TY - JOUR
T1 - Full-Scale Assessment of Ultrasonic Sewage Sludge Pretreatment Using a Novel Double-Tube Reactor
AU - Lippert, Thomas
AU - Bandelin, Jochen
AU - Vogl, Dominik
AU - Tesieh, Zahra Alipour
AU - Wild, Thomas
AU - Drewes, Jörg E.
AU - Koch, Konrad
N1 - Publisher Copyright:
© 2020 American Chemical Society.
PY - 2021/2/12
Y1 - 2021/2/12
N2 - The performance of a novel double-tube ultrasound (US) reactor for waste activated sludge (WAS) pretreatment was assessed at a full-scale wastewater treatment plant (WWTP). For high transferability of the results, a well-performing WWTP with rather typical operating conditions was selected. The effects of the treatment (conducted at a specific energy input of 200 kJ per kg of total solids) were monitored regarding improvements in sludge viscosity, methane production, biosolids removal, and digestate dewaterability. The pretreatment caused a significant reduction of WAS viscosity (−5.8% on average, at p < 0.01) and a maximum yet insignificant increase in methane yield (+6.2%, at p < 0.1). No effect was observed for solids content, viscosity, or dewaterability of the digestate. The economic benefit of the reduced WAS viscosity was negligible, as the reduced pumping costs were less than 1% of the US reactor’s electricity costs. Additional methane yields enabled for partial cost recovery (roughly equivalent to the energy costs), while investment costs of the US equipment could not be regained. Yet, the incorporation of improved methane production in the economic assessment remains somewhat speculative, given the only insignificant increase. Results suggest that an economical application of ultrasonic WAS pretreatment is challenging for typical, well-performing WWTPs.(Figure
AB - The performance of a novel double-tube ultrasound (US) reactor for waste activated sludge (WAS) pretreatment was assessed at a full-scale wastewater treatment plant (WWTP). For high transferability of the results, a well-performing WWTP with rather typical operating conditions was selected. The effects of the treatment (conducted at a specific energy input of 200 kJ per kg of total solids) were monitored regarding improvements in sludge viscosity, methane production, biosolids removal, and digestate dewaterability. The pretreatment caused a significant reduction of WAS viscosity (−5.8% on average, at p < 0.01) and a maximum yet insignificant increase in methane yield (+6.2%, at p < 0.1). No effect was observed for solids content, viscosity, or dewaterability of the digestate. The economic benefit of the reduced WAS viscosity was negligible, as the reduced pumping costs were less than 1% of the US reactor’s electricity costs. Additional methane yields enabled for partial cost recovery (roughly equivalent to the energy costs), while investment costs of the US equipment could not be regained. Yet, the incorporation of improved methane production in the economic assessment remains somewhat speculative, given the only insignificant increase. Results suggest that an economical application of ultrasonic WAS pretreatment is challenging for typical, well-performing WWTPs.(Figure
KW - Ultrasound pretreatment
KW - biogas production
KW - full-scale assessment
KW - sewage sludge
KW - sludge viscosity
UR - http://www.scopus.com/inward/record.url?scp=85096968969&partnerID=8YFLogxK
U2 - 10.1021/acsestengg.0c00138
DO - 10.1021/acsestengg.0c00138
M3 - Article
AN - SCOPUS:85096968969
SN - 2690-0645
VL - 1
SP - 298
EP - 309
JO - ACS ES and T Engineering
JF - ACS ES and T Engineering
IS - 2
ER -