聚 N-异丙基丙烯酰胺-丙烯酸共聚微凝胶对水溶液中 Ni（Ⅱ）的吸附性能

摘要

以聚 N-异丙基丙烯酰胺-丙烯酸共聚微凝胶(PNIPA-co-AA)为吸附剂，采用静态批试法研究了 Ni(Ⅱ)在共聚微凝胶上的吸附行为。探讨了震荡时间、固液比、pH 值、离子强度及温度等因素对吸附结果的影响，测定了共聚微凝胶在不同温度下对 Ni(Ⅱ)的吸附等温线。结果表明：固液比、pH 值和离子强度均对吸附过程有明显影响；吸附过程在30 min 内即可达到平衡；Langmiur 方程能够很好的拟合吸附等温线。热力学参数(ΔH 、ΔS 和ΔG)表明，此吸附过程是一个自发、吸热的过程。吸附能力在经过7次的吸附-解吸附过程后没有明显的下降。离子交换是此吸附过程的主要机理。%In this work, the copolymer microgel of N-isopropyl acrylamid-co-acrylic acid (PNIPA-co-AA)were used as a novel adsorbent for removing Ni(Ⅱ)from aqueous solution. The adsorption of Ni(Ⅱ)onto PNIPA-co-AA was studied as a function of contact time,sol-id/liquid ratio,pH value,ionic strength and temperature.The adsorption isotherm of Ni(Ⅱ)adsorption onto copolymer microgels at different temperature were measured.The results show that Ni(Ⅱ)adsorption onto PNIPA-co-AA is strongly depend on solid/liquid ratio,pH value and ionic strength.Kinetic data indicate that the adsorption process achieves equilibrium within 30 min.Thermodynamics data indicate that the adsorption fits the Lang-miur model and its linearized form well and the Ni(Ⅱ)adsorption onto copolymer microgels is a spontaneous and endothermic nature process.The adsorption capacity is not signification reduced after seven times of adsorption-desorption cycles.Ions exchange is the predominant mechanism of Ni(Ⅱ)adsorption onto PNIPA-co-AA.Present study suggests that the copol-ymer microgels maybe a promising candidate for concentration of heavy metal ions and radio-nuclides from industrial wastewater.