Effects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin

Watershed-scale nitrogen pollution in aquatic systems has become a worldwide concern due to its continuous impact on water quality deterioration, while the knowledge of key influencing factors dominating nitrogen transportation and transformation at the sediment-water interface (SWI) remains limited...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Yongmei Hou, Xiaolong Liu, Sainan Chen, Jie Ren, Li Bai, Jun Li, Yongbo Gu, Lai Wei
Formato:	article
Lenguaje:	EN
Publicado:	MDPI AG 2021
Materias:	thermal stratification nitrogen transformation sediment-water interface reservoir NH<sub>4</sub><sup>+</sup> diffusion Hydraulic engineering TC1-978 Water supply for domestic and industrial purposes TD201-500
Acceso en línea:	https://doaj.org/article/5ffad47f45f949a8b75d4aaabcd6d0f4
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:5ffad47f45f949a8b75d4aaabcd6d0f4
record_format	dspace
spelling	oai:doaj.org-article:5ffad47f45f949a8b75d4aaabcd6d0f42021-11-25T19:15:23ZEffects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin10.3390/w132231942073-4441https://doaj.org/article/5ffad47f45f949a8b75d4aaabcd6d0f42021-11-01T00:00:00Zhttps://www.mdpi.com/2073-4441/13/22/3194https://doaj.org/toc/2073-4441Watershed-scale nitrogen pollution in aquatic systems has become a worldwide concern due to its continuous impact on water quality deterioration, while the knowledge of key influencing factors dominating nitrogen transportation and transformation at the sediment-water interface (SWI) remains limited, especially in impounded rivers with an artificial reservoir. Hence, for a better understanding of the effects of thermal stratification on nitrogen transformation, we investigated the nitrogen species and isotopes in the sediment of a deep reservoir in Southwest China. Our results confirmed a significant difference in nitrogen species and isotopic composition in sediment between those in the thermal stratification period and non-thermal stratification period and indicated that the sediment biogeochemical process and transportation were clearly linked to the variations in water temperature and dissolved oxygen dominated by the process of thermal stratification. Significant seasonal differences in NH<sub>4</sub><sup>+</sup>-N and NO<sub>3</sub><sup>−</sup>-N in pore water of the upper layer (0–19 cm) revealed that nitrification exhausted NH<sub>4</sub><sup>+</sup> in the non-stratified period (NSP), and a potential low mineralization rate appeared when compared with those in the stratified period (SP). Seasonal differences in nitrogen species and isotope fractionation of δ<sup>15</sup>N-PON (about 2.3‰ in SP) in the upper layer sediment indicated a higher anaerobic mineralization rate of organic matter in SP than that in NSP. The diffusion fluxes of NH<sub>4</sub><sup>+</sup>-N at SWI were 9.48 and 15.66 mg·m<sup>−2</sup>·d<sup>−1</sup> in NSP and SP, respectively, and annual NH<sub>4</sub><sup>+</sup>-N diffusion accounted for 21.8% of total storage in the reservoir. This study demonstrated that the nitrogen cycling processes, especially nitrification, denitrification, and mineralization, have been largely altered along with the changes in dissolved oxygen and that the diffusion of nitrogen species varied with the presence of the oxygen. The results contribute to the future study of watershed nitrogen budget evaluation and suggest that the endogenous nitrogen released from the sediment-water interface should be emphasized when aiming to fulfil water management policies in deep reservoirs.Yongmei HouXiaolong LiuSainan ChenJie RenLi BaiJun LiYongbo GuLai WeiMDPI AGarticlethermal stratificationnitrogen transformationsediment-water interfacereservoirNH<sub>4</sub><sup>+</sup> diffusionHydraulic engineeringTC1-978Water supply for domestic and industrial purposesTD201-500ENWater, Vol 13, Iss 3194, p 3194 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	thermal stratification nitrogen transformation sediment-water interface reservoir NH<sub>4</sub><sup>+</sup> diffusion Hydraulic engineering TC1-978 Water supply for domestic and industrial purposes TD201-500
spellingShingle	thermal stratification nitrogen transformation sediment-water interface reservoir NH<sub>4</sub><sup>+</sup> diffusion Hydraulic engineering TC1-978 Water supply for domestic and industrial purposes TD201-500 Yongmei Hou Xiaolong Liu Sainan Chen Jie Ren Li Bai Jun Li Yongbo Gu Lai Wei Effects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin
