Dynamic Modelling of the Secondary Settler of a Wastewater Treatment Via Activated Sludge to Low-load

The aim of this study is to apply a mathematical treatment to a case study that concerns the biological wastewater treatment. Its objective was to develop a model that aims at predicting the conditions that would lead to an outlet clear water out from a secondary settler. It deals with a wastewater treatment process which consists of the separation by decantation of an activated sludge coming out of an aerobic low-load reactor. First, it was necessary to estimate the pollution parameters namely: the total suspended solid (TSS), the chemical oxygen demand (COD), the biological oxygen demand (BOD5) and ammonia content (NH3-N). Secondly a mathematical model for the secondary settler was developed. The monitoring of the wastewater treatment plant as well as the knowledge of the experimental parameters such as the sludge blanket height, the TSS, and decantation time enabled us to develop the mathematical model. The advantage of this model is that it would allow a better process control.