Surface Dissolved N2O Concentration and Emission Fluxes in an Urban River-canal-artificial Lake Linkage System

doi:10.16258/j.cnki.1674-5906.2025.10.010

Ecology and Environmental Sciences ›› 2025, Vol. 34 ›› Issue (10): 1598-1608.DOI: 10.16258/j.cnki.1674-5906.2025.10.010

• Research Article [Environmental Science] • Previous Articles Next Articles

Surface Dissolved N₂O Concentration and Emission Fluxes in an Urban River-canal-artificial Lake Linkage System

CHEN Fan¹(), CHI Shanqing², LIN Caiqiang², YU Bolin²^,^*(), XIE Rongrong¹^,³^,⁴, LI Jiabing¹^,³^,⁴, HUANG Xiangfeng⁵, ZHANG Haiping⁵, LIU Jia⁵, WU Qiaofeng²^,⁵

1. College of Environmental and Resource Science/College of Carbon Neutral Modern Industry, Fujian Normal University, Fuzhou 350007, P. R. China
2. Fuzhou Urban and Rural Construction Group Co., Ltd., Fuzhou 350001, P. R. China
3. Digital Fujian Internet-of-things Laboratory of Environmental Monitoring, Fujian Normal University, Fuzhou 350007, P. R. China
4. Digital Fujian Environmental Monitoring Internet of Things Laboratory, Fuzhou 350007, P. R. China
5. College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China

Received:2025-03-04 Online:2025-10-18 Published:2025-09-26

城市河渠-人工湖连通系统表层溶存N₂O浓度及排放通量研究

陈凡¹(), 池善庆², 林财强², 俞伯林²^,^*(), 谢蓉蓉¹^,³^,⁴, 李家兵¹^,³^,⁴, 黄翔峰⁵, 张海平⁵, 刘佳⁵, 吴乔枫²^,⁵

1.福建师范大学环境与资源学院/碳中和现代产业学院，福建福州 350007
2.福州市城乡建总集团有限公司，福建福州 350001
3.福建师范大学/福建省污染控制与资源循环利用重点实验室，福建福州 350007
4.数字福建环境监测物联网实验室，福建福州 350007
5.同济大学环境科学与工程学院，上海 200092

通讯作者: *E-mail: 791803575@qq.com
作者简介:陈凡（2001年生），女，硕士研究生，主要研究方向为水域温室气体排放。E-mail: 1194881687@qq.com

Abstract

Abstract:

A comprehensive examination of the production and discharge characteristics of dissolved N₂O, along with its influencing factors, in urban water bodies affected by residential drainage is imperative to effectively regulate greenhouse gases in urban waters. A natural river-drainage canal-artificial lake linkage system in Fuzhou was selected to study the daily and seasonal changes of dissolved N₂O in the surface layer of a typical urban water body under the influence of residential drainage water and to the identify the main environmental impact factors. The findings indicated that the surface-dissolved N₂O concentrations in the study area were moderate, ranging from 11 to 476 nmol·L⁻¹. However, the emission fluxes were lower than those observed in most urban rivers, ranging from 5 to 763 nmol·m⁻²·h⁻¹. This discrepancy can be attributed to the mitigation of greenhouse gas production and emissions by the river-lake connectivity system. Second, the surface-dissolved N₂O concentration in the outfall channel was significantly higher than that in natural rivers and artificial lakes. This variation was primarily attributed to the high nitrogen environment, pH, and DO levels, with significant daily variations observed in all seasons. Conversely, the concentration of dissolved N₂O in natural rivers and artificial lakes exhibited a minor peak at 6:00 p.m. in the fall season. Third, the surface layer of the outfall channel exhibited a substantially elevated emission flux compared with that of natural rivers and artificial lakes. This surface layer exhibited substantial daily variations at all observation points, which were influenced by wind speed and nitrogen content. Emission peaks were observed at 6:00 p.m. in all seasons except fall, when the urban rivers and canals reached their peak at 1:00 p.m. The natural rivers flowing through the city (R1) exhibited a substantial response to nitrogen and wind speed. Conversely, natural rivers that traverse woodlands and parks (R3) exhibited negligible correlations with the environmental factors. The environmental impact factors associated with sewage canals and man-made lakes fell within the ranges of R1 to R3. This study provides a foundational theoretical framework for examining N₂O greenhouse gas distribution patterns, emission characteristics, and environmental impact factors within urban river and lake systems.

