《厦门大学学报（自然科学版）》

选取非雨季(2018年11月)和雨季(2019年4月)对闽江感潮河段7个断面进行水样采集,研究不同季不同形态氮的时空分布规律,采用相关性分析及主成分分析并结合2016—2019年来水情况,深入探讨不同季氮组分分布及转化的影响因素.结果表明:1)非雨季盐水入侵明显,各理化指标盐度、温度、pH和溶解氧的波动均强于雨季.2)非雨季上游NH4+-N低于雨季,下游则高于雨季,而非雨季NO3--N和总氮(TN)总体均高于雨季.从上游到下游,非雨季NH4+-N变化波动较大,NO3--N平缓而TN呈轻微上升; 雨季NH4+-N、NO3--N和TN变化均较平缓.3)相关性分析表明非雨季的氮转化活跃.雨季NH4+-N浓度是影响TN浓度的主要因素.结合主成分分析及长期上游来水氮的污染负荷发现,人为排放和各形态氮的相互转化是非雨季不同形态氮变化的主要因素,雨季水体反硝化对不同形态氮的分布发挥重要作用,而上游来水的氮污染负荷对不同形态氮的浓度影响较小.

Objective s: Elevated nitrogen (N) concentrations in estuarine ecosystems have led to significant eutrophication. The coastal environments are under great threats due to the N input from the upstream. The study of aquatic N speciation and transformation processes in different seasons could provide important scientific support to management efforts aimed at the N reduction in estuarine areas. Methods : Two field surveys in the Minjiang River tidal reach were conducted to investigate the spatiotemporal distributions of different species of nitrogen during a non-monsoon season (November, 2018) and a monsoon season (April, 2019), respectively with a total of 7 cross-sections. Then, the influencing factors of nitrogen distribution in different seasons were explored using Pearson’s correlation analysis, principal component analysis and historical water data of the upstream environment from 2016 to 2019. Results : The salinity, temperature, pH and dissolved oxygen (DO) were 0.04-6.27, 19.9-21.9 ℃, 6.90-7.90 and 5.96-10.70 mg/L, respectively in the non-monsoon season and 0.02-0.64, 19.8-21.9 ℃, 6.98-7.20 and 6.01-7.80 mg/L, respectively in the monsoon season. The results showed that salinity intrusion was stronger in the non-monsoon season than in the monsoon season, which caused salinity, temperature, pH and DO to fluctuate more significantly in the non-monsoon season. As for different nitrogen species, the NH4+-N concentration in the non-monsoon season and monsoon seasons were 0.11-0.78 mg/L and 0.16-0.45 mg/L, respectively, while the NO3--N were 1.23-2.11 mg/L and 0.93-1.15 mg/L, and the total nitrogen (TN) were 1.74-3.37 mg/L and 1.50-2.37 mg/L, respectively. The upstream (i.e. stations S1-S3) NH4+-N concentration in the non-monsoon season was lower than in the monsoon season, while an opposite trend was present in the downstream (i.e. stations S4-S7). However, the NH3--N and total nitrogen (TN) concentrations in the whole river reach in the non-monsoon season were higher than in the monsoon season. From the upstream to the downstream, the NH4+-N concentration fluctuated significantly, the NO3--N concentration kept the same level, and TN increased slightly in the non-monsoon season. In the monsoon season, the concentrations of all nitrogen species (NH4+-N, NO3--N and TN) changed slightly. Finally, the correlation analysis suggested that the nitrogen transformation was active in the non-monsoon season. In the monsoon season, the NH4+-N concentration was the key factor controlling the fluctuation of the TN concentration. Combined with the principal component analysis and upstream inflow nitrogen pollution load, anthropogenic discharge and the nitrogen cycle in different nitrogen species were the main factors of nitrogen species distribution in the non-monsoon season, while in the monsoon season denitrification process played an important role in controlling the distribution of different nitrogen species. The upstream inflow nitrogen pollution load had little influence on the concentration of different nitrogen species. Conclusion s: Our field investigations showed that the non-monsoon season and monsoon season had a profound impact on aquatic N speciation and transformation processes in different reaches of the tidal river water. The saline water would intrude upstream during the non-monsoon, which led to a larger variation in the physicochemical indexes in the research area. Besides, the low temperature water from the upstream reservoir was the main influencing factor for the N changes during the monsoon season. Our results demonstrated the spatiotemporal distribution and influencing factors of different forms of nitrogen during the non-monsoon and monsoon seasons in the Minjiang River tidal reach. Compared with other estuarine ecosystems, nitrification process dominated the transformation of different forms of N during the monsoon season, which provided an important theoretical benchmark in the water environment protection and improvement under different hydrodynamic conditions and technical support to explore N cycling in the tidal river reach.

