Economical and Eco-Friendly Adsorbent Derived from Coffee Waste for Efficient Adsorption of Methylene Blue: Characterization, Evaluation and Optimization Studies

In this study, treated coffee ground wastes (CGW) was evaluated for adsorption of methylene blue (MB) from contaminated solution using contact time, initial dye concentrations, adsorbent dose, and solution temperature as operational factors. The adsorbent was treated using chemical activation with potassium carbonate (K2CO3), followed by thermomechanical treatment via an extrusion process. The characterization study of the adsorbent was conducted using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and X-ray fluorescence spectroscopy techniques. The adsorption equilibrium was reached after 30 min for MB and it was observed also that adsorption capacity decreased but percentage removal increased with increases in adsorbent mass. The maximum adsorption capacity of K2CO3-coffee powder was found to be 169.49 mg/g.