Impact of Uneven Flow Wastewater Distribution on the Technological Efficiency of a Sequencing Batch Reactor

Variability in the load of pollutants significantly influences the efficiency of activated sludge technology in municipal wastewater treatment plants, both in terms of flow systems and in sequencing batch reactors (SBR). Diversified inflow of wastewater to the treatment plant has a significant impact on the technological efficiency of sequencing batch reactors. Additionally, this problem is intensified in technological systems in which there is no storage tank for raw wastewater. It is assumed, however, that the flexible operation of an SBR reactor allows it to be easily adapted to a variable load of pollutants. The aim of the article is to present the effects of uneven wastewater inflow on the operation of sequencing batch reactors using the example of the wastewater treatment plant in Rabka-Zdrój (Poland). The conducted research has shown that, in wastewater treatment plants, the use of sequencing batch reactors as an independent element of biological wastewater treatment does not always ensure a high degree of pollutant removal in the event of a very uneven wastewater inflow. Therefore, the use treated wastewater equalizing tanks is recommended, which can additionally clean residual contaminants from wastewater.