TY - JOUR
T1 - Full-Scale Highly-Loaded Wastewater Treatment Processes (A-Stage) to Increase Energy Production from Wastewater
T2 - Performance and Design Guidelines
AU - De Graaff, Marthe S.
AU - Van Den Brand, Tessa P H
AU - Roest, Kees
AU - Zandvoort, Marcel H.
AU - Duin, Olaf
AU - Van Loosdrecht, Mark C M
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Current practice of wastewater treatment does not recover the full potential of energy present in wastewater. The potential of using anammox bacteria for autotrophic nitrogen removal combined with a desire for energy optimization brings new attention to the A-stage technology for organic carbon harvesting from municipal wastewater. The goal of this research was to investigate operational conditions of four full-scale A-stage processes and gain insight in the optimal conditions to harvest the maximum amount of organics present in sewage as excess sludge from the A stage. Large differences in removal efficiencies and design aspects were found between the four operational A-stage processes in the Netherlands. Biochemical oxygen demand (BOD) removal efficiencies vary between 40% and 80%, indicating that a good removal efficiency is possible, but that local conditions or design can be very influential. An optimal solid retention time (SRT) for maximal sludge production of 0.3 days was found; a longer SRT resulted in more mineralization of the chemical oxygen demand (COD). SRT control might be an important design aspect for the optimization of A-stage process. A short contact time with a minimum of 15 min and sufficient aeration were found to be optimal for soluble COD removal. Iron addition aided the removal of colloidal/suspended COD by coagulation/flocculation. Sludge flocs formed in the A-stage process are weak and sensitive to anaerobic conditions as well as shear due to, for example, pumping. Besides a good design of the A-stage itself, the further processing of the produced sludge also needs careful attention to optimize the sludge production and energy production.
AB - Current practice of wastewater treatment does not recover the full potential of energy present in wastewater. The potential of using anammox bacteria for autotrophic nitrogen removal combined with a desire for energy optimization brings new attention to the A-stage technology for organic carbon harvesting from municipal wastewater. The goal of this research was to investigate operational conditions of four full-scale A-stage processes and gain insight in the optimal conditions to harvest the maximum amount of organics present in sewage as excess sludge from the A stage. Large differences in removal efficiencies and design aspects were found between the four operational A-stage processes in the Netherlands. Biochemical oxygen demand (BOD) removal efficiencies vary between 40% and 80%, indicating that a good removal efficiency is possible, but that local conditions or design can be very influential. An optimal solid retention time (SRT) for maximal sludge production of 0.3 days was found; a longer SRT resulted in more mineralization of the chemical oxygen demand (COD). SRT control might be an important design aspect for the optimization of A-stage process. A short contact time with a minimum of 15 min and sufficient aeration were found to be optimal for soluble COD removal. Iron addition aided the removal of colloidal/suspended COD by coagulation/flocculation. Sludge flocs formed in the A-stage process are weak and sensitive to anaerobic conditions as well as shear due to, for example, pumping. Besides a good design of the A-stage itself, the further processing of the produced sludge also needs careful attention to optimize the sludge production and energy production.
KW - A-stage
KW - AB-process
KW - energy recovery from wastewater
KW - high-loaded activated sludge
KW - operational conditions
UR - http://www.scopus.com/inward/record.url?scp=84979697050&partnerID=8YFLogxK
U2 - 10.1089/ees.2016.0022
DO - 10.1089/ees.2016.0022
M3 - Article
SN - 1092-8758
VL - 33
SP - 571
EP - 577
JO - Environmental Engineering Science (Print)
JF - Environmental Engineering Science (Print)
IS - 8
ER -