海藻酸钠凝胶海绵体的制备及在重金属吸附中的应用

Preparation of alginate gel sponge and its application in heavy metal adsorption

摘要:

为解决重金属污染问题，本研究以海藻酸钠与钙离子交联形成凝胶，采用真空冷冻干燥技术将凝胶制备成超轻海绵体，此海绵体对重金属有吸附作用.实验结果表明：天然多糖海藻酸钠溶解过程，微观结构首先由丝状结构逐渐向片层结构伸展，而海藻酸钠凝胶海绵体则形成了致密的多孔结构，微观结构发生变化.其中海藻酸钠与氯化钙交联比是1：1时，所得的凝胶海绵体的比表面积达到2.1543 m2/g.在pH=3时，海藻酸钠凝胶海绵体对Cu2 和Pb2 的饱和吸附量分别达到29.2和90.22 mg/g.当海藻酸钠凝胶海绵体添加量为50 mg时，对Cu2 和Pb2 的最大吸附达到87.7和240.8 mg/g.吸附温度是40 ℃时,对Cu2 和Pb2 的吸附量达到最大,吸附量为29.4和89.6 mg/g.吸附速率实验表明，在50 min时,对Cu2 和Pb2 达到平衡吸附，吸附量为30.2 mg/g和89.7 mg/g.

Abstract:

In order to solve the problem of heavy metal pollution, the gel was formed by crosslinking sodium alginate with calcium ion, and the gel was prepared into ultralight sponge by vacuum freeze-drying. The experimental results showed that the natural polysaccharide alginate dissolution process, the microstructure first gradually extended from the filamentous structure to the lamellar structure, while the alginate gel sponge formed a dense porous structure and the microstructure changed. The cross-linking ratio of sodium alginate to calcium chloride is 1:1, the specific surface area of the resulting gel reaches 2.1543 m2/g. The saturated adsorption capacity of alginate hydrogel to Cu2 and Pb2 reached 29.2 and 90.22 mg/g at pH=3, respectively. The maximum adsorption of Cu2 and Pb2 reached 87.7 and 240.8 mg/g. When the adsorbent addition amount was 50 mg. When the adsorption temperature is 40 ℃, the adsorption capacity of Cu2 and Pb2 reaches the maximum, and the adsorption capacity is 29.4 and 89.6 mg/g. The adsorption rate experiments showed that equilibrium adsorption of Cu2 and Pb2 was achieved at 50 min with adsorption capacity of 30.2 and 89.7 mg/g.