木质素活性炭的制备及其对硝基苯的吸附.pdf

化工环保
2014年第34卷第4期
ENVIRONMENTAL PROTECTION OF CHEMICAL INDUSTRY
305
木质素活性炭的制备及其对硝基苯的吸附
黎先发
(西南科技大学生命科学与工程学院,四川绵阳621010)
摘要]利用工业碱木质素分别经KOH及H3PO2活化制备两种木质素活性炭(KAC和PAC),并用于模拟硝基苯废水的处理。
采用SEM和R等手段对木质素活性炭进行了表征。考察了木质素活性炭加入量、废水pH、吸附时间等因素对硝基苯吸附量的
影响。表征结果显示,KAC具有丰富的孔结构,PAC表面含有多种功能基团。实验结果表明:在吸附温度298K、初始硝基
苯质量浓度250mgL、木质素活性炭加入量1.0gL、废水pH3、吸附时间24h的条件下,KAC及PAC对硝基苯的吸附量分别为
237.8mg/g和219mgg,去除率分别达到91%和84%;KAC及PAC对硝基苯的吸附过程符合拟二级动力学方程,吸附等温线满
足 Langmuir等温吸附方程;当解吸剂的(乙醇):(去离子水)=9时,在PAC和KAC上吸附的硝基苯的解吸率分别达到99%和
93%;木质素活性炭重复使用5次后,KAC和PAC对硝基苯的吸附量分别为114mg/g和130.7mgg
关键词]木质素;活性炭;硝基苯;吸附剂;废水处理
中图分类号]X783[文献标志码]A[文章编号]1006-1878(2014)04-0305-06
Preparation of n- ased A iva Ca ons and d option of Nitrobenzene
(School of Life Science and Engineer ng, Southwest University of Science and Tecnology, Mianyang Sichuan 621010, China)
Abstract: Two kinds of lignin-based activated carbons(KAC and PAC)were prepared from industrial
alkali lignin by chemical activation with KOH and H; PO respectively, and used to treat the simulated
nitrobenzene(NB )wastewater. They were characterized by SEM and IR. The factors affecting the
nitrobenzene adsorption were studied. The characterization results show that KAC has a fully-porous
structure, while PAC surface has many functional groups. The experimental results show that: Under
the conditions of adsorption temperature 298 K, initial NB mass concentration 250 m/L, lignin-based
activated carbon dosage 1. 0 g/L, wastewater PH 3 and adsorption time 24 h, the adsorption capacities of
KAC and PAC to NB are 237.8 mg/g and 211.9 mg/g with 91% and 84% of removal rate respectively; The
adsorption of NB on KAC and PAC can be represented by the pseudo-second-order kinetic model, and their
adsorption isotherms fit well with the Langmuir equation; When the mixed liquid of ethanol and deionized
water with (ethanol): (deionized water)=9 is used as desorption agent, the desorption rates of NB from
PAC and KAC are 99% and 93% respectively; After reused by 5 times, the adsorption capacity of KAC
and PAC to NB remain 115.4 mg/g and 130.7 mg/g respectively
Key words: lignin; activated carbon; nitrobenzene; adsorbent; wastewater treatment
硝基苯是重要的有机溶剂和化学中间体,主法具有操作简单、成本低等优点。常用的吸附剂包
要用于医药、燃料、农药及炸药等行业,在环境中
的排放量较大日。硝基苯是典型的高毒性有机污染[收稿日期]203-12-15;[修订日期]2014-04-09
物之一,我国及许多发达国家已将硝基苯列人优先
[作者筒介]黎先发(1969-),男,重庆市人,硕士,副研究员,
主要从事生物质化学行生改性与应用研究。电话13981191296,
控制的污染物名单。目前,硝基苯废水的治理方
电邮lixianfa(@swus.ecdu.cno
法主要有生物降解法、还原法4、氧化法?
[基金项目]生物质材料教育部工程研究中心开放基金项目
电化学法?及物理吸附法等。其中,物理吸附(12xbk05)。