TY - JOUR
T1 - Microbial kinetics of aerobic and anoxic ethanolamine biodegradation
T2 - Substrate and free nitrous acid inhibition
AU - Abdu, Basila
AU - Allegue, Tomás
AU - Rodríguez, Jorge
N1 - Publisher Copyright:
© 2025 Elsevier Ltd
PY - 2025/4
Y1 - 2025/4
N2 - Abstract Mono-ethanolamine (MEA) is widely used in carbon capture and nuclear power applications. Traditional physicochemical treatment of MEA-rich effluents is costly and environmentally impactful, highlighting the need for sustainable biological alternatives. This study investigates MEA biodegradation kinetics under aerobic and anoxic conditions using open microbial cultures, providing higher-confidence kinetic and inhibition parameters than those previously reported. MEA biodegradation begins with hydrolysis to acetaldehyde (CH3CHO) and ammonia (NH3). Under aerobic conditions, acetaldehyde is oxidized to CO2, and ammonia is sequentially oxidized by ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). In anoxic conditions, heterotrophic denitrifiers oxidize MEA to CO2 using nitrate as an electron acceptor. Batch kinetic tests suggest a Haldane-like substrate inhibition, likely due to acetaldehyde accumulation, with Ks and KI values of 3 and 1.5 gCOD/L, respectively, and an estimated qmax of 24 gCOD/gVSS·d. During chemostat operation at 1800 mgCOD/L feed, nitrite accumulation was observed, potentially inhibiting heterotrophs due to free nitrous acid (FNA), with a KI value of 28.53 μg/L. Continuous chemostat experiments confirmed MEA degradation, achieving over 97 % COD removal in aerobic conditions (900–1800 mgCOD/L feed) with a maximum removal rate of 13.5 gCOD/gVSS·d, and 94 % COD removal in anoxic conditions (900 mgCOD/L feed) with a rate of 18 gCOD/gVSS·d. These findings confirm the feasibility of biological MEA treatment, offering high removal efficiencies and reliable kinetic parameters to support industrial-scale wastewater treatment design.
AB - Abstract Mono-ethanolamine (MEA) is widely used in carbon capture and nuclear power applications. Traditional physicochemical treatment of MEA-rich effluents is costly and environmentally impactful, highlighting the need for sustainable biological alternatives. This study investigates MEA biodegradation kinetics under aerobic and anoxic conditions using open microbial cultures, providing higher-confidence kinetic and inhibition parameters than those previously reported. MEA biodegradation begins with hydrolysis to acetaldehyde (CH3CHO) and ammonia (NH3). Under aerobic conditions, acetaldehyde is oxidized to CO2, and ammonia is sequentially oxidized by ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). In anoxic conditions, heterotrophic denitrifiers oxidize MEA to CO2 using nitrate as an electron acceptor. Batch kinetic tests suggest a Haldane-like substrate inhibition, likely due to acetaldehyde accumulation, with Ks and KI values of 3 and 1.5 gCOD/L, respectively, and an estimated qmax of 24 gCOD/gVSS·d. During chemostat operation at 1800 mgCOD/L feed, nitrite accumulation was observed, potentially inhibiting heterotrophs due to free nitrous acid (FNA), with a KI value of 28.53 μg/L. Continuous chemostat experiments confirmed MEA degradation, achieving over 97 % COD removal in aerobic conditions (900–1800 mgCOD/L feed) with a maximum removal rate of 13.5 gCOD/gVSS·d, and 94 % COD removal in anoxic conditions (900 mgCOD/L feed) with a rate of 18 gCOD/gVSS·d. These findings confirm the feasibility of biological MEA treatment, offering high removal efficiencies and reliable kinetic parameters to support industrial-scale wastewater treatment design.
KW - AOB
KW - Ethanolamine-rich wastewater
KW - Free nitrous acid inhibition
KW - Microbial treatment
KW - NOB
KW - Substrate inhibition
UR - https://www.scopus.com/pages/publications/105000109636
U2 - 10.1016/j.jwpe.2025.107448
DO - 10.1016/j.jwpe.2025.107448
M3 - Article
AN - SCOPUS:105000109636
SN - 2214-7144
VL - 72
JO - Journal of Water Process Engineering
JF - Journal of Water Process Engineering
M1 - 107448
ER -
