Europium-Doped Y2O3-Coated Diatomite Nanomaterials: Hydrothermal Synthesis, Characterization, Optical Study with Enhanced Photocatalytic Performance

Eu-doped Y2O3 coated diatomite nanostructures with variable Eu3+ contents were synthesized by a facile hydrothermal technique. The products were characterized by means of energy dispersive X-ray photoelectron spectroscopy (EDX), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Brunauer–Emmett–Teller (BET), UV-vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy techniques. As claimed by PXRD, the particles were crystallized excellently and attributed to the cubic phase of Y2O3. The influence of substitution of Eu3+ ions into Y2O3 lattice caused a redshift in the absorbance and a decrease in the bandgap of as-prepared coated compounds. The pore volume and BET specific surface area of Eu-doped Y2O3-coated diatomite is greater than uncoated biosilica. The sonophotocata-lytic activities of as-synthesized specimens were evaluated for the degradation of Reactive Blue 19. The effect of various specifications such as ultrasonic power, catalyst amount, and primary dye concentration was explored.

Optimization of Anthraquinone Dye Wastewater Treatment using Ozone in the Presence of Persulfate Ion in a Semi-batch Reactor

The degradation of anthraquinone dye Reactive Blue 19 by using O3 and O3 / S2O8 2- in the advanced oxidation processes is studied to investigate the performance of these two systems. The response surface method with a Box-behnken Design was successfully applied to identify the relationship between operating variables such as initial concentration, S2O8 2- dosage and contact time in order to determine the optimum operating condition. The quadratic model for the percentage COD removal (response) proved to be significant for the degradation of the dye. The COD removal efficiency under Box-behnken Design and experimental test were found to be 96.2% and 83.9% under the optimum conditions. Furthermore, the result obtained showed that the O3 / S2O8 2- system is more effective than the O3 only in treating the Reactive Blue 19.

Process Optimization and Adsorptive Mechanism for Reactive Blue 19 Dye by Magnetic Crosslinked Chitosan/MgO/Fe3O4 Biocomposite

A new biocomposite magnetic crosslinked glutaraldehyde-chitosan/MgO/Fe3O4 (CTS-GL/MgO/Fe3O4) adsorbent was prepared and applied for the removal of reactive blue 19 (RB 19) synthetic textile dye. The prepared CTS-GL/MgO/Fe3O4 was subjected to the several instrumental characterizations such as XRD, FTIR, SEM-EDX, pH-potentiometric titration, and pHpzc analyses. The influence of the input adsorption parameters such as A: CTS-GL/MgO/Fe3O4 dosage, B: initial solution pH, C: process temperature, and D: contact time on RB 19 removal efficiency was statistically optimized using Box-Behnken design (BBD). The analysis of variance (ANOVA) indicates the presence of five significant statistical interactions between input adsorption parameters i.e. (AB, AC, AD, BC, and BD). The adsorption kinetic and equilibrium study reveals a good to the pseudo-second-order model, and multilayer adsorption as proven by Freundlich isotherm model, respectively. The maximum adsorption capacity of CTS-GL/MgO/Fe3O4 towards RB19 was found to be 193.2 mg/g at 45 ºC. This work highlights the development of feasible and recoverable magnetic biocompsite adsorbent with desirable adsorption capacity towards textile dyes with good separation ability by using an external magnetic field.