Fly ash as stimulant for anaerobic digestion: effect over hydrolytic stage and methane generation rate

Guerrero L.; da Silva C.; Barahona A.; Montalvo S.; Huiliñir C.; Borja R.; Peirano C.; Toledo M.; Carvajal A.

Abstract

Thermoelectric fly ash was used as a micronutrient source for microorganisms in the anaerobic digestion process of thermally pretreated (1 hour, 120 degrees C) secondary sludge. The obtained results not only suggest that fly ash improves methane generation in the conversion of volatile fatty acids into methane, but also show a new observation, that the fly ash contributes in the particulate organic solubilization. The maximum methane production rate increased from 6.52 mL/L/d to 22.59 mL/L/d when fly ash was added at a dosage of 150 mg/L in biochemical methane potential tests compared with tests with no added ash. Additionally, the kinetic constants of the hydrolysis of particulate organic matter were obtained in both cases (with and without added ash) in batch reactors using a first-order kinetic model; in the case of no addition, the first-order kinetic parameter was 0.019 +/- 0.002 d(-1), while with ashes this value increased to 0.045 +/- 0.000 d(-1). Therefore, the addition of fly ash improves methane generation and hydrolytic kinetics in different orders of magnitude.

Más información

Título según WOS: Fly ash as stimulant for anaerobic digestion: effect over hydrolytic stage and methane generation rate
Título según SCOPUS: Fly ash as stimulant for anaerobic digestion: Effect over hydrolytic stage and methane generation rate
Título de la Revista: WATER SCIENCE AND TECHNOLOGY
Volumen: 80
Número: 7
Editorial: IWA Publishing
Fecha de publicación: 2019
Página de inicio: 1384
Página final: 1391
Idioma: English
DOI:

10.2166/wst.2019.391

Notas: ISI, SCOPUS