid treatment method. These methods can regulate the pore size and pore structure of activated carbon and improve its adsorption performance.

[0011] Furthermore, the adsorption resin is prepared by suspension polymerization of styrene, hexamethylenebisacrylamide, porogen and initiator in a dispersion medium. Styrene, hexamethylenebisacrylamide, porogen and initiator constitute an oil phase, and the dispersion medium is an aqueous phase.

[0012] In some preferred technical solutions, the mass ratio of styrene to hexamethylenebisacrylamide is (60-80):(20-40). In the present invention, styrene and hexamethylenebisacrylamide are used as polymerization monomers.

[0013] In some preferred technical solutions, the porogen includes but is not limited to one or more of toluene, xylene, isooctane, and n-pentane. The porogen exists in the monomer droplets in the form of small droplets during the suspension polymerization process. After the polymerization reaction is completed, the porogen is removed, and holes of various shapes and sizes are formed inside the resin. These holes not only increase the specific surface area of ​​the resin, but also provide more adsorption sites, thereby improving the adsorption efficiency and capacity of the resin.

[0014] In some preferred technical solutions, the porogen is toluene and methyl isopropyl sulfide, and the volume ratio of the two is (8-9): (1-2). By adding an appropriate amount of methyl isopropyl sulfide to toluene, the pore size distribution and void structure of the resin can be regulated, the specific surface area of ​​the resin can be increased, and thus the adsorption performance of the resin can be improved.

[0015] In some preferred technical solutions, the amount of the porogen is 50-200% of the total mass of styrene and hexamethylenebisacrylamide.

[0016] In some preferred technical solutions, the initiator includes but is not limited to one or more of benzoyl peroxide and azobisisobutyronitrile.

[0017] In some preferred technical solutions, the amount of the initiator is 0.5-2% of the total mass of styrene and hexamethylenebisacrylamide.

[0018] In some preferred technical solutions, the dispersion medium is water or sodium chloride aqueous solution containing a dispersant.

[0019] In some preferred technical solutions, the mass concentration of the dispersion medium is 0.5-5%.

[0020] In some preferred technical solutions, the dispersant includes but is not limited to one or more of gelatin, polyvinyl alcohol, and carboxymethyl cellulose. The function of the dispersant is to promote the uniform dispersion of resin particles during the suspension polymerization process, thereby ensuring the stability of the pore structure and adsorption performance of the resin.

[0021] In some preferred technical solutions, the amount of the dispersion medium is 1 to 5 times the total volume of styrene, hexamethylenebisacrylamide, porogen and initiator.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention uses a combination of an adsorbent and a photocatalyst so that the prepared purifier has the dual functions of adsorbing and degrading formaldehyde. The photocatalyst generates free radicals with strong oxidizing ability under the irradiation of light. These free radicals can react with formaldehyde and decompose it into carbon dioxide and water.

[0024] 2. The present invention improves the adsorption capacity of the adsorbent for formaldehyde by using a combination of sludge activated carbon and adsorption resin, which can solve the problem of limited adsorption capacity when only activated carbon is used as a purifier. In addition, the large-scale use of sludge activated carbon can promote the resource utilization of sludge. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments.

[0026] The specific surface area of ​​the sludge activated carbon in the following examples and comparative examples is 450-500m 2 / g, pore size is 0.5~80nm.

[0027] Example 1

[0028] Preparation of adsorption resin:

[0029] Mix 60g of styrene, 40g of hexamethylenebisacrylamide, 100g of toluene and 0.5g of benzoyl peroxide evenly to obtain an oil phase; dissolve gelatin and polyvinyl alcohol in a mass ratio of 1:3 in water to obtain an aqueous phase with a mass concentration of 2.5%; mix the aqueous phase and the oil phase in a volume ratio of 3:1 evenly, heat to 75-80°C and react for 6h; filter after the reaction, wash the obtained spheres with water and load them into a Soxhlet extractor, extract with acetone to remove the porogen, wash the spheres with water again to remove the acetone, and dry them to obtain an adsorption resin.

