Exploring the potential of fur farming wastes and byproducts as substrates to anaerobic digestion process

Mink farming is a well-established economic activity with a significant environmental footprint. In this work mink farming derived organic waste was assessed, for the first time, as substrate to anaerobic digestion plants. The substrates assessed were; (a)fresh mink manures, (b)weathered mink manures, (c) waste feed and (d)mink derived meat and bone meal. Substrates with in inoculum to substrate ratio of 2 offered specific methane productions ranging between 368 and 591 mLCH(4)/gVS(added) corresponding to 67.4 and 91.1% of their theoretical methane potential. In the second phase of the experiments three organic loading rates and three inoculum to substrate ratios were assessed. Substrate/inoculum ratios, in batch mode, lower than 1 seem to affect negatively the process, due to slow hydrolysis and acetogenesis of the macromolecules. In addition, initial organic loading rates of up to 50 gVS/L can be applied in batch systems when manure is utilized as substrate. In contrast to this, when mink derived byproducts are used the same loading rate will result into an irreversible process inhibition due to the accumulation of intermediate products. (C) 2016 Elsevier Ltd. All rights reserved.