改性磁纳米粒子对水体中腐植酸的吸附研究

Study on the Adsorption of Humic Acid in Water with Modified Magnetic Nanoparticles

利用FeCl_3对磁性纳米粒子Fe_3O_4@SiO_2进行表面改性,考察不同初始浓度、接触时间、pH、盐离子浓度对含腐植酸的水体的吸附效果,进而分析其吸附等温特性及动力学特性。结果表明:Langmuir等温吸附方程能够更好地描述其等温吸附特性,改性后的磁性纳米吸附剂对腐植酸的饱和吸附量为3.60 mg/g,且其在酸性条件下吸附效果更佳,在pH=3时的饱和吸附量为16.50 mg/g,对水体中腐植酸的去除率达到90%以上。吸附动力学表明Fe_3O_4@SiO_2-FeCl_3对HA的吸附过程符合准二级动力学,其相关系数达到0.997。

The surface modification of magnetic nanoparticles Fe3O4@SiO2 by FeCl3 was used to investigate the adsorption effect of different initial concentration, contact time, pH and salt concentration on the water containing humic acid, the adsorption isotherm and kinetic characteristics were analyzed subsequently. The results showed that the isothermal adsorption equation of Langmuir could better describe its isothermal adsorption characteristics. The saturated adsorption capacity of the magnetic nano adsorbent for humic acid after modification was 3.60 mg/g, especially under the acid condition, the saturated adsorption capacity at pH=3 was 16.50 mg/g, and the removal rate of humic acid in the water was above 90%. The adsorption kinetics showed that the adsorption process of Fe3O4@SiO2-FeCl3 on HA conformed to pseudo secondorder kinetics, and the correlation coefficient was 0.997.