引言
1 材料与方法
2 结果与讨论
3 结论

图1 研究区域采样点示意图<br/>Fig.1 Sampling sites in research area

图1 研究区域采样点示意图
Fig.1 Sampling sites in research area

图2 非雨季(a～d)和雨季(e～h)水体理化性质时空分布<br/>Fig.2 Spatiotemporal distribution of physiochemical characteristics in non-monsoon(a-d)and monsoon(e-h)seasons

图2 非雨季(a～d)和雨季(e～h)水体理化性质时空分布
Fig.2 Spatiotemporal distribution of physiochemical characteristics in non-monsoon(a-d)and monsoon(e-h)seasons

图3 非雨季(a～c)和雨季(d～f)不同形态氮的时空分布<br/>Fig.3 Spatiotemporal distribution of different nitrogen speciation in non-monsoon(a-c)and monsoon(d-f)seasons

图3 非雨季(a～c)和雨季(d～f)不同形态氮的时空分布
Fig.3 Spatiotemporal distribution of different nitrogen speciation in non-monsoon(a-c)and monsoon(d-f)seasons

$表1 闽江感潮河段水体氮指标与其他河流水体氮指标质量浓度<br/>Tab.1 The mass concentrations of nitrogen fractionation in the water of the Minjiang River tidal reach and other river water body$

表1 闽江感潮河段水体氮指标与其他河流水体氮指标质量浓度
Tab.1 The mass concentrations of nitrogen fractionation in the water of the Minjiang River tidal reach and other river water body

$表2 非雨季不同形态氮及理化指标的相关性分析<br/>Tab.2 Correlation analysis for nitrogen fractionation and physicochemical indexes in non-monsoon season$

表2 非雨季不同形态氮及理化指标的相关性分析
Tab.2 Correlation analysis for nitrogen fractionation and physicochemical indexes in non-monsoon season

$表3 雨季不同形态氮及理化指标的相关性分析<br/>Tab.3 Correlation analysis for nitrogen fractionation and physicochemical indexes in monsoon season$

表3 雨季不同形态氮及理化指标的相关性分析
Tab.3 Correlation analysis for nitrogen fractionation and physicochemical indexes in monsoon season

表4 非雨季和雨季的主成分分析<br/>Tab.4 Principal component analysis in non-monsoon and monsoon seasons

表4 非雨季和雨季的主成分分析
Tab.4 Principal component analysis in non-monsoon and monsoon seasons

图4 2016—2019年研究区域上游来水月均流量<br/>Fig.4 Upstream discharge changes of research area from 2016 to 2019

图4 2016—2019年研究区域上游来水月均流量
Fig.4 Upstream discharge changes of research area from 2016 to 2019

图5 2016—2019年研究区域上游来水NH4+-N和TN的污染负荷<br/>Fig.5 Pollution fluxes of NH4+-N and TN in the upstream of research area from 2016 to 2019

图5 2016—2019年研究区域上游来水NH4+-N和TN的污染负荷
Fig.5 Pollution fluxes of NH4+-N and TN in the upstream of research area from 2016 to 2019

表5 2016—2019年研究区域非雨季和雨季上游来水的NH4+-N和TN污染负荷和质量浓度对比<br/>Tab.5 Comparison of pollution fluxes and mass concentration of NH4+-N and TN between non-monsoon and monsoon season in the upstream of research area from 2016 to 2019