[0030] Preparation of formaldehyde purifier:

[0031] First, the sludge activated carbon and the adsorption resin in a mass ratio of 10:1 are evenly mixed to obtain an adsorbent; then the adsorbent and nano titanium dioxide in a mass ratio of 100:0.5 are evenly mixed to obtain a formaldehyde purifier.

[0032] Example 2

[0033] Preparation of adsorption resin:

[0034] Mix 70g of styrene, 30g of hexamethylenebisacrylamide, 150g of xylene and 0.85g of benzoyl peroxide evenly to obtain an oil phase; dissolve gelatin and polyvinyl alcohol in a mass ratio of 1:1 in water to obtain an aqueous phase with a mass concentration of 5%; mix the aqueous phase and the oil phase in a volume ratio of 2:1 evenly, heat to 75-80°C and react for 8h; filter after the reaction, wash the obtained spheres with water and load them into a Soxhlet extractor, extract with acetone to remove the porogen, wash the spheres with water again to remove acetone, and dry to obtain an adsorption resin.

[0035] Preparation of formaldehyde purifier:

[0036] First, the sludge activated carbon and the adsorption resin in a mass ratio of 8:1 are evenly mixed to obtain an adsorbent; then the adsorbent and nano zinc oxide in a mass ratio of 100:1 are evenly mixed to obtain a formaldehyde purifier.

[0037] Example 3

[0038] Preparation of adsorption resin:

[0039] Mix 75g of styrene, 25g of hexamethylenebisacrylamide, 200g of toluene and 1g of azobisisobutyronitrile evenly to obtain an oil phase; dissolve gelatin, polyvinyl alcohol and carboxymethyl cellulose in a mass ratio of 1:1:1 in water to obtain an aqueous phase with a mass concentration of 3%; mix the aqueous phase and the oil phase in a volume ratio of 1:1 evenly, heat to 75-80°C and react for 8h; filter after the reaction, wash the obtained spheres with water and load them into a Soxhlet extractor, extract with acetone to remove the porogen, wash the spheres with water again to remove the acetone, and dry them to obtain an adsorption resin.

[0040] Preparation of formaldehyde purifier:

[0041] First, the sludge activated carbon and the adsorption resin in a mass ratio of 5:1 are evenly mixed to obtain an adsorbent; then the adsorbent and nano molybdenum disulfide in a mass ratio of 100:2 are evenly mixed to obtain a formaldehyde purifier.

[0042] Example 4

[0043] Preparation of adsorption resin:

[0044] 80g of styrene, 20g of hexamethylenebisacrylamide, 75g of toluene, 75g of xylene and 1g of azobisisobutyronitrile are mixed evenly to obtain an oil phase; sodium chloride is dissolved in water to obtain an aqueous phase with a mass concentration of 2%; the aqueous phase and the oil phase are mixed evenly in a volume ratio of 5:1, and the temperature is raised to 75-80°C for reaction for 10h; after the reaction is completed, the reaction is filtered, and the obtained spheres are washed with water and loaded into a Soxhlet extractor, extracted with acetone to remove the porogen, and the spheres are washed with water again to remove the acetone, and dried to obtain an adsorption resin.

[0045] Preparation of formaldehyde purifier:

[0046] First, the sludge activated carbon and the adsorption resin in a mass ratio of 1:1 are evenly mixed to obtain an adsorbent; then the adsorbent and nano titanium dioxide in a mass ratio of 100:3 are evenly mixed to obtain a formaldehyde purifier.

[0047] Example 5

[0048] Preparation of adsorption resin:

[0049] Mix 75g of styrene, 25g of hexamethylenebisacrylamide, 150g of toluene and 1g of benzoyl peroxide evenly to obtain an oil phase; dissolve gelatin and polyvinyl alcohol in a mass ratio of 1:2 in water to obtain an aqueous phase with a mass concentration of 4%; mix the aqueous phase and the oil phase in a volume ratio of 3:1 evenly, heat to 75-80°C and react for 12h; filter after the reaction, wash the obtained spheres with water and load them into a Soxhlet extractor, extract with acetone to remove the porogen, wash the spheres with water again to remove acetone, and dry to obtain an adsorption resin.