description	Watershed-scale nitrogen pollution in aquatic systems has become a worldwide concern due to its continuous impact on water quality deterioration, while the knowledge of key influencing factors dominating nitrogen transportation and transformation at the sediment-water interface (SWI) remains limited, especially in impounded rivers with an artificial reservoir. Hence, for a better understanding of the effects of thermal stratification on nitrogen transformation, we investigated the nitrogen species and isotopes in the sediment of a deep reservoir in Southwest China. Our results confirmed a significant difference in nitrogen species and isotopic composition in sediment between those in the thermal stratification period and non-thermal stratification period and indicated that the sediment biogeochemical process and transportation were clearly linked to the variations in water temperature and dissolved oxygen dominated by the process of thermal stratification. Significant seasonal differences in NH<sub>4</sub><sup>+</sup>-N and NO<sub>3</sub><sup>−</sup>-N in pore water of the upper layer (0–19 cm) revealed that nitrification exhausted NH<sub>4</sub><sup>+</sup> in the non-stratified period (NSP), and a potential low mineralization rate appeared when compared with those in the stratified period (SP). Seasonal differences in nitrogen species and isotope fractionation of δ<sup>15</sup>N-PON (about 2.3‰ in SP) in the upper layer sediment indicated a higher anaerobic mineralization rate of organic matter in SP than that in NSP. The diffusion fluxes of NH<sub>4</sub><sup>+</sup>-N at SWI were 9.48 and 15.66 mg·m<sup>−2</sup>·d<sup>−1</sup> in NSP and SP, respectively, and annual NH<sub>4</sub><sup>+</sup>-N diffusion accounted for 21.8% of total storage in the reservoir. This study demonstrated that the nitrogen cycling processes, especially nitrification, denitrification, and mineralization, have been largely altered along with the changes in dissolved oxygen and that the diffusion of nitrogen species varied with the presence of the oxygen. The results contribute to the future study of watershed nitrogen budget evaluation and suggest that the endogenous nitrogen released from the sediment-water interface should be emphasized when aiming to fulfil water management policies in deep reservoirs.
format	article
author	Yongmei Hou Xiaolong Liu Sainan Chen Jie Ren Li Bai Jun Li Yongbo Gu Lai Wei
author_facet	Yongmei Hou Xiaolong Liu Sainan Chen Jie Ren Li Bai Jun Li Yongbo Gu Lai Wei
author_sort	Yongmei Hou
title	Effects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin
title_short	Effects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin
title_full	Effects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin
title_fullStr	Effects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin
title_full_unstemmed	Effects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin
title_sort	effects of seasonal thermal stratification on nitrogen transformation and diffusion at the sediment-water interface in a deep canyon artificial reservoir of wujiang river basin
publisher	MDPI AG
publishDate	2021
url	https://doaj.org/article/5ffad47f45f949a8b75d4aaabcd6d0f4
work_keys_str_mv	AT yongmeihou effectsofseasonalthermalstratificationonnitrogentransformationanddiffusionatthesedimentwaterinterfaceinadeepcanyonartificialreservoirofwujiangriverbasin AT xiaolongliu effectsofseasonalthermalstratificationonnitrogentransformationanddiffusionatthesedimentwaterinterfaceinadeepcanyonartificialreservoirofwujiangriverbasin AT sainanchen effectsofseasonalthermalstratificationonnitrogentransformationanddiffusionatthesedimentwaterinterfaceinadeepcanyonartificialreservoirofwujiangriverbasin AT jieren effectsofseasonalthermalstratificationonnitrogentransformationanddiffusionatthesedimentwaterinterfaceinadeepcanyonartificialreservoirofwujiangriverbasin AT libai effectsofseasonalthermalstratificationonnitrogentransformationanddiffusionatthesedimentwaterinterfaceinadeepcanyonartificialreservoirofwujiangriverbasin AT junli effectsofseasonalthermalstratificationonnitrogentransformationanddiffusionatthesedimentwaterinterfaceinadeepcanyonartificialreservoirofwujiangriverbasin AT yongbogu effectsofseasonalthermalstratificationonnitrogentransformationanddiffusionatthesedimentwaterinterfaceinadeepcanyonartificialreservoirofwujiangriverbasin AT laiwei effectsofseasonalthermalstratificationonnitrogentransformationanddiffusionatthesedimentwaterinterfaceinadeepcanyonartificialreservoirofwujiangriverbasin
_version_	1718410092881117184

Effects of Seasonal Thermal Stratification on Nitrogen Transformation and Diffusion at the Sediment-Water Interface in a Deep Canyon Artificial Reservoir of Wujiang River Basin

Ejemplares similares