Characterization of nitrogen and phosphorus at the ice-water-sediment interface and the effect of their migration on overlying water quality in Daihai Lake (China) during the freezing period

Rong Wu; Yu Liu; Sheng Zhang; Xiaohong Shi; Shengnan Zhao; Junping Lu; Xueer Kang; Shihuan Wang; Yue Wu; Lauri Arvola

doi:10.1016/j.scitotenv.2023.164863

Characterization of nitrogen and phosphorus at the ice-water-sediment interface and the effect of their migration on overlying water quality in Daihai Lake (China) during the freezing period

Sci Total Environ. 2023 Oct 1:893:164863. doi: 10.1016/j.scitotenv.2023.164863. Epub 2023 Jun 14.

Authors

Rong Wu¹, Yu Liu², Sheng Zhang¹, Xiaohong Shi³, Shengnan Zhao¹, Junping Lu⁴, Xueer Kang⁵, Shihuan Wang¹, Yue Wu⁶, Lauri Arvola⁷

Affiliations

¹ Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China.
² Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China; Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River, Hohhot 010018, China. Electronic address: yuliu@imau.edu.cn.
³ Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China; State Gauge and Research Station of Wetland Ecosystem, Wuliangsuhai Lake, Inner Mongolia, China.
⁴ State Gauge and Research Station of Wetland Ecosystem, Wuliangsuhai Lake, Inner Mongolia, China.
⁵ Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River, Hohhot 010018, China; Inner Mongolia Key Laboratory of Protection and Utilization of Water Resources, Hohhot 010018, China.
⁶ Inner Mongolia Key Laboratory of Protection and Utilization of Water Resources, Hohhot 010018, China.
⁷ Faculty of Biological and Environmental Sciences, Ecosystems and Environment Research Programme, Lammi Biological Station, University of Helsinki, Lammi FI-16900, Finland.

PMID: 37321494
DOI: 10.1016/j.scitotenv.2023.164863

Abstract

Approximately one-third of the year, Daihai Lake experiences freezing conditions. During this period, the primary mechanisms that impact the quality of the lake water quality include the freezing of nutrients by the ice sheet and the migration of nutrients between the ice, water, and sediment. The present investigation involved the collection of samples of ice, water, and sediment, followed by the utilization of the thin film gradient diffusion (DGT) technique to and explore the distribution and migration of diverse nitrogen (N) and phosphorus (P) forms at the interface of ice, water and sediment. The findings indicate that the freezing process led to the precipitation of ice crystals, which in turn caused the migration of a significant proportion (28-64 %) of nutrients to the subglacial water. The predominant constituents of N and P in subglacial water, were NO₃^--N and PO₄^3--P, which constituted 62.5-72.5 % of total N (TN) and 53.7-69.4 % of total P(TP). Respectively, with increasing depth, the TN and TP of sediment interstitial water increased. The sediment in the lake acted as a source of PO₄^3--P and NO₃^--N while acting as a sink or NH₄⁺-N. Soluble reactive P (SRP) flux and NO₃^--N flux were responsible for 76.5 % and 2.5 % of the P and N present in the overlying water. Additionally, it was observed that 60.5 % of the NH₄⁺-N flux in the overlying water was absorbed and subsequently deposited in the sediment. The presence of soluble and active P in the ice sheet could play a crucial role in the regulation of sediment release of both SRP and NH₄⁺-N. Additionally, the presence of high nutritional salts and the concentration of nitrate nitrogen in the overlying water would certainly increase the pressure of the water environment. Endogenous contamination must be urgently controlled.

Keywords: Daihai; Migration flux; Nitrogen and phosphorus restriction; Sediment nutrients.