Shandong (Jinan) Water & Waste Water Monitoring Center, Jinan, People's Republic of China.
Soil and Water Sciences Department, University of Florida, Gainesville, FL, USA.
Environ Sci Pollut Res Int. 2020 Jan;27(3):2805-2818. doi: 10.1007/s11356-019-07040-7. Epub 2019 Dec 13.
The purpose of this study was to assess the water quality and variations in stable carbon and nitrogen isotopes of particulate organic matter (δC and δN), as well as to evaluate the sources of carbon and nitrogen that contribute to the POM pools in lakes and reservoirs located in the water-receiving area of the Eastern Route of South-to-North Water Transfer Project (SNWTP) in Northern China. During each season from October 2013 to July 2014, samples of POM from 14 lakes and reservoirs in Northern China were collected. The lakes and reservoirs were meso-eutrophic with considerably high brackish ions (SO, 173 mg/L; Cl, 296 mg/L) in Yangtze River lake, and high total nitrogen: total phosphorus ratio (averaged with 772) or dissolved inorganic nitrogen: soluble reactive phosphorus molar ratios (averaged with 1077) in mountainous reservoirs. The δC, δN, carbon to nitrogen (C/N) ratios showed significant seasonal variation, with ranges of - 32.5 to - 17.4‰, - 3.6 to 13.5‰, and 5.1-13.2, respectively, while they were hard to be distinguished among types of water sources. Principal component analysis (PCA) indicated that brackish ions, nutrients, and their molar ratios were the main factors influencing variations in δC and δN. δC and C/N ratios suggested autochthonous primary production mainly contributed to POM during from April to October, while exogenous organic matter might mainly contribute these carbon pools in January. The low values of δN (< 0‰) and negative correlation between δN and TN suggested discharge of agricultural waste water (e.g., fertilizers, irrigation tailwater) in Bailanghe, Xinan, and Taihe Reservoir during the fertilization season, while higher values indicated domestic sewage input to waterbodies (e.g., Mishan, Gengjing, Donghai Reservoir). Our results suggested that the aquatic ecosystem in water-receiving area of SNWTP would be potentially affected by the inter-basin water diversion, and thus, ecosystem-based strategies were also presented accordingly.
本研究旨在评估中国北方南水北调东线受水区湖泊和水库中颗粒有机物质（δC 和 δN）的水质和稳定碳、氮同位素变化，并评估导致这些水库颗粒有机物质库中碳、氮来源。2013 年 10 月至 2014 年 7 月，每个季节均从中国北方的 14 个湖泊和水库采集颗粒有机物质样品。这些湖泊和水库均为中营养型，长江水系湖泊的咸离子（SO ，173mg/L；Cl ，296mg/L）含量较高，山区水库的总氮：总磷比值（平均为 772）或溶解无机氮：可溶活性磷摩尔比（平均为 1077）较高。δC、δN、碳氮比（C/N）均表现出显著的季节性变化，范围分别为-32.5 至-17.4‰、-3.6 至 13.5‰和 5.1-13.2，而这些指标在不同水源类型之间难以区分。主成分分析（PCA）表明，咸离子、营养物质及其摩尔比是影响 δC 和 δN 变化的主要因素。δC 和 C/N 比值表明，4 月至 10 月期间，自源初级生产是颗粒有机物质的主要来源，而 1 月则主要以外源有机物质贡献这些碳库。δN 值较低（<0‰）以及 δN 与 TN 之间的负相关表明，在施肥季节，北八里河、西安和泰和水库的农业废水中含有肥料、灌溉尾水等物质，而较高的 δN 值则表明生活污水进入水体，如密山、耿井和东海水库。研究结果表明，南水北调东线受水区的水生态系统可能会受到跨流域调水的影响，因此，也相应提出了基于生态系统的策略。
