Organic carbon mineralization pathways in the muddy sediments of the South Yellow Sea: Insights from steady-state modeling of porewater

doi:10.1016/j.apgeochem.2022.105237

	Organic carbon mineralization pathways in the muddy sediments of the South Yellow Sea: Insights from steady-state modeling of porewater
	Ren, Jian-Hua 1; Zhu, Mao-Xu 1; Wang, De-Yan 1; Tan, Ting-Ting 1; Li, Tie 1; Zhao, Miao 2; Pan, Da-Wei2
发表期刊	APPLIED GEOCHEMISTRY
ISSN	0883-2927
	2022-03-01
卷号	138 页码:12
关键词	China marginal Seas Organic carbon Marine sediments Diagenetic modeling Mineralization pathways Mineralization rate
DOI	10.1016/j.apgeochem.2022.105237
英文摘要	In marine sediments, microbial mineralization of organic carbon (OC) proceeds through a cascade of pathways using different electron acceptors. Rates and relative importance of individual pathways can provide quantitative constraints on biogeochemical cycling of a number of elements, such as carbon, nitrogen, sulfur, iron, and manganese. However, such information is hitherto very scarce in the China marginal seas. To fill the gap, a multicomponent-coupled reaction-transport model CANDI was applied to quantify the rates and relative contributions of individual pathways of OC mineralization at three sites in the South Yellow Sea (SYS) sediments, based on which OC budgets were constructed. Model results at steady state generally well-reproduced the profiles of measured porewater solutes. The fast degrading OC pools G1 become exhausted over the upper 4 cm at the studied sites with the degradation rate constants k1 ranging between 0.6 and 1.65 yr(- 1), while the slow degrading OC pool G2 remains almost undegradable on the timescales of the studied depth (-25 cm) due to the low degradation rate constants k2 (10(- 5)-10(-4) yr(- 1)) The depth-integrated rates of OC mineralization at the studied sites are in the range of 5.1-18.3 mmol C m(- 2) d(- 1), and aerobic respiration stands out as the dominant pathway, with its average contribution of 62%, followed by sulfate reduction (22.6%), dissimilatory manganese/ iron reduction (8.4%), and denitrification (6.1%). Methanogenesis is a negligible process of OC mineralization within the studied depths. The contributions of aerobic respiration in the SYS sediments are much higher than the global average for marginal seas, but the contributions of sulfate reduction and iron dissimilatory reduction are much lower than their global averages, which could be ascribed to the low availability of degradable OC for anaerobic respiration. Budget of OC indicates that the mineralization and burial of OC in the muddy sediments account for 7.3 and 1.7%, respectively, of the total OC supplied to the sea, with the net OC accumulation efficiency of-19%.
收录类别	SCI
语种	英语
关键词[WOS]	EAST CHINA SEA ; ORGANIC-MATTER MINERALIZATION ; EARLY DIAGENETIC PROCESSES ; SURFACE SEDIMENTS ; MARINE-SEDIMENTS ; IRON REDUCTION ; SULFATE-REDUCTION ; PROVENANCE DISCRIMINATION ; CONTINENTAL SHELVES ; MARGIN SEDIMENTS
研究领域[WOS]	Geochemistry & Geophysics
WOS记录号	WOS:000799846100002
引用统计	被引频次：2[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.yic.ac.cn/handle/133337/31175
专题	中国科学院海岸带环境过程与生态修复重点实验室中国科学院海岸带环境过程与生态修复重点实验室_海岸带环境工程技术研究与发展中心
通讯作者	Zhu, Mao-Xu
作者单位	1.Ocean Univ China, Coll Chem & Chem Engn, Key Lab Marine Chem Theory & Technol, Minist Educ, Qingdao 266100, Peoples R China 2.Chinese Acad Sci, Yantai Inst Coastal Zone Res, Yantai 264003, Peoples R China
推荐引用方式 GB/T 7714	Ren, Jian-Hua,Zhu, Mao-Xu,Wang, De-Yan,et al. Organic carbon mineralization pathways in the muddy sediments of the South Yellow Sea: Insights from steady-state modeling of porewater[J]. APPLIED GEOCHEMISTRY,2022,138:12.
APA	Ren, Jian-Hua.,Zhu, Mao-Xu.,Wang, De-Yan.,Tan, Ting-Ting.,Li, Tie.,...&Pan, Da-Wei.(2022).Organic carbon mineralization pathways in the muddy sediments of the South Yellow Sea: Insights from steady-state modeling of porewater.APPLIED GEOCHEMISTRY,138,12.
MLA	Ren, Jian-Hua,et al."Organic carbon mineralization pathways in the muddy sediments of the South Yellow Sea: Insights from steady-state modeling of porewater".APPLIED GEOCHEMISTRY 138(2022):12.