This study investigated the chance to couple the conventional Oxic Settling Anaerobic (OSA) process with athermic treatment at moderate temperature (35 °C). The maximum excess sludge reduction rate (80%) wasachieved when the plant was operated under 3 h of hydraulic retention time (HRT). Compared with the conventionalOSA system, the thermic treatment enabled a further improvement in excess sludge minimization of35%. The observed yield coefficient decreased from 0.25 gTSS gCOD−1 to 0.10 gTSS gCOD−1 when the temperaturein the anaerobic reactor was increased to 35 °C, despite the lower HRT (3 h vs 6 h). Moreover, thethermic 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 ofendogenous decay rate (from 0.64 d−1 to 1.16 d−1) that reduced the biomass active fraction (from 22% to 4%).
|Numero di pagine||9|
|Stato di pubblicazione||Published - 2020|
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