Using Iron-activated Peroxymonosulfate With Ultrasound-Assisted for Azo Dyes enhanced Removal from Wastewater
The presence of dyes in the terrestrial environment and in surface waters poses significant public health concerns. In the context of this project, a novel and eco-friendly process system was established for the purpose of dye removal from water. The X-ray diffraction (XRD) characterization of the catalyst revealed the presence of multiple mineralogical phases, including calcite, Filipstadite, eucryptite, geothite and cristobalite. Subsequent elemental chemical analysis by X-ray Fluorescence Spectrometer (SFX) revealed a substantial presence of iron oxide (31.41 %) and cristobalite (37.42 %). Furthermore, the kinetics of methylene blue (MB) degradation by a natural catalyst in conjunction with an oxidant (PMS) activated by ultrasound were monitored. The present study investigates the influence of specific parameters (i.e. [PMS], [MB], catalyst dose) on MB degradation, with the objective of determining the optimal conditions for this process. The degradation rate was 96.17% under the best conditions (i.e. [MB] = 40 µM, [PMS] = 0.5 mM, [catalyst dose] = 0.2 g/L, pH = 6.7 and T = 30°C). Ultimately, the degradation of MB was attributed to SO₄•-, OH• and O2•-, with SO₄•- accounting for the majority at 53.81%. The relative contributions of SO₄•-, OH• and O₂•- to the MB degradation (96.17%) were therefore estimated to be 55.95%, 34.16% and 9.89%, respectively. At the end of the fifth cycle, the degradation efficiency decreased to 7% ± 2%. However, the TOC provided confirmation of the system's excellent stability, a finding that was previously demonstrated by US/PMS/Clay, thereby underscoring a good mineralization (i.e., 62 ± 2%), which remained consistent even after five oxidation cycles. The implementation of this process system is an effective approach for the treatment of dyes in wastewater.