A method for absorbing disperse dyes in printing and dyeing wastewater by using modified cotton powder

Abstract

The present invention relates to the technical field of wastewater treatment, and discloses a method for adsorbing disperse dyes in printing and dyeing wastewater using modified cotton powder. The method comprises: (1) mixing ethanol, cotton powder, acrylate and water to obtain a mixed material; (2) adding a silane coupling agent and an initiator to the mixed material in sequence, then reacting under stirring, and then centrifuging, washing and drying to obtain a modified cotton powder; (3) mixing and contacting the modified cotton powder with printing and dyeing wastewater containing disperse dyes; wherein the particle size of the cotton powder is 20-30 μm; and the weight ratio of the amount of the cotton powder, acrylate and silane coupling agent is 1:1-3:0.5-1. The present invention modifies the cotton powder by acrylate and silane coupling agent, and the obtained modified cotton powder can effectively adsorb disperse dyes in printing and dyeing wastewater.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a method for utilizing modified cotton powder to absorb disperse dyes in printing and dyeing wastewater. Background Art

[0002] Printing and dyeing wastewater mainly comes from the pretreatment, printing, dyeing, finishing and other processes in the printing and dyeing process. The amount of printing and dyeing wastewater discharged is large, accounting for about 70-90% of its water consumption.

[0003] Disperse dyes are slightly soluble in water and are highly dispersed in water with the help of dispersants. Therefore, the dyeing process usually requires the use of auxiliaries to increase the diffusion rate of dye molecules. Based on this, disperse dye printing and dyeing wastewater contains a large amount of residual dyes and auxiliaries, and has a deep chromaticity. Therefore, disperse dye printing and dyeing wastewater has the characteristics of high concentration, high chromaticity and difficulty in degradation, and belongs to difficult-to-degrade industrial organic wastewater. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems of complex printing and dyeing wastewater treatment process and low disperse dye removal efficiency in the prior art, and to provide a method for absorbing disperse dyes in printing and dyeing wastewater by using modified cotton powder.

[0005] In order to achieve the above object, the present invention provides a method for absorbing disperse dyes in printing and dyeing wastewater by using modified cotton powder, and the method comprises the following steps:

[0006] (1) mixing ethanol, cotton powder, acrylate and water to obtain a mixed material;

[0007] (2) adding a silane coupling agent and an initiator to the mixture in sequence, reacting the mixture under stirring, and then centrifuging, washing and drying the mixture to obtain a modified cotton powder;

[0008] (3) mixing and contacting the modified cotton powder with printing and dyeing wastewater containing disperse dyes;

[0009] Wherein, the particle size of the cotton powder is 20-30 μm;

[0010] The weight ratio of the cotton powder, acrylate and silane coupling agent is 1:1-3:0.5-1.

[0011] Preferably, the preparation process of the cotton powder comprises: cutting, crushing and ball milling the cotton in sequence to obtain the cotton powder.

[0012] Preferably, in step (1), the weight ratio of cotton powder to water is 1:5-15.

[0013] Preferably, in step (1), the weight ratio of cotton powder to ethanol is 1:0.5-1.5.

[0014] Preferably, the initiator is a persulfate, preferably ammonium persulfate.

[0015] Preferably, the weight ratio of the cotton powder to the initiator is 1:0.02-0.1.

[0016] Preferably, the acrylic acid ester is selected from one or more of butyl methacrylate, lauryl methacrylate, hydroxypropyl methacrylate, isooctyl acrylate and n-butyl acrylate.

[0017] Preferably, the silane coupling agent is selected from one or more of vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tri(β-methoxyethoxy) silane, vinyl tri-tert-butoxy silane and vinyl triacetoxy silane.

[0018] Preferably, in step (2), the reaction conditions include: temperature of 75-100° C. and time of 40-90 min.

[0019] Preferably, the disperse dye is selected from at least one of disperse blue, disperse black, disperse gray, disperse red, disperse violet and disperse yellow.

