Analysis of flow and sedimentation processes in secondary sedimentation tank

Abstract

In the process of design and operation of sewerage system are used empirical formulas, which are in many cases, become obsolete and unusable when somebody can use nowadays modern technologies and materials. Therefore there is the possibility of using the mathematical models enormous importance for the enhanced environmental protection with the lowest operating and investment costs. In this modern method of analyzing of sewers has been designated as the first object, the object sedimentation tank. The purpose of the primary and secondary settling tank is to ensure the reduction of concentration the floating solids. For the solution of research work has been chosen, after consultations with representatives of the Western Slovakia Water Company as interesting object of sedimentation tank located on the waste water treatment plant Nitra - Dolné Krškany. Measurements on the object settlement tank situated at waste water treatment plant Nitra confirmed the expected speed parameters of the sewage in the tank. The velocity of wastewater is in the most cases very low, and even insignificant. However, finding that the sludge cloud has a non-standard form of a double wave gives the opportunity to optimize the operation of facilities sedimentation tank. The measured parameters are used as calibration parameters to input to the mathematical simulations, which are created by software ANSYS fluent.