|Title||Acceleration of Biochar Surface Oxidation during Composting?|
|Publication Type||Journal Article|
|Year of Publication||2015|
|Authors||Wiedner, Katja, Fischer Daniel, Walther Sabine, Criscuoli Irene, Favilli Filippo, Nelle Oliver, and Glaser Bruno|
|Journal||Journal of Agricultural and Food Chemistry|
Biochar composting experiments were performed to determine whether composting is a suitable method to accelerate biochar surface oxidation. To assess the results, surface properties of Terra Preta (Brazil) and ancient charcoal pit (Northern Italy) biochars were additionally investigated. Calculation of O/C ratios by energy-dispersive X-ray spectroscopy demonstrated the anticipated increasing values from fresh biochars (0.13) to composted biochars (0.40), and finally charcoal pit biochars (0.54) and ancient Terra Preta biochars (0.64). By means of Fourier transformation infrared microscopy, creation of carboxylic and phenolic groups on biochars surface could be detected. Carboxylic acids of three composted biochars increased up to 14%, whereas one composted biochar showed a 21% lower proportion of carboxylic acids compared to the corresponding fresh biochar. Phenolic groups increased by 23% for the last mentioned biochar, and on all other biochars phenolic groups decreased up to 22%. Results showed that biochar surface oxidation can be accelerated through composting but still far away from ancient biochars.
|Short Title||J. Agric. Food Chem.|