巯基改性木薯秸秆吸附水体Cu(Ⅱ)和Zn(Ⅱ)特性

以废弃木薯秸秆为原料,经碱化、添加巯基官能团进行改性得到吸附剂,对其进行了表征,并研究了不同条件下吸附剂的对Cu(Ⅱ)和Zn(Ⅱ)吸附性能。结果表明,木薯秸秆成功引入巯基基团。经过巯基改性后的木薯秸秆的吸附量得到提升,吸附量随p H的升高而增大,在30 min内吸附量可迅速达到平衡,吸附动力学符合准2级动力学方程。对Cu(Ⅱ)的等温吸附符合Langmiur等温模型,近似于单层吸附,理论最高吸附量为65.36 mg/g;对Zn(Ⅱ)的等温吸附符合Freundlich等温模型,以多分子层吸附为主,理论最高吸附量为60.24 mg/g。两者吸附过程均为自发的放热过程。

Adsorption Characteristics of Cu(Ⅱ)and Zn(Ⅱ)in Water on Sulfhydryl Modified Cassava Straw

Using waste cassava straw as raw material,after alkalization and adding sulfhydryl functional group for modification to obtain the adsorbent,and it was characterized.The adsorption properties of adsorbents for Cu(Ⅱ)和Zn(Ⅱ)under different conditions were studied.The results showed that,sulfhydryl groups were successfully introduced into cassava straw.The adsorption capacity of cassava straw modified by sulfhydryl group was increased,and the adsorption capacity increased with the increase of pH.The adsorption capacity could reach equilibrium rapidly within 30 min.The adsorption kinetics accorded with the quasi-second-order kinetic equation.The isotherm adsorption of Cu(Ⅱ)accorded with Langmiur isotherm model,it was similar to monolayer adsorption,and the theoretical maximum adsorption capacity was 65.36 mg/g.The isotherm adsorption of Zn(Ⅱ)was in accordance with Freundlich isotherm model,and it was mainly multi-molecular layer adsorption,and the theoretical maximum adsorption capacity was 60.24 mg/g.Both adsorption processes were spontaneous exothermic processes.