Title : Photoreduction of Cr VI by ZnS ZnO/MCM-41 based on blast furnace slag and electric arc furnace dust
Iron/ steel production in the electric arc furnace (EAF) produces a dust by-product consisting mainly of iron oxides and non-ferrous metals (ZnO, PbO, CaO,….etc). This industry is a weed that produces large quantities of slag and dust. The objective of the present study was to develop a procedure for obtaining and characterizing photocatalysts derived from this waste for chromium remediation. The MCM-41 was synthesized via sodium silicate (Na2SiO3) derived from Blast Furnace Slag (BFS), and ZnO and ZnS were synthesized based on zinc extracted from Electric Arc Furnace Dust (EAFD). Subsequently, ZnS/ZnO were sono-chemically loaded on the MCM-41 and were tested for the Cr (IV) photoreduction, as heavy metal ions are one of the main wastewater pollutants with the development of the industrial revolution. The resultant ZnO, ZnS, MCM-41, and composites were characterized by X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), N2 adsorption–desorption isotherms, Fourier-transform infrared (FT-IR) spectrometry, Dynamic Light scattering, and Transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). A regular hexagonal structure of typical mesoporous MCM-41 had been proven by small-angle XRD, HRTEM, and N2 adsorption–desorption. The photoreduction activity of ZnS-ZnO/MCM-41 nanocomposite has obvious efficiency compared to ZnO and ZnO/MCM-41, achieving a 94% photoreduction of Cr (VI) in 180 minutes under UV irradiation. The slight activity loss after 4 cycles (84.7 %) reveals the good photoreduction properties of catalysts. Based on these results, ZnS-ZnO/MCM-41 composite material seems to be high efficiency, green, stable, environment, and economical alternative to be used as a photocatalyst for the reduction of Cr (VI).
Audience Take away:
- The audience will learn the importance of working in wastewater treatment
- Also, they will learn how to make a good use of solid waste by converting them into valuable materials.
- The take-home message will be how to remove waste by waste, in a trial to attain zero waste.