表5 2016—2019年研究区域非雨季和雨季上游来水的NH4+-N和TN污染负荷和质量浓度对比
Tab.5 Comparison of pollution fluxes and mass concentration of NH4+-N and TN between non-monsoon and monsoon season in the upstream of research area from 2016 to 2019

[1] 王菊英,郑楠,马德毅.近海生态系统的人为营养盐输入及其控制对策浅析[J].海洋学报,2020,42(6):1-8.
[2] 陈慧敏,孙承兴,仵彦卿.近23 a来长江口及其邻近海域营养盐结构的变化趋势和影响因素分析[J].海洋环境科学,2011,30(4):551-553,563.
[3] SMOLDERS E,BRANS K,COPPENS F,et al.Potential nitrification rate as a tool for screening toxicity in metal-contaminated soils[J].Environmental Toxicology Chemistry,2010,20(11):2469-2474.
[4] SEITZINGER S P.Denitrification in freshwater and coastal marine ecosystems:ecological and geochemical significance[J].Limnology Oceanography,1988,33(4part2):702-724.
[5] MIDDELBURG J J,NIEUWENHUIZE J.Nitrogen uptake by heterotrophic bacteria and phytoplankton in the nitrate-rich Thames Estuary[J].Marine Ecology Progress,2000,203(1):13-21.
[6] 陶怡乐,温东辉.细菌硝酸盐异化还原成铵过程及其在河口生态系统中的潜在地位与影响[J].微生物学通报,2016,43(1):172-181.
[7] HU J W,ZHANG H L,LI L,et al.Seasonal changes of organic matter origins and anammox activity in the Changjiang Estuary deduced from multi-biomarkers in suspended particulates[J].Science China Earth Sciences,2016,59(7):1339-1352.
[8] 龚骏,张晓黎.微生物在近海氮循环过程的贡献与驱动机制[J].微生物学通报,2013,40(1):44-58.
[9] 郑群威,苏维词,杨振华,等.乌江流域水环境质量评价及污染源解析[J].水土保持研究,2019,26(3):204-212.
[10] 于淼,魏源送,郑祥,等.温榆河水化学特征演变及其影响因素分析[J].环境科学学报,2012,32(1):1-8.
[11] 卢少勇,焦伟,王强,等.环太湖河流水质时空分布特征[J].环境科学研究,2011,24(11):1220-1225.
[12] 程学宁,卢毅敏.基于SOM和PCA的闽江流域地表水水质综合评价[J].水资源保护,2017,33(3):59-67.
[13] 胡文,李春华,叶春,等.生态模型在水体富营养化研究领域的应用进展[J].环境科学研究,2020,33(2):349-362.
[14] 方涛,敖鸿毅,刘剑彤,等.滇池水体理化环境状况时空分布格局研究[J].水生生物学报,2004(2):124-130.
[15] 苏斌,史正涛,叶燎原,等.宝象河雨季径流过程氮素输移特征及来源示踪[J].环境化学,2019,38(3):686-696.
[16] 谢婷婷,陈芸芝,卢文芳,等.面向 GF-1 WFV 数据的闽江下游叶绿素 a反演模型研究[J].环境科学学报,2019,39(12):4276-4283.
[17] 奚姗姗,周春财,刘桂建,等.巢湖水体氮磷营养盐时空分布特征[J].环境科学,2016(2):542-527.
[18] 刘明清,刘志刚,赵肖,等.盐度对河口区水体中NH3-N降解的影响研究[J].环境污染与防治,2014,36(9):47-49.
[19] XIE R R,PANG Y,LUO B R,et al.Spatiotemporal variability in salinity and hydraulic relationship with salt intrusion in the tidal reaches of the Minjiang River,Fujian Province,China[J].Environmental Science and Pollution Research,2017,24(12):11847-11855.
[20] REISINGER A J,GROFFMAN P M,ROSI-MARSHALL E J.Nitrogen-cycling process rates across urban ecosystems[J].FEMS Microbiology Ecology,2016,92(12):fiw198.
[21] 中华人民共和国生态环境部.2019中国生态环境状况公报[R/OL].(2020- 06- 02)[2021- 05-28].http:∥www.mee.gov.cn/hjzl/sthjzk/zghjzkgb/.
