Efficiency of Thermophilic Bacteria in Wastewater Treatment

The present work was carried out to assess the efficiency of thermophilic bacteria in wastewater treatment. A consortium of four thermophilic bacterial strains was used in this study. At 50 °C, the thermophilic consortium showed a very high efficiency in removing total organic carbon (TOC), which reached around 79% in 60 h. Removal of phosphorous was relatively low at 15.4%, while removal of nitrogen was about 83% in 60 h of incubation time. Dissolved oxygen was significantly decreased from 3.43 ppm down to 0.13 ppm in the same period. The consortium of mesophilic bacteria grown at 37 °C showed a substantially different performance from the thermophilic consortium incubated at 50 °C. For example, after 60 h of incubation at 37 °C, only 58.5% of TOC, 13.2% of phosphorous and 75.9% of nitrogen were removed, respectively. Dissolved oxygen was decreased from 3.43 ppm down to 0.28 ppm in the same period. Efficiency of removal rate by thermophilic conditions is higher than the mesophilic conditions. Properties such as fast growth of thermophiles (compared to mesophiles) may explain the exceptional ability of these thermophilic organisms in waste removal.