Microbial kinetics of aerobic and anoxic ethanolamine biodegradation: Substrate and free nitrous acid inhibition

IF 6.3 2区工程技术 Q1 ENGINEERING, CHEMICAL

Journal of water process engineering Pub Date : 2025-03-19 DOI:10.1016/j.jwpe.2025.107448

Basila Abdu, Tomás Allegue, Jorge Rodríguez

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引用次数: 0

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 K_I values of 3 and 1.5 gCOD/L, respectively, and an estimated q_max 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 K_I 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.

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来源期刊

Journal of water process engineering Biochemistry, Genetics and Molecular Biology-Biotechnology

CiteScore

10.70

自引率

8.60%

发文量

846

审稿时长

24 days

期刊介绍： The Journal of Water Process Engineering aims to publish refereed, high-quality research papers with significant novelty and impact in all areas of the engineering of water and wastewater processing . Papers on advanced and novel treatment processes and technologies are particularly welcome. The Journal considers papers in areas such as nanotechnology and biotechnology applications in water, novel oxidation and separation processes, membrane processes (except those for desalination) , catalytic processes for the removal of water contaminants, sustainable processes, water reuse and recycling, water use and wastewater minimization, integrated/hybrid technology, process modeling of water treatment and novel treatment processes. Submissions on the subject of adsorbents, including standard measurements of adsorption kinetics and equilibrium will only be considered if there is a genuine case for novelty and contribution, for example highly novel, sustainable adsorbents and their use: papers on activated carbon-type materials derived from natural matter, or surfactant-modified clays and related minerals, would not fulfil this criterion. The Journal particularly welcomes contributions involving environmentally, economically and socially sustainable technology for water treatment, including those which are energy-efficient, with minimal or no chemical consumption, and capable of water recycling and reuse that minimizes the direct disposal of wastewater to the aquatic environment. Papers that describe novel ideas for solving issues related to water quality and availability are also welcome, as are those that show the transfer of techniques from other disciplines. The Journal will consider papers dealing with processes for various water matrices including drinking water (except desalination), domestic, urban and industrial wastewaters, in addition to their residues. It is expected that the journal will be of particular relevance to chemical and process engineers working in the field. The Journal welcomes Full Text papers, Short Communications, State-of-the-Art Reviews and Letters to Editors and Case Studies