Pig waste (PW) and paper sludge (PS) possess complementary properties that can be combined for successful anaerobic digestion. Biochemical methane potential (BMP) tests revealed that a PW:PS 3:1 (v/v) ratio had the highest normalized CH4-COD removal (54%), while PS had the lowest value (11%) and PW had 44%. Batch BMP tests revealed a significant decrease in lag times for methane production in the order of PW:PS 1:3 (14days)<PW:PS 1:1 (17days)<PW:PS 3:1 (20days)<PW (23days). Hydrolysis constants (khyd) were higher for all PW:PS combinations than for either of the individual waste streams: 0.004d-1 (PS)<0.02d-1 (PW)<0.024d-1 (PW:PS 3:1)<0.03d-1 (PW:PS 1:1)<0.05d-1 (PW:PS 1:3). Semi-continuous reactors performing co-digestion of PW and PS at a 2:1 ratio showed 1.5 times higher methane production than baseline PW-only reactors, confirming the BMP results.
- Paper sludge
- Pig waste
ASJC Scopus subject areas
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal