摘要
本研究探讨用香蕉皮和玉米芯两类生物质制备的生物炭、多壁纳米碳管(CNTs)和活性炭(AC)对氧氟沙星(OFL)的吸附动力学过程.结果表明,吸附动力学过程符合双室一级动力学模型.OFL在两类生物炭上的吸附能力随炭化温度的升高而减弱,归因于生物质炭化程度的增大,芳香性增加,生物炭有机分配相减少.生物炭的O含量极大地影响了其与水分子之间形成水膜的能力,OFL穿透水膜在生物炭表面上的吸附过程成为控制OFL吸附快慢的关键环节.OFL在CNTs和AC的快室吸附比在生物炭上的先趋于平衡,这可能与CNTs和AC较为单一的表面性质有关.CNTs的慢室吸附比AC的慢室吸附需要更长时间达到平衡,主要原因是随着OFL分子在CNTs表面持续吸附,原先由于疏水性作用聚合在一起的CNTs逐渐分散开,暴露出更多的表面积,导致OFL持续的吸附,在动力学上表现为慢室吸附.此外,单位比表面积上CNTs对OFL的吸附量最高,表明如果能够使CNTs充分分散,大量暴露的表面可能使CNTs成为去除有机污染的高效吸附剂.
In this study,the adsorption of ofloxacin（ OFL） on different carbonaceous sorbents,including biochars produced by pyrolysis of banana peel and corncob,multi-walled carbon nanotubes（ CNTs） and activated carbon（ AC） were investigated. The adsorption kinetics of OFL could be well fitted using two-compartment model. With the increased carbonization temperature of biochars,the aromaticity increased but organic components for partition reduced, leading to the decreased adsorption of OFL. The O-contents of biochars greatly affected the formation of water cluster on the surface of biochars which inhibited fast adsorption of OFL. The fast sorption of OFL onto CNTs and AC were faster than biochars,attributed to the relatively uniform surface properties of CNTs and AC.As more surface area was exposed with increasing sorption,the slow sorption of OFL onto CNTsbecame slower than AC. Furthermore,the highest OFL adsorption based on unit surface was observed on CNTs,implying that if CNTs could be completely dispersed,it might be an efficient adsorbent for organic pollutants removal due to the abundant exposed surface area.
出处
《环境化学》
CAS
CSCD
北大核心
2016年第4期651-657,共7页
Environmental Chemistry
基金
国家自然科学基金(41303093)
云南省自然科学基金(2014FB121)
昆明理工大学人才启动经费(14118762)资助~~
关键词
碳基吸附剂
氧氟沙星
吸附动力学
双室一级动力学模型
carbonaceous sorbents
ofloxacin
adsorption kinetics
two-compartment first-order model
