Modified extruded activated carbon filter element and preparation method thereof

Abstract

The invention discloses a modified extruded activated carbon filter element and a preparation method thereof.The preparation method comprises the following steps that 1, activated carbon powder is dehydrated till the water content is lower than 5%, then the dehydrated activated carbon powder is soaked in a ferrous sulfate solution with the concentration being 27 wt%, stirring is conducted for 18 h, washing is conducted till the solution is neutral, drying is conducted, and modified activated carbon powder is obtained; (2) uniformly mixing the modified activated carbon powder, an adhesive, a boosting agent, an antibacterial agent and activated carbon fibers in a mass ratio of (70-80): (10-15): (3-5): (1-2): (2-3) to obtain a mixture; (3) extruding the mixed material to obtain the modified extruded activated carbon filter element; wherein the mass volume ratio of the dehydrated activated carbon powder to the ferrous sulfate solution is 1g: 8mL. Compared with a traditional common extruded activated carbon filter element, the modified extruded activated carbon filter element has the advantages that the removal rates of heavy metals, chlorine and microorganisms are obviously improved through optimal design of a formula, and meanwhile, the modified extruded activated carbon filter element also has good mechanical strength, iodine adsorption performance and water discharge capacity.

Description

Technical Field

[0001] The invention belongs to the technical field of water pollution control and waste liquid recovery, and particularly relates to a modified extruded activated carbon filter element and a preparation method thereof. Background Art

[0002] Common activated carbon filter elements on the market are primarily categorized as pressed, particle-filled, sintered, and extruded. Extruded filter elements are manufactured by mixing activated carbon powder with an appropriate binder and then extruding it through an extruder at a constant temperature. These extruded filter elements offer advantages such as high production efficiency and easier size control. However, conventional extruded activated carbon filter elements lack effective antibacterial treatment and targeted functional modifications, resulting in suboptimal performance when treating complex water quality issues. Summary of the Invention

[0003] The purpose of the present invention is to provide a modified extruded activated carbon filter element, which has good removal ability for various impurities and can be used for treating complex water quality.

[0004] The technical solutions of the present invention are as follows:

[0005] A method for preparing a modified extruded activated carbon filter element comprises the following steps:

[0006] (1) dehydrating the activated carbon powder to a water content of less than 5%, then immersing the dehydrated activated carbon powder in a 27 wt % ferrous sulfate solution, stirring for 18 h, washing until neutral, and drying to obtain a modified activated carbon powder;

[0007] (2) mixing modified activated carbon powder, a binder, a propellant, an antibacterial agent, and activated carbon fibers in a mass ratio of 70-80:10-15:3-5:1-2:2-3 to obtain a mixture;

[0008] (3) extruding the mixed material to obtain a modified extruded activated carbon filter element;

[0009] The mass volume ratio of the dehydrated activated carbon powder to the ferrous sulfate solution is 1 g:8 mL.

[0010] In the above technical solution, by making the activated carbon powder have better adsorption properties, and then by adding antibacterial agents, adhesives, propellants and activated carbon fibers and optimizing the ratio, a modified extruded activated carbon filter element with high mechanical strength, filtration performance and antibacterial ability is obtained.

[0011] In some preferred embodiments, the extrusion temperature is 150-200° C. and the extrusion pressure is 5-10 MPa. Under these extrusion conditions, the prepared modified extruded activated carbon filter element has good density and structural strength.

[0012] In some preferred embodiments, the activated carbon powder is coconut shell charcoal powder and / or wood charcoal powder, which has a low ash content and a well-developed porous structure. Furthermore, the activated carbon powder preferably has a particle size of 80-120 mesh. By controlling the particle size of the activated carbon powder, the raw material can be ensured to have an appropriate extrusion viscosity, and the resulting modified extruded activated carbon filter element can have good filtration accuracy.

[0013] In some preferred embodiments, the antibacterial agent is selected from nanosilver and / or graphene oxide (GO).

[0014] In some preferred embodiments, the binder is selected from at least one of polyethylene (PE), low-density polyethylene (LDPE) and ultra-high molecular weight polyethylene (UHMWPE);

[0015] The weight average molecular weight of polyethylene is 10,000-1,000,000 g / mol, and the melt index (MFI) is 1-10 g / 10 min;

[0016] The low-density polyethylene has a weight average molecular weight of 20,000-500,000 g / mol and a melt index (MFI) of 2-50 g / 10 min;

[0017] The weight average molecular weight of the ultra-high molecular weight polyethylene is 1,000,000-3,000,000 g / mol, and the melt index (MFI) is 0.1-1 g / 10 min.

