Knowledge on Suspended Sediment Concentration (SSC) leads to a better understanding of sediment transport dynamics, which is of main interest to understand river geomorphology or handle the wastewater regulation and treatment. For this purpose, optical and acoustic turbidity are both used to monitor continuously the suspended solids content in water. Optical turbidity is the mainly used method,
... [Show full abstract] and brings benefit in comparison to classical sampling. However, recent studies showed optical measurements inconsistency. A long term acoustic and optical monitoring campaign in a wastewater network reveals noticeable differences between the two techniques, especially during storm weather recordings. In regard to the latest studies, in exceptional situations such as rainy periods in wastewater or floods in rivers, the optical turbidity data are false and may lead to a huge underestimation of the SSC. This misinterpretation can have heavy consequences on water treatment and management. Our laboratory work will compare the acoustic and optical behaviour for suspension of fine material (mineral and organic) at huge concentrations, e.g. 50 g/l, as expected during floods or rain events.
