Comparative study between activated charcoal, coffee grounds and fish scales as adsorbents for Congo Red dye present in aqueous solution

Activated Carbon is a form of pure carbon of great porosity that shows remarkable adsorptive properties attributed to its surface area, among them, the removal of impurities dissolved in solution.1 Solid residues known as coffee grounds are the result of the industrial production of soluble coffee (Coffea arabica L.).2 Tainha (Mugil brasiliensis) is a much consumed fish in Brazil and has scales firm and porous structure.3 In this study, dry activated carbon had yours adsorptive properties compared to coffee grounds and fish scales. The two biomass was dried crushed and subsequently grinding and separated using a mechanical sieve. The biomasses were tested “in nature” and treated with NaOH (aq) 0.1 mole L-1 for the removal of dye. UV-Visible Spectrophotometry method was used to determine the presence of Congo Red dye initially present in aqueous solution at the concentration of 1.0 mg/L.4 After the analyzes were calculated the amount of adsorbed dye (Qeq) and the percentage of the Congo Red removed from the solution (%R). Table 1 presents the results including the Congo Red concentration after treatment with the adsorbents (Ceq). In it the conditions under which the tests were performed are also presented.