Method for preparing heavy metal ion adsorption resin by taking chitosan oligosaccharide as porogen

A heavy metal ion, adsorption resin technology, applied in chemical instruments and methods, other chemical processes, etc., can solve the problems of difficult granulation of cross-linked chitosan, limited application scope, slow sedimentation, etc., and achieve non-toxic biological phase. Capacitance, increase mechanical properties, the effect of simple method

Active Publication Date: 2014-07-09
OCEAN UNIV OF CHINA
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Problems solved by technology

Early studies found that when chitosan was used to adsorb metal ions in an acidic environment, the -NH in the molecule would 2 is protonated to form -NH 3 + Dissolving in water causes the loss of the adsorbent, which is not conducive to regeneration and utilization. At the same time, -NH 3 + Repulsion with metal cations limits its range of applications
Cross-linking chitosan by glutaraldehyde, formaldehyde, epichlorohydrin, etc. can make chitosan insoluble in acid, but research has found that cross-linked chitosan is difficult to granulate, has low density, and settles from the solution The speed is slow, and the cross-linking agent will occupy the adsorption sites of chitosan, reducing its adsorption performance

Method used

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preparation example Construction

[0009] A preparation method of a heavy metal ion adsorption resin using chitosan oligosaccharide as a porogen. The specific method includes the following steps: (1) making the viscosity between 15~45 cps and the degree of deacetylation between 85%~95%. The chitosan in between is dissolved in 2% acetic acid or lactic acid aqueous solution, and after it is completely dissolved, chitosan oligosaccharide with a molecular weight between 2000 and 5000 Da is added to fully stir and dissolve to obtain a mixed solution of chitosan and chitosan oligosaccharide , the total concentration of the mixed solution is 5~7% (w / v), the ratio of chitosan and chitooligosaccharide in the mixed solution is 6:1~8:1; (2) chitosan and chitooligosaccharide Add the mixed solution of sugar to the dispersed phase solvent containing emulsifier, keep the temperature at 20~30°C, react for 30~50 minutes, add pre-crosslinking agent to the mixed solution, react for 50~80 minutes, wash with water for 30~60 minutes ...

Embodiment 1

[0017] 3.0 g of chitosan with a viscosity of 45 cps and a degree of deacetylation of 90% was fully dissolved in 50 ml of 2% acetic acid aqueous solution, and then 0.43 g of chitosan with a molecular weight of 5000 Da was added to fully dissolve to obtain chitosan Mixed solution with chitosan. With 250 ml of toluene as the dispersed phase, add 0.8 ml of Tween-80 and 0.8 ml of Span-80 as emulsifiers, and mix well. Add the mixed solution of chitosan and chitosan oligosaccharide into the dispersed phase containing emulsifier, react at 25°C for 40 min, add 15 ml of formaldehyde for pre-crosslinking for 60 min, stop the reaction, wash with water for 30 min and wash with 50%, 75 % and 100% ethanol for fractional dehydration, separated and dried to obtain 1.45 g of pre-crosslinked resin. The pre-crosslinked resin was added to 150 ml of glutaraldehyde aqueous solution with a mass concentration of 0.05%, and reacted at a constant temperature of 60 °C for 18 h, and after separation, it ...

Embodiment 2

[0019] 7.0g viscosity is 30cps, and the degree of deacetylation is 95% chitosan fully dissolved in 140 ml 2% acetic acid aqueous solution, then add 1.1g molecular weight is 3000Da chitosan oligosaccharide fully dissolves, makes chitosan and chitosan A mixed solution of oligosaccharides. With 1120 ml of liquid paraffin as the dispersed phase, add 4.5 ml of Tween-80 and mix well. Add the mixed solution of chitosan and chitosan oligosaccharide into the dispersed phase containing emulsifier, react at 20°C for 35 min, add 28 ml formaldehyde for pre-crosslinking for 50 min, stop the reaction, wash with water for 50 min, wash with 50%, 75 % and 100% ethanol for fractional dehydration, separated and dried to obtain 3.22 g of pre-crosslinked resin. Add the pre-crosslinked resin to 300 ml of 0.05% aqueous epichlorohydrin solution, react at a constant temperature of 55 °C for 12 h, and then add it to 350 ml of 0.1 mol / L hydrochloric acid aqueous solution for 14 h at a constant temperatu...

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Abstract

The invention relates to a method for preparing heavy metal ion adsorption resin by taking chitosan oligosaccharide as porogen. The method comprises the following steps: preparing a mixed solution of chitosan and chitosan oligosaccharide; adding the mixed solution into a dispersion phase with an emulsifier, reacting for 30 to 50 minutes, then adding a pre-crosslinking agent for reaction to obtain pre-crosslinked resin; separating and drying, adding the pre-crosslinked resin into the crosslinking agent solution for secondary crosslinking, and thus obtaining secondary crosslinked resin; and adding the secondary crosslinked resin into a diluted hydrochloric acid aqueous solution with a concentration of 0.1 mol / L for reaction to release an adsorption bit occupied by the pre-crosslinking agent, fully deacidifying, separating and drying, and thus obtaining the heavy metal ion adsorption resin. The method is easy to operate; the preparation process is stable; and the cost is low. Due to pre-crosslinking and secondary crosslinking, the acid resistance and the mechanical performance of the heavy metal ion adsorption resin are improved; due to the reaction with diluted acid, the adsorption bit is fully released; the chitosan oligosaccharide is used as porogen, the specific surface area is increased; the adsorption performance of the heavy metal ion adsorption resin is improved; and the method can be widely applied to environment-friendly fields.

Description

technical field [0001] The invention belongs to the field of environmental protection, and relates to a preparation method of a heavy metal ion adsorption resin using chitosan oligosaccharide as a porogen. Background technique [0002] In the field of environmental protection, heavy metals refer to metal elements or metalloid elements that are obviously toxic to organisms. Such pollutants are enriched, difficult to degrade in the environment, and seriously endanger human health. Therefore, seeking effective metal pollution control methods and materials has become a problem that human beings pay close attention to, and effective treatment methods should have the characteristics of high efficiency, convenience, and no secondary pollution. [0003] As the only basic polysaccharide among natural polysaccharides, chitosan has the advantages of good biocompatibility, biodegradability, and non-toxicity, and is widely used in the fields of medicine, food, and chemical industry. Chi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J20/24B01J20/30
Inventor 刘成圣党奇峰宋磊王玉杰于德君
Owner OCEAN UNIV OF CHINA
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