Sediment is the most dominant reservoir of organic pollutants in the aquatic environment. Understanding carbon and nitrogen sources in sediments and factors that controls distribution enhances our understanding of biogeochemical cycles of carbon and nitrogen. Different end-members and surface sediments of rivers and sediments profiles of lakes were collected. The concentrations of TOC and TON and their δ¹³C and δ¹⁵N were studied for qualitative and quantitative analysis of natural and anthropogenic sources. The results show that TOC and TON concentrations of the sediments from rivers range from 0.63% to 10.83% and 0.06%–0.86%, respectively, indicating substantial great environmental risks in these rivers. The concentrations of TOC and TON for the four sediment profiles below the 5 cm, increase in the order of Miyun < Chuidiao < Qunming < Houhai, as influenced by their respective environment condition. Moreover, water quality was quite good and there was no risk of eutrophication in Miyun reservoir. δ¹³C_org and δ¹⁵N_org in surface sediments of the studied 18 rivers range from −27.2‰ to −24.9‰ and −2.2‰ to +10.9‰, respectively. Based on a simple δ¹³C-based end-member mixing and a C/N ratio model, organic matter in the surface sediments of these rivers were mainly derived from sewage and C3 plant. In addition, the sources of organic matter differed in each layer of the four sediment profiles. This study provides a reliable method for qualitative and quantitative identification of the source of organic matter in sediments, and offers theoretical basis for better management of rivers and lakes.

沉积物是水生环境中最主要的有机污染物库。了解沉积物中的碳和氮源以及控制分布的因素可以增进我们对碳和氮的生物地球化学循环的了解。收集了河流的不同最终成员和地表沉积物以及湖泊的沉积物剖面。TOC和TON及δ的浓度¹³ C和δ ¹⁵研究了N对自然和人为来源的定性和定量分析。结果表明，河流沉积物中TOC和TON的浓度分别为0.63％〜10.83％和0.06％〜0.86％，表明这些河流的环境风险很大。5 cm以下四种沉积物剖面的TOC和TON浓度受其各自环境条件的影响，按密云<垂条<群明<后海的顺序增加。此外，密云水库水质良好，没有富营养化的风险。δ ¹³ Ç_有机和δ ¹⁵ Ñ_有机被研究的18条河流的表层沉积物中的范围分别为-27.2‰至-24.9‰和-2.2‰至+ 10.9‰。基于简单的δ ¹³基于C的端员混合和C / N比的模式，在这些河流的表面沉积物有机物主要来自污水和C3植物。此外，四种沉积物剖面的每一层中有机物的来源也不同。该研究为定性和定量鉴定沉积物中有机物的来源提供了可靠的方法，并为更好地管理河流和湖泊提供了理论依据。