摘要:
将羟乙基纤维素(HEC)与海藻酸钠(SA)进行混合,利用戊二醛交联处理后制备了HEC/SA高分子复合多孔薄膜,并探讨了其对模拟含铀废水中的六价铀(U(Ⅵ))的吸附特性。通过静态实验,探讨了初始pH值、U(Ⅵ)初始浓度、温度和吸附时间等对HEC/SA复合膜吸附U(Ⅵ)效果的影响;对吸附过程进行了热力学与动力学分析,利用FTIR、SEM和X射线能谱等手段分析了其吸附机制。实验结果表明,U(Ⅵ)的吸附量与温度正相关,吸附平衡时间约为90 min,最佳吸附效果的初始pH值为5.0;吸附过程符合准二级动力学模型,主要表现为颗粒内部扩散;等温吸附过程符合Langmuir等温吸附线模型,在45 ℃时,HEC/SA复合膜对U(Ⅵ)的最大吸附容量达357.1 mg·g-1,HEC/SA复合膜对U(Ⅵ)的吸附存在离子交换作用,与U(Ⅵ)的相互作用基团为羧基。
Abstract:
Hydroxyethyl cellulose/sodium alginate (HEC/SA) polymer composite porous films were made by blending HEC and SA together and crosslinked by glutaraldehyde, and its adsorption properties for uranium(Ⅵ) (U(Ⅵ)) in simulated wastewater containing uranium were studied. The effects of initial pH value, initial U(Ⅵ) ions concentration, temperature and adsorption time et al on the adsorption of HEC/SA blend films for U(Ⅵ) were investigated by static experiment. The process of adsorption was investigated by thermodynamic and kinetic analysis. The adsorption mechanism was investigated by FTIR, SEM, energy dispersive X-ray spectrum and so on. The experimental results show that there is a positive correlation between temperature and the U(Ⅵ) adsorption quantity, adsorption equilibrium time is about 90 min, and the optimal initial pH value is 5.0. The adsorption process conforms to the pseudo-second-order kinetics model, and mainly preforms particle internal diffusion. The isothermal adsorption process conforms to the Langmuir isothermal adsorption model, when the temperature is 45 ℃, the maximum adsorption capacity of HEC/SA blend films for U(Ⅵ) ions reaches 357.1 mg·g-1. The adsorption of HEC/SA blend films for U(Ⅵ) presents ion-exchange process, and the interaction groups with U(Ⅵ) is carboxyl.
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