江苏沿海沉积物有机磷含量、总有机碳、总氮与同位素特征及有机质来源解析  

Organic Phosphorus Contents,Total Organic Carbon,Total Nitrogen and Their Isotopic Characteristics from Sediments in Jiangsu Coast,China and Source Identification of Organic Matter

作　　者：严维兵 饶文波[2] 栗天宁 徐祖阳 杨宇航 茅昌平[2] YAN Wei-bing;RAO Wen-bo;LI Tian-ning;XU Zu-yang;YANG Yu-hang;MAO Chang-ping(Geological Exploration Technology Institute of Jiangsu Province,Nanjing 210049,Jiangsu,China;School of Earth Sciences and Engineering,Hohai University,Nanjing 211100,Jiangsu,China)

机构地区：[1]江苏省地质勘查技术院,江苏南京210049 [2]河海大学地球科学与工程学院,江苏南京211100

出　　处：《地球科学与环境学报》2024年第1期67-80,共14页Journal of Earth Sciences and Environment

基　　金：江苏省自然科学基金项目(BK20191304);江苏省自然资源厅2022年地质勘查资金项目(202307018K1S);国家重点研发计划项目(2018YFC0406601)。

摘　　要：沉积物有机质分布与来源是海陆过渡带生物地球化学循环和沿海生态环境研究中的重点和难点问题,一直受到广泛关注。选择江苏沿海为研究区域,于2016年采集61个表层沉积物样品,查明其中的有机磷(OP)含量、总有机碳(TOC)、总氮(TN)及有机碳和总氮同位素(δ^(13)C_(org)、δ^(15)N_(tot))特征,试图阐明江苏沿海沉积物有机质来源。结果表明:沉积物有机磷含量、总有机碳、总氮与粒度之间存在显著的相关关系,明显受水动力作用的影响。元素比值与同位素的定性分析表明,沉积物有机质主要由海洋生物提供,也受陆源输入的影响。同位素混合模型计算结果进一步发现,海源对沿海沉积物有机质平均贡献比例达到56.9%,其次为陆源C3植物、土壤以及农业肥料,平均贡献比例为38.5%,生活污水的贡献比例仅为4.6%。海源有机质通过洋流和潮波输送至江苏沿海,而河流输入和沿海养殖可能是陆源输入的重要方式。尽管陆源输入不是江苏沿海沉积物有机质的主要贡献来源,但可能是沿海水体富营养化的驱动因子。The distribution and source of sediment organic matter are a key and difficult issue in the studies of the sea-land transition biogeochemical cycle and coastal ecological environments,and have been widely concerned.The Jiangsu coast was chosen as a study area,61 surface sediment samples were collected in 2016,the organic phosphorus(OP)contents,total organic carbon(TOC),total nitrogen(TN),and the isotopic compositions of organic carbon and total nitrogen(δ^(13)C_(org),δ^(15)N_(tot) values)were investigated to identify the sources of organic matter from sediments in Jiangsu coast.The results show that the significant correlations between OP contents,TOC,and TN in sediments and particle sizes,which are significantly influenced by the hydrodynamic effects.The qualitative analysis of the element ratios and isotopes show that the sediment organic matter is mainly provided by marine organisms and is also supplied by terrestrial inputs to some extent.The calculated results of the isotope mixing model further find that the contribution proportion of the marine source to sediment organic matter of Jiangsu coast is averagely 56.9%,followed by terrestrial C3 plants,soil,and agricultural fertilizers with an average contribution proportion of 38.5%,and domestic sewage contributes only 4.6%.Marine organic matter is transported to Jiangsu coast through oceanic currents and tidal waves,and river input and coastal aquaculture might be important patterns of terrestrial input.Terrestrial input is not the main contributor to the organic matter of sediments in Jiangsu coast,but is probably a driving factor for coastal eutrophication.The findings are helpful in deeply understanding the biogeochemistry cycle in the land-sea transition zone,and provide a theoretical guidance for the prevention and control of coastal organic pollution.

关 键 词：沉积物 有机质 有机磷 有机碳 总氮 稳定同位素 物质来源 江苏 

分 类 号：X55[环境科学与工程—环境工程] P76[天文地球—海洋科学]