[22] 魏姗姗.福建省主要江河入海口水质状况及其变化趋势研究[J].环境科学与管理,2014,39(10):37-42.
[23] 鹿世瑾.福建气候[M].北京:气象出版社,1999.
[24] 环境保护部科技标准司.水质氨氮的测定纳氏试剂分光光度法:HJ 535—2009[S].北京:中国环境科学出版社,2009.
[25] 环境保护部科技标准司.水质硝酸盐氮的测定紫外分光光度法(试行):HJ/T 346—2007[S].北京:中国环境科学出版社,2007.
[26] 环境保护部科技标准司.水质总氮的测定碱性过硫酸钾消解紫外分光光度法:HJ 636—2012[S].北京:中国环境科学出版社,2012.
[27] 薛刚.黄河上游大型水库水温数值模拟及下泄低温水研究[D].西安:西安理工大学,2019.
[28] 严登华,邓伟,何岩.图们江水系天然水体pH值变化特征及成因分析[J].农业环境保护,2001(1):4-6.
[29] ZHANG P,PANG Y,SHI C C,et al.Analysis and numerical simulation of natural and human-caused low dissolved oxygen in the Minjiang River Estuary[J].Water Science Technology,2016,73(10):2475-2485.
[30] 侯昱廷,高爱国,林建杰,等.闽江河口营养盐的季节变化及混合行为[J].厦门大学学报(自然科学版),2016,55(4):540-546.
[31] BILLEN G,SOMVILLE M,DE BECKER E,et al.A nitrogen budget of the Scheldt hydrographical basin[J].Netherlands Journal of Sea Research,1985,19(3/4):223-230.
[32] NELSON W G.An evaluation of factors controlling the abundance of epiphytes on Zostera marina along an estuarine gradient in Yaquina Bay,Oregon,USA[J].Aquatic Botany,2018,148:53-63.
[33] 洪小筠.闽江下游感潮河段水污染特性分析[J].水利科技,2010(3):4-5,16.
[34] CHOI O,HU Z.Size dependent and reactive oxygen species related nanosilver toxicity to nitrifying bacteria[J].Environmental Science Technology,2008,42(12):4583-4588.
[35] 张雷,曹伟,马迎群,等.大辽河感潮河段及近岸河口氮、磷的分布及潜在性富营养化[J].环境科学,2016,37(5):1677-1684.
[36] 张继民,刘霜,张琦,等.黄河口附近海域营养盐特征及富营养化程度评价[J].海洋通报,2008(5):65-72.
[37] 党二莎,唐俊逸,周连宁,等.珠江口近岸海域水质状况评价及富营养化分析[J].大连海洋大学学报,2019,34(4):580-587.
[38] 张万磊,张永丰,张建乐,等.北戴河赤潮监控区营养盐变化及富营养化状况分析[J].海洋湖沼通报,2014(1):143-147.
[39] UNCLES R J,HOWLAND R J M,EASTON A E,et al.Seasonal variability of dissolved nutrients in the Humber-Ouse Estuary,UK[J].Marine Pollution Bulletin,1999,37(98):234-246.
[40] SHILLER A M.A mixing rate approach to understanding nutrient distributions in the plume of Mississippi River[J].Marine Chemistry,1993,43(1/2/3/4):211-216.
[41] FALCO S,NIENCHESKI L F,RODILLA M,et al.Nutrient flux and budget in the Ebro Estuary[J].Estuarine Coastal Shelf Science,2010,87(1):92-102.
[42] DAVIS J C,SAMPSON R J.Statistics and data analysis in geology[M].New York:Wiley,1986.
[43] VAROL M,瘙塁EN B.Assessment of surface water quality using multivariate statistical techniques:a case study of Behrimaz Stream,Turkey[J].Environmental Monitoring Assessment,2009,159(1/2/3/4):543.

备注

引言

1 材料与方法

2 结果与讨论

3 结论

学报简介

备注

引言

1 材料与方法

2 结果与讨论

3 结 论

学报简介

3 结论