Preparation and Characterization of Activated Carbon from Coffee Waste: Removal of Organic

摘要

The coffee fruits processing is one of the most pollutant activities in agriculture due to a large amount of waste generated in the process. In this work, two types of coffee waste, coffee bean pulp and parchment, were employed as precursor for the production of carbons activated with ZnCl_2. In a typical preparation the raw material was impregnated with 50% (m/m) of ZnCl_2- The mixture was dried at 383 K for 24 h. The dried mixture was pyrolyzed at 773 K for 3 h. The pyrolyzed material was washed with HCl 20% and water. The materials were characterized by N_2 adsorption/desorption at 77 K, infrared spectroscopy (FTIR), scanning electronic microscopy (SEM).The activated carbons were tested as adsorbent for the removal of the methylene blue dye from aqueous medium. In comparison with the commercial carbons, the activated carbons from coffee waste showed higher specific surface areas with values of 974 m~2g~(-1) for pulp and 522 m~2g~(-1) for parchment. Both materials showed mainly micropores structure. Methylene blue removal capacity showed to be comparable to commercial product, with adsorption capacities of 500 mgg~(-1) for pulp and 188 mgg~(-1) for parchment.