Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement

Conductive materials have been applied to assist syntrophic metabolism in anaerobic digestion. However, their role in the transformation of organic compounds, particularly recalcitrant compounds, has not been revealed. In this study, iron-based materials - magnetite nanoparticles and Fe2+- were empl...

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Main Authors: Yan, Wangwang, Qian, Tingting, Soh, Annie Yan Ni, Zhou, Yan
Other Authors: School of Civil and Environmental Engineering
Format: Article
Language:English
Published: 2022
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Online Access:https://hdl.handle.net/10356/154880
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-1548802022-01-15T20:11:18Z Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement Yan, Wangwang Qian, Tingting Soh, Annie Yan Ni Zhou, Yan School of Civil and Environmental Engineering Advanced Environmental Biotechnology Centre (AEBC) Nanyang Environment and Water Research Institute Engineering::Civil engineering Magnetite Nanoparticles Anaerobic Digestion Conductive materials have been applied to assist syntrophic metabolism in anaerobic digestion. However, their role in the transformation of organic compounds, particularly recalcitrant compounds, has not been revealed. In this study, iron-based materials - magnetite nanoparticles and Fe2+- were employed to explore their effects on the transformation of different organic matters in anaerobic system. Prompted methane production rates and quantity in iron-based materials groups were found due to the improved solubilization of organic particles, enhanced degradation of recalcitrant compounds, and maintained microbial activity under substrate-limited conditions. Specifically, the proportion of the reducing functional groups (C-C/H or CC) and O/C ratio were always significantly lower in iron-based materials supplemented groups (Fe groups) compared to Control group, despite hydrolysis was greatly enhanced in Fe groups. The greater dehydrogenation oxidation was confirmed in the presence of iron-based materials. The remaining humic-like substances (HS), a typical type of recalcitrant compound, was about 2.5 times higher in Control group (221.2 ± 5.3 mg/L-C) compared to Fe groups after 30 days degradation. By tracking the aromaticity of HS and individual compounds at molecular level, this study reveals that iron-based materials were more effective in stimulating the degradation of aliphatic moieties than the aromatic moieties of recalcitrant compounds. When readily biodegradable substrates were limited, Fe groups continued methane generation by using recalcitrant compounds (e.g. thiethylperazine and fluvoxamino acid) as carbon source, and the microbial activity was maintained according to higher relative abundance of protonated nitrogen and continuous methanogenesis activity at starvation phase. Published version 2022-01-14T06:21:17Z 2022-01-14T06:21:17Z 2020 Journal Article Yan, W., Qian, T., Soh, A. Y. N. & Zhou, Y. (2020). Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement. Environment International, 135, 105362-. https://dx.doi.org/10.1016/j.envint.2019.105362 0160-4120 https://hdl.handle.net/10356/154880 10.1016/j.envint.2019.105362 31830729 2-s2.0-85076007605 135 105362 en Environment International © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/). application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Civil engineering
Magnetite Nanoparticles
Anaerobic Digestion
spellingShingle Engineering::Civil engineering
Magnetite Nanoparticles
Anaerobic Digestion
Yan, Wangwang
Qian, Tingting
Soh, Annie Yan Ni
Zhou, Yan
Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement
description Conductive materials have been applied to assist syntrophic metabolism in anaerobic digestion. However, their role in the transformation of organic compounds, particularly recalcitrant compounds, has not been revealed. In this study, iron-based materials - magnetite nanoparticles and Fe2+- were employed to explore their effects on the transformation of different organic matters in anaerobic system. Prompted methane production rates and quantity in iron-based materials groups were found due to the improved solubilization of organic particles, enhanced degradation of recalcitrant compounds, and maintained microbial activity under substrate-limited conditions. Specifically, the proportion of the reducing functional groups (C-C/H or CC) and O/C ratio were always significantly lower in iron-based materials supplemented groups (Fe groups) compared to Control group, despite hydrolysis was greatly enhanced in Fe groups. The greater dehydrogenation oxidation was confirmed in the presence of iron-based materials. The remaining humic-like substances (HS), a typical type of recalcitrant compound, was about 2.5 times higher in Control group (221.2 ± 5.3 mg/L-C) compared to Fe groups after 30 days degradation. By tracking the aromaticity of HS and individual compounds at molecular level, this study reveals that iron-based materials were more effective in stimulating the degradation of aliphatic moieties than the aromatic moieties of recalcitrant compounds. When readily biodegradable substrates were limited, Fe groups continued methane generation by using recalcitrant compounds (e.g. thiethylperazine and fluvoxamino acid) as carbon source, and the microbial activity was maintained according to higher relative abundance of protonated nitrogen and continuous methanogenesis activity at starvation phase.
author2 School of Civil and Environmental Engineering
author_facet School of Civil and Environmental Engineering
Yan, Wangwang
Qian, Tingting
Soh, Annie Yan Ni
Zhou, Yan
format Article
author Yan, Wangwang
Qian, Tingting
Soh, Annie Yan Ni
Zhou, Yan
author_sort Yan, Wangwang
title Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement
title_short Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement
title_full Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement
title_fullStr Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement
title_full_unstemmed Micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of AD enhancement
title_sort micro-level evaluation of organic compounds transformation in anaerobic digestion under feast and famine conditions assisted by iron-based materials - revealing the true mechanism of ad enhancement
publishDate 2022
url https://hdl.handle.net/10356/154880
_version_ 1722355357714481152