Activated Carbon Obtained from Coffee and Orange Wastes

Abstract

Organic coffee and orange wastes have increased considerably in the last decade. In order to utilize this "garbage", the present study focuses on the obtaining of activated carbon from them. The pyrolysis of the samples, followed by chemical activation and subsequent neutralization, allowed the establishment of two protocols “A” and “B”, with slight variations depending on the residue. The results indicate that the efficiency of the activated carbon from coffee grounds using protocol "A" and "B" was 3.68% and 6.30%, respectively. On the other hand, the carbon obtained from orange peels had an efficiency of 5.00 % and 2.88 %, respectively. To confirm that the activated carbon from each type of waste has adsorption and absorption capacity, we performed a colorimetric analysis with methyl blue. These analyses showed that the activated carbon from coffee grounds and orange peels have a retention capacity of 91.09 and 95.25%, respectively, while the retention capacity of a commercial activated carbon was 99.23 %. In this preliminary study, it is shown that several residues considered "garbage" can be used sustainably.