Decoloring flocculant and preparation method thereof

Abstract

The invention provides a decolorizing flocculant and a preparation method thereof, and the decolorizing flocculant is mainly prepared from the following raw materials in parts by mass: 10-20 parts of polyferric sulfate, 8-16 parts of polyferric aluminum sulfate, 2-5 parts of sodium humate, 18-33 parts of poly dimethyl diallyl ammonium chloride, 28-48 parts of dicyandiamide formaldehyde resin and 30-45 parts of deionized water. The decolorizing flocculant provided by the invention has a good decolorizing effect, also has the coagulating sedimentation performance of a traditional flocculant, and can effectively solve the problems of high effluent chromaticity and high chemical oxygen demand in wastewater treatment in the prior art.

Description

Technical Field

[0001] The invention relates to the field of flocculant preparation, and in particular to a decolorizing flocculant and a preparation method thereof. Background Art

[0002] The amount of wastewater from printing and dyeing factories is large. Each printing and dyeing process of 1 ton of textile consumes 100 to 200 tons of water, of which 80% to 90% is discharged as wastewater. Printing and dyeing wastewater has the characteristics of large water volume, high content of organic pollutants, high alkalinity, and large changes in water quality. It is one of the difficult-to-treat industrial wastewaters. The wastewater contains dyes, slurries, additives, oils, acids and alkalis, fiber impurities, sand substances, inorganic salts, etc. The large-scale discharge of printing and dyeing wastewater has become one of the important factors threatening the safety of my country's water environment. Therefore, it is of great practical significance to seek an efficient remover for organic wastewater.

[0003] At present, activated carbon, activated clay, polyiron, polyaluminum, etc. are commonly used in China to decolorize and flocculate industrial wastewater, but the decolorization effect is not very ideal. For the treatment of printing and dyeing wastewater, it is very necessary to develop a flocculation agent with good decolorization effect.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The first purpose of the present invention is to provide a decolorizing flocculant with a simple formula, which has a good decolorizing effect while taking into account the coagulation and sedimentation performance of traditional flocculants, and can effectively solve the problems of high chromaticity and high chemical oxygen demand of effluent in wastewater treatment in the prior art.

[0006] The second object of the present invention is to provide a method for preparing the above-mentioned decolorizing flocculant, which is simple to operate, has mild operating conditions, has few impurities, and has little waste, and can achieve the best effect of cleaning wastewater.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted: The invention provides a decolorizing flocculant, which is mainly prepared from the following raw materials: by weight, 10-20 parts of polyferric sulfate, 8-16 parts of polyaluminium ferric sulfate, 2-5 parts of sodium humate, 18-33 parts of polydimethyldiallylammonium chloride, 28-48 parts of dicyandiamide formaldehyde resin and 30-45 parts of deionized water.

[0008] Preferably, as a further feasible scheme, in parts by mass, there are 12-18 parts of polyferric sulfate, 9-14 parts of polyaluminium ferric sulfate, 3-4 parts of sodium humate, 19-27 parts of polydimethyldiallylammonium chloride, 30-40 parts of dicyandiamide formaldehyde resin, and 35-40 parts of deionized water.

[0009] Preferably, as a further feasible scheme, 15 parts of polyferric sulfate, 10 parts of polyaluminium ferric sulfate, 3.5 parts of sodium humate, 25 parts of polydimethyldiallylammonium chloride, 35 parts of dicyandiamide formaldehyde resin, and 37 parts of deionized water are used.

[0010] In the present invention, both polydimethyldiallylammonium chloride and dicyandiamide formaldehyde resin provide a large amount of cations to neutralize the negative charges attached to the dye molecules in the wastewater, thereby making them unstable, and finally generating a large amount of flocs, which can adsorb the dye molecules after flocculation and destabilization, thereby achieving the purpose of decolorization, and the combination of the two can play a synergistic role; polyferric sulfate and polyaluminium ferric sulfate are both excellent inorganic flocculants, which can well remove the flocs produced by oxidation and reaction, thereby achieving the purpose of removing the chromaticity in the wastewater; sodium humate is non-toxic, odorless and non-corrosive, is a multifunctional high molecular compound, contains a large number of active groups such as hydroxyl, quinone, carboxyl, etc., has a large internal surface area, and has strong adsorption, exchange, complexation and chelation capabilities.

[0011] In the above formula, it is necessary to pay attention to the dosage relationship between each substance. The dosage of each substance needs to be controlled within a reasonable range, because if the dosage of any component is too large, it will cover up the effect of other components. Although the stability is improved, the cleaning effect will be affected. Therefore, in addition to paying attention to the specific combination between the formulas, you must also pay attention to the compatibility relationship between the dosages.

