Two methods of assessment of the effectiveness of sewage treatment plant operationwere presented in the paper: first one – with the use of the reliability theory, and second one, with the use of the statistical quality control process by means of control charts. The analysis was carried out in a sewage treatment plant located in the village of Rokiciny Podhalańskie. The sewage treatment plant works in the A2/O system. The evaluation of effectiveness of the sewage treatment was made for the following pollutants: BOD, ammonia nitrogen, total nitrogen and total phosphorus. The analysis showed the proper work of the sewage treatment plant for BOD and total phosphorus. The calculated reliability level were 93,3% and more than 99,9%. For total nitrogen the reliability level was lower: more than 46% for empirical distribution and more than 37% for normal distribution. This was caused by the character of inflow sewage. The analysis of control chart showed the stable work in reducting organic pollutants, and in spring and summer period unstable work for ammonia nitrogen and total phosphorus. Only once a disturb of process effectiveness of total nitrogen changes caused probably by inflow of storm water to the sewage system was observed. ...
The aim of the study was analysis of the reliability of the municipal sewage treatment plant Bioblok PS -50. The sewage treatment plant is in Gruszow in municipality Palecznica in the Malopolska province. Time of research was from 2008 to 2010 year. During this period, collected and analyzed the physico- chemical 18 samples of raw sewage and treated with an average frequency of once every two months in accordance with the reference methods. The evaluation of the effectiveness of contaminant removal in this treatment was determined using the Weibull reliability theory elements. The studies included pollution indicators specified in the authorization issued of law for this object: BOD5, COD and total suspension. Moreover determined regarding the reliability of wastewater nitrogen. On the basis of the assessment of the reliability of operation of the facility in relation to the indicators of the primary group: BOD5, COD and total suspension has been shown that the probability of exceeding the limit values can be from 3 to 8 days in the year. Number of days with possible exceeding of the limit values of indicators of pollution indicates that the test treatment meets the level of technological reliability. With respect to the reliability of ...
The aim of this study was to assess the reliability of two on-site sewage treatment facilities (BCT S-12 and TJ EP-4) serving two school buildings located in rural communes in Małopolska region. The reliability was determined using Weibull reliability method. The research was conducted for 24 months and it involved the collection and analysis of 48 samples of raw and treated sewage from each facility. The analyses included organic and biogenic pollution, i.e. BOD5, COD, and total nitrogen. Reliability assessment revealed the following effectiveness for BCT S-12 facility: 77% for BOD5, 96% for COD and 25% for total nitrogen. For TJ EP-4 facility, the effectiveness was 81%, 88% and 72% for BOD5, COD and total nitrogen, respectively. Both facilities used the activated sludge process and experienced periodic disturbances in the treatment flow that resulted in reduced sewage treatment efficiency. Considering the above, the processes of nitrification and denitrification in the biological reactor should be streamlined to provide more effective removal of organic and nitrogen-based compounds in the investigated facilities. ...
