The study was conducted to assess the effectiveness of wastewater treatment at the municipal wastewater treatment plant in Wolbrom, to which predominantly domestic wastewater and industrial sewage flow. The assessment was made based on the analysis of the physical and chemical research results of raw and treated wastewater. The research was carried out in the period from January 2014 to December 2014. To perform the analysis of the treatment plant efficiency, four indicators of wastewater pollutants such as BOD5, COD, total nitrogen and total phosphorus were selected for further investigation. For each of the indicators degrees of reduction and coefficients of treatment plant operational reliability were calculated. The calculated degrees of reduction for each of the indicators were high and amounted to 99.0% for BOD5, 95.2% for COD, 91.0% for total nitrogen and 91.6%. for total phosphorus. These results prove the effective reduction in the amount of pollutants. The determined coefficients of treatment plant operational reliability were at a low level: BOD5 - 0.27, COD - 0.44, total nitrogen - 0.33 and total phosphorus - 0.53. The conducted analyses prove the effective operation of the treatment plant, which was confirmed by high efficiency of pollutants removal. ...
The aim of the paper was to determine the possibility of the use of Shewhart control charts to monitor changes in the forms of nitrogen, showing the quality of wastewater discharged from the wastewater treatment plant in Krosno in the years 2010-2015. The performed statistical analysis showed the highest number of cases of elevated nitrate nitrogen and/or ammonium nitrogen when the temperature of treated wastewater was below 8-9°C. This low temperature resulted in adverse effect on the activity of bacteria that were involved in biological removal of nitrogen. It was found that in the winter months, the second stage of nitrifying bacteria responsible for oxidation of nitrite to nitrate, exhibited higher activity than the denitrifying bacteria. Graphical presentation of total nitrogen content using control charts for the mean of the process revealed the exceedance of the upper specification line (USL = 10 mgNtot·dm-3) in the months from December to April. It was observed that the total nitrogen removal process in the months from June to November was stable with a very high 90% reduction in biogenic activity. The obtained results confirm the efficacy of control charts as a tool which can easily be applied in the statistical process control of ...
