节点文献
Fe(NO3)3改性活性炭吸附氨氮的性能研究
Adsorption of ammonia on activated carbon modified by Fe(NO3)3
【摘要】 通过超声浸渍法对活性炭进行负载Fe(NO3)3改性,采用扫描电镜(SEM)、比表面积分析(BET)、质量滴定、红外光谱分析(FT-IR)和Boehm滴定等多种分析方法对未改性活性炭(AC)和改性活性炭(AC-Fe)进行表征,探讨了在不同条件下改性前后活性炭对污水中氨氮的吸附能力和动力学特性.结果表明,经超声浸渍铁元素改性后,活性炭大孔和中孔的孔容积以及比表面积减小,平均孔径略有增大,表面含氧官能团种类基本没有变化. AC-Fe的内酯基、酚羟基及碱基分别增加了12.8%、13. 3%、4. 4%,羧基减少了28. 6%,其等电点由5. 8增大到8. 2.当氨氮质量浓度为10 mg/L,活性炭投加量20g/L,温度5℃时,AC-Fe对氨氮的吸附量为0. 138 mg/g,较AC对氨氮的吸附量提高了29. 0%. Langmuir方程和Freundlich方程均能较好地描述改性前后活性炭对氨氮的等温吸附过程,吸附动力学数据符合准二级动力学方程.
【Abstract】 Activated carbon was modified with loading Fe(NO3)3 by ultrasonic impregnation method. AC and AC-Fe were characterized by scanning electron microscopy( SEM),N2 Brunauer-Emmett-Teller( BET) adsorption analysis,mass titration,Fourier transform infrared spectroscopy( FT-IR) and Boehm titration. The adsorption capacity and kinetic characteristics of ammonia in sewage water before and after modification under different conditions were discussed. The results showed that the pore volume and the BET surface area of macropore and mesopore decreased,the average pore diameter increased slightly,with no obvious change in the type of oxygen-containing groups on the surface. The amount of lactone groups,phenolic hydroxyl groups,basic groups on AC-Fe increased by 12. 8%,13. 3%,4. 4%,respectively. While the amount of carboxyl groups decreased by 28. 6%. And the isoelectric point increased from 5. 8 to 8. 2. When the ammonia initial concentration was 10 mg/L,the AC-Fe dosage was 20 g/L,and the temperature was 5 ℃,the adsorption ca-pacity of ammonia by AC-Fe was 0. 138 mg/g. Compared with AC,its adsorption capacity increased by 29. 0%. Further results indicated that the equilibrium adsorption process was described well by the Langmuir model and Freundlich model. And the kinetic data fit better with the pseudo-second model.
【Key words】 activated carbon; modification; ammonia; adsorption; kinetic;
- 【文献出处】 哈尔滨商业大学学报(自然科学版) ,Journal of Harbin University of Commerce(Natural Sciences Edition) , 编辑部邮箱 ,2019年01期
- 【分类号】X703
- 【被引频次】3
- 【下载频次】353