Formaldehyde purifying agent with adsorption and degradation functions

Abstract

The application 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; the combination of the adsorbent and the photocatalyst enables the prepared purifying agent to have the double functions of adsorption and degradation of formaldehyde, the combination of the sludge activated carbon and the adsorption resin improves the adsorption capacity of the adsorbent for formaldehyde, and the large use of the sludge activated carbon can promote the resource utilization of sludge.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air purification, in particular to a formaldehyde purifying agent with adsorption and degradation functions. BACKGROUND

[0002] Formaldehyde, a colorless gas, is not easy to be perceived at low concentration and can be easily covered by other odors such as air fresheners. At high concentration, it has a strong irritating and suffocating odor, which can irritate the eyes, nose, etc. of human beings. Formaldehyde is a toxic gas that seriously endangers human health, and is often found in substandard furniture and decoration materials. Long-term exposure to high concentrations of formaldehyde can cause dizziness, headache, tearing, nausea and vomiting, coughing, chest tightness, leukemia, and even death. Therefore, in life, we should avoid formaldehyde, and regularly ventilate and monitor the content of formaldehyde in newly renovated houses.

[0003] A formaldehyde purifying agent is a product used to remove or reduce the content of formaldehyde in the environment. At present, the commonly used formaldehyde purifying agent is activated carbon, which can adsorb formaldehyde in the pores of activated carbon by physical adsorption method to achieve purification effect. However, activated carbon only has adsorption function and cannot degrade formaldehyde. Moreover, the adsorption capacity of activated carbon for formaldehyde is limited, and it cannot effectively reduce the concentration of formaldehyde in the environment. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a formaldehyde purifying agent with adsorption and degradation functions by using a combination of adsorbent and photocatalyst, and to improve the adsorption capacity of the adsorbent for formaldehyde by using a combination of sludge activated carbon and adsorption resin.

[0005] The technical problem to be solved by the present application is solved by the following technical solution:

[0006] One of the objects of the present application is to provide a formaldehyde purifying agent with adsorption and degradation functions, which comprises an adsorbent and a photocatalyst, and the adsorbent is composed of sludge activated carbon and adsorption resin.

[0007] Further, 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-iron trioxide. The addition of photocatalyst can not only adsorb formaldehyde, but also degrade formaldehyde, thereby better achieving the control of formaldehyde.

[0008] Further, the mass ratio of the adsorbent to the photocatalyst is 100:(0.5-10). Controlling the mass ratio of the adsorbent to the photocatalyst enables the purifying agent to have excellent adsorption and degradation functions for formaldehyde.

[0009] Further, the mass ratio of the sludge activated carbon to the adsorption resin is (1-10):1. In the present application, the sludge activated carbon and the adsorption resin are used in combination, the adsorption advantages of the sludge activated carbon and the adsorption resin are fully utilized, and the adsorption capacity of the purifying agent to formaldehyde is improved.

[0010] Further, 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, and common methods include high-temperature combustion and high-temperature steam treatment. The chemical pyrolysis method introduces chemicals for treatment on the basis of the physical pyrolysis method, and common methods include alkali fusion method and acid treatment method. These methods can control the pore size and pore structure of the activated carbon and improve the adsorption performance thereof.

[0011] Further, the adsorption resin is prepared by a suspension polymerization method in a dispersion medium, using styrene, hexamethylene bisacrylamide, a porogen and an initiator. The styrene, hexamethylene bisacrylamide, porogen and initiator form an oil phase, and the dispersion medium is an aqueous phase.

[0012] In some preferred technical solutions, the mass ratio of the styrene to the hexamethylene bisacrylamide is (60-80):(20-40). In the present application, the styrene and hexamethylene bisacrylamide 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 form of small droplets in the monomer droplets in the suspension polymerization process, and when the polymerization reaction is completed, various shapes and sizes of pores are formed in the resin by removing the porogen. These pores 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 controlled, the specific surface area of the resin is increased, and the adsorption performance of the resin is improved.

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

[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 the styrene and hexamethylene bisacrylamide.

[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 dispersant functions to promote uniform dispersion of resin particles during the suspension polymerization process, thereby ensuring stability of the pore structure and adsorption performance of the resin.

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

[0022] The present application has the following beneficial effects:

[0023] 1. The present application uses a combination of adsorbent and photocatalyst, so that the prepared purification agent has dual functions of adsorption and degradation of formaldehyde. The photocatalyst generates free radicals with strong oxidizing ability under light irradiation, which can react with formaldehyde to decompose it into carbon dioxide and water.

[0024] 2. The present application uses a combination of sludge activated carbon and adsorption resin, which improves the adsorption capacity of the adsorbent for formaldehyde, solves the problem of limited adsorption capacity when only activated carbon is used as the purification agent, and promotes the resource utilization of sludge. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the present application is further described below in combination with specific embodiments.

