Abstract:
The purification of aqueous effluents from the textile industry to eliminate dyes constitutes a major
challenge in the treatment of wastewater. To achieve this goal, photocatalysis and adsorption are often
used. In this experimental study, we examined the elimination of a specific dye, Congo red, using
heterogeneous photocatalysis. We combined a biomass called Saccharothrix algeriensis (SA) with
FeCl3, 6H2O, to form Fe-SA. The objective was to study the influence of various parameters such as the
contact time, the pH of the solution and the initial concentration of the dye on the adsorption capacity of
Congo red by Fe-SA. The results obtained revealed a maximum discoloration rate of 43% for Congo red
thanks to the photocatalytic process. The analysis of the data using kinetic models has shown that the
pseudo-second-order model offers a better representation of the evolution of the adsorbed amount of the
Congo red pollutant over time. In addition, the Langmuir model proved to be the most suitable for
reproducing the experimental adsorption isotherms. The experiments also demonstrated that the
maximum adsorption capacity was reached at a pH of 2 and that equilibrium was reached after one hour
of contact. In conclusion, the results of this experimental study clearly indicated that the photocatalysis
process obtained a decolorization yield higher than that of adsorption.
