A critical review of clarifier modelling: State-of-the-art and engineering practices

This outline paper aims to provide a critical review of secondary settling tank (SST) modelling approaches used in current wastewater engineering and develop tools not yet applied in practice. We address the development of different tier models and experimental techniques in the field with a particular emphasis on works published since the reference work by Ekama et al. (1997). We give insight into the current engineering practice, identify how recent developments can be transferred to engineering practice and pinpoint limitations and potential pathways for further development of models and measurement techniques. As a follow-up to the present work, we believe there is a need for the development of a protocol for systematic clarifier modelling depending on the modelling objective and in line with good modelling practice.