Biological Treatment of Wastewater by Sequencing Batch Reactors

Tsvetko Prokopov,
Dasha Mihaylova,
Nikolay Mihalkov

In the present paper the operation of wastewater treatment plant (WWTP) in the town of Hisarya which includes a biological stage with aeration basins of cyclic type (SBR-method) was studied. The values of the standard indicators of input and output water from the wastewater treatment plant were evaluated. Moreover, the reached effects due to the biological treatment of the wastewater in terms of the COD (95.7%), BOD5 (96.6%), total nitrogen (81.3%), total phosphorus (53.7%) and suspended solids (95.7%) were established. It was concluded that the indexes of the treated water were significantly below the emission limits specified in the discharge permit.