[0020] In the method of the present invention, cotton is treated to obtain cotton powder with a large specific surface area, and then the cotton powder is modified by using acrylate and silane coupling agent together, so that the surface of the cotton powder has more hydrophobic groups and active sites. The modified cotton powder obtained by the above scheme can effectively adsorb disperse dyes in printing and dyeing wastewater. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0022] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0023] The present invention provides a method for absorbing disperse dyes in printing and dyeing wastewater by using modified cotton powder, and the method comprises the following steps:

[0024] (1) mixing ethanol, cotton powder, acrylate and water to obtain a mixed material;

[0025] (2) adding a silane coupling agent and an initiator to the mixture in sequence, reacting the mixture under stirring, and then centrifuging, washing and drying the mixture to obtain a modified cotton powder;

[0026] (3) mixing and contacting the modified cotton powder with printing and dyeing wastewater containing disperse dyes;

[0027] Wherein, the particle size of the cotton powder is 20-30 μm;

[0028] The weight ratio of the cotton powder, acrylate and silane coupling agent is 1:1-3:0.5-1.

[0029] In a specific embodiment, the weight ratio of the cotton powder to the acrylic ester can be 1:1, 1:1.2, 1:1.5, 1:2, 1:2.2, 1:2.5, 1:2.8 or 1:3.

[0030] In a specific embodiment, the weight ratio of the cotton powder to the silane coupling agent can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1.

[0031] In the present invention, cotton powder with smaller particle size and larger specific surface area is obtained by processing cotton, which can provide more modification sites, facilitate later modification, and thus improve the adsorption performance of the modified material for disperse dyes.

[0032] In a preferred embodiment, the preparation process of the cotton powder comprises: cutting, crushing and ball milling the cotton in sequence to obtain the cotton powder.

[0033] In a specific embodiment, the cutting may be performed using a cutting machine commonly used in the art to cut the cotton into pieces of similar size, which is beneficial for the subsequent crushing process.

[0034] In a specific embodiment, the pulverization can be performed using a pulverizer commonly used in the art. The rotation speed of the pulverizer can be 2800-3000 rpm.

[0035] In a preferred embodiment, in step (1), the weight ratio of cotton powder to water is 1:5-15. Specifically, it can be 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, or 1:15.

[0036] In a preferred embodiment, in step (1), the weight ratio of cotton powder to ethanol is 1:0.5-1.5. Specifically, it can be 1:0.5, 1:0.7, 1:0.8, 1:1, 1:1.2 or 1.5.

[0037] In a preferred embodiment, the initiator is a persulfate, more preferably ammonium persulfate.

[0038] In order to further promote the adsorption effect of the modified cotton powder on disperse dyes, in a preferred embodiment, the weight ratio of the cotton powder to the initiator is 1:0.02-0.1. Specifically, it can be 1:0.02, 1:0.05, 1:0.07, 1:0.08 or 1:0.1.

[0039] In order to provide more adsorption sites and promote the adsorption effect of the modified cotton powder on disperse dyes, preferably, in a preferred embodiment, the acrylate is selected from one or more of butyl methacrylate, lauryl methacrylate, hydroxypropyl methacrylate, isooctyl acrylate and n-butyl acrylate. More preferably, it is isooctyl acrylate and / or lauryl methacrylate.

[0040] In order to provide more adsorption sites and promote the adsorption effect of modified cotton powder on disperse dyes, preferably, in a preferred embodiment, the silane coupling agent is selected from one or more of vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tri (β-methoxyethoxy) silane, vinyl tri-tert-butoxy silane and vinyl triacetoxy silane. More preferably, it is vinyl tri (β-methoxyethoxy) silane and / or vinyl tri-tert-butoxy silane.

[0041] In a preferred embodiment, in order to make the reaction in step (2) proceed better, in step (1), the mixing method is ultrasonic mixing, and the mixing temperature is 40-50°C.

[0042] In a preferred embodiment, in step (2), the reaction conditions include: a temperature of 75-100°C and a time of 40-90 min. Specifically, the reaction temperature may be 75°C, 80°C, 82°C, 85°C, 90°C, 95°C or 100°C; and the reaction time may be 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min or 90 min.