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

[0027] Example 1

[0028] Preparation of adsorption resin:

[0029] Mix 60 g of styrene, 40 g of hexamethylene bisacrylamide, 100 g of toluene and 0.5 g of benzoyl peroxide to obtain an oil phase; dissolve gelatin and polyvinyl alcohol with 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 with a volume ratio of 3:1, and react at 75-80°C for 6 h; after the reaction, filter, wash the obtained spheres with water, load them into a Soxhlet extractor, extract with acetone to remove the pore-forming agent, wash the spheres with water again to remove acetone, and dry to obtain the adsorption resin.

[0030] Preparation of formaldehyde purifier:

[0031] Mix sludge activated carbon and adsorption resin with a mass ratio of 10:1 to obtain an adsorbent; then mix the adsorbent and nano-titanium dioxide with a mass ratio of 100:0.5 to obtain the formaldehyde purifier.

[0032] Example 2

[0033] Preparation of adsorption resin:

[0034] Mix 70 g of styrene, 30 g of hexamethylene bisacrylamide, 150 g of dimethylbenzene and 0.85 g of benzoyl peroxide to obtain an oil phase; dissolve gelatin and polyvinyl alcohol with 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 with a volume ratio of 2:1, and react at 75-80°C for 8 h; after the reaction, filter, wash the obtained spheres with water, load them into a Soxhlet extractor, extract with acetone to remove the pore-forming agent, wash the spheres with water again to remove acetone, and dry to obtain the adsorption resin.

[0035] Preparation of formaldehyde purifier:

[0036] Mix sludge activated carbon and adsorption resin with a mass ratio of 8:1 to obtain an adsorbent; then mix the adsorbent and nano-zinc oxide with a mass ratio of 100:1 to obtain the formaldehyde purifier.

[0037] Example 3

[0038] Preparation of adsorption resin:

[0039] Mix 75 g of styrene, 25 g of hexamethylene bisacrylamide, 200 g of toluene and 1 g of azobisisobutyronitrile to obtain an oil phase; dissolve gelatin, polyvinyl alcohol and carboxymethyl cellulose with 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 with a volume ratio of 1:1, and react at 75-80°C for 8 h; after the reaction, filter, wash the obtained spheres with water, load them into a Soxhlet extractor, extract with acetone to remove the pore-forming agent, wash the spheres with water again to remove acetone, and dry to obtain the adsorption resin.

[0040] Preparation of formaldehyde purifying agent:

[0041] Firstly, sludge activated carbon and adsorption resin with mass ratio of 5:1 are mixed uniformly to obtain adsorbent; then the adsorbent and nanometer molybdenum disulfide with mass ratio of 100:2 are mixed uniformly to obtain formaldehyde purifying agent.

[0042] Example 4

[0043] Preparation of adsorption resin:

[0044] 80g of styrene, 20g of hexamethylene bisacrylamide, 75g of toluene, 75g of dimethylbenzene and 1g of azobisisobutyronitrile are mixed uniformly to obtain oil phase; sodium chloride is dissolved in water to obtain water phase with mass concentration of 2%; water phase and oil phase with volume ratio of 5:1 are mixed uniformly, and the temperature is raised to 75-80℃ for 10h; after the reaction, the obtained spheres are filtered, washed with water, put into a soxhlet extractor, extracted with acetone to remove pore-forming agent, the spheres are washed with water again to remove acetone, and dried to obtain adsorption resin.

[0045] Preparation of formaldehyde purifying agent:

[0046] Firstly, sludge activated carbon and adsorption resin with mass ratio of 1:1 are mixed uniformly to obtain adsorbent; then the adsorbent and nanometer titanium dioxide with mass ratio of 100:3 are mixed uniformly to obtain formaldehyde purifying agent.

[0047] Example 5

[0048] Preparation of adsorption resin:

[0049] 75g of styrene, 25g of hexamethylene bisacrylamide, 150g of toluene and 1g of benzoyl peroxide are mixed uniformly to obtain oil phase; gelatin and polyvinyl alcohol with mass ratio of 1:2 are dissolved in water to obtain water phase with mass concentration of 4%; water phase and oil phase with volume ratio of 3:1 are mixed uniformly, and the temperature is raised to 75-80℃ for 12h; after the reaction, the obtained spheres are filtered, washed with water, put into a soxhlet extractor, extracted with acetone to remove pore-forming agent, the spheres are washed with water again to remove acetone, and dried to obtain adsorption resin.

[0050] Preparation of formaldehyde purifying agent:

[0051] Firstly, sludge activated carbon and adsorption resin with mass ratio of 4:1 are mixed uniformly to obtain adsorbent; then the adsorbent and nanometer titanium dioxide with mass ratio of 100:5 are mixed uniformly to obtain formaldehyde purifying agent.

[0052] Comparative Example 1

[0053] Comparative Example 1 is only to replace hexamethylene bisacrylamide in Example 5 with acrylamide.

