This study uses a waste iron oxide material (BT3), which is a by-product of the fluidized-bed Fenton reaction (FBR-Fenton), for the treatment of a fluoride (F-) solution. The purpose of this study is to investigate a low-cost sorbent as a replacement for the current costly methods of removing fluoride from wastewater. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) are used to characterize the BT3. Contact time, F- concentration (from 0.75 to 6 mmol L-1), and temperature (from 303 to 323K) are used as operation parameters to treat the fluoride. The highest F- adsorption capacity of the BT3 adsorbent was determined to be 1.17 mmol g-1 (22.2 mg g-1) for a 6 mmol L-1 initial F- concentration at pH 3.9 ± 0.2 and 303 ± 1 K. Adsorption data were well described by the Langmuir model, and the thermodynamic constants of the adsorption process, ΔG°, ΔH°, and ΔS°, were evaluated as -1.63 kJ mol-1 (at 303 K), -1.75 kJ mol-1, and -52.4 J mol-1 K-1, respectively. Additionally, a pseudo-second-order rate model was adopted to describe the kinetics of adsorption. BT3 could be regenerated with NaOH, and the regeneration efficiency reached 95.1% when the concentration of NaOH was 0.05 mol L-1.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Process Chemistry and Technology
- Filtration and Separation