Determination of element composition in CoffeeBricks before and after incineration

Abstract: The purpose for this study was to determine the element composition in CoffeeBricks before and after incineration. The difference between element composition in CoffeeBricks (barbecue briquettes made out of spent coffee grounds) and regular barbecue briquettes was also evaluated in this study. Aqua regia digests from the ash residues of CoffeeBricks and the ash residues of regular barbecue briquettes were analyzed with Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). H2SO4/H2O2 digests from unburned CoffeeBricks and plain spent coffee grounds were also analyzed with ICP-AES in order to evaluate the concentration for selected elements before and after incineration. The chosen elements evaluated in this study had concentrations higher than 0.1 ppm in the measured samples according to the ICP-AES analyses. Element concentrations are presented as mg trace element/g ashes or mg trace element/g sample. The ash residues of regular barbecue briquettes contained higher concentration of Al, Ca, Fe, Mg and S.The ash residues of CoffeeBricks contained higher concentration of B, Cu, Fe, K, Mn, Na and P. One-way ANOVA showed that there were differences in concentration for the elements Ca, K, P, Na and S between the ash residues of the two different types of CoffeeBricks and regular barbecue briquettes for =0.001. One-way ANOVA also showed differences in concentration for the elements Ca, K, P and Na between the two different types of unburned CoffeeBricks and plain spent coffee grounds for =0.01.