title: Rheology measurements for online monitoring of solids in activated sludge reactors of municipal wastewater treatment plant.
abstract: Rheological behaviour of recycled sludge from a secondary clarifier of a municipal wastewater treatment plant was studied by using the rate controlled coaxial cylinder viscometer Rotovisko-Haake 20, system M5-osc., measuring device NV. The tests (hysteresis cycles) were performed under continuous flow conditions and following an ad hoc measurement protocol. Sludge shear stress versus shear rate curves were fitted very satisfactorily by rheological models. An experimental equation correlating the solid concentration of sludge to relative viscosity and fitting satisfactorily flow curves at different Total Suspended Solids (TTS%) was obtained. Application of the empirical correlation should allow the monitoring of the proper functioning of a wastewater treatment plant measuring viscosity of sludge.
authors.affiliation: Dipartimento di Chimica, Fisica e Ambiente, Università degli Studi di Udine, Via Cotonificio, 108, 33100 Udine, Italy.
authors.forename: Luciano
authors.identifier: 0000-0002-4635-4336
authors.initials: L
authors.lastname: Piani
authors.affiliation: Dipartimento di Chimica, Fisica e Ambiente, Università degli Studi di Udine, Via Cotonificio, 108, 33100 Udine, Italy.
authors.forename: Claudia Bruna
authors.identifier: 0000-0003-1450-5643
authors.initials: CB
authors.lastname: Rizzardini
authors.affiliation: Dipartimento di Chimica, Fisica e Ambiente, Università degli Studi di Udine, Via Cotonificio, 108, 33100 Udine, Italy.
authors.forename: Adriano
authors.initials: A
authors.lastname: Papo
authors.affiliation: Dipartimento di Chimica, Fisica e Ambiente, Università degli Studi di Udine, Via Cotonificio, 108, 33100 Udine, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Goi
mesh_terms: D019149:Bioreactors; D006801:Humans; D008962:Models, Theoretical; D012212:Rheology / Q000379:methods; D012722:Sewage; D064091:Waste Disposal Facilities; D062065:Wastewater
chemical_list: D012722:Sewage; D062065:Wastewater