Method for preparing chitosan-like efficient flocculant

A technology of flocculant and chitosan, which is applied in the field of preparation of high-efficiency chitosan flocculants, can solve the problems of high production cost, achieve convenient application, good effect, and be conducive to industrial production

Active Publication Date: 2013-03-20
ZHEJIANG SILK TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] At present, the existing dicyandiamide-formaldehyde and chitosan flocculants use glutaraldehyde as a

Method used

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  • Method for preparing chitosan-like efficient flocculant

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The preparation method of chitosan high-efficiency flocculant, carries out following steps successively:

[0021] 1) Chitosan pretreatment: dissolve chitosan in acetic acid solution with pH=5, stir evenly, add alkali to pH=9 to precipitate chitosan, and suction filter for later use;

[0022] 2) Preparation of high-efficiency flocculant: Take 1 part of chitosan, 3 parts of glutaraldehyde crosslinking agent, 1 part of urea, and 1.5 parts of aluminum sulfate in a four-necked flask, stir, and pre-react in a water bath at 60 ° C for 1 Hour; Then add 2.1 parts of dicyandiamide, 0.9 part of urea, continue to react for 2 hours, obtain urea-chitosan-dicyandiamide composite flocculant;

[0023] 3) Purification of the product: After the reaction is completed, the product is precipitated with acetone, filtered with suction, and then washed with ethanol, filtered with suction and dried in an oven at 90°C for later use.

[0024] The flocculant obtained in Example 1 above was used to...

Embodiment 2

[0028] The preparation method of chitosan high-efficiency flocculant, carries out following steps successively:

[0029] 1) Pretreatment of carboxymethyl chitosan: dissolve carboxymethyl chitosan in acetic acid solution with pH=5, stir evenly, add alkali to pH=9 to precipitate carboxymethyl chitosan, and filter with suction.

[0030] 2) Preparation of high-efficiency flocculant: Take 2 parts of carboxymethyl chitosan, 5 parts of glyoxal crosslinking agent, 1 part of urea, and 3 parts of aluminum sulfate in a four-necked flask, stir, and pre- React for 0.5 hours. Then add 2.4 parts of dicyandiamide and 0.6 part of urea, and continue to react for 4 hours to obtain urea-chitosan-dicyandiamide composite flocculant;

[0031] 3) Purification of the product: After the reaction is completed, the product is precipitated with acetone, filtered with suction, and then washed with ethanol, filtered with suction and dried in an oven at 90°C for later use.

[0032] The flocculant obtained ...

Embodiment 3

[0036] The preparation method of chitosan high-efficiency flocculant, carries out following steps successively:

[0037] 1) Pretreatment of 0-hydroxyethyl chitosan: dissolve 0-hydroxyethyl chitosan in acetic acid solution with pH=5, stir evenly, add alkali to pH=9 to make O-hydroxyethyl chitosan The sugar precipitated out and was filtered by suction.

[0038] 2) Preparation of high-efficiency flocculant: Take 1.5 parts of the above-mentioned O-hydroxyethyl chitosan, 4 parts of glutaraldehyde crosslinking agent, 1 part of urea, and 2 parts of aluminum sulfate in a four-necked flask, stir, and place in a 70°C water bath Medium pre-reaction for 0.8 hours. Then add 2.4 parts of dicyandiamide and 0.6 part of urea, and continue to react for 3 hours to obtain urea-chitosan-dicyandiamide composite flocculant;

[0039] 3) Purification of the product: After the reaction is completed, the product is precipitated with acetone, filtered with suction, and then washed with ethanol, filtere...

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Abstract

The invention discloses a method for preparing chitosan-like efficient flocculant, which comprises the following steps of: (1) pre-treatment of chitosan and derivatives of chitosan: dissolving chitosan and derivatives of chitosan in an acetic acid solution with pH value being 5, uniformly stirring, adding alkali until the pH value is 9 and chitosan separates out, and carrying out suction filtration for later use; (2) preparation of efficient flocculant: adding 1-2 parts of the pre-treated chitosan and derivatives of chitosan, 3-5 parts of cross-linking agents, 1 part of carbamide and 1.5-3 parts of aluminum sulfate in a four-port flask, stirring, pre-reacting for 0.5-1h in a water bath at 60-80 DEG C, then adding 3-8 parts of a dicyandiamide and carbamide mixed modifier, continuing to react for 2-4h, to obtain carbamide-chitosan-dicyandiamide like composite flocculant; and (3) purification of the product: after the reaction, separating out the product by using acetone; carrying out suction filtration; washing the product with ethanol; carrying out suction filtration, and drying in an oven at 90 DEG C for further use.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and in particular relates to a preparation method of a chitosan high-efficiency flocculant. Background technique [0002] China is a big country in textile printing and dyeing. Tens of thousands of tons of wastewater are discharged every day. Printing and dyeing wastewater has the characteristics of large water volume, high chroma, high COD value and difficult biodegradation. It is difficult to treat and the treatment effect is poor. At present, the coagulation method, which is relatively easy to operate, is usually used to treat printing and dyeing wastewater, mainly using aluminum salts, iron salts and polyacrylamide coagulants. However, these coagulants have their own shortcomings and deficiencies. When the concentration of aluminum ions in water is greater than 0.5 mg / L, it can kill salmon and have toxic effects on soil, plants and microorganisms; and iron salt itself has a light gre...

Claims

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Application Information

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IPC IPC(8): C08B37/08C08J3/24C08L5/08C02F1/56
Inventor 骆文贤
Owner ZHEJIANG SILK TECH
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