BIOLOGICAL TREATMENT OF WHEY IN AN UASFF BIOREACTOR FOLLOWING A THREE-STAGE RBC

Biological treatment of a high strength chesses whey wastewater was investigated in a series of aerobic-anaerobic experiments. The aerobic treatment of the wastewater was conducted in a three-stage rotating biological contactor (NRBC), while the anaerobic process was performed in an up-flow anaerobic sludge fixed film (UASFF) bioreactor. Various concentrations of wastewater with influent COD of 40 to 70 g/L were introduced into the NRBC system. Treatability of the samples at various HRTs of 8, 12 and 16 h was evaluated in the NRBC reactor. The effluent streams of the NRBC system were introduced into a UASFF bioreactor. The anaerobic treatment of pretreated samples was investigated in the UASFF at the same HRTs of 8, 12 and 16 h. The obtained results revealed that more than 53, 69 and 78% of the influent COD (50 g/L) were removed in the NRBC reactor at HRTs of 8, 12 and 16 h, respectively. Maximum COD removal efficiencies of 96, 96.8, 97.4 and 96.4% were achieved in the combined systems at total HRT of 32 h for the influent COD of 40, 50, 60 and 70 g/L, respectively.