磁性海藻酸钠凝胶球对持久性有机污染物甲基橙的吸附研究

Adsorption of Persistent Organic Pollutants Methyl Orange by Magnetic Gel Balls of Sodium Alginates

本文提出了将海藻酸钠和纳米Fe3O4以物理共混的方法,制备一定粒度的磁性海藻酸钠凝胶球。以持久性有机污染物甲基橙(methyl orange,简写MO)为研究对象,考察了初始p H值、磁性凝胶球的加入量、MO初始浓度和吸附时间等因素对吸附效果的影响;同时对吸附过程进行等温式和动力学拟合,初步分析了吸附机理。结果表明:利用纳米Fe3O4比表面积大和表面原子配位不足的特点,制备的磁性凝胶球对MO的吸附率可达90%以上;磁性凝胶球对持久性污染物MO的吸附遵循Langmuir等温方程和准二级反应动力学,说明吸附过程为单分子层吸附和化学吸附作用为主。在外加磁场作用下,纳米Fe3O4粒子超顺磁性有助于吸附剂能快速有效地从液相分离。经4次重复使用后,磁性凝胶球对MO仍具有很好的吸附效果,可进行多次重复使用。

The new adsorbent,magnetic gel balls of sodium alginates was prepared through blending method in order to improve the efficiency of wastewater contained persistent organic pollutants methyl orange（ MO） in this paper. The effects of performance parameters such as p H,amount of magnetic gel balls,initial concentration of MO and adsorption time etc. were investigated. The adsorption kinetics and adsorption isotherms were simulated to supply theoretic evidence for application. And the mechanism was preliminarily analyzed. The results show that based on the characters of huge surface area and lack of surface coordination of nano-Fe3O4 particles,magnetic gel balls have good performance of adsorption ability to MO. The removal rate could reach to 90%. The adsorption kinetics was described by pseudosecond rate model and the adsorption equilibrium was accorded with Langmuir isotherm adsorption equation. Typical single-molecule layer adsorption of magnetic gel balls of sodium alginates for MO could be described. Under the condition of magnetic field in addition,the superparamagnetism of nano-Fe3O4 particles could help the adsorbent be quickly separated from liquid. After they were used for four times,magnetic gel balls still have excellent adsorption characteristics for MO. And this can indicate that magnetic gel balls could be reused many times.