[0054] Preparation of adsorption resin:

[0055] 75g of styrene, 25g of acrylamide, 150g of toluene and 1g of benzoyl peroxide were mixed to obtain an oil phase; gelatin and polyvinyl alcohol with a mass ratio of 1:2 were dissolved in water to obtain an aqueous phase with a mass concentration of 4%; the aqueous phase and the oil phase were mixed with a volume ratio of 3:1, and then heated to 75-80℃ for 12h; after the reaction was completed, the obtained spheres were filtered, washed with water, and then loaded into a Soxhlet extractor for extraction with acetone to remove the pore-forming agent; the spheres were washed with water again to remove the acetone, and then dried to obtain the adsorption resin.

[0056] Preparation of the formaldehyde purifying agent:

[0057] First, the sludge activated carbon and the adsorption resin were mixed with a mass ratio of 4:1 to obtain an adsorbent; then, the adsorbent and nano-titanium dioxide were mixed with a mass ratio of 100:5 to obtain the formaldehyde purifying agent.

[0058] Comparative Example 2

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

[0060] Preparation of the formaldehyde purifying agent:

[0061] The sludge activated carbon and nano-titanium dioxide were mixed with a mass ratio of 100:5 to obtain the formaldehyde purifying agent.

[0062] Example 6

[0063] Example 6 only replaces the toluene in Example 5 with toluene and methyl isopropyl sulfide with a volume ratio of 9:1.

[0064] Preparation of the adsorption resin:

[0065] 75g of styrene, 25g of acrylamide, 150g of toluene and 1g of benzoyl peroxide were mixed to obtain an oil phase; gelatin and polyvinyl alcohol with a mass ratio of 1:2 were dissolved in water to obtain an aqueous phase with a mass concentration of 4%; the aqueous phase and the oil phase were mixed with a volume ratio of 3:1, and then heated to 75-80℃ for 12h; after the reaction was completed, the obtained spheres were filtered, washed with water, and then loaded into a Soxhlet extractor for extraction with acetone to remove the pore-forming agent; the spheres were washed with water again to remove the acetone, and then dried to obtain the adsorption resin.

[0066] Preparation of the formaldehyde purifying agent:

[0067] First, the sludge activated carbon and the adsorption resin were mixed with a mass ratio of 4:1 to obtain an adsorbent; then, the adsorbent and nano-titanium dioxide were mixed with a mass ratio of 100:5 to obtain the formaldehyde purifying agent.

[0068] Example 7

[0069] Example 7 is only to replace toluene in Example 5 with toluene and methyl isopropyl sulfide in a volume ratio of 8:2.

[0070] Preparation of the adsorption resin:

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

[0072] Preparation of the formaldehyde purifying agent:

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

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

[0075] According to the test method of CN201811046843: 1.00g of the purifying agent was weighed into a culture dish and placed in a closed saturated formaldehyde atmosphere, and the formaldehyde was adsorbed statically for 7d, then the culture dish was taken out and transferred to a beaker, 25mL of distilled water was added and soaked for 12h, filtered with qualitative filter paper, washed with a small amount of distilled water, and the filtrate was combined and diluted to 50mL, then diluted 500 times, and the absorbance of the solution was measured by acetylacetone spectrophotometry, and the adsorption capacity of the purifying agent for formaldehyde was calculated by 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] As can be seen from Table 1, the use of the adsorption resin described in the application can significantly improve the adsorption capacity of the purifying agent for formaldehyde, and the use of the pore-forming agent described in the application can further improve the adsorption capacity of the purifying agent for formaldehyde.

[0079] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A formaldehyde purifier with both adsorption and degradation functions, characterized in that: The adsorbent is composed of sludge activated carbon and adsorption resin, and 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-iron trioxide. The adsorption resin is prepared by suspension polymerization of styrene, hexamethylene bisacrylamide, porogen and initiator in a dispersion medium. 2.The formaldehyde purifying agent with 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 purifying agent 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-iron trioxide.

4. The formaldehyde purifying agent with 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 purifying agent with adsorption and degradation functions according to claim 1, characterized in that: The mass ratio of the styrene to the hexamethylene bisacrylamide is (60-80):(20-40). 6.The formaldehyde purifying agent with both adsorption and degradation functions according to claim 1, characterized in that: The porogen is selected from one or more of toluene, xylene, isooctane and n-pentane. The amount of the porogen is 50-200% of the total mass of the styrene and the hexamethylene bisacrylamide.

7. The formaldehyde purifying agent with adsorption and degradation functions according to claim 1, characterized in that: The initiator is selected from one or more of benzoyl peroxide and azobisisobutyronitrile. The amount of the initiator is 0.5-2% of the total mass of the styrene and the hexamethylene bisacrylamide. 8.The formaldehyde purifying agent with both adsorption and degradation functions according to claim 1, 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 1-5 times the total volume of the styrene, the hexamethylene bisacrylamide, the porogen and the initiator. 9.The formaldehyde scavenger with both adsorption and degradation functions according to claim 8, characterized in that: The dispersant is selected from one or more of gelatin, polyvinyl alcohol and carboxymethyl cellulose.