| Title | Microbial population dynamics in biowaste mesophilic anaerobic digestion: the impact of sewage sludge addition |
| Abstract | Complex organic materials such as biowaste range from highly recalcitrant material to extremely
biodegradable compounds, so the best option to improve the AD performances is a case-specific
and properly designed strategy. In the case of food waste (FW), mainly composed by prompt
biodegradable carbohydrates, the high load long-term digestion leads to inhibition phenomena
due to intermediate accumulation suggesting the need of co-digestion with other substrates to
stabilize the entire process. The addition of waste activated sludge (WAS), typically recalcitrant
due to the floc structure, may be a feasible way to increase the organic loading rate utilizing the
free digestion capacity at existing sewage treatment facilities. Currently, general knowledge on AD
microbial community compositions is well established, while only a few studies have investigated
correlations between microbial community composition, feedstock and process parameters.
Hence, main scope of this research was to study changes in the microbial population community
as a response to variation of feedstock and organic load in long- term semi-continuous systems.
Compared to the feeding with FW alone, the co-digestion with WAS permitted the establishment
of a stable microbial population by reducing the unbalance between fermentative bacteria
and methanogens. The availability of a slow degrading substrate, in fact, allowed to limit VFA
accumulation and pH drop favoring the activity of the archaeal population, as confirmed by the
improved process stability and methane yield. Remarkably, the beneficial effect of co-digestion
increased with the increase of OLR. |
| Source | Sludge Management In Circular Economy - SMICE 2018, Rome, 23-25/05/2018 |
| Keywords | Anaerobic DigestionWaste Activated SludgeFood WasteNext Generation SequencingMixed Microbial Communities |
| Year | 2018 |
| Type | Abstract in atti di convegno |
| Authors | B. Tonanzi, C.M. Braguglia, A. Gallipoli, A. Gianico, P. Pagliaccia, S. Rossetti |
| Text | 458532 2018 Anaerobic Digestion Waste Activated Sludge Food Waste Next Generation Sequencing Mixed Microbial Communities Microbial population dynamics in biowaste mesophilic anaerobic digestion the impact of sewage sludge addition B. Tonanzi, C.M. Braguglia, A. Gallipoli, A. Gianico, P. Pagliaccia, S. Rossetti Water Research Institute IRSA CNR, Area della Ricerca RM1, 00015 Monterotondo, Roma, IT Sludge Management In Circular Economy SMICE 2018 Abstract Book CNR Edizioni CNR Edizioni 978 88 8080 292 1 Published version Sludge Management In Circular Economy SMICE 2018 Rome 23 25/05/2018 Internazionale Contributo Complex organic materials such as biowaste range from highly recalcitrant material to extremely biodegradable compounds, so the best option to improve the AD performances is a case specific and properly designed strategy. In the case of food waste FW , mainly composed by prompt biodegradable carbohydrates, the high load long term digestion leads to inhibition phenomena due to intermediate accumulation suggesting the need of co digestion with other substrates to stabilize the entire process. The addition of waste activated sludge WAS , typically recalcitrant due to the floc structure, may be a feasible way to increase the organic loading rate utilizing the free digestion capacity at existing sewage treatment facilities. Currently, general knowledge on AD microbial community compositions is well established, while only a few studies have investigated correlations between microbial community composition, feedstock and process parameters. Hence, main scope of this research was to study changes in the microbial population community as a response to variation of feedstock and organic load in long term semi continuous systems. Compared to the feeding with FW alone, the co digestion with WAS permitted the establishment of a stable microbial population by reducing the unbalance between fermentative bacteria and methanogens. The availability of a slow degrading substrate, in fact, allowed to limit VFA accumulation and pH drop favoring the activity of the archaeal population, as confirmed by the improved process stability and methane yield. Remarkably, the beneficial effect of co digestion increased with the increase of OLR. Abstract in atti di convegno barbara.tonanzi TONANZI BARBARA simona.rossetti ROSSETTI SIMONA camillamaria.braguglia BRAGUGLIA CAMILLA MARIA andrea.gianico GIANICO ANDREA agata.gallipoli GALLIPOLI AGATA |
