Dr. Lide Chen
Associate Professor, Waste Management Engineer, Department of Soil and Water Systems & Biological Engineering, University of Idaho, USA
Dr. Lide Chen earned both B.S. (1989) and M.S. (1993) from China Agricultural University and a Ph.D. (2008) from Iowa State University. His research and extension focus on value-added products from waste, mitigation of environmental impacts caused by waste, and dissemination of science-based information to help stakeholders make informed decisions, leading to positive changes. Currently, Dr. Chen serves as an Associate Editor for ASABE journals (Transactions of ASABE, Applied Engineering in Agriculture, Biological Engineering Transactions, and the Journal of Agricultural Safety and Health).

Speech Title: Anaerobic Co-digestion of Dairy manure and Potato waste

Abstract: Idaho ranks first and fourth nationally in potato and dairy productions. The vibrancy and growth of these agricultural commodities are of obvious economic importance to not only Idaho but the nation as a whole. While these agriculture commodities bring many benefits to Idaho, they also generate huge amounts of wastes. Anaerobic digestion of agricultural wastes has been regarded as a promising technology that reduces GHG emissions and generates renewable energies. Research on anaerobic co-digestion of dairy manure (DM) and potato waste (PW) is much needed to generate science-based information helping address waste management challenges that Idaho’s two important agricultural commodity groups face. The objectives of this research were to investigate the feasibility of co-digestion of DM and PW, and to find out the biogas generation potential at different co-digestion ratios.

Batch anaerobic digestion tests of different mixing ratios of DM and PW (DM-100%, PW-12%, PW-24%, PW-43%, PW-64% and PW-100%) were carried out using 0.6 L digesters under two mesophilic temperatures (35^oC and 42^oC). The organic loading rate was fixed at 2.5 g VS/L and a feed to inoculum ratio (F/I) was maintained at 0.5 in all the batch digesters. During a test period of 95 days, biogas production and methane content were measured periodically. The biogas and methane potential for DM was calculated in the range of 358-497 and 238-332 ml/g VS added, respectively, and for PW was calculated in the range of 526-555 and 304-321 ml/g VS added, respectively. The mixture of DM and PW produced higher biogas and methane yields compared to DM alone at both the temperatures. Among the tested mixing ratios, PW-64% produced highest biogas and methane yields at both the tested temperatures. In conclusion, the potato waste could be a potential substrate for co-digestion with dairy manure under mesophilic temperatures (35-42^oC).