[0043] In a preferred embodiment, in step (2), the stirring rate during the reaction under stirring is 500-1000 rpm.

[0044] In a preferred embodiment, in step (2), the washing process includes: mixing the material to be washed with a washing liquid, and then centrifuging.

[0045] The modified cotton powder of the present invention exhibits excellent adsorption performance for a variety of disperse dyes. The disperse dye can be selected from at least one of disperse blue, disperse black, disperse gray, disperse red, disperse violet and disperse yellow.

[0046] In a preferred embodiment, in step (3), the volume ratio of the modified cotton powder to the printing and dyeing wastewater containing disperse dyes is 1:3-15, preferably 1:5-10.

[0047] In a preferred embodiment, in step (3), the process of mixing and contacting the modified cotton powder with the printing and dyeing wastewater containing disperse dyes is carried out under stirring.

[0048] In a preferred embodiment, in step (3), the modified cotton powder is mixed with the printing and dyeing wastewater containing disperse dyes for a contact time of 1-3 hours.

[0049] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0050] Example 1

[0051] (1) mixing ethanol, cotton powder, acrylate (isooctyl acrylate) and water at 45° C. to obtain a mixed material;

[0052] (2) adding a silane coupling agent (vinyl tri-tert-butyloxysilane) and an initiator (ammonium persulfate) to the mixture in sequence, reacting the mixture at 95° C. for 55 min under stirring, and then centrifuging, washing and drying the mixture to obtain modified cotton powder S1;

[0053] (3) Under stirring, the modified cotton powder S1 is added to the printing and dyeing wastewater containing disperse red, the volume ratio of the two is 1:8, the mixture is mixed and contacted for 2 hours, and the solid-liquid separation is performed to obtain the treated printing and dyeing wastewater A1;

[0054] Among them, the particle size of the cotton powder is 20-30 μm, the weight ratio of cotton powder, acrylate and silane coupling agent is 1:2:0.8, the weight ratio of cotton powder to water is 1:10, the weight ratio of cotton powder to ethanol is 1:1, and the weight ratio of cotton powder to initiator is 1:0.05.

[0055] Example 2

[0056] (1) mixing ethanol, cotton powder, acrylate (isooctyl acrylate) and water at 45° C. to obtain a mixed material;

[0057] (2) adding a silane coupling agent (vinyl tri-tert-butyloxysilane) and an initiator (ammonium persulfate) to the mixture in sequence, reacting the mixture at 85° C. for 65 min under stirring, and then centrifuging, washing and drying the mixture to obtain modified cotton powder S2;

[0058] (3) under stirring, the modified cotton powder S2 is added to the printing and dyeing wastewater containing disperse red, the volume ratio of the two is 1:8, the mixture is mixed and contacted for 2 hours, and the solid-liquid separation is performed to obtain the treated printing and dyeing wastewater A2;

[0059] Among them, the particle size of the cotton powder is 20-30 μm, the weight ratio of cotton powder, acrylate and silane coupling agent is 1:2.2:0.6, the weight ratio of cotton powder to water is 1:12, the weight ratio of cotton powder to ethanol is 1:1, and the weight ratio of cotton powder to initiator is 1:0.05.

[0060] Example 3

[0061] (1) mixing ethanol, cotton powder, acrylate (isooctyl acrylate) and water at 40° C. to obtain a mixed material;

[0062] (2) adding a silane coupling agent (vinyl tri-tert-butyloxysilane) and an initiator (ammonium persulfate) to the mixture in sequence, reacting the mixture at 85° C. for 65 min under stirring, and then centrifuging, washing and drying the mixture to obtain modified cotton powder S3;

[0063] (3) under stirring, the modified cotton powder S3 is added to the printing and dyeing wastewater containing disperse red, the volume ratio of the two is 1:8, the mixture is mixed and contacted for 2 hours, and the solid-liquid separation is performed to obtain the treated printing and dyeing wastewater A3;

[0064] Among them, the particle size of the cotton powder is 20-30 μm, the weight ratio of the cotton powder, acrylate and silane coupling agent is 1:1.5:1.6, the weight ratio of cotton powder to water is 1:12, the weight ratio of cotton powder to ethanol is 1:1, and the weight ratio of cotton powder to initiator is 1:0.07.

