摘要
针对褐煤氧解残煤的多孔性和含氧官能团的结构特点,研究了褐煤氧解残煤及其改性残煤对Cr(Ⅵ)的吸附性能。改性残煤是由1 g褐煤氧解残煤与10 mL 1 mol/L的NaOH溶液和3 mL环氧氯丙烷在40℃下反应1 h后,再与1 mL乙二胺溶液和10 mL H2O在60℃下反应2 h制得。利用分光光度法研究影响Cr(Ⅵ)吸附行为的因素,例如溶液pH值、吸附时间和溶液中Cr(Ⅵ)的初始质量浓度。结果表明:在pH值小于2.5的强酸性溶液中,三种煤基吸附剂对Cr(Ⅵ)都具有良好的吸附能力;吸附动力学过程涉及快速的物理吸附和缓慢的化学吸附,其化学吸附过程符合准二级动力学模型,等温吸附符合Freundlich模型和Langmuir模型,且Freundlich模型的拟合效果优于Langmuir模型的拟合效果;三种煤基吸附剂对Cr(Ⅵ)显示不同的吸附机理。原煤的吸附量大,吸附强度弱;氧解残煤的吸附量小,吸附强度大;改性残煤在Cr(Ⅵ)初始质量浓度为20 mg/L^70 mg/L时对Cr(Ⅵ)具有显著的吸附率。
With regard to the porosity and abundant oxygen-containing functional groups in oxidized residue from lignite,the adsorption performances of Cr(Ⅵ)on lignite,oxidized residue and its modified residue were investigated.Oxidized residues were modified by being mixed with 10 mL 1 mol/L NaOH and 3 mL epichlorhydrin at 40℃for 1 h.And then 1 mL ethylenediamine and 10 mL H2O were added to the modified residues at 60℃for 2 h.Factors affecting the adsorption behavior of Cr(Ⅵ),such as pH value,adsorption time and initial mass concentration of Cr(Ⅵ),were investigated.Results show that three adsorbents have better adsorption abilities for Cr(Ⅵ)in the aqueous solution under pH<2.5.The adsorption of Cr(Ⅵ)includes the rapid physical adsorption and the slow chemical adsorption processes.The latter has quasi-secondary dynamics.The isothermal adsorption corresponds to the Freundlish and Langmuir adsorption model,and the Freundlish adsorption model fits better than the Langmuir adsorption model.In addition,the three adsorbents show different adsorption mechanisms.Raw coal has large adsorption capacity and weak adsorption strength;oxidized residual coal has small adsorption capacity and large adsorption strength;modified residual coal has a significant adsorption rate of Cr(Ⅵ)at Cr(Ⅵ)initial mass concentration between 20 mg/L and 70 mg/L.
作者
周璁
吴泽全
孙磊
王知彩
ZHOU Cong;WU Zequan;SUN Lei;WANG Zhicai(School of Chemistry and Chemical Engineering, Anhui University of Technology, 243032 Maanshan, China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2020年第4期66-71,共6页
Coal Conversion
基金
国家自然科学基金资助项目(21875001).
关键词
氧解残煤
改性
Cr(Ⅵ)
吸附性能
吸附机理
oxidized residue
modification
Cr(Ⅵ)
adsorption performance
adsorption mechanism
