This study demonstrates mathematical description of sewage sludge composting based on identification and separate characterisation of simple process parts. For a description of the microbial processes an aSM3-based mathematical model developed for autothermal thermophilic aerobic sludge digestion is used. The oxygen mass transfer was characterized in a separate way. The 2.964·10-3 m2·d-1 value ...

PCR and PCR-DGGE techniques have been evaluated to monitor biodiversity indexes within an ATAD (autothermal thermophilic aerobic digestion) system treating domestic sludge for land spread, by examining microbial dynamics in response to elevated temperatures during treatment. The ATAD process utilises a thermophilic population to generate heat and operates at elevated pH due to degradation of sl...

There has been an increase in community-associated Clostridium difficile infections with biosolids derived from wastewater treatment being identified as one potential source. The current study evaluated the efficacy of thermophilic digestion in decreasing levels of C. difficile ribotype 078 associated with sewage sludge. Five isolates of C. difficile 078 were introduced (final density of 5 log ...

Anaerobic digestion of sewage sludge (SS) and co-digestion with cheese whey (CW) was evaluated in batch conditions under mesophilic and thermophilic regimens. Results indicated that the co-digestion can be successfully attained despite some inhibitory stages that may be initially present due to the accumulation of volatile fatty acids. Degradation of the mixture SS-CW followed a similar pattern...

The degradation of sludge solids in an insulated reactor during Autothermal Thermophilic Aerobic Digestion (ATAD) processing results in auto-heating, thermal treatment and total solids reduction, however, the ability to eliminate pathogenic organisms has not been analysed under large scale process conditions. We evaluated the ATAD process over a period of one year in a two stage, full scale Iri...

This study aims to determine suitable start-up conditions and inoculum sources for thermophilic anaerobic digestion. Within days of incubation MSW at 55°C, methane was produced at a high rate. In an attempt to narrow down which components of typical MSW contained the thermophilic methanogens, vacuum cleaner dust, banana peel, kitchen waste, and garden waste were tested as inoculum for thermophi...