China Plastics ›› 2021, Vol. 35 ›› Issue (10): 37-44.DOI: 10.19491/j.issn.1001-9278.2021.10.007

• Materials and Properties • Previous Articles     Next Articles

Synthesis of Carboxylated Magnetic Fe3O4 Composites and Their Adsorption Behavior to Pb2+

LI Meilan1,2(), DOU Xiaoyu1, HE Jiao1, GONG Wei1,2(), XIE Chengcheng1, LIU Bailing2   

  1. 1.Key Laboratory of Comprehensive Utilization of Tailings Resources in Shanxi Province,Shangluo University,Shangluo 726000,China
    2.Chengdu Institute of Organic Chemistry,Chinese Academy of Sciences,Chengdu 610041,China
  • Received:2021-04-07 Online:2021-10-26 Published:2021-10-27

Abstract:

Fe3O4 magnetic particles were prepared by co?precipitation and then surface?treated through silanization and amidation reactions to obtain a carboxylated composite (Fe3O4?SiO2?NH?COOH). The structure of Fe3O4?SiO2?NH?COOH, the effect of reaction condition on the Pb2+ adsorption of the Fe3O4?SiO2?NH?COOH and its repetitive utilization efficiency was analyzed by FTIR, SEM, TEM, VSM and XRD. The results indicated that the Fe3O4?SiO2?NH?COOH were successfully prepared with a desired structure and could be obtained through a rapid magnetic separation. Meanwhile, the static adsorption experiment showed that the adsorption kinetics belonged to the second order. The adsorption system reached an equilibrium with a maximum adsorbent capacity of 207.8 mg/g with a pH 4.5, a temperature of 55 ℃, a contact time of 100 min, and an Fe3O4?SiO2?NH?COOH concentration of 1.0 g/L. The Langmuir equation is able to better describe the adsorption isotherm, indicating an endothermic process for the adsorption of Pb2+. The adsorption capacity of Fe3O4?SiO2?NH?COOH toward Pb2+ showed an increase at first and then tended to stabilize with an increase in time. However, it increased at first and then decreased with an increase in pH. Compared to monovalent cations, the presence of divalent Ca2+ and Mg2+ in the solution could generate a certain inhibitory effect on the adsorption reaction. The Pb2+ removal rate was still above 50 % after regeneration of Fe3O4?SiO2?NH?COOH for six times.

Key words: carboxylation, adsorption, lead ion, structure, magnetism, composite

CLC Number: