Distribution and sources of n-alkanes in sediments in the Fangchenggang sea area
PANG Guo-Tao1(), YANG Yuan-Zhen1, XIE Lei1, LI Wei1, ZHANG Xiao-Lei1,2, YAN Xing-Guo1
1. Yantai Center of Coastal Zone Geological Survey, China Geological Survey, Yantai 264000, China 2. College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
n-alkanes, exhibiting stable chemical properties, are ubiquitous in nature. They are favorable indicators of the source of organic matter. Using the gas chromatography-mass spectrometry (GC/MS), this study detected n-alkanes in the surface sediments sampled from the Fangchenggang sea area in September 2021. It analyzed their content and distribution, as well as their source based on characteristic parameters. The results are as follows: ① The n-alkanes of the Fangchenggang sea area manifested a content range of (67.51~850.08)×10-9 (dw), averaging 476.69×10-9 (dw), with high values primarily distributed in the southern sea area of Qisha Peninsula; ② They were principally composed of extensive n-C14~n-C35n-alkane homologues in a bimodal distribution. The former peak group displayed an even-carbon number advantage, while the latter showed an odd-carbon number advantage; ③ The terrestrial-marine alkane ratio (ΣT/ΣM), carbon predominance index (CPI), and terrestrial-marine alkane predominance ratio (TAR) all indicate a significant terrestrial influence on n-alkanes in the Fangchenggang sea area; ④ The average chain length (ACL), alkane index (AI), and Pmar-aq further suggest that n-alkanes were mainly from terrestrial herbs; ⑤ The T-ALK/C16 ratio implies that the Fangchenggang sea area experienced oil pollution; ⑥ The pristane/phytane ratio (Pr/Ph) reveals that n-alkanes in the sediments of the Fangchenggang sea area formed in an oxidizing environment.
庞国涛, 杨源祯, 谢磊, 李伟, 张晓磊, 闫兴国. 防城港海域沉积物中正构烷烃分布和来源解析[J]. 物探与化探, 2024, 48(2): 527-533.
PANG Guo-Tao, YANG Yuan-Zhen, XIE Lei, LI Wei, ZHANG Xiao-Lei, YAN Xing-Guo. Distribution and sources of n-alkanes in sediments in the Fangchenggang sea area. Geophysical and Geochemical Exploration, 2024, 48(2): 527-533.
Akram B B A R, Mohammadi J, et al. Characterization and ecological risk of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in sediments of Shadegan international wetland,the Persian Gulf[J]. Marine Pollution Bulletin, 2017, 124(1): 155-170.
doi: 10.1016/j.marpolbul.2017.07.015
Li Z L, Ma Q M, Cheng H O, et al. Normal alkanes characteristic parameters of Jinzhou Bay surface sediments[J]. Environmental Science, 2011, 32(11): 3300-3304.
[3]
Bush R T, Mcinerney F A. Leaf wax n-alkane distributions in and across modern plants: Implications for paleoecology and chemotaxonomy[J]. Geochimica et Cosmochimica Acta, 2013, 117:161-179.
doi: 10.1016/j.gca.2013.04.016
Zhu C, Pan J M, Lu B, et al. Compositional feature of n-alkanes in modern sediment from the Changjiang Estuary and adjacent area and its implication to transport and distribution of organic carbon[J]. Acta Oceanologica Sinica, 2005, 27(4):59-67.
[5]
Venturini N, Pita A L, Brugnoli E, et al. Benthic trophic status of sediments in a metropolitan area (Rio de la Plata estuary): Linkages with natural and human pressures[J]. Estuarine Coastal & Shelf Science, 2012, 112:139-152.
[6]
Eglinton G, Hamilton R J. Leaf epicuticular waxes[J]. Science, 1967, 156(3780):1322-1335.
pmid: 4975474
[7]
Duan Y. Organic geochemistry of recent marine sediments from the Nansha Sea,China[J]. Organic Geochemistry, 2000, 31(2/3):159-167.
doi: 10.1016/S0146-6380(99)00135-7
[8]
Silliman J E, Schelske C L. Saturated hydrocarbons in the sediments of Lake Apopka,Florida[J]. Organic Geochemistry, 2003, 34(3):253-260.
doi: 10.1016/S0146-6380(02)00169-9
[9]
Wang Z, Liu W G. Carbon chain length distribution in n-alkyl lipids:A process for evaluating source inputs to Lake Qinghai[J]. Organic Ceochemistry, 2012, 50:36-43.
Zhao M X, Zhang Y Z, Xing L, et al. The composition and distribution of n-alkanes in surface sediments from the South Yellow Sea and their potential as organic matter source indicators[J]. Periodical of Ocean University of China, 2011, 41(4):90-96.
[11]
防城港市地方志编纂委员会办公室. 防城港年鉴2016[M]. 南宁: 广西人民出版社, 2018.