[0012] The present invention also provides a method for preparing a decolorizing flocculant, comprising the following steps: First add deionized water, then add polyferric sulfate, polyaluminium ferric sulfate and sodium humate in sequence and stir, then add polydimethyldiallylammonium chloride and stir, and finally add dicyandiamide formaldehyde resin.

[0013] Preferably, as a further feasible solution, polyferric sulfate, polyaluminium ferric sulfate and sodium humate are added in sequence with a stirring rate of 70-100 rpm and a stirring time of 20-40 min.

[0014] Preferably, as a further feasible solution, polydimethyldiallylammonium chloride is then added and stirred for more than 45 minutes.

[0015] Preferably, as a further feasible solution, the stirring time for finally adding the dicyandiamide formaldehyde resin is more than 30 minutes.

[0016] By limiting each operating parameter in the preparation method, the quality of the prepared decolorizing flocculant is improved, and the decolorizing flocculant of the present invention is better applied to wastewater treatment, and the synergistic effect between the inorganic flocculant and the organic flocculant can be better exerted, and the invention has the characteristics of low investment cost, low operating cost, low effluent chromaticity, etc. The scheme of the present invention is of great significance to social environmental governance. DETAILED DESCRIPTION

[0017] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0018] Example 1 The specific preparation process of the decolorizing flocculant is carried out according to the following steps: The decolorizing flocculant was weighed according to the following mass: 10 kg of polyferric sulfate, 8 kg of polyaluminium ferric sulfate, 2 kg of sodium humate, 18 kg of polydimethyldiallylammonium chloride, 28 kg of dicyandiamide formaldehyde resin, and 45 kg of deionized water.

[0019] First add deionized water into the reactor, then add polyferric sulfate, polyaluminum ferric sulfate, and sodium humate in sequence, stir at 80 rpm for 30 minutes, add polydimethyldiallylammonium chloride, stir for 45 minutes, and finally add dicyandiamide formaldehyde resin, stir evenly to obtain the product.

[0020] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 15 times, reaching the national Class A emission standard.

[0021] Example 2 The specific preparation process of the decolorizing flocculant is carried out according to the following steps: The decolorizing flocculant was weighed according to the following mass: 20 kg of polyferric sulfate, 16 kg of polyaluminium ferric sulfate, 5 kg of sodium humate, 33 kg of polydimethyldiallylammonium chloride, 48 kg of dicyandiamide formaldehyde resin, and 30 kg of deionized water.

[0022] First add deionized water into the reactor, then add polyferric sulfate, polyaluminum ferric sulfate, and sodium humate in sequence, stir at 70 rpm for 20 minutes, add polydimethyldiallylammonium chloride, stir for 50 minutes, and finally add dicyandiamide formaldehyde resin, stir for 30 minutes to obtain the product.

[0023] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 14 times, reaching the national Class A emission standard.

[0024] Example 3 The specific preparation process of the decolorizing flocculant is carried out according to the following steps: The decolorizing flocculant was weighed according to the following mass: 12 kg of polyferric sulfate, 14 kg of polyaluminium ferric sulfate, 3 kg of sodium humate, 27 kg of polydimethyldiallylammonium chloride, 30 kg of dicyandiamide formaldehyde resin, and 40 kg of deionized water.

[0025] First add deionized water into the reactor, then add polyferric sulfate, polyaluminum ferric sulfate, and sodium humate in sequence, stir at 100 rpm for 40 minutes, add polydimethyldiallylammonium chloride, stir for 50 minutes, and finally add dicyandiamide formaldehyde resin, stir for 30 minutes to obtain the product.

[0026] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 13 times, reaching the national Class A emission standard.

[0027] Example 4 The specific preparation process of the decolorizing flocculant is carried out according to the following steps: The decolorizing flocculant was weighed according to the following mass: 18 kg of polyferric sulfate, 9 kg of polyaluminium ferric sulfate, 4 kg of sodium humate, 19 kg of polydimethyldiallylammonium chloride, 40 kg of dicyandiamide formaldehyde resin, and 35 kg of deionized water.

[0028] First add deionized water into the reactor, then add polyferric sulfate, polyaluminum ferric sulfate, and sodium humate in sequence, stir at 80 rpm for 30 minutes, add polydimethyldiallylammonium chloride, stir for 60 minutes, and finally add dicyandiamide formaldehyde resin, stir for 40 minutes to obtain the product.

[0029] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 13 times, reaching the national Class A emission standard.

