摘要
As a common macromolecular carbohydrate, pectin has a strong affinity for Pb 2+ . An ethylenediamine modified pectin (EP 48 ) with 48 % of amidation was prepared and exhibited great removal efficiency towards Pb 2+ in our previous study. However, the EP 48 has drawbacks in adsorption including low mechanical strength and difficulty in separation. In this study, EP 48 was compounded with sodium alginate (Alg) and Fe 3 O 4 to synthesize EP 48 /Alg/Fe 3 O 4 microsphere. The physicochemical properties and Pb 2+ adsorption characteristics of microsphere were analyzed. It was found that the microsphere exhibited good thermal stability, mechanical strength, porous structure, as well as acid tolerance. The pseudo-second-order model well described the kinetics of adsorption process, indicating the chemical adsorption is dominant. The Langmuir model fitted the experimental data well, and the maximum adsorption capacity reached 175.19 mg/g. Adsorption-desorption experiments showed that the removal rate of the microsphere maintained over 98.9 % after 10 cycles. The X-ray photoelectron spectroscopy (XPS) analyses revealed that the potential adsorption mechanism included ion-exchange and chelation. The above results suggested its potential use for the removal of Pb 2+ from wastewater.
危险品化学品经营许可证（带存储）