水利学报2017，Vol.48Issue(10)：1195-1205,11.DOI:10.13243/j.cnki.slxb.20170478
利用氮氧同位素示踪技术解析巢湖支流店埠河硝酸盐污染源
Using δ15N and δ18O values to identify sources of nitrate in the Dianbu River in the Chaohu Lake Basin
摘要
Abstract
Since nitrate pollution in aquatic system has become an environmental problem in many regions of the world,it is of great importance to identify the sources of nitrate for pollution control To identify dif ferent NO3-sources in surface water and to estimate their proportional contribution to nitrate mixture,a dual isotope approach (δ15N-NO3-and δ18O-NO3-) and a Bayesian model (Stable Isotope Analysis in R,SIAR) were applied for the water of Dianbu River,a tributary of Chaohu Lake,during the period of dry season (January 2016) and flood season (July,2016).Four potential sources (NO3-atmospheric deposi-tion,AD;NO3-derived from soil organic matter nitrification,NS;NO3-derived from chemical fertilizer nitrification NF;NO3 and manure and sewage,M&S) were identified.The results indicate that the different nitrogen fractions in the water possess significant spatial-temporal variability.The average concentrations of total nitrogen(TN) and NO3-N in the up-stream water during the flood season were 4.87 mg/L and 2.73 mg/L respectively,higher than those(3.09 and 1.17 mg/L) during the dry season,while NH4+-N concentrations during the dry season were higher than that during the flood season.TN,NO3--N and NH4+-N concentrations at middle-lower reaches during the flood season were 6.62,3.23 and 1.57 mg/L respectively,signif-icantly lower than those(10.52,4.26 and 3.66 mg/L)during the dry season.Nitrate is the dominant form of inorganic nitrogen,while the ammonium in sewage.The δ15N-NO3-values of water ranged from 3.89‰ to 9.35‰ (with a mean value of 6.38‰) during the dry season,which were higher than those during the flood reason (in the range of 1.98‰-9.12‰o,with a mean value of 5.02‰);however,the δ18O values of NO3-during the flood season (in the range of 5.11‰‰-11.86‰,with a mean value of 9.17‰) were lower than those during the dry season (in the range of 1.46‰-7.53‰,with a mean value of 4.50‰).Manure and sewage,soil N and chemical fertilizer might be the main NO3-polluted sources to the water of Dianbu River.Both chemical and isotope characteristic indicate that denitrification is not the main N cycling pro cess in the study area.Using SIAR,the contribution of each source is apportioned.The source apportionment results showed that the contribution of AD,NS,NF and M&S were 7％-18％,24％-29％,18％-30％ and 28％-48％ respectively.Therefore,it will be more effective to reduce the nitrate pollutant loads of the river to lake by control the agricultural non-point source pollution input at the up-stream of Dianbu River,and the strictly prohibited discharge of domestic sewage from towns,as well as the industrial waste water according to the watershed spatial distribution.关键词
硝酸盐污染/氮氧同位素/SIAR模型/贡献率/店埠河Key words
nitrate pollution/nitrogen and oxygen isotope/SIAR model/contribution rate/Dianbu River分类
资源环境引用本文复制引用
王静,叶寅,王允青,王道中,吕国安,郭熙盛..利用氮氧同位素示踪技术解析巢湖支流店埠河硝酸盐污染源[J].水利学报,2017,48(10):1195-1205,11.基金项目
国家自然科学基金项目(41401308) （41401308）
国家水体污染控制与治理科技重大专项(2015ZX07204-007) （2015ZX07204-007）
安徽省重点实验室绩效评价补助项目(1606c08231) （1606c08231）
安徽省农业科学院院长青年创新基金项目(15b1006) （15b1006）
