Fixed-bed-column Studies for Methylene Blue Removal and Recovery by Untreated Coffee Residues

Abstract

This paper contributes to the Industrial Ecology Concept by using a common urban solid waste, i.e., coffee residues, to clean industrial wastewaters polluted by basic dyes, e.g., Methylene Blue. For the data from the continuous fixed-bed column system, two common models, namely (a) Bohart and Adams and (b) Clark were implemented. The Bohart and Adams capacity was up to N = 46,166 mg·L-1 or q0 = 104.5 mg·g-1 for bed-depth 15 cm, initial dye concentration 800 mg·L-1 and flow rate 20 mL·min-1. The results revealed that the Methylene Blue is fairly adsorbed on coffee residues. Consequently, this process can be applied as a low cost technique for cleaning basic dyes from the aquatic environment.