Key words: urban river and lake connectivity system, dissolved N₂O, emission flux, spatio-temporal change, nitrogen

摘要：

研究受居民用排水影响的城市水体溶存N₂O的产排特征及影响因子对控制城市水域温室气体具有重要意义。选择福州城区自然河流-排污渠-人工湖连通系统，研究居民用排水影响下典型城市水体的表层溶存N₂O的日变化及季节变化过程，并识别主要的环境影响因子。结果表明，1）研究区域表层溶存N₂O浓度为中等水平（11-476 nmol·L⁻¹），但排放通量低于大多数城市河流（5-763 nmol·m⁻²·h⁻¹），与河湖连通系统减缓温室气体产排有关。2）排污渠表层溶存N₂O浓度显著高于自然河流和人工湖，主要受高氮环境以及pH、溶解氧（DO）的影响，各季节的日变化均显著；自然河流和人工湖溶存N₂O仅在秋季18:00时出现浓度小高峰。3）排污渠表层N₂O排放通量也显著高于自然河流和人工湖，各点位均有显著日变化；受风速和氮元素的影响，除秋季城市河渠在13:00达到峰值外，其余季节均于18:00达到排放峰值；流经城市的自然河流（R1）主要受到氮元素和风速的显著影响；流经林地和公园的自然河流（R3）与环境因子的相关性小；排污渠和人工湖的环境影响因子介于R1和R3之间。该研究为城市河湖系统的N₂O温室气体分布格局、排放特征及环境影响因子研究提供了重要的理论依据。

关键词: 城市河湖连通系统, 溶存N₂O, 排放通量, 时空变化, 氮元素

CLC Number:

CHEN Fan, CHI Shanqing, LIN Caiqiang, YU Bolin, XIE Rongrong, LI Jiabing, HUANG Xiangfeng, ZHANG Haiping, LIU Jia, WU Qiaofeng. Surface Dissolved N₂O Concentration and Emission Fluxes in an Urban River-canal-artificial Lake Linkage System[J]. Ecology and Environmental Sciences, 2025, 34(10): 1598-1608.

陈凡, 池善庆, 林财强, 俞伯林, 谢蓉蓉, 李家兵, 黄翔峰, 张海平, 刘佳, 吴乔枫. 城市河渠-人工湖连通系统表层溶存N₂O浓度及排放通量研究[J]. 生态环境学报, 2025, 34(10): 1598-1608.

Figures/Tables 11

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采样点	采样时间	pH	ρ（DO）/（mg∙L⁻¹）	t_w/℃	ρ（BOD₅）/（mg∙L⁻¹）	ρ（COD_Mn）/（mg∙L⁻¹）	ρ（叶绿素a）/（μg∙L⁻¹）
R1	夏季	6.62±0.26C	6.09±0.43cB	28.7±0.33aB	1.16±0.07cB	2.86±0.19bC	2.50±0.49bB
	秋季	7.06±0.52B	5.92±0.23cA	22.3±0.52b	1.54±0.27cB	2.60±0.19bB	5.24±1.22bB
	冬季	7.28±0.15C	9.73±0.42a	17.5±3.26c	3.15±0.51b	2.81±0.36bAB	17.8±3.34aA
	春季	6.52±0.71B	7.07±0.06bB	18.6±1.27c	4.30±0.55aA	3.37±0.08aB	2.96±0.21bB
R2	夏季	6.69±0.08cC	3.60±0.13bB	31.4±0.91aA	4.33±0.91aA	6.13±0.68aA	3.49±1.25B
	秋季	7.69±0.20aAB	7.27±0.41aA	22.4±0.90b	1.85±0.73bAB	3.16±0.19bB	1.74±0.54B
	冬季	7.20±0.24bC	8.26±0.63a	19.8±2.77b	3.10±1.37ab	3.36±0.42bA	3.67±1.78B
	春季	7.08±0.28bAB	7.63±0.84aAB	20.0±2.34b	1.56±0.96bB	3.44±0.39bB	3.77±2.24B
R3	夏季	7.70±0.22B	4.48±0.56cB	28.1±1.88aB	1.60±0.32bB	3.32±0.27bcC	3.37±0.67B
	秋季	7.69±0.30AB	3.69±0.37cB	21.9±1.29b	3.30±0.90bA	4.56±1.05abA	2.29±0.64B
	冬季	7.96±0.20B	8.94±0.37a	17.8±3.00b	2.32±0.50b	2.12±0.60cB	3.65±1.02B
	春季	8.15±0.22A	7.85±0.42bAB	18.3±0.70b	5.50±1.78aA	4.98±0.74aA	4.33±2.17B
LC	夏季	9.11±0.16aA	11.4±2.35A	32.7±0.85aA	3.81±0.45A	4.73±0.22aB	33.2±5.15aA
	秋季	7.80±0.06bA	7.48±1.39A	21.9±0.35b	2.38±1.00AB	3.58±0.34bAB	14.9±7.40bA
	冬季	8.80±0.09aA	8.61±4.13	17.5±2.16c	2.85±0.74	2.33±0.19cB	14.2±5.46bA
	春季	7.75±0.85bA	8.98±1.41A	19.2±0.78bc	4.46±1.42A	5.05±0.49aA	33.2±10.1aA

