Fabrication of MNPs/rGO/PMMA composite for the removal of hazardous Cr(VI) from tannery wastewater through batch and continuous mode adsorption
Document Type
Article
Publication Date
11-1-2021
Abstract
Herein, we report the synthesis of magnetic nanoparticle (MNP)-reduced graphene oxide (rGO) and polymethylmethacrylate (PMMA) composite (MNPs/rGO/PMMA) as adsorbent via an in situ fabrication strategy and, in turn, the application for adsorptive removal and recovery of Cr(VI) from tannery wastewater. The composite material was characterized via XRD, FTIR and SEM analyses. Under batch mode experiments, the composite achieved maximum adsorption of the Cr(VI) ion (99.53 & PLUSMN; 1.4%, i.e., 1636.49 mg of Cr(VI)/150 mg of adsorbent) at pH 2, adsorbent dose of 150 mg/10 mL of solution and 30 min of contact time. The adsorption process was endothermic, feasible and spontaneous and followed a pseudo-2nd order kinetic model. The Cr ions were completely desorbed (99.32 & PLUSMN; 2%) from the composite using 30 mL of NaOH solution (2M); hence, the composite exhibited high efficiency for five consecutive cycles without prominent loss in activity. The adsorbent was washed with distilled water and diluted HCl (0.1M), then dried under vacuum at 60 & DEG;C for reuse. The XRD analysis confirmed the synthesis and incorporation of magnetic iron oxide at 2 theta of 30.38 & DEG;, 35.5 & DEG;, 43.22 & DEG; and 57.36 & DEG;, respectively, and graphene oxide (GO) at 25.5 & DEG;. The FTIR analysids revealed that the composite retained the configurations of the individual components, whereas the SEM analysis indicated that the magnetic Fe3O4-NPs (MNPs) dispersed on the surface of the PMMA/rGO sheets. To anticipate the behavior of breakthrough, the Thomas and Yoon-Nelson models were applied to fixed-bed column data, which indicated good agreement with the experimental data. This study evaluates useful reference information for designing a cost-effective and easy-to-use adsorbent for the efficient removal of Cr(VI) from wastewater. Therefore, it can be envisioned as an alternative approach for a variety of unexplored industrial-level operations.
Keywords
Reduced graphene oxide, Hexavalent chromium, Tannery wastewater, Fixed bed adsorption
Divisions
sch_che
Funders
Malaysia-Thailand Joint Authority [Grant No: IF062-2019],Fundamental Research Grant Scheme from the University of Malaya [Grant No: FP050-2019A],National Priorities Research Program Grant from the Qatar National Research Fund (Qatar Foundation) [Grant No: NPRP11S-1128-170042],European Commission,Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCHCREATEINNOVATE (2nd Cycle); acronymSEMI-WEB [Grant No: T2EDK-02073],Higher Education Commission of Pakistan [Grant No: NRPU-9056]
Publication Title
Materials
Volume
14
Issue
22
Publisher
MDPI
Publisher Location
ST ALBAN-ANLAGE 66, CH-4052 BASEL, SWITZERLAND