Biological Treatment of Wastewaters through Thermophilic Aerobic Process

Wastewater treatment using Thermophilic aerobic method was reviewed in this article. Most of thermophilic processes have been studied in laboratory or pilot scale, while full-scale applications are rare. The thermophilic aerobic treatment includes advantages like fast biodegradation rates, low sludge production yield, resistance against high organic loading rates, and effective inactivation of pathogenic microorganism. Substrate utilization rates, reported in the literatures are 3-10 times greater than that observed with analogous mesophilic processes. Sludge production values reported under thermophilic condition is less than 0.3 Kg SS/Kg CODremoved, which is lower than generally obtained in mesophilic processes. Also the stability against high loading rates in thermophilic processes is reported 30–180 Kg COD/m3.d which is obviously more than those of mesophilic treatments. Thermophilic aerobic process is particularly advantageous for the treatment of high-strength wastewaters because of fast biodegradation rates and low sludge yields. However, despite of above-mentioned advantages, many researchers have reported poor bacterial flock formation as well as weak sludge dewaterability for thermophiles. Therefore, further work on thermophilic aerobic processes is still needed to identify optimum operating conditions, and determine the best method to accommodate the oxygen uptake rates of these systems.