Rheology Serving the Environment to Characterize Sludge from Wastewater Treatment Plants (WWTPs)

Received 13 November 2020 Revised, 29 November 2020 Accepted 05 December 2020 Rheological parameters were a fundamental importance in sludge characterization, as they strongly affected almost all treatment, utilization and disposal operations, such as storage, pumping, transport and drying. This paper will present different sludge rheological parameters from wastewater treatment systems. These parameters were obtained by fitting the experimental data of various shear rates ?̇? from 0 to 100 s, under a series of Total Suspended Solids (TSS) content. The temperature was maintained constant at 20 ± 2 °C. The apparatus used was a rheostress RS600. The results obtained showed that viscosity of sludge of concentrations 25% and 30% (Total Solids TS), underwent an increase of 1.71 to 2.06 mPa.s and of 1.56 to 2.12 mPa.s successively. In the same way for the other concentrations studied. The rheological results showed that the sludge study belonged to a non-Newtonian family. The most fitting model to describe this rheological behavior was the Ostwald one. This research confirmed that rheological characterization was considered as a relevant tool to understand the wastewater sludge suspension behavior in order to improve wastewater treatment process operation.