Porous magnetic chitosan gel microsphere with controllable particle size and preparation method thereof

Abstract

The invention provides a porous magnetic chitosan gel microsphere with controllable particle size based on an in-situ co-precipitation principle and a preparation method thereof. The preparation method comprises the following main steps: firstly, carrying out a complexation reaction on a mixed solution of Fe<2+>, Fe<3+> and chitosan to prepare precursor-induced pre-sol; secondly, dropwise dripping the pre-sol into an alkaline soaking solution containing NaOH, sodium citrate and the like for coprecipitating to generate nano-Fe3O4; thirdly, carrying out a crosslinking reaction on the pre-sol and then curing, wherein the crosslinked chitosan gel microsphere is of a porous reticular structure and the Fe3O4 is uniformly distributed in the chitosan gel microsphere. The particle size of the chitosan gel microsphere is controlled by adjusting the rotating speed of a peristaltic pump and the concentration of the solution. The chitosan gel microsphere prepared by the method has the advantages of abundant pores, large specific surface area, and high adsorption and acid resistance; in addition, the preparation method has the characteristics of simplicity, wide source in raw materials, low cost, easiness in separation and recovery, no secondary pollution and the like. The porous magnetic chitosan gel microsphere disclosed by the invention can be used for enrichment, recovery and contamination remediation of metals in mines, smelting plants, electronic factories, electroplating plants and radioactive wastewater.

Description

technical field [0001] The invention belongs to the field of environmental functional materials, and relates to a porous magnetic chitosan gel microsphere with controllable particle size and a preparation method. Background technique [0002] Heavy metals have the characteristics of high toxicity, refractory degradation and easy accumulation in organisms, which have caused great harm to the ecological environment and human health [1]. At present, the treatment methods of heavy metal wastewater mainly include chemical method, physical chemical method and biological method [2]. Among them, the chemical method and physical chemical method have high treatment efficiency and are widely used [3], but they have the limitations of secondary pollution and poor treatment effect on low-concentration heavy metal wastewater. In contrast, the biosorption method has gradually attracted the attention of researchers due to its advantages of high treatment efficiency, complete reaction, and ...

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Problems solved by technology

Most of these methods have extremely high requirements on the reaction preparation conditions [13], or the preparation of gel microspheres needs to be completed through a complicated preparation process [14]. Not only the preparation cost is high, but also the emulsifier, crosslinking Poisonous and harmful chemical reagents such as reagents and initiators [15] have potential hazards of secondary pollution to the environment [16]

At the same time, limited by the shape of the adsorbent in practical application, the adsorbent of a specific size is only suitable for specific situations, and due to poor acid resistance, it is not suitable for the treatment of acidic wastewater, and there are certain limitations in application.

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