[0030] Example 5 The specific preparation process of the decolorizing flocculant is carried out according to the following steps: The decolorizing flocculant was weighed according to the following mass: 15 kg of polyferric sulfate, 10 kg of polyaluminium ferric sulfate, 3.5 kg of sodium humate, 25 kg of polydimethyldiallylammonium chloride, 35 kg of dicyandiamide formaldehyde resin, and 37 kg of deionized water.

[0031] First add deionized water into the reactor, then add polyferric sulfate, polyaluminum ferric sulfate, and sodium humate in sequence, stir at 80 rpm for 30 minutes, add polydimethyldiallylammonium chloride, stir for 60 minutes, and finally add dicyandiamide formaldehyde resin, stir for 40 minutes to obtain the product.

[0032] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 10 times, reaching the national Class A emission standard.

[0033] Example 6 The specific preparation process of the decolorizing flocculant is carried out according to the following steps: The decolorizing flocculant was weighed according to the following mass: 14 kg of polyferric sulfate, 12 kg of polyaluminium ferric sulfate, 3.5 kg of sodium humate, 25 kg of polydimethyldiallylammonium chloride, 41 kg of dicyandiamide formaldehyde resin, and 38 kg of deionized water.

[0034] First add deionized water into the reactor, then add polyferric sulfate, polyaluminum ferric sulfate, and sodium humate in sequence, stir at 80 rpm for 30 minutes, add polydimethyldiallylammonium chloride, stir for 60 minutes, and finally add dicyandiamide formaldehyde resin, stir for 40 minutes to obtain the product.

[0035] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 11 times, reaching the national Class A emission standard.

[0036] Comparative Example 1 The specific operation steps are the same as those in Example 5, except that polydimethyldiallylammonium chloride is not added.

[0037] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 30 times, reaching the national Class I B emission standard.

[0038] Comparative Example 2 The specific operation steps are the same as those in Example 5, except that polyaluminium ferric sulfate is not added.

[0039] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 33 times, reaching the national Class I B emission standard.

[0040] Comparative Example 3 The specific operation steps are the same as those in Example 5, except that no dicyandiamide formaldehyde resin is added.

[0041] In the printing and dyeing wastewater with a chromaticity of 300 times, 250 mg / l of a decolorizing flocculant was added, stirred at a speed of 120 rpm for 3 minutes, and settled for 30 minutes. The chromaticity of the effluent wastewater was 28 times, reaching the national Class I B emission standard.

[0042] Although the present invention has been illustrated and described with specific embodiments, it will be appreciated that many other changes and modifications may be made without departing from the spirit and scope of the present invention. Therefore, it is intended to include all such changes and modifications within the scope of the present invention in the appended claims.

Claims

1. A decolorizing flocculant, characterized in that: The invention is mainly prepared from the following raw materials: by weight, 10-20 parts of polyferric sulfate, 8-16 parts of polyaluminium ferric sulfate, 2-5 parts of sodium humate, 18-33 parts of polydimethyldiallylammonium chloride, 28-48 parts of dicyandiamide formaldehyde resin and 30-45 parts of deionized water.

2. The decolorizing flocculant according to claim 1, characterized in that: In parts by mass, the ingredients include 12-18 parts of polyferric sulfate, 9-14 parts of polyaluminium ferric sulfate, 3-4 parts of sodium humate, 19-27 parts of polydimethyldiallylammonium chloride, 30-40 parts of dicyandiamide formaldehyde resin and 35-40 parts of deionized water.

3. The decolorizing flocculant according to claim 1, characterized in that In parts by mass, there are 15 parts of polyferric sulfate, 10 parts of polyaluminium ferric sulfate, 3.5 parts of sodium humate, 25 parts of polydimethyldiallylammonium chloride, 35 parts of dicyandiamide formaldehyde resin and 37 parts of deionized water.

4. The method for preparing the decolorizing flocculant according to any one of claims 1 to 3, characterized in that: The steps include: First add deionized water, then add polyferric sulfate, polyaluminium ferric sulfate and sodium humate in sequence and stir, then add polydimethyldiallylammonium chloride and stir, and finally add dicyandiamide formaldehyde resin.

5. The preparation method according to claim 4, characterized in that: Polyferric sulfate, polyaluminium ferric sulfate and sodium humate are added in sequence, and the stirring rate is 70-100 rpm, and the stirring time is 20-40 min.

6. The preparation method according to claim 4, characterized in that: Then add polydimethyldiallylammonium chloride and stir for more than 45 minutes.

7. The preparation method according to claim 4, characterized in that: Finally, add dicyandiamide formaldehyde resin and stir for more than 30 minutes.