[0018] In some preferred embodiments, the propellant is stearic acid and / or polyethylene wax. The propellant can improve the fluidity of the raw material.

[0019] In some preferred embodiments, the preparation method further comprises step (3): polishing and electrostatically removing the modified extruded activated carbon filter element at one time.

[0020] In some preferred embodiments, the dehydration operation is drying at 120-150° C. for 0.5 h.

[0021] A modified extruded activated carbon filter element is prepared by the above preparation method.

[0022] The present invention has at least the following beneficial effects: compared with traditional ordinary extruded activated carbon filter elements, this application optimizes the design of the formula to significantly improve the removal rate of heavy metals, chlorine and microorganisms of the modified extruded activated carbon filter element, while also having good mechanical strength, iodine adsorption performance and water flow rate. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0024] In the following examples, the water used can be one or more of distilled water, purified water, and drinking water; unless otherwise specified, the detection methods in the following examples are conventional detection methods; and the reagents in the following examples are purchased from commercial channels unless otherwise specified.

[0025] In the following examples and comparative examples, the prepared filter elements were cylindrical, 241 mm in length, 13 mm in inner diameter, and 71 mm in outer diameter. The polyethylene used in these examples and comparative examples had a weight-average molecular weight of 560,000 g / mol and a melt index (MFI) of 4.8 g / 10 min; the low-density polyethylene had a weight-average molecular weight of 340,000 g / mol and a melt index (MFI) of 18 g / 10 min; and the ultra-high molecular weight polyethylene had a weight-average molecular weight of 3,400,000 g / mol and a melt index (MFI) of 0.2 g / 10 min.

[0026] Example 1

[0027] This embodiment provides a modified extruded activated carbon filter element, the preparation method of which includes the following steps:

[0028] (1) Coconut shell carbon powder with a particle size range of 80-120 mesh was dried at 135 ° C for 0.5 h, then immersed in a 27 wt% ferrous sulfate solution (the mass volume ratio of coconut shell carbon powder to ferrous sulfate solution was 1 g: 8 mL), stirred for 18 h, washed with deionized water until neutral, and then dried at 130 ° C for 8 h to obtain modified activated carbon powder.

[0029] (2) Modified activated carbon powder, binder (PE), propellant (stearic acid), antibacterial agent (GO) and activated carbon fiber were mixed in a mass ratio of 75:15:3:2:5 to obtain a mixture;

[0030] (3) Extruding the mixed material to obtain a modified extruded activated carbon filter element at an extrusion temperature of 173° C. and an extrusion pressure of 7 MPa.

[0031] Example 2

[0032] This embodiment provides a modified extruded activated carbon filter element, the preparation method of which includes the following steps:

[0033] (1) Wood charcoal powder with a particle size range of 80-120 mesh was dried at 150°C for 0.5 h, then immersed in a 27 wt% ferrous sulfate solution (the mass volume ratio of wood charcoal powder to ferrous sulfate solution was 1 g:8 mL), stirred for 18 h, washed with deionized water until neutral, and then dried at 130°C for 8 h to obtain modified activated carbon powder.

[0034] (2) Modified activated carbon powder, binder (LDPE), propellant (stearic acid), antibacterial agent (nanosilver) and activated carbon fiber are mixed in a mass ratio of 75:15:3:2:5 to obtain a mixture;

[0035] (3) Extruding the mixed material to obtain a modified extruded activated carbon filter element at an extrusion temperature of 173° C. and an extrusion pressure of 7.5 MPa.

[0036] Example 3

[0037] This embodiment provides a modified extruded activated carbon filter element, the preparation method of which includes the following steps:

[0038] (1) Coconut shell carbon powder with a particle size range of 80-120 mesh was dried at 120 ° C for 0.5 h, then immersed in a 27 wt% ferrous sulfate solution (the mass volume ratio of coconut shell carbon powder to ferrous sulfate solution was 1 g: 8 mL), stirred for 18 h, washed with deionized water until neutral, and then dried at 130 ° C for 8 h to obtain modified activated carbon powder.

