磁性铁基改性生物炭去除水中氨氮

Synthesis of Magnetic Iron Modifying Biochar for Ammonia Nitrogen Removal from Water

氨氮的过度排放是水体富营养化的一个重要原因.然而,随着环境法规的日益严格,传统方法处理效果难以达到要求.吸附法因高效、安全等优点近年来开始应用于去除水中的氨氮.本研究中以共沉淀法将磁性铁基材料负载到市政污泥生物炭上,结果表明其对水中氨氮有良好的去除效果.80℃下合成的材料(MB80)在293 K下对氨氮的饱和吸附量可达17.52mg·g^(-1).动力学与热力学结果表明,MB_(80)吸附氨氮的过程更符合伪二级动力学和Langmuir等温线.MB_(80)对氨氮的吸附机制可归纳为静电吸引、孔隙填充、离子交换和氢键结合.且5次循环后对氨氮的吸附量仍十分理想,可达3.18 mg·g^(-1).本研究的结果可以为高效去除水中氨氮提供一种行之有效的方法,并为市政污泥的处理提供新的出路.

A significant factor for eutrophication is the excessive discharge of ammonia nitrogen.Unfortunately,traditional methods to remove ammonia nitrogen are ineffective when facing gradually strict rules.Recently,adsorption has gained interest from scholars due to its efficiency and safety in ammonia nitrogen treatment.In this study,a novel biochar,modified with magnetic iron,was synthesized through co-precipitation,which performed well in ammonia nitrogen removal.The maximum adsorption amount at 293 K of the composite that was synthesized at 80℃(MB_(80))was 17.52 mg·g^(-1).Meanwhile,the simulation results displayed a good fitting with the pseudo second order model and Langmuir model.Additionally,the adsorption mechanism could be attributed to electrostatic adsorption,porous filling,ion exchange,and hydrogen bonding.Noticeably,MB_(80)maintained a good performance after 5 cycles,with desirable adsorption amount of 3.18 mg·g^(-1).This study aimed to provide an efficient method to treat ammonia nitrogen as well as a new way to dispose of municipal sludge.