Preparation of biochar grafted with amino-riched dendrimer by carbonization, magnetization and functional modification for enhanced copper removal

Cu (II) is one of the most harmful heavy metals in the environment, due to the hazardous effects to aquatic organisms, plants, animals, and human beings. In this work, a novel modified magnetic biochar (MBC@APTES-PAMAM) was prepared by PAMAM dendrimer for the removal of Cu (II). The analysis of structural properties identically demonstrated that the abundant -NH2 groups were successfully loaded onto magnetic biochar surfaces. The sorption kinetics process of Cu (II) onto MBC@APTES-PAMAM was better fitted by the pseudo-second-order model. Langmuir isotherm model was better described for Cu (II) sorption process. MBC@APTES-PAMAM showed outstanding performances on Cu (II) removal, and the maximal adsorption amount was 251.81 mg/g. Adsorption experiment indicated that MBC@APTES-PAMAM had a higher Cu (II) removal efficiency under the pH range from 2 to 8. The adsorption capacity of Cu (II) onto MBC@APTESPAMAM was decreased in the presence of competing ions. The existence of surfactant and humic acid had great influences on Cu (II) adsorption process. The Cu (II) adsorption mechanism was connected to the -NH2 by complexation reaction, due to the increased electrostatic attraction and bridging influences. In addition, MBC@APTES-PAMAM also exhibited comparable removal performances for COD (70.82%), TN (71.10%), TP (100%), NH3_N (55.03%) and Cu (II) (99.68%) in the practical treatment of landfill leachate. Overall, MBC@APTES-PAMAM is a green, low-cost, and high efficiency adsorbent for Cu (II) removal. (c) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

The study developed a novel modified magnetic biochar for Cu (II) removal, which demonstrated excellent removal efficiency in practical treatment of landfill leachate, with good fitting to adsorption kinetics and isotherm models.