Abstract:

A magnetic crosslinking polymer, Fe₃O₄ encapsulated by sodium polyacrylate (CPAANa@Fe₃O₄), was prepared via dispersed solution polymerization followed by Ca²⁺ surface-crosslinking and characterized by techniques of XRD, FT-IR, SEM and TGA. Static adsorption of Pb²⁺ and Cd²⁺ ions to the polymer in aqueous solutions was investigated by varying solution pH, polymer adsorbent dosage, and initial concentration of heavy metal ions. The CPAANa@Fe₃O₄ magnetic crosslinking polymer showed good adsorption performance in solutions with pH in the range of 2-6. The maximum adsorptions for Pb²⁺ and Cd²⁺ were observed at adsorbent dosage of 1.0 and 1.6 g·L^-1 for initial Pb²⁺ concentration of 200 mg·L^-1 and initial Cd²⁺ concentration of 100 mg·L^-1, respectively, such that the residual Pb²⁺ concentration could meet the standard for discharge (GB 8978-1996). The adsorption kinetics of both Pb²⁺ and Cd²⁺ on CPAANa@Fe₃O₄ polymer followed pseudo-second order model and their adsorption isotherms obeyed the Langmuir model. Maximum adsorption capacities of the polymer for Pb²⁺ and Cd²⁺ were 454.55 and 275.48 mg·g^-1, respectively. The CPAANa@Fe₃O₄ polymer effectively removed Pb²⁺ and Cd²⁺ from complex electrolytic pulp wastewater, indicating its potential application advantages as an efficient adsorbent.

Key words: composites, preparation, adsorption, magnetic polymer, Pb²⁺, Cd²⁺, kinetics

摘要：

采用溶液分散聚合和Ca²⁺表面交联制备了聚丙烯酸钠包覆Fe₃O₄的磁性交联聚合物（CPAANa@Fe₃O₄），对其进行了XRD、FT-IR、SEM和TGA等表征。以CPAANa@Fe₃O₄为吸附剂研究了CPAANa@Fe₃O₄对水溶液中Pb²⁺、Cd²⁺的静态吸附，考察了溶液pH、吸附剂投加量、金属离子初始浓度对吸附的影响。结果表明：CPAANa@Fe₃O₄在pH 2～6范围内均具有较好的吸附性能，当吸附剂投加量分别为1.0 g·L^-1和1.6 g·L^-1时对初始浓度分别为200 mg·L^-1的Pb²⁺和100 mg·L^-1的Cd²⁺的去除率达到最大，可使Pb²⁺实现达标排放（GB 8978-1996）；CPAANa@Fe₃O₄对Pb²⁺和Cd²⁺的吸附动力学符合准二级模型，吸附等温线符合Langmuir模型，对Pb²⁺和Cd²⁺的最大吸附量分别为454.55 mg·g^-1和275.48 mg·g^-1。将CPAANa@Fe₃O₄用于处理实际电解矿浆废水，发现能有效吸附其中的Pb²⁺和Cd²⁺，具有潜在实用价值。

关键词: 复合物, 制备, 吸附, 磁性聚合物, 铅离子, 镉离子, 动力学