Mg-doped nano ferrihydrite鈥擜 new adsorbent for fluoride removal from aqueous solutions
- 作者：M. Mohapatra ; mamatamohapatra@yahoo.com ; D. Hariprasad ; L. Mohapatra ; S. Anand ; B.K. Mishra
- 关键词：Fluoride ; Adsorption ; Nano iron oxides ; Kinetics ; TEM
- 刊名：Applied Surface Science
- 出版年：2012
- 期刊代码：6_01694332
- 类别：ms
- 出版时间：1 March, 2012
- 卷：258
- 期：10
- 页码：4228-4236
- 文件大小：572 K
摘要
The present study evaluates synthesized Mg-doped nano ferrihydrite powder as an adsorbent for F鈭?/sup> removal from aqueous solutions. High surface area Mg-doped ferrihydrite was prepared by co-precipitation method under controlled conditions. Samples were prepared by varying Mg content in the range of 0.39-1.12%. Preliminary test work revealed that under similar conditions, with the increase in Mg content from 0.39 to 0.98%in doped ferrihydrite,%F鈭?/sup> adsorption increased from 66 to 91%. Hence this sample was characterized by XRD, TEM, SAED and TG-DTA. Batch adsorption experiments were carried out by varying contact time (30-480 min), initial pH (1.0-10), initial fluoride concentration (10-150 mg/L), adsorbent dose (0.5-4 g/L), temperature (20-45 掳C) and Cl鈭?/sup> or SO42鈭?/sup> concentrations (nil to 50 mg/L). The results showed 0.98%Mg-doped ferrihydrite to be an excellent fluoride adsorbent giving maximum adsorption capacity of 64 mg/g. The time data fitted well to pseudo second order kinetic model. The isothermal data followed Langmuir model. Thermodynamic parameters confirmed the adsorption process to be spontaneous and endothermic. 89%of fluoride could be desorbed from loaded sample using 1 M NaOH.