6533b823fe1ef96bd127e0f3

RESEARCH PRODUCT

Combination of the OSA process with thermal treatment at moderate temperature for excess sludge minimization

Marco CapodiciDaniele Di TrapaniMichele TorregrossaSanto Fabio CorsinoGaspare Viviani

subject

0106 biological sciencesEnvironmental EngineeringHydraulic retention timeSegmented filamentous bacteriaBiomassBioengineeringThermal treatment010501 environmental sciencesWaste Disposal Fluid01 natural sciencesBioreactorsExtracellular polymeric substanceSettling010608 biotechnologyThermic treatmentAnaerobiosisBiomassWaste Management and Disposal0105 earth and related environmental sciencesOSA proceSewageSettore ICAR/03 - Ingegneria Sanitaria-AmbientaleRenewable Energy Sustainability and the EnvironmentChemistryTemperatureGeneral MedicinePulp and paper industryActivated sludgeActivated sludgeSludge minimizationBiomass kineticAnaerobic exercise

description

Abstract This study investigated the chance to couple the conventional Oxic Settling Anaerobic (OSA) process with a thermic treatment at moderate temperature (35 °C). The maximum excess sludge reduction rate (80%) was achieved when the plant was operated under 3 h of hydraulic retention time (HRT). Compared with the conventional OSA system, the thermic treatment enabled a further improvement in excess sludge minimization of 35%. The observed yield coefficient decreased from 0.25 gTSS gCOD−1 to 0.10 gTSS gCOD−1 when the temperature in the anaerobic reactor was increased to 35 °C, despite the lower HRT (3 h vs 6 h). Moreover, the thermic treatment enabled the decrease of filamentous bacteria, thereby improving the sludge settling properties. The thermic treatment enhanced the destruction of extracellular polymeric substances and the increase of endogenous decay rate (from 0.64 d−1 to 1.16 d−1) that reduced the biomass active fraction (from 22% to 4%).

yearjournalcountryeditionlanguage
2019-10-28Bioresource Technology
https://doi.org/10.1016/j.biortech.2019.122679