[0039] (2) Modified activated carbon powder, binder (UHMWPE), propellant (polyethylene wax), antibacterial agent (GO) and activated carbon fiber in a mass ratio of 75:15:3:2:5 were mixed to obtain a mixture;

[0040] (3) Extruding the mixed material to obtain a modified extruded activated carbon filter element at an extrusion temperature of 173° C. and an extrusion pressure of 7.5 MPa.

[0041] Comparative Example 1

[0042] Comparative Example 1 is a traditional sintered filter element purchased from JNC Filter brand.

[0043] Comparative Example 2

[0044] Comparative Example 2 is a traditional extruded activated carbon filter element, and its preparation method includes the following steps:

[0045] (1) Coconut shell carbon powder (particle size range 80-120 mesh), binder (LDPE), propellant (stearic acid) and activated carbon fiber are mixed in a mass ratio of 75:15:3:7 to obtain a mixture;

[0046] (2) The mixed material was extruded to obtain a modified extruded activated carbon filter element at an extrusion temperature of 173° C. and an extrusion pressure of 7.5 MPa to obtain a comparative extruded activated carbon filter element.

[0047] Performance Testing

[0048] In accordance with GB5749-2006, the sanitary standard for drinking water, heavy metals (hexavalent chromium, lead) and microorganisms (ATCC8739 Escherichia coli) were tested in 50 L of spiked water. In accordance with GB7702, the iodine adsorption value, mechanical strength, and water flow rate were tested. The test results are shown in Table 1.

[0049] Table 1 Performance characteristics of comparative examples 1, 2 and examples 1-3

[0050]

[0051] As can be seen from Table 1, the residual chlorine removal rate, microbial removal rate and heavy metal removal rate of Examples 1-3 are significantly better than those of Comparative Example 1 and Comparative Example 2. At the same time, Examples 1-3 also have good iodine value, mechanical strength and water throughput.

[0052] The above description is merely a preferred embodiment of the present invention and therefore cannot be used to limit the scope of the present invention. In other words, equivalent changes and modifications made within the scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A method for preparing a modified extruded activated carbon filter element, characterized in that: The steps include: (1) dehydrating the activated carbon powder to a water content of less than 5%, then immersing the dehydrated activated carbon powder in a 27 wt % ferrous sulfate solution, stirring for 18 h, washing until neutral, and drying to obtain a modified activated carbon powder; (2) mixing the modified activated carbon powder, the binder, the propellant, the antibacterial agent and the activated carbon fiber in a mass ratio of 70-80:10-15:3-5:1-2:2-3 to obtain a mixture; (3) extruding the mixed material to obtain the modified extruded activated carbon filter element; The mass volume ratio of the dehydrated activated carbon powder to the ferrous sulfate solution is 1 g:8 mL. 2 . The preparation method according to claim 1 , wherein the extrusion temperature is 150-200° C. and the extrusion pressure is 5-10 MPa.

3. The preparation method according to claim 1 or 2, wherein The activated carbon powder is coconut shell carbon powder and / or wood carbon powder.

4. The preparation method according to claim 3, wherein The particle size of the activated carbon powder is 80-120 meshes.

5. The preparation method according to claim 1, wherein The antibacterial agent is selected from nanosilver and / or graphene oxide.

6. The preparation method according to claim 1, wherein The adhesive is selected from at least one of polyethylene, low-density polyethylene and ultra-high molecular weight polyethylene; The polyethylene has a weight average molecular weight of 10,000-1,000,000 g / mol and a melt index of 1-10 g / 10 min; The low-density polyethylene has a weight average molecular weight of 20,000-500,000 g / mol and a melt index of 2-50 g / 10 min; The ultra-high molecular weight polyethylene has a weight average molecular weight of 1,000,000-3,000,000 g / mol and a melt index of 0.1-1 g / 10 min.

7. The preparation method according to claim 1, wherein The propellant is stearic acid and / or polyethylene wax.

8. The preparation method according to claim 1, wherein The method further comprises step (3): performing polishing treatment and electrostatic dust removal on the modified extruded activated carbon filter element at one time.

9. The preparation method according to claim 1, wherein The dehydration operation is drying at 120-150° C. for 0.5 h.

10. A modified extruded activated carbon filter element, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

Images