title: Microwave assisted thermal treatment of defective coffee beans press cake for the production of adsorbents.
abstract: Defective coffee press cake, a residue from coffee oil biodiesel production, was evaluated as an adsorbent for removal of basic dyes (methylene blue--MB) from aqueous solutions. The adsorbent was prepared by microwave treatment, providing a significant reduction in processing time coupled to an increase in adsorption capacity in comparison to conventional carbonization in a muffle furnace. Batch adsorption tests were performed at 25 degrees C and the effects of particle size, contact time, adsorbent dosage and initial solution pH were investigated. Adsorption kinetics was better described by a second-order model. The experimental adsorption equilibrium data were fitted to Langmuir, Freundlich and Tempkin adsorption models, with Langmuir providing the best fit. The results presented in this study show that microwave activation presents great potential as an alternative method in the production of adsorbents.
authors.affiliation: Departamento de Engenharia Mecânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. adriana@demec.ufmg.br
authors.forename: Adriana S
authors.initials: AS
authors.lastname: Franca
authors.forename: Leandro S
authors.initials: LS
authors.lastname: Oliveira
authors.forename: Anne A
authors.initials: AA
authors.lastname: Nunes
authors.forename: Cibele C O
authors.initials: CC
authors.lastname: Alves
mesh_terms: D000327:Adsorption; D000383:Agriculture; D001709:Biotechnology / Q000379:methods*; D003069:Coffee / Q000737:chemistry*; D019649:Food Industry; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry; D008872:Microwaves; D015233:Models, Statistical; D010316:Particle Size; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D003069:Coffee; D007220:Industrial Waste; D008751:Methylene Blue