研究报告
季恺悦,李琦,单保庆,张超.白洋淀沼泽区与开阔水域区颗粒物组分特征与沉降通量研究[J].环境科学学报,2022,42(8):271-281
白洋淀沼泽区与开阔水域区颗粒物组分特征与沉降通量研究
- Study on deposition flux and components characteristic of particulates in marsh and open water area of Baiyangdian Lake
- 基金项目:国家自然科学基金(No.41907267)
- 季恺悦
- 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085;中国科学院大学, 北京 100049
- 李琦
- 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085;中国科学院大学, 北京 100049
- 单保庆
- 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 张超
- 中国科学院生态环境研究中心环境水质学国家重点实验室, 北京 100085
- 摘要:选取白洋淀的沼泽区(烧车淀)与开阔水域区(采蒲台)为研究区域,分析了水体中新生沉降颗粒物组分组成、沉降通量及其来源.结果表明,两种典型水域中水体颗粒物组分差异显著,其中,烧车淀水域颗粒物成分以有机质(OM)为主,质量占比达到49.59%~74.14%;而采蒲台水域颗粒物以无机组分为主,占比为54.52%~79.27%.烧车淀沉降颗粒物中总碳(TC)、总氮(TN)含量分别为(221.16±39.73) g·kg-1和(21.10±1.67) g·kg-1;采蒲台沉降颗粒物中TC和TN的含量分别为(172.28±91.22) g·kg-1和(15.72±8.12) g·kg-1.由固相13C CP/MAS NMR光谱结果分析出白洋淀沉降颗粒物中碳组分以烷基碳、烷氧基碳为主,其中,烧车淀淀面水域颗粒物中以易分解碳烷氧基碳为主(65.65%),采蒲台淀面水域颗粒物中以较稳定烷基碳为主(50.76%).开阔水域区颗粒物沉降通量高于沼泽化区,均值分别为10.63 g·m-2·d-1和6.07 g·m-2·d-1;开阔水域区不同水域类型颗粒物沉降通量排序为水道((19.91±8.87) g·m-2·d-1)>沟壕((7.06±2.94) g·m-2·d-1)>淀面((4.92±3.48) g·m-2·d-1).沉降颗粒物的C/N和 C/P比值结果表明,白洋淀沉降颗粒物中有机质主要来源可能为维管束植物和浮游植物.颗粒物沉降通量与组分特征研究有利于剖析白洋淀典型区域湖泊沉积和物质转化过程,为白洋淀能量流动和物质流动研究提供支撑.
- Abstract:This paper investigated the composition, sedimentation flux and source of newly settled particles in the water body of marsh area (Shaochedian) and open water area (Caiputai) in Baiyangdian Lake. The results showed that there were significant differences in the settled particulates component of the two typical water areas. The particulates in Shaochedian mainly consisted of organic matter (OM), accounting for 49.59%~74.14%; while the particulate matter in Caiputai water area was mainly inorganic matter, accounting for 54.52%~79.27%. The contents of total carbon (TC) and total nitrogen (TN) in the settled particulates of Shaochedian were (221.16±39.73) g·kg-1 and (21.10±1.67) g·kg-1, respectively; while the content of TC and TN in Caiputai were (172.28±91.22) g·kg-1 and (15.72±8.12) g·kg-1, respectively. The results of solid-phase 13C CP/MAS NMR spectra showed that the carbon components in the settled particulates of Baiyangdian Lake were mainly alkyl carbon and alkoxy carbon. The alkoxy carbon, which is easily decomposed, was the main fraction of settled particulates in the open water area of Shaochedian (65.65%), and the alkyl carbon in the particulates of Caiputai accounted for 50.76%. The flux experiment showed that the deposition flux of particulate matter in open water area was higher than that in marsh area, with the mean values of 10.63 and 6.07 g·m-2·d-1, respectively. The order of particulate deposition flux in open lake surface waters was water channel ((19.91±8.87) g·m-2·d-1) > trench ((7.06±2.94) g·m-2·d-1) > lake area ((4.92±3.48) g·m-2·d-1). The C/N and C/P ratios showed that the main sources of OM may be vascular plants and phytoplankton in the settled particulates of Baiyangdian Lake. The study on the characteristics of particulate deposition flux and composition is conducive to analyze the process of particle deposition and material transformation in typical areas of Baiyangdian Lake, and provides support for the research on energy flow and logistics transformation of Baiyangdian Lake.