为寻求蚯蚓粪便(EM)新型的资源化利用途径,以EM为原料制备生物炭(EMBC),用于吸附废水中Cu(Ⅱ)。在探讨EMBC基本性质的基础上,研究了Cu(Ⅱ)初始浓度、时间、pH、温度、离子强度、EMBC投加量等因素对吸附效果的影响,并分析了潜在的吸附机理。结果表明:EMBC对Cu(Ⅱ)吸附量随初始浓度和温度的增加而增加;EMBC对Cu(Ⅱ)的吸附在24 h内可达到平衡;单位质量EMBC对Cu(Ⅱ)的吸附量随EMBC投加量的增加而减小,EMBC对Cu(Ⅱ)吸附量随pH和离子强度的增加先降后升。Freundlich等温吸附模型能更好地拟合EMBC对Cu(Ⅱ)的吸附行为(R2=1),且二级吸附动力学可以更好地描述吸附过程(R2=0.99),结合傅立叶红外光谱分析,表明EMBC对Cu(Ⅱ)的吸附机制可能是化学吸附作用为主。
As a novel technique to utilize earthworm manure( EM),biochar was prepared by slow pyrolysis of EM to be used as adsorbent for Cu( Ⅱ) removal from aqueous solution. In this study,based on the basic characterization of earthworm manure biochar( EMBC),the initial Cu( Ⅱ) concentration,adsorption time,solution pH,temperature,ionic strength,and biochar amount were mainly investigated to clarify their effects on Cu( Ⅱ)adsorption; the potential adsorption mechanisms were discussed as well. Results showed that Cu( Ⅱ) adsorption capacity of EMBC increased with increasing initial Cu( Ⅱ) concentration and temperature. Cu( Ⅱ) adsorption was equilibrated in 24 h,and adsorption capacity decreased with increasing biochar amount. With increasing solution pH and ionic strength,the Cu( Ⅱ) adsorption decreased initially,and then increased. Adsorption isotherm and kinetics for Cu( Ⅱ) adsorption could be well fitted by Freundlich model( R2= 1) and second-order kinetic model( R2= 0. 99),respectively,this indicated that Cu( Ⅱ) removal by EMBC was mainly controlled by chemical adsorption,which was confirmed by FT-IR spectrum analysis.