Characterization of synthesized Mn-

Characterization of synthesized Mn-Zn ferrite
Scanning electron microscopy (Quanta FEG 250, Bruker, Germany) coupled with energy dispersive X-ray spectroscopy (EDS) was used to study the morphology, microstructure, and composition of the synthesized Mn-Zn ferrite. X-ray powder diffraction (XRD) was performed to determine the crystalline structure of Mn-Zn ferrite on a Bruker D8-Advance diffractometer with Cu K_ radiation (_ = 0.15406 nm). The synthesized Mn-Zn ferrite was scanned from 20◦ to 80◦ (2_) with a scanning rate 0.5◦/min and a
step size 0.02◦. A Superconducting Quantum Interference Device (MPMS-XL7, Quantum Design, USA) was used to reveal the saturation magnetization of the Mn-Zn ferrite generated from the ferrite
process. BET surface area (m2/g), pore volume (cm3/g), and average pore size (A) were determined by an ASAP 2010 surface analyzer (Micromeritics Co., USA).












2.4. Adsorption experiments
To evaluate the adsorption behavior of the synthesized Mn-Zn ferrite, stock solutions of As, Cd, and Pb (1000 mg/L) were prepared by dissolving (NaH2AsO4•7H2O), Cd(NO3)2•4H2O, and Pb(NO3)2
(Merck, Darmstadt, Germany) in Milli-Q water, respectively. Working solutions for various experiments were freshly prepared from the stock solutions. All experiments were performed in triplicate
using 15 mL centrifuge tubes under 30 rpm shaking at 27±1 ◦C. An initial As, Cd, and Pb concentration of 500 _g/L and 10 mL solution was used for the batch experiments. To investigate the effects of pH on As, Cd, and Pb adsorption by the Mn-Zn ferrite, the solution pH was controlled at 3.3 ±0.1, 6.9 ±0.1, and 11.2
±0.1 byadding 0.1 M NaOH or 0.1 M HNO3 under the condition of 0.005 g Mn-Zn ferrite and reaction for 60 min. The concentrations of As, Cd, and Pb in the filtrate were determined by ICP-MS (Element II,Thermal Scientific, Germany). The detection limit of As, Cd, and Pb is 0.08 _g/L, 0.07 _g/L and 0.09 _g/L, respectively.