[0050] Preparation of formaldehyde purifier:

[0051] First, the sludge activated carbon and the adsorption resin in a mass ratio of 4:1 are evenly mixed to obtain an adsorbent; then the adsorbent and nano titanium dioxide in a mass ratio of 100:5 are evenly mixed to obtain a formaldehyde purifier.

[0052] Comparative Example 1

[0053] Comparative Example 1 is just a method in which the hexamethylenebisacrylamide in Example 5 is replaced by acrylamide.

[0054] Preparation of adsorption resin:

[0055] Mix 75g of styrene, 25g of acrylamide, 150g of toluene and 1g of benzoyl peroxide evenly to obtain an oil phase; dissolve gelatin and polyvinyl alcohol in water at a mass ratio of 1:2 to obtain an aqueous phase with a mass concentration of 4%; mix the aqueous phase and the oil phase in a volume ratio of 3:1 evenly, heat to 75-80°C and react for 12h; filter after the reaction, wash the obtained spheres with water and load them into a Soxhlet extractor, extract with acetone to remove the porogen, wash the spheres with water again to remove acetone, and dry to obtain an adsorption resin.

[0056] Preparation of formaldehyde purifier:

[0057] First, the sludge activated carbon and the adsorption resin in a mass ratio of 4:1 are evenly mixed to obtain an adsorbent; then the adsorbent and nano titanium dioxide in a mass ratio of 100:5 are evenly mixed to obtain a formaldehyde purifier.

[0058] Comparative Example 2

[0059] Comparative Example 2 does not use adsorption resin, and only uses sludge activated carbon as adsorbent.

[0060] Preparation of formaldehyde purifier:

[0061] The sludge activated carbon and nano titanium dioxide in a mass ratio of 100:5 were evenly mixed to obtain a formaldehyde purifier.

[0062] Example 6

[0063] Example 6 is simply a matter of replacing the toluene in Example 5 with toluene and methyl isopropyl sulfide in a volume ratio of 9:1.

[0064] Preparation of adsorption resin:

[0065] Mix 75g of styrene, 25g of hexamethylenebisacrylamide, 135g of toluene, 15g of methyl isopropyl sulfide and 1g of benzoyl peroxide to obtain an oil phase; dissolve gelatin and polyvinyl alcohol in a mass ratio of 1:2 in water to obtain an aqueous phase with a mass concentration of 4%; mix the aqueous phase and the oil phase in a volume ratio of 3:1 to obtain a uniform mixture, heat to 75-80°C and react for 12h; filter after the reaction, wash the obtained spheres with water and load them into a Soxhlet extractor, extract with acetone to remove the porogen, wash the spheres with water again to remove the acetone, and dry them to obtain an adsorption resin.

[0066] Preparation of formaldehyde purifier:

[0067] First, the sludge activated carbon and the adsorption resin in a mass ratio of 4:1 are evenly mixed to obtain an adsorbent; then the adsorbent and nano titanium dioxide in a mass ratio of 100:5 are evenly mixed to obtain a formaldehyde purifier.

[0068] Example 7

[0069] Example 7 is just the case where the toluene in Example 5 is replaced by toluene and methyl isopropyl sulfide in a volume ratio of 8:2.

[0070] Preparation of adsorption resin:

[0071] 75g of styrene, 25g of hexamethylenebisacrylamide, 120g of toluene, 30g of methyl isopropyl sulfide and 1g of benzoyl peroxide are mixed evenly to obtain an oil phase; gelatin and polyvinyl alcohol in a mass ratio of 1:2 are dissolved in water to obtain an aqueous phase with a mass concentration of 4%; the aqueous phase and the oil phase in a volume ratio of 3:1 are mixed evenly, and the temperature is raised to 75-80°C for reaction for 12h; after the reaction is completed, the reaction is filtered, and the obtained spheres are washed with water and loaded into a Soxhlet extractor, extracted with acetone to remove the porogen, and the spheres are washed with water again to remove the acetone, and dried to obtain an adsorption resin.

