黄河下游颗粒有机碳的来源,降解与输运特征

发布时间：2018-11-13 15:23

【摘要】：2012年在黄河利津逐月采集悬浮颗粒物(SPM),通过分析粒度组成,颗粒有机碳(POC)及其稳定同位素丰度(513C),木质素等参数,讨论了黄河下游POC的来源,分布,降解状态和输运的季节变化特点.结果表明,2012年黄河利津径流量,SPM浓度和中值粒径(MGS)均有明显的季节变化,且变化规律基本一致.春季降水较少,且下游灌溉较多,导致径流量较小(300m~3/S左右),较粗的颗粒物更容易沉降到河床上,而且不易再悬浮,使得SPM较低(平均0.44kg/m~3),MGS较小(平均7.77μm);夏秋季黄河流域降水较多,径流量较大(1000m~3/S以上),使得河床上较粗的颗粒物容易被带入悬移质中,因此SPM较高(0.67kg/m~3),MGS较大(10.6μm).POC及δ~(13)C的结果表明了不同来源有机碳贡献的季节变化,春季POC含量较高,δ~(13)C较负.颗粒物中木质素含量季节规律变化与流量较为一致,春季木质素含量较高,秋季较低.木质素参数C/V(0.21~0.34)和S/V(0.83~1.28)表明黄河SPM中木质素为被子植物草本和木本组织混合来源,降解参数(Ad/Al)_v(0.33~0.52),3,5-Bd/V(0.03~0.12)和P/(S+V)(0.20~0.36)均表明黄河SPM中木质素存在一定程度的降解,且秋季降解程度较大,与流量和有机碳来源变化有关.
[Abstract]:In 2012, suspended particulate matter (SPM),) was collected monthly in Lijin, Yellow River. The source and distribution of POC in the lower Yellow River were discussed by analyzing the particle size composition, particulate organic carbon (POC) and its stable isotopic abundance (513C), lignin and so on. The seasonal variation of degradation state and transport. The results showed that the runoff, SPM concentration and median particle size (MGS) of the Yellow River in 2012 had obvious seasonal variation, and the variation law was basically the same. Less precipitation in spring and more irrigation downstream resulted in smaller runoff (about 300m~3/S), easier subsidence of coarse particles on the riverbed and less resuspension, resulting in lower SPM (average 0.44kg/m~3). MGS is small (mean 7.77 渭 m);) In summer and autumn, the Yellow River basin has more precipitation and larger runoff (above 1000m~3/S), which makes the coarse particles on the river bed easy to be brought into suspended sediment, so the SPM is higher (0.67kg/m~3). The results of large MGS (10.6 渭 m). POC and 未 ~ (13) C) indicated that the contribution of organic carbon from different sources varied in seasons. The content of POC was higher in spring and 未 ~ (13) C was negative. The seasonal variation of lignin content in particulate matter was consistent with the flow rate. The content of lignin in spring was higher than that in autumn. The lignin parameters C / V (0.21 ~ 0.34) and S / V (0.83 ~ 1.28) indicate that lignin is a mixed source of angiosperm herbaceous and woody tissue in the Yellow River SPM, and the degradation parameter (Ad/Al) _ v (0.330.52). The results showed that the degradation of lignin in the Yellow River SPM was significant in autumn, which was related to the flow rate and the source of organic carbon.
【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;
【基金】：国家重点研发计划“全球变化及应对”重点专项课题(2016YFA0600902) 国家自然科学基金创新群体研究项目(41521064)
【分类号】：X522

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