采样点	采样时间	pH	ρ（DO）/（mg∙L⁻¹）	t_w/℃	ρ（BOD₅）/（mg∙L⁻¹）	ρ（COD_Mn）/（mg∙L⁻¹）	ρ（叶绿素a）/（μg∙L⁻¹）
R1	夏季	6.62±0.26C	6.09±0.43cB	28.7±0.33aB	1.16±0.07cB	2.86±0.19bC	2.50±0.49bB
	秋季	7.06±0.52B	5.92±0.23cA	22.3±0.52b	1.54±0.27cB	2.60±0.19bB	5.24±1.22bB
	冬季	7.28±0.15C	9.73±0.42a	17.5±3.26c	3.15±0.51b	2.81±0.36bAB	17.8±3.34aA
	春季	6.52±0.71B	7.07±0.06bB	18.6±1.27c	4.30±0.55aA	3.37±0.08aB	2.96±0.21bB
R2	夏季	6.69±0.08cC	3.60±0.13bB	31.4±0.91aA	4.33±0.91aA	6.13±0.68aA	3.49±1.25B
	秋季	7.69±0.20aAB	7.27±0.41aA	22.4±0.90b	1.85±0.73bAB	3.16±0.19bB	1.74±0.54B
	冬季	7.20±0.24bC	8.26±0.63a	19.8±2.77b	3.10±1.37ab	3.36±0.42bA	3.67±1.78B
	春季	7.08±0.28bAB	7.63±0.84aAB	20.0±2.34b	1.56±0.96bB	3.44±0.39bB	3.77±2.24B
R3	夏季	7.70±0.22B	4.48±0.56cB	28.1±1.88aB	1.60±0.32bB	3.32±0.27bcC	3.37±0.67B
	秋季	7.69±0.30AB	3.69±0.37cB	21.9±1.29b	3.30±0.90bA	4.56±1.05abA	2.29±0.64B
	冬季	7.96±0.20B	8.94±0.37a	17.8±3.00b	2.32±0.50b	2.12±0.60cB	3.65±1.02B
	春季	8.15±0.22A	7.85±0.42bAB	18.3±0.70b	5.50±1.78aA	4.98±0.74aA	4.33±2.17B
LC	夏季	9.11±0.16aA	11.4±2.35A	32.7±0.85aA	3.81±0.45A	4.73±0.22aB	33.2±5.15aA
	秋季	7.80±0.06bA	7.48±1.39A	21.9±0.35b	2.38±1.00AB	3.58±0.34bAB	14.9±7.40bA
	冬季	8.80±0.09aA	8.61±4.13	17.5±2.16c	2.85±0.74	2.33±0.19cB	14.2±5.46bA
	春季	7.75±0.85bA	8.98±1.41A	19.2±0.78bc	4.46±1.42A	5.05±0.49aA	33.2±10.1aA

指标	时间差异（季节对比）	空间差异（点位对比）
pH	R2：秋季>冬、春季>夏季；LC：夏、冬季>秋、春季	LC>R1、R2、R3（夏、冬季）
DO	R1、R2、R3：冬季最高；LC：夏季最高	非冬季时，LC最高
t_w	夏季>秋、冬、春季	R2、LC>R1、R3（夏季）
BOD₅	R2：夏、冬季>秋、春季；其他点位：春季最高	R2、LC>R1、R3（夏季）；R1、R3、LC>R2（冬季）
COD_Mn	除R2外，春季普遍偏高	R2>LC>R1、R3（夏季）；R3、LC>R1、R2（春季）
叶绿素a	R1：冬季>夏、秋、春季；LC：夏、春季>秋、冬季	LC>R1、R2、R3（夏、秋、春季）

指标	时间差异（季节对比）	空间差异（点位对比）
pH	R2：秋季>冬、春季>夏季；LC：夏、冬季>秋、春季	LC>R1、R2、R3（夏、冬季）
DO	R1、R2、R3：冬季最高；LC：夏季最高	非冬季时，LC最高
t_w	夏季>秋、冬、春季	R2、LC>R1、R3（夏季）
BOD₅	R2：夏、冬季>秋、春季；其他点位：春季最高	R2、LC>R1、R3（夏季）；R1、R3、LC>R2（冬季）
COD_Mn	除R2外，春季普遍偏高	R2>LC>R1、R3（夏季）；R3、LC>R1、R2（春季）
叶绿素a	R1：冬季>夏、秋、春季；LC：夏、春季>秋、冬季	LC>R1、R2、R3（夏、秋、春季）

点位	夏季		秋季		冬季		春季
点位	z	p	z	p	z	p	z	p
R1	−4.32	0	−3.62	0.002	−2.35	0.114	−3.63	0.002
R3	4.21	0	1.95	0.310	4.18	0	2.57	0.061
LC	1.71	0.528	4.34	0	3.7	0.001	2.61	0.054