[11]
Office of Fangchenggang Local Chronicles Compilation Committee. Fangchenggang yearbook 2016[M]. Nanning: Guangxi People's Publishing House, 2018.
The Standardization Administration of China. GB 17378.3—2007 The specification for marine monitoring.Part 3:Sample collection, storage and transportation[S]. Beijing: Chinese Standard Publishing house,2008.
Zhou Z Q, Xia W. An analysis of tidal current characteristics of Fangchenggang sea area[J]. Transactions of Oceanology and Limnology, 2021, 43(4):62-67.
[14]
Lei X, Zhang R, Liu Y, et al. Biomarker records of phytoplankton productivity and community structure changes in the Japan Sea over the last 166 kyr[J]. Quaternary Science Reviews, 2011, 30(19):2666-2675.
doi: 10.1016/j.quascirev.2011.05.021
[15]
Ternois Y, Kawamura K, Keigwin L, et al. A biomarker approach for assessing marine and terrigenous inputs to the sediments of Sea of Okhotsk for the last 27,000 years[J]. Geochimica et Cosmochimica Acta, 2001, 65(5):791-802.
doi: 10.1016/S0016-7037(00)00598-6
Yan K, Pang G T, Li W. Characteristics and sources of organic matter in surface sediments of the intertidal zone in Maowei sea,Guangxi[J]. Marine Environmental Science, 2022, 41(2):303-308.
[17]
Mead R, Xu Y, Chong J, et al. Sediment and soil organic matter source assessment as revealed by the molecular distribution and carbon isotopic composition of n-alkanes[J]. Organic Geochemistry, 2005, 36(3):363-370.
doi: 10.1016/j.orggeochem.2004.10.003
[18]
Ficken K J, Li B, Swain D L, et al. An n-alkane proxy for the sedimentary input of submerged/floating freshwater aquatic macrophytes[J]. Organic Geochemistry, 2000, 31(7/8):745-749.
doi: 10.1016/S0146-6380(00)00081-4
[19]
Blumer M, Guillard R R L, Chase T. Hydrocarbons of marine phytoplankton[J]. Marine Biology, 1971, 8(3):183-189.
doi: 10.1007/BF00355214
[20]
Eglinton G, Hamilton R J. Leaf epicuticular waxes[J]. Science, 1967, 156(3780):1322-1335.
pmid: 4975474
Li F, Xu G, He X L, et al. Composition,distribution and source of N-alkanes in surface sediments from the coast of East China Sea[J]. Marine Environmental Science, 2016, 35(3):398-403.
Kuang W M, Chen W F, Chen J M. The characteristic parameters of N-alkanes and petroleum pollution of Xiamen bay[J]. Marine Environmental Science, 2017, 36(1):76-80.
Li S Y, Deng W, Zhang D H, et al. Distribution and its indication significance of hydrocarbons in surface sediments from Bohai Sea and adjacent area[J]. Marine Environmental Science, 2017, 36(4):501-508.
[24]
Xiao B, Han Y, Liu J. Evaluation of biohydrogen production from glucose and protein at neutral initial pH[J]. International Journal of Hydrogen Energy, 2010, 35(12):6152-6160.
doi: 10.1016/j.ijhydene.2010.03.084
[25]
Li J Z, Zheng G C, He J G, et al. Hydrogen-producing capability of anaerobic activated sludge in three types of fermentations in a continuous stirred-tank reactor[J]. Biotechnology Advances, 2009, 27(5):573-577.
doi: 10.1016/j.biotechadv.2009.04.007
pmid: 19393312
[26]
Duan Y. Organic geochemistry of recent marine sediments from the Nansha Sea,China-Science direct[J]. Organic Geochemistry, 2000, 31(2/3):159-167.
doi: 10.1016/S0146-6380(99)00135-7
[27]
Guo W, He M, Yang Z, et al. Characteristics of petroleum hydrocarbons in surficial sediments from the Songhuajiang River (China):Spatial and temporal trends[J]. Environmental Monitoring & Assessment, 2011, 179(1-4):81-92.
Li C L. Pristane/phytane ratio in recent marine sediment (sedimentary layer) and its geochemical significance[J]. Marine Geology & Quaternary Geology, 1990, 10(4):77-88.
[29]
Ten H H L, De L J W, Rullkotter J, et al. Restricted utility of the pristane/phytane ratio as a palaeoenvironmental indicator[J]. Nature, 1987, 330(6149):641-643.
doi: 10.1038/330641a0
Han X B, Zhao J, Chu F Y, et al. The source of organic matter and its sedimentary environment of the bottomsurface sediment in northeast waters to Antarctic Peninsulabased on the biomarker features[J]. Acta Oceanologica Sinica, 2015, 37(8):26-38.
doi: 10.1007/s13131-018-1279-0