长江口水淘选分级颗粒物中有机碳的来源、分布与降解

发布时间：2018-06-25 15:01

本文选题：长江口 + 悬浮颗粒物　；参考：《中国海洋大学学报(自然科学版)》2016年02期

【摘要】：对河流颗粒有机碳的来源和归宿的认识是全球碳循环研究的重要方面,而从分级的角度研究颗粒有机碳的输运过程,有助于深入了解其迁移转化过程。于2012年3月采集了长江口的表层悬浮颗粒物,采用水淘选法对其进行了分级分离,分析了这些颗粒物的有机碳含量、稳定碳同位素丰度及木质素等参数,结合颗粒物的质量百分组成,讨论了不同粒级颗粒物有机碳的分布、来源及降解情况。从质量分布上来说,长江口悬浮颗粒物的主要组成部分是32μm粒级的颗粒物。随粒径增大,颗粒有机碳的含量逐渐降低,但并不是最小粒级赋存最多的有机碳,大部分站位颗粒有机碳集中在16~32μm粒级颗粒物上(55%以上)。粗颗粒物(63μm)中有机碳含量低,N/C比较小,13 C较亏损,木质素含量较高,说明粗颗粒物中陆源有机碳的贡献较大,而在细颗粒物,尤其是8μm和8~16μm颗粒物中,除δ13 C外,其它参数的变化均与粗颗粒物的相反,其13 C则比粗颗粒物还要亏损,说明在这些粒级中,除了陆地高等植物外,土壤有机碳或淡水浮游植物的贡献可能也很重要。长江口不同粒级悬浮颗粒物的C/V值和S/V值均较小,表明颗粒物中木质素是被子植物组织与裸子植物组织的混合来源。随粒径增大,木质素降解参数,如(Ad/Al)v、P/(S+V)和3,5-Bd/V均逐渐降低,表明细颗粒物中木质素的降解程度最高。
[Abstract]:Understanding the origin and fate of particulate organic carbon in rivers is an important aspect in the study of the global carbon cycle, and studying the transport process of particulate organic carbon from the perspective of classification is helpful to further understand the migration and transformation process of particulate organic carbon. The suspended particles in the surface layer of the Yangtze Estuary were collected in March 2012 and separated by water scouring method. The organic carbon content, stable carbon isotope abundance and lignin of these particles were analyzed. The distribution, source and degradation of organic carbon in different particles were discussed in combination with the mass percent composition of particulate matter. In terms of mass distribution, the main component of suspended particles in the Changjiang Estuary is 32 渭 m particles. With the increase of particle size, the content of particulate organic carbon decreased gradually, but it was not the most abundant organic carbon at the smallest grain level, and most of the particulate organic carbon at the station was concentrated on 16 ~ 32 渭 m particles (55% or more). The content of organic carbon in coarse particulate matter (63 渭 m) was lower than that in small N / C ratio of 13C, and the content of lignin was higher, which indicated that the contribution of terrestrial organic carbon in coarse particulate matter was greater, but in fine particulate matter, especially in 8 渭 m and 816 渭 m particulate matter, except 未 13 C. The change of other parameters is contrary to that of coarse particulate matter, and its 13C is lower than that of coarse particulate matter, indicating that the contribution of soil organic carbon or freshwater phytoplankton may also be important in these grain-level, in addition to the terrestrial higher plants, the contribution of soil organic carbon or freshwater phytoplankton may also be very important. The C / V and S / V values of suspended particles of different grain levels in the Changjiang Estuary were small, which indicated that lignin in particles was the mixed source of angiosperm and gymnosperms. The degradation parameters of lignin, such as (Ad/Al) V P / (S V) and (35 B / V), gradually decreased with the increase of particle size, indicating that the degradation degree of lignin in fine particles was the highest.
【作者单位】：中国海洋大学海洋化学理论与工程技术教育部重点实验室;中国海洋大学化学化工学院;海洋科学与技术青岛协同创新中心;中国海洋大学海洋有机地球化学研究所;
【基金】：国家自然科学基金项目(41176063;41221004)资助~~
【分类号】：P734

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