改性纳米级Fe3O4对地下水中氟的吸附性能研究

Adsorption of Fluoride from Groundwater by Modified Nanoscale Fe3O4

采用共沉淀法制备纳米级四氧化三铁,比较了酸改性前后纳米级铁氧化物对模拟地下水中氟离子的去除,研究了溶液pH值、吸附剂用量、反应时间、初始氟离子浓度、竞争离子、腐殖酸等因素对四氧化三铁吸附性能的影响。结果表明,改性纳米级四氧化三铁粒径大多<20 nm。当氟离子初始浓度为5 mg/L,溶液pH为5,吸附剂用量为10 g/L,反应时间为150 min,氟去除率达84.8%。竞争离子和腐殖酸对改性四氧化三铁吸附氟离子的性能影响较小。酸改性的纳米级四氧化三铁对氟的吸附等温线符合Freundlich方程,吸附动力学符合假二级动力学方程。

Nanoscale Fe3 O4 as a adsorbent,prepared by coprecipitation and modified using hydrochloric acid,was used to remove fluoride from simulated groundwater.The effects of initial pH value,dosage of the adsorbent,reaction time,initial concentration of fluoride,competitive ions and humic acid on the adsorption capacity of nanoscale iron oxides were investigated.The results showed that the diameter of modified nanoscale Fe3 O4 was less than 20 nm.Under the conditions of initial fluoride concentration of 5 mg/L,solution pH of 5,adsorbent dosage of 10 g/L,and reaction time of 150 min,the removal efficiency of fluoride reached 84.8%.The competitive ions and humic acid have little effect on the absorptive capacity of modified nanoscale Fe3 O4.The adsorption of fluoride by modified nanoscale Fe3 O4 was fitted to Freundlich isotherm equation and adsorption kinetic data was fitted to pseudo-second-order model.