[0065] Example 4

[0066] The method described in Example 1 was followed, except that the acrylate was hydroxypropyl methacrylate, to obtain treated printing and dyeing wastewater A4.

[0067] Comparative Example 1

[0068] The method described in Example 1 was followed, except that no acrylate was used in step (1), to obtain treated printing and dyeing wastewater D1.

[0069] Comparative Example 2

[0070] The method described in Example 1 is used, except that no silane coupling agent is used in step (2), to obtain treated printing and dyeing wastewater D2.

[0071] Comparative Example 3

[0072] The method described in Example 1 was followed, except that the weight ratio of cotton powder, acrylate and silane coupling agent was 1:0.8:0.2 to obtain treated printing and dyeing wastewater D3.

[0073] Comparative Example 4

[0074] The method described in Example 1 was used, except that the particle size of the cotton powder was 35-40 μm to obtain treated printing and dyeing wastewater D4.

[0075] Test Case

[0076] The content of disperse dyes in the printing and dyeing wastewater and the treated printing and dyeing wastewater in the above-mentioned embodiments and comparative examples is detected. The specific detection method is: the printing and dyeing wastewater and the treated printing and dyeing wastewater are diluted, dissolved, separated and filtered respectively, and then detected by high performance liquid chromatography, and the weight percentage (X%) of the disperse dyes in the treated printing and dyeing wastewater to the disperse dyes in the printing and dyeing wastewater before treatment is calculated by the measured high performance liquid chromatography peak area. The results are shown in Table 1 below.

[0077] Table 1

[0078] serial number X％ Example 1 3.1％ Example 2 3.5％ Example 3 3.4％ Example 4 5.3％ Comparative Example 1 38.3％ Comparative Example 2 30.7％ Comparative Example 3 9.8％ Comparative Example 4 8.5％

[0079] It can be seen from Table 1 that the method according to the present invention can effectively adsorb disperse dyes in printing and dyeing wastewater.

[0080] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for absorbing disperse dyes in printing and dyeing wastewater using modified cotton powder, characterized in that: The method comprises the following steps: (1) mixing ethanol, cotton powder, acrylate and water to obtain a mixed material; (2) adding a silane coupling agent and an initiator to the mixture in sequence, reacting the mixture under stirring, and then centrifuging, washing and drying the mixture to obtain a modified cotton powder; (3) mixing and contacting the modified cotton powder with printing and dyeing wastewater containing disperse dyes; Wherein, the particle size of the cotton powder is 20-30 μm; The weight ratio of the cotton powder, acrylate and silane coupling agent is 1:1-3:0.5-1; The acrylic acid ester is selected from one or more of butyl methacrylate, hydroxypropyl methacrylate, isooctyl acrylate and n-butyl acrylate; In step (1), the weight ratio of cotton powder to water is 1:5-15, and the weight ratio of cotton powder to ethanol is 1:0.5-1.5; The disperse dye is selected from at least one of disperse blue, disperse black, disperse gray, disperse red, disperse violet and disperse yellow; The preparation process of the cotton powder comprises: cutting, crushing and ball-milling the cotton in sequence to obtain the cotton powder; The silane coupling agent is selected from one or more of vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri(β-methoxyethoxy)silane, vinyl tri-tert-butoxysilane and vinyl triacetoxysilane.

2. The method according to claim 1, characterized in that The initiator is persulfate.

3. The method according to claim 2, characterized in that The initiator is ammonium persulfate.

4. The method according to claim 1, characterized in that: The weight ratio of the cotton powder to the initiator is 1:0.02-0.

1.

5. The method according to any one of claims 1 to 4, characterized in that: In step (2), the reaction conditions include: temperature of 75-100° C. and time of 40-90 min.