Removal of Crystal Violet Dye from Aqueous Solution Using Ecuadorian Black Sands as Photocatalytic Adsorbents

In the present work, the removal (discoloration) of the crystal violet dye (CV) in aqueous solution was carried out, through the Integrated Photocatalysis and Adsorption (IPCA) process, using two black sands from different parts of Ecuador, Mompiche and the Quilotoa volcano. Sand samples used as photocatalytic adsorbents are characterized by their optical properties (Band-Gap) using UV-Vis diffuse reflectance spectroscopy. The determined values are in the appropriate range for a photocatalyst in comparison with those reported by the literature. The experiments provided band-gap values of 3.37 eV and 3.68 eV for Mompiche and Quilotoa respectively. Concentration of hydrogen peroxide, pH and light irradiation were optimized by an 2n experimental design for the removal of CV on SEM-205 and SXQ-102. Optimum pH value for dye adsorption was determined to be 8. The UV-Vis absorption spectra at different time intervals showed that in the adsorption process with SEM-205 and SXQ-102 there is only a decrease in peaks which confirms its absorbent nature. The UV-Vis spectra of the integrated photocatalysis and adsorption process with SEM-205 and SXQ-102 showed the appearance of new peaks in the spectrum which meant the appearance of intermediaries and by-products. It was seen that under optimized conditions, 97.1% dye could be removed from the solution in 2 hours using Mompiche’s sand (SEM-205).

• 1. Verfasser: Gómez Gómez, Johanna Mishell (author)
• Format: bachelorThesis
• Sprache: eng
• Veröffentlicht: 2020
• Schlagworte: Black sand; Integrated Photocatalysis and Adsorption (IPCA); Crystal violet; Dye removal; Adsorption Isotherms; Kinetics models; Arena negra; Adsorción y Fotocatálisis Integrada (IPCA); Cristal violeta; Isotermas de adsorción; Modelos Cinéticos
• Online Zugang: http://repositorio.yachaytech.edu.ec/handle/123456789/119