6533b854fe1ef96bd12af4d4

RESEARCH PRODUCT

Long-term thermophilic mono-digestion of rendering wastes and co-digestion with potato pulp

M. OjanperäPrasad KaparajuSuvi BayrJukka Rintala

subject

Hydraulic retention timeWaste managementChemistryta1172Industrial Wastefood and beveragesPulp and paper industryIndustrial wasteAnaerobic digestionRendering (animal products)Biodegradation EnvironmentalBioreactorsBiogasBiofuelBioenergyAnaerobiosisMethaneWaste Management and DisposalKjeldahl methodAbattoirsSolanum tuberosum

description

In this study, mono-digestion of rendering wastes and co-digestion of rendering wastes with potato pulp were studied for the first time in continuous stirred tank reactor (CSTR) experiments at 55°C. Rendering wastes have high protein and lipid contents and are considered good substrates for methane production. However, accumulation of digestion intermediate products viz., volatile fatty acids (VFAs), long chain fatty acids (LCFAs) and ammonia nitrogen (NH4-N and/or free NH3) can cause process imbalance during the digestion. Mono-digestion of rendering wastes at an organic loading rate (OLR) of 1.5 kg volatile solids (VS)/m(3)d and hydraulic retention time (HRT) of 50 d was unstable and resulted in methane yields of 450 dm(3)/kg VS(fed). On the other hand, co-digestion of rendering wastes with potato pulp (60% wet weight, WW) at the same OLR and HRT improved the process stability and increased methane yields (500-680 dm(3)/kg VS(fed)). Thus, it can be concluded that co-digestion of rendering wastes with potato pulp could improve the process stability and methane yields from these difficult to treat industrial waste materials.

yearjournalcountryeditionlanguage
2014-02-18Waste Management
https://doi.org/10.1016/j.wasman.2014.06.005