Digested Sludge Quality in Mesophilic, Thermophilic and Temperature-Phased Anaerobic Digestion Systems
| Autor: | Iryna Lanko, Jakub Hejnic, Pavel Jenicek, Jana Říhová-Ambrožová, Ivet Ferrer |
|---|---|
| Přispěvatelé: | Universitat Politècnica de Catalunya. Doctorat en Enginyeria Ambiental, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. GEMMA - Grup d'Enginyeria i Microbiologia del Medi Ambient |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Mesophilic
Sludge quality Geography Planning and Development 0207 environmental engineering Sludge valorisation 02 engineering and technology 010501 environmental sciences Aquatic Science 01 natural sciences 7. Clean energy Biochemistry temperature-phased anaerobic digestion (TPAD) Biogas Llots de depuradora Thermophilic sludge valorisation Temperature-phased anaerobic digestion (TPAD) Sewage sludge -- Management 020701 environmental engineering Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament dels residus [Àrees temàtiques de la UPC] dewaterability TD201-500 0105 earth and related environmental sciences Water Science and Technology Water supply for domestic and industrial purposes Chemistry Thermophilic digester Hydraulic engineering thermophilic Pulp and paper industry sludge quality 6. Clean water Anaerobic digestion Activated sludge Digestate mesophilic Sewage treatment Dewaterability TC1-978 Sludge Mesophile |
| Zdroj: | Water, Vol 13, Iss 2839, p 2839 (2021) UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) Water Volume 13 Issue 20 |
| ISSN: | 2073-4441 |
| Popis: | Anaerobic digestion (AD) technology is commonly used to treat sewage sludge from activated sludge systems, meanwhile alleviating the energy demand (and costs) for wastewater treatment. Most often, anaerobic digestion is run in single-stage systems under mesophilic conditions, as this temperature regime is considered to be more stable than the thermophilic one. However, it is known that thermophilic conditions are advantageous over mesophilic ones in terms of methane production and digestate hygienisation, while it is unclear which one is better concerning the digestate dewaterability. Temperature-phased anaerobic digestion (TPAD) is a double-stage AD process that combines the above-mentioned temperature regimes, by operating a thermophilic digester followed by a mesophilic one. The aim of this study is to compare the digestate quality of single-stage mesophilic and thermophilic AD and TPAD systems, in terms of the dewaterability, pathogenic safety and lower calorific value (LCV) and, based on the comparison, consider digested sludge final disposal alternatives. The research is conducted in lab-scale reactors treating waste-activated sludge. The dewaterability is tested by two methods, namely, centrifugation and mechanical pressing. The experimental results show that the TPAD system is the most beneficial in terms of organic matter degradation efficiency (32.4% against 27.2 for TAD and 26.0 for MAD), producing a digestate with a high dewaterability (8.1–9.8% worse than for TAD and 6.2–12.0% better than for MAD) and pathogenic safety (coliforms and Escherichia coli were not detected, and Clostridium perfringens were counted up to 4.8–4.9 × 103, when for TAD it was only 1.4–2.5 × 103, and for MAD it was 1.3–1.8 × 104), with the lowest LCV (19.2% against 15.4% and 15.8% under thermophilic and mesophilic conditions, respectively). Regarding the final disposal, the digested sludge after TAD can be applied directly in agriculture after TPAD, it can be used as a fertilizer only in the case where the fermenter HRT assures the pathogenic safety. The MAD digestate is the best for being used as a fuel preserving a higher portion of organic matter, not transforming into biogas during AD. |
| Databáze: | OpenAIRE |
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