Ferric oxide stimulates medium-chain carboxylic acids synthesis from waste activated sludge via ethanol-driven chain elongation: Mechanisms and implications

Wang, Y; He, Y; Zheng, K; Wei, W; Ngo, HH; Guo, W; Ni, BJ; Zhu, T; Horn, H; Liu, Y

Ferric oxide stimulates medium-chain carboxylic acids synthesis from waste activated sludge via ethanol-driven chain elongation: Mechanisms and implications

Wang, Y He, Y Zheng, K Wei, W Ngo, HH Guo, W Ni, BJ Zhu, T Horn, H Liu, Y

Permalink

Publisher:: Elsevier
Publication Type:: Journal Article
Citation:: Journal of Cleaner Production, 2023, 389, pp. 136044
Issue Date:: 2023-02-20

Closed Access

	Filename	Description	Size
	1-s2.0-S0959652623002020-main.pdf	Published version	2.52 MB	Adobe PDF	View/Open

Copyright Clearance Process

Recently Added
In Progress
Closed Access

This item is closed access and not available.

Full metadata record

Field	Value	Language
dc.contributor.author	Wang, Y
dc.contributor.author	He, Y
dc.contributor.author	Zheng, K
dc.contributor.author	Wei, W
dc.contributor.author	Ngo, HH
dc.contributor.author	Guo, W
dc.contributor.author	Ni, BJ
dc.contributor.author	Zhu, T
dc.contributor.author	Horn, H
dc.contributor.author	Liu, Y https://orcid.org/0000-0001-6677-7961
dc.date.accessioned	2023-05-05T05:05:06Z
dc.date.available	2023-05-05T05:05:06Z
dc.date.issued	2023-02-20
dc.identifier.citation	Journal of Cleaner Production, 2023, 389, pp. 136044
dc.identifier.issn	0959-6526
dc.identifier.uri	http://hdl.handle.net/10453/170227
dc.description.abstract	Nowadays, conductive iron-containing materials (i.e., Fe3O4 and zerovalent iron) have attracted greatly attention in improving medium-chain carboxylic acids (MCCA) from waste activated sludge (WAS). However, the feasibility and mechanism of semi-conductive iron oxide, i.e., ferric oxide (Fe2O3), in stimulating MCCA synthesis from WAS via ethanol-driven chain elongation (CE) has been unclear. Therefore, this work is aimed to fill up the knowledge gap. Results showed that the MCCA yield in the Fe2O3-supplemented fermenter attained at 9162 mg COD/L (i.e., 6268 mg COD/L caproate and 2895 mg COD/L caprylate), which was 2.4 times that of the control system. Kinetic analysis proved that Fe2O3 enhanced both the potential and rate of MCCA synthesis. Mechanism analysis indicated that Fe2O3 facilitated the individual steps for MCCA production, i.e., hydrolysis, acidification and CE. Further investigation disclosed that the dissimilatory iron reduction (DIR) induced by Fe2O3 corrosion and released ferrous ions improved enzymes activities of hydrolysis and acidification, while the promotion of CE was mainly ascribed to increased electron transfer efficiency by crystalline Fe2O3. Further, Fe2O3 promotes electron transfer through several mechanisms, including stimulating extracellular polymeric substance (EPS) excretion, increasing EPS electroactivity, and enhancing electron transport system activity. Microbial analysis revealed that Fe2O3 induced microflora structure shifting towards substrates transformation, iron reduction and MCCA generation, and up-regulated the key enzymes in CE pathways. This work provides an efficient strategy for MCCA generation and WAS management.
dc.language	en
dc.publisher	Elsevier
dc.relation.ispartof	Journal of Cleaner Production
dc.relation.isbasedon	10.1016/j.jclepro.2023.136044
dc.rights	info:eu-repo/semantics/closedAccess
dc.subject	0907 Environmental Engineering, 0910 Manufacturing Engineering, 0915 Interdisciplinary Engineering
dc.subject.classification	Environmental Sciences
dc.title	Ferric oxide stimulates medium-chain carboxylic acids synthesis from waste activated sludge via ethanol-driven chain elongation: Mechanisms and implications
dc.type	Journal Article
utslib.citation.volume	389
utslib.for	0907 Environmental Engineering
utslib.for	0910 Manufacturing Engineering
utslib.for	0915 Interdisciplinary Engineering
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology
pubs.organisational-group	/University of Technology Sydney/Faculty of Engineering and Information Technology/School of Civil and Environmental Engineering
pubs.organisational-group	/University of Technology Sydney/Strength - CTWW - Centre for Technology in Water and Wastewater Treatment
utslib.copyright.status	closed_access	*
dc.date.updated	2023-05-05T05:05:05Z
pubs.publication-status	Published
pubs.volume	389

Abstract:

Nowadays, conductive iron-containing materials (i.e., Fe3O4 and zerovalent iron) have attracted greatly attention in improving medium-chain carboxylic acids (MCCA) from waste activated sludge (WAS). However, the feasibility and mechanism of semi-conductive iron oxide, i.e., ferric oxide (Fe2O3), in stimulating MCCA synthesis from WAS via ethanol-driven chain elongation (CE) has been unclear. Therefore, this work is aimed to fill up the knowledge gap. Results showed that the MCCA yield in the Fe2O3-supplemented fermenter attained at 9162 mg COD/L (i.e., 6268 mg COD/L caproate and 2895 mg COD/L caprylate), which was 2.4 times that of the control system. Kinetic analysis proved that Fe2O3 enhanced both the potential and rate of MCCA synthesis. Mechanism analysis indicated that Fe2O3 facilitated the individual steps for MCCA production, i.e., hydrolysis, acidification and CE. Further investigation disclosed that the dissimilatory iron reduction (DIR) induced by Fe2O3 corrosion and released ferrous ions improved enzymes activities of hydrolysis and acidification, while the promotion of CE was mainly ascribed to increased electron transfer efficiency by crystalline Fe2O3. Further, Fe2O3 promotes electron transfer through several mechanisms, including stimulating extracellular polymeric substance (EPS) excretion, increasing EPS electroactivity, and enhancing electron transport system activity. Microbial analysis revealed that Fe2O3 induced microflora structure shifting towards substrates transformation, iron reduction and MCCA generation, and up-regulated the key enzymes in CE pathways. This work provides an efficient strategy for MCCA generation and WAS management.

Please use this identifier to cite or link to this item:

http://hdl.handle.net/10453/170227