Evaluation of the Generation of Technofossils by Different Coffee Brewing Methods During COVID-19 Pandemic

Coffee is the second most consumed beverage in the world and an important international agricultural commodity, but the increasing use of single-serve coffee machines has led to major environmental concerns, as they produce non-biodegradable solid waste called technofossils, which are considered anthropogenic markers of the technosphere in the Anthropocene. Currently, Brazil is the world's largest coffee producer and the second largest consumer of this beverage. In this study, we evaluated the production of solid waste (biodegradable and technofossil) by the three most commonly used coffee preparation methods in Brazil during the COVID-19 pandemic: the "Brazilian coffee brewing method" (with cloth filter), electric coffee machine (with paper filter) and machines using single-serve Keurig Cups (R) (K-Cups). K-Cups produce a total waste mass 56% and 42% higher than those generated by the methods using the "Brazilian coffee brewing method" and the electric coffee machine, respectively. The K-Cups produce about 10 times more technofossil waste than the other two methods, but have a nearly equal distribution among all their generated waste (biodegradable: 50.5% and technofossil waste: 49.5%), with no statistically significant difference (p > 0.05). On the other hand, the "Brazilian coffee brewing method" and the one using an electric coffee machine, basically produce biodegradable solid waste, predominantly 93.5% for the "Brazilian coffee brewing method" and 84.0% for the one using an electric coffee machine, respectively. The technofossil residues generated mainly by the method that uses K-Cups are difficult to recycle, which poses increasing environmental risks if these solid residues are inadequately treated in the environment. This fact is worrisome, since during the COVID-19 pandemic a significant increase in the generation of municipal solid waste (>10%) was observed, as well as a significant increase in coffee consumption in Brazilian and worldwide households.