木素对Pb^(2+)吸附类型及脱附性的影响

Lignin for Pb^(2+) adsorption type and the impact of desorption

本文中,通过改变Pb^(2+)初始浓度的方法,研究了等量木素对Pb^(2+)的吸附性能。根据Langmuir、Freundlich、Temkin、Henry方程模型做吸附等温线,其中按Langmuir吸附模型得到的方程中方差R^2最大,确定木素对Pb^(2+)的吸附符合Langmuir吸附模型,且吸附方式主要以化学吸附为主。通过降低温度、降低pH、缩短时间3种方法考察木素吸附Pb^(2+)后的脱附情况。实验数据表明,通过降低温度的方法无法使被吸附的Pb^(2+)脱附,通过降低pH可以使被木素吸附的Pb^(2+)有效脱附,在低pH的环境下,被吸附的Pb^(2+)在短时间内即可实现大量的脱附。

Abstract: By changing the initial concentration of Pb2+, the adsorption capacity of lignin on Pb2+ was studied in this paper. By the adsorption isotherms based on the Langmuir, Freundlich,Temkin, and Henry equation models, the variance R 2 is the largest in the Langmuir adsorption model.Therefore, it was found that the adsorption of lignin on Pb2+ was main chemical adsorption according with the Langmuir adsorption model. Three methods of decreasing temperature, time and pH were usedto investigate desorption after the lignin had absorbed Pb2+. The experimental data showed that theadsorbed Pb2+ couldn’t be desorbed by means of a decrease of temperature, but the adsorbed Pb2+ could be efficiently and heavily desorbed under the environment of low pH in a short time.