摘要
针对铬(Ⅵ)严重危害环境和生物的问题,以海泡石、麦饭石和褐煤为原料,采用化学共沉淀法将Fe3O4微粒负载在海泡石、麦饭石、褐煤上,进行磁改性。通过静态吸附试验对比分析3种磁改性材料及未改性材料对Cr(Ⅵ)的吸附效果。并基于动力学和动边界原理,探究不同磁改性材料对Cr(Ⅵ)的吸附动力学模型及速率控制步骤。结果表明:磁性海泡石、磁性麦饭石、磁性褐煤对Cr(Ⅵ)的平衡吸附量分别为2.7 mg/g、3.235mg/g、3.25 mg/g,其平衡吸附量分别是磁改性前的16倍、21倍和50倍;吸附过程均符合准二级动力学模型,说明是以化学吸附为主。磁性褐煤吸附效果最好,准二级动力学方程为y=0.2751t+1.8456。3种磁性材料吸附Cr(Ⅵ)过程的速率控制步骤是以液膜扩散和颗粒内扩散联合控制,其中以颗粒内扩散为控制主导。
In view of the serious environmental and biological problems caused by chromium(Ⅵ),using sepiolite,maifa stone and lignite as raw materials,where Fe3O4 particles were loaded on,by chemical coprecipitation method for magnetic modification.The adsorption effects of three magnetically modified materials and their unmodified materials on Cr(Ⅵ)were compared by static adsorption experiments.Based on the dynamics and dynamic boundary principle,the adsorption kinetics model and rate control steps of Cr(Ⅵ)with different magnetically modified materials were investigated.The results show that the equilibrium adsorption capacity of magnetic sepiolite,magnetic maifan stone and magnetic lignite to Cr(Ⅵ)is 2.7 mg/g,3.235 mg/g,3.25 mg/g,respectively,which is 16 times,21 times and 50 times before the magnetic modification respectively.The adsorption process is in accordance with the second-order kinetic model,indicating that the chemical adsorption is the main.The second-order kinetic equation of the magnetic lignite with the best adsorption effect is y=0.2751 t+1.8456.The rate control step of the three magnetic materials adsorbing Cr(Ⅵ)is controlled by the combination of liquid film diffusion and intraparticle diffusion,in which intraparticle diffusion is the dominant control.
作者
狄军贞
林鑫
董艳荣
Di Junzhen;Lin Xin;Dong Yanrong(College of Civil Engineering,Liaoning Technical University,Fuxin,Liaoning 123000)
出处
《非金属矿》
CAS
CSCD
北大核心
2019年第6期86-89,共4页
Non-Metallic Mines
基金
国家自然科学基金（41672247,41102157）
辽宁省“兴辽英才”青年拔尖人才计划支持（XLYC1807159）
辽宁省自然科学基金（2015020619）
辽宁省教育厅一般项目（LJYL031）
