Evaluation Of Wastewater Treatment Plant Efficiency And Emission Limits.pdf

The study presents variation of wastewater inflow and its components during a year, considering a situation with and without precipitation. Two renovated wastewater treatment plants (WWTP) were selected to analyze the available parameters and relation between them. Both WWTP served to treat domestic and industrial wastewater with similar characteristics. One WWTP is only for the town purposes, while the second one serves for the surrounding villages. The relation between the concentration of pollutants and a flow of wastewater is very low. The correlation and a coefficient of determination between pollutants were over 0.5. The combine sewage system with a storm-water inlet is built-up in both towns, and we presume that no inflow variation would be evident during the season with high precipitation. However, we do not have any information about the capacity of the storm-water inlet. The first WWTP consists of mechanical treatment, wastewater pumping, biological treatment, tertiary treatment, sludge, and gas management. The second WWTP was renovated in 2012 and has a part of the old WWTP still in operation, constructed as mechanical and biological treatment with cascades of an activation process and sludge regeneration. The input data for analysis were from 2011-2015 years, including daily flow, daily precipitation, and bi-weekly data for biochemical oxygen demand in 5 days (BOD5). The parameters of the selected WWTP are presented in Table 2. The knowledge of inflow changes is important for the appropriate design and service of WWTP, as well as for evaluating the impact of climate, town size, economic activities, and water supply quality on the variability of inflow. The aim of this paper is to compare the inflow changes and selected parameters of wastewater quality during the season with and without rainfalls in two WWTP in Slovakia.