Comparison of performance of three different seeding sludge under three different hyper-thermophilic temperatures

Abstract

Performance of three seeding sludge under three different hyper-thermophilic temperatures, 60°C, 65°C and 70°C was investigated and compared with mesophilic (37°C) and thermophilic (55°C) temperatures using the same seeding sludge and substrate in batch tests. Based on German guidelines for batch tests, the seeding sludge were selected for the batch tests using eudiometer tubes. Daily volumes of methane production for the three sludge was measured. Methane yields and degrees of COD degradation of the black water was also calculated and compared. Cow manure at 65°C recorded the highest net normalized cumulative volume of methane content (387.2 mlNCH4-%), methane yield (231.7 mlNCH4/gVS) and degree of COD degradation (79.1%) while BTU at 70°C recorded the least performance of methane yield (0.0 mlNCH4/gVS) and content (0.0 mlNCH4-%) and degree of COD degradation (0.0%). Cow manure at 65°C should be considered when setting-up large-scale hyper-thermophilic digesters