TY - JOUR
T1 - Coupling electrochemical ammonia extraction and cultivation of methane oxidizing bacteria for production of microbial protein
AU - Khoshnevisan, Benyamin
AU - Dodds, Mark
AU - Tsapekos, Panagiotis
AU - Torresi, Elena
AU - Smets, Barth F.
AU - Angelidaki, Irini
AU - Zhang, Yifeng
AU - Valverde-Pérez, Borja
N1 - Funding Information:
The authors would like to thank Copenhagen municipality, the Danish EPA - MUDP (Project FUBAF J. nr. Mst-11700508) and Novo Nordisk Foundation (Project BioCAT Grant No. NNF14OC0011277) for funding this research.
Funding Information:
The authors would like to thank Copenhagen municipality, the Danish EPA - MUDP (Project FUBAF J. nr. Mst-11700508 ) and Novo Nordisk Foundation (Project BioCAT Grant No. NNF14OC0011277 ) for funding this research.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/7/1
Y1 - 2020/7/1
N2 - Conventional treatment of residual resources relies on nutrient removal to limit pollution. Recently, nutrient recovery technologies have been proposed as more environmentally and energetically efficient strategies. Nevertheless, the upcycling of recovered resources is typically limited by their quality or purity. Specifically, nitrogen extracted from residual streams, such as anaerobic digestion (AD) effluents and wastewaters, could support microbial protein production. In this context, this study was performed as a proof-of-concept to combine nitrogen recovery via electrochemical reactors with the production of high quality microbial protein via cultivation of methanotrophs. Two types of AD effluents, i.e., cattle manure and organic fraction of municipal solid waste, and urine were tested to investigate the nitrogen extraction efficiency. The results showed that 31–51% of the nitrogen could be recovered free of trace chemicals from residual streams depending on the substrate and voltage used. Based on the results achieved, higher nitrogen concentration in the residual streams resulted in higher nitrogen flux between anodic and cathodic chambers. Results showed that the extraction process has an energy demand of 9.97 (±0.7) - 14.44 (±1.19) kWh/kg-N, depending on the substrate and operating conditions. Furthermore, a mixed-culture of methanotrophic bacteria could grow well with the extracted nitrogen producing a total dry weight of 0.49 ± 0.01 g/L. Produced biomass contained a wide range of essential amino acids making it comparable with conventional protein sources.
AB - Conventional treatment of residual resources relies on nutrient removal to limit pollution. Recently, nutrient recovery technologies have been proposed as more environmentally and energetically efficient strategies. Nevertheless, the upcycling of recovered resources is typically limited by their quality or purity. Specifically, nitrogen extracted from residual streams, such as anaerobic digestion (AD) effluents and wastewaters, could support microbial protein production. In this context, this study was performed as a proof-of-concept to combine nitrogen recovery via electrochemical reactors with the production of high quality microbial protein via cultivation of methanotrophs. Two types of AD effluents, i.e., cattle manure and organic fraction of municipal solid waste, and urine were tested to investigate the nitrogen extraction efficiency. The results showed that 31–51% of the nitrogen could be recovered free of trace chemicals from residual streams depending on the substrate and voltage used. Based on the results achieved, higher nitrogen concentration in the residual streams resulted in higher nitrogen flux between anodic and cathodic chambers. Results showed that the extraction process has an energy demand of 9.97 (±0.7) - 14.44 (±1.19) kWh/kg-N, depending on the substrate and operating conditions. Furthermore, a mixed-culture of methanotrophic bacteria could grow well with the extracted nitrogen producing a total dry weight of 0.49 ± 0.01 g/L. Produced biomass contained a wide range of essential amino acids making it comparable with conventional protein sources.
KW - Electrochemical cells
KW - Methane oxidizing bacteria
KW - Microbial protein
KW - Nutrient recovery
U2 - 10.1016/j.jenvman.2020.110560
DO - 10.1016/j.jenvman.2020.110560
M3 - Journal article
C2 - 32421560
AN - SCOPUS:85083837881
SN - 0301-4797
VL - 265
JO - Journal of Environmental Management
JF - Journal of Environmental Management
M1 - 110560
ER -