The effect of mesophilic and thermophilic temperature on the performance of an up-flow anaerobic sludge bed (UASB) reactor

Performance of a reactor can depend on various factors such as wastewater composition, organic loading rate (OLR), hydraulic retention time (HRT), seed sludge, temperature, and reactor configuration. In the present study, an up-flow anaerobic sludge bed (UASB) was used for the treatment synthetic wastewater subjected to anaerobic treatment. Specifically, this study was carried out in order to investigate the effect of temperature to the reactor performance when Organic Loading Rate (OLR) was gradually increased. The reactors were operated at two different temperature range mesophilic (37oC) and thermophilic (57oC). The maximum COD removal efficiency of the mesophilic operation was found to be lesser than thermophilic operation which was 75.3 and 81.2% respectively. The Volatile acid generation observed to be below 80 mg/L throughout the entire thermophilic and mesophilic operation. The MLVSS/MLSS ratio showed that utilization of feed by biomass during thermophilic operation was more efficient compared to mesophilic operation throughout the reactor operation period. From the present study it was concluded that temperature plays a major role in reactor operation, furthermore the performance of the reactor was better at thermophilic than mesophilic operation phase.