[0072] Preparation of formaldehyde purifier:

[0073] First, the sludge activated carbon and the adsorption resin in a mass ratio of 4:1 are evenly mixed to obtain an adsorbent; then the adsorbent and nano titanium dioxide in a mass ratio of 100:5 are evenly mixed to obtain a formaldehyde purifier.

[0074] The formaldehyde purifiers prepared in Examples 1 to 7 and Comparative Examples 1 to 2 were tested for adsorption capacity, and the test results are shown in Table 1.

[0075] Referring to the test method of CN201811046843: weigh 1.00g of the purifier and add it to a culture dish, place it in a closed saturated formaldehyde atmosphere, statically adsorb formaldehyde for 7 days, take it out and transfer it to a beaker, add 25mL of distilled water and soak it for 12 hours, filter it with qualitative filter paper, and wash it with a small amount of distilled water. Combine the filtrate and make it to 50mL, then dilute it 500 times and use the acetylacetone spectrophotometry to determine the absorbance of the solution, and calculate the adsorption amount of formaldehyde by the purifier through the known formaldehyde standard working curve.

[0076] Table 1

[0077] Adsorption capacity (mg / g) Example 1 340 Example 2 349 Example 3 356 Example 4 367 Example 5 375 Comparative Example 1 281 Comparative Example 2 302 Example 6 394 Example 7 403

[0078] It can be seen from Table 1 that the use of the adsorption resin of the present invention can significantly improve the adsorption capacity of the purifier for formaldehyde, and the use of the porogen of the present invention can further improve the adsorption capacity of the purifier for formaldehyde.

[0079] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A formaldehyde purifier having both adsorption and degradation functions, characterized in that: The invention comprises an adsorbent and a photocatalyst, wherein the adsorbent is composed of sludge activated carbon and adsorption resin.

2. The formaldehyde purifier having both adsorption and degradation functions according to claim 1, characterized in that: The mass ratio of the adsorbent to the photocatalyst is 100:(0.5-10).

3. The formaldehyde purifier with both adsorption and degradation functions according to claim 1 or 2, characterized in that: The photocatalyst is selected from one or more of nano titanium dioxide, nano zinc oxide, nano silicon dioxide, nano zirconium dioxide, nano molybdenum disulfide, and nano ferric oxide.

4. The formaldehyde purifier having both adsorption and degradation functions according to claim 1, characterized in that: The mass ratio of the sludge activated carbon to the adsorption resin is (1-10):

1.

5. The formaldehyde purifier having both adsorption and degradation functions according to claim 1, characterized in that: The adsorption resin is prepared by suspension polymerization of styrene, hexamethylenebisacrylamide, a porogen and an initiator in a dispersion medium.

6. The formaldehyde purifier having both adsorption and degradation functions according to claim 5, characterized in that: The mass ratio of styrene to hexamethylenebisacrylamide is (60-80):(20-40).

7. The formaldehyde purifier having both adsorption and degradation functions according to claim 5, characterized in that: The porogen is selected from one or more of toluene, xylene, isooctane, and n-pentane; The amount of the porogen used is 50-200% of the total mass of styrene and hexamethylenebisacrylamide.

8. The formaldehyde purifier having both adsorption and degradation functions according to claim 5, characterized in that: The initiator is selected from one or more of benzoyl peroxide and azobisisobutyronitrile; The amount of the initiator used is 0.5-2% of the total mass of styrene and hexamethylenebisacrylamide.

9. The formaldehyde purifier having both adsorption and degradation functions according to claim 5, characterized in that: The dispersion medium is water or sodium chloride solution containing a dispersant; The mass concentration of the dispersion medium is 0.5-5%; The amount of the dispersion medium is 1 to 5 times the total volume of styrene, hexamethylenebisacrylamide, porogen and initiator.

10. The formaldehyde purifier with both adsorption and degradation functions according to claim 9, characterized in that: The dispersant is selected from one or more of gelatin, polyvinyl alcohol and carboxymethyl cellulose.