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摘要
工业的迅速发展导致水体环境污染问题也愈加严重,针对重金属废水的处理极为迫切。以海藻酸钠微球为基质,合成出海藻酸钙和聚丙烯酰胺双网络结构的NH2-SA/PAM微球水凝胶。通过扫描电镜、红外光谱、X射线光电子能谱(XPS)等手段表征可知,该凝胶具有多孔网络结构,具有大量的羟基、氨基等活性位点,能实现离子在凝胶内部的快速扩散。通过对Cu2+的吸附实验可知,NH2-SA/PAM微球水凝胶具有较好的吸附性能,基于 Langmuir模型,在30℃下qmax为265.31mg/g,在100min内便达到吸附平衡的80%,通过均相表面扩散模型(HSDM)其凝胶内部的扩散系数Ds为2.83×10-11m/s。该NH2-SA/PAM对Pb2+、Cd2+、Zn2+、Mn2+、Ni2+和Cu2+均有较好的吸附性能,其分配系数与离子电负性具有较大关系。此外,通过XPS对NH2-SA/PAM吸附Cd2+前后样品进行分析,发现凝胶主要通过氨基和羟基对Cd2+进行配位吸附。以上实验说明NH2-SA/PAM微球水凝胶在处理水体中重金属污染方面有着巨大的潜力。
Abstract
The rapid development of industry has led to more serious environmental pollution of water bodies,so it is urgent to treat heavy metal in wastewater.Sodium alginate monomer was used to drop calcium chloride solution to form a calcium alginate microsphere.Then using the calcium alginate microspheres as matrix,NH2-SA/PAM microsphere hydrogel was prepared with the dual-network of sodium alginate/polyacrylamide.After that,NH2-SA/PAM was characterized by scanning electron microscopy,infrared spectroscopy and X-ray photoelectron spectroscopy.The results showed that the hydrogels possessed porous network structure and had a large number of active sites such as hydroxyl and amino groups,which realized the fast diffusion of ions inside the hydrogel.The experiment of adsorption of Cu2+ revealed that NH2-SA/PAM microsphere hydrogel had advanced adsorption property.Based on Langmuir model,qmax was 265.31mg/g at 30℃,and the adsorption reached 80% of equilibrium within100min.By homogeneous surface diffusion model (HSDM),the diffusion coefficient inside hydrogel Ds was 2.83×10-11m/s.The NH2-SA/PAM had strong adsorption capacity for Pb2+,Cd2+,Zn2+,Mn2+,Ni2+ and Cu2+.The samples before and after adsorption of Cd2+ were analyzed,which demonstrated that the adsorption of hydrogel was conducted mainly through coordination adsorption of hydroxyl and amino for Cd2+.The above experiments illustrated that NH2-SA/PAM microsphere hydrogel had great potential to treat heavy metal pollution in water bodies.
关键词
水凝胶微球
/
吸附
/
Cu2+
Key words
hydrogel microsphere
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adsorption
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Cu2+
双网络微球水凝胶对Cu2+的吸附行为研究[J].
化工新型材料, 2023, 51(1): 227-232 DOI:10.19817/j.cnki.issn1006-3536.2023.01.043
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基金资助
国家自然科学基金(52070078);湖南省自然科学基金项目(2019JJ50137);湖南省教育厅(19C0568和17C0463)
