EDTA Functionalized Fe-Mn Binary Oxide/Hydrochar from GreenTea Waste Composite

Abstract

In this study, a novel ethylenediaminetetraacetic acid (EDTA) functionalized hydrochar from green tea (Camellia sinensis) waste, doped with manganese ferrite, was synthesized by hydrothermal carbonization (HTC) coupled with the activation process. This adsorbent was applied to remove Rhodamine B (RhB) and copper ions (Cu2+) from aqueous solutions. The characterization of adsorbent was carried out using Field Emission Scanning Electron Microscopy-Electron Dispersive X-ray Spectroscopy, CHNO analyzer, BET gas sorption analyzer, X-ray Diffraction, Zeta Potential Analyzer, Vibrating Sample Magnetometer, Fourier Transform Infrared Spectroscopy and X-ray Photoelectron Spectroscopy. Some parameters such as adsorbent weight, contact time and initial concentration, temperature and pH were investigated in the adsorption experiment. The Langmuir isotherm and pseudo-second-order kinetic model fitted well with the obtained data with the maximum adsorption capacities (max) for RhB and copper ions (Cu2*) of 21.41 and 9.49 mg.g ̈1 at natural pH, respectively. The adsorption mechanism of RhB and copper ions (Cu2+) were facilitated via hydrogen bonding and the complexation process between the adsorbates and the adsorbent surface, respectively Furthermore, the regeneration studies of EDTA FMHC-700 exhibits a good reusability, high stability and fast separation within 4 successive cycles. The use of EDTA-FMHC-700 as a low-cost adsorbent with good separation performance can be developed for industrial applications and environmental remediation.