History and Objectives: Exited sewage following mechanical methods contains pathogenic agents. Therefore, swage clearance with chlorine and other compounds is necessary. It has been reported that in fixation ponds with regard to a long-time standing, there is a high rate of clearance and there is no need of additional clearance and this reduces the costs. Therefore, this study was carried out to determine the clearance rate of fecal coliforms in fixation ponds of Shoosh sewage refinery in Tehran in 1999.
Materials and Methods: The semi-experimental strategy of this study was carried out on integrated stabilization pond in all of the seasons using two feeding sewage methods. The system is a combination of anaerobic and facultative ponds and then two high-performance and complementary with a total time of 20 days. Sampling was done every two weeks from inlet and outlet sewage and number of fecal coliforms was counted and data were analyzed statistically.
Results: It was found out that clearance rate of fecal coliforms was greater in spring than other seasons (99.97%) and was rather great in winter (Greater than 99.5%). This indicates the high performance of the system for clearance of pathogenic agents from sewage.
Conclusion and Recommendations: It is concluded that combinational fixation ponds have an appropriate performance for clearance of pathogenic agents. Feeding through upward current can increase the performance, as does the facultative pond. It is recommended to carry out more studies in this field.
Miranzaeh M B, Mahvi A H. Evaluation of elimination of fecal Coliforms in sewage fixation ponds . Feyz Med Sci J 2002; 5 (4) :54-60 URL: http://feyz.kaums.ac.ir/article-1-350-en.html