Kouassi Kouadio Dobi-Brice¹, Ekou Lynda¹, Yacouba Zoungranan^2,, Ekou Tchirioua¹

Among the methods of wastewater treatment, adsorption is the one that remains accessible because it is easy to implement. It uses less expensive, abundant and available adsorbent supports. Adsorption can be implemented through two types of processes: continuous adsorption and discontinuous adsorption. Continuous adsorption allows the treatment of large volumes of water compared to discontinuous adsorption, which is suitable for the treatment of small quantities of water [1]. This study is part of an approach to the removal of toxic dyes using the continuous mode adsorption method. Two dyes were used: crystal violet and methyl red. The adsorbent fixed bed of the column consists of biomass of previously deactivated lichens. The influence of some physico-chemical parameters on the column such as flow rate, lichen grain size, adsorbent bed mass and initial dye concentration were evaluated. The application of Bohart-Adams, Thomas and Yonn-Nelson models to the experimental data made it possible to predict the theoretical characteristics of the column. For a given dye, under the influence of a given physico-chemical parameter, the application of the Bohart-Adams model determined the saturation concentration of the adsorbent bed (N₀). The application of the Thomas model allowed to determine the theoretical adsorption capacity of the column (Q_the), and the Yonn-Nelson model allowed to predict the time (τ) necessary for the 50% breakthrough of the adsorbent bed.

wastewater, adsorption, column, lichens, models, dyes