Date of Award


Publication Type

Master Thesis

Degree Name



Civil and Environmental Engineering


Anaerobic digestion, Bioenergy, co-digestion, Methane, pig manure, potato peel


R. Seth




The influence of mixing ratio, thermal pre-treatments and biological-acidification pre-treatment on methane yield was evaluated for anaerobic co-digestion of potato peel and pig manure, in a batch study at mesophilic conditions. The biological-acidification pre-treatment was conducted at mesophilic (37 °C) and thermophilic (55 °C) condition at a retention time of 6 days, with a food-microorganism ratio of 0.5. The thermal pre-treatment was performed at 100 °C for 1 hour, using a reflux heating method. A food-microorganism ratio of 0.5 was applied in a biochemical methane potential test for the untreated and pre-treated substrate, at a mesophilic temperature. Results showed that the highest experimental methane yield for the untreated substrate was 231 ml CH4/��������������������, which was attained at 50:50 mix of potato peel to pig manure. The pre-treated substrates had the highest methane yield of 285 ml CH4/�������������������� and 283 ml CH4/��������������������, for the thermally treated and biological-thermophilic treated substrate, respectively, at 50:50 mix of potato peel to pig manure. This was 23% higher than the methane yield from untreated substrate. However, the biological-acidification at mesophilic temperature attained the highest experimental methane yield of 255 ml CH4/�������������������� at 75:25 mix of PP to PM. The reaction kinetics showed that the biological acidification pre-treatment had the highest methane production rate. However, the thermal pre-treatment produced 95% of the cumulative methane in less than 15 days due to the longer pre-treatment time in biological acidification. Hence, biological-acidification and thermal pre-treatment enhanced methane yield and reaction kinetics from co-digestion of potato peel and pig manure.