CAJ | 학술논문

地表水和地下水中硝酸盐污染已成为重要的环境问题之一.随着对全球变暖的贡献增加,N2O(氧化亚氮)也得到IPCC越来越多的关注.反硝化在水生生态系统氮循环过程中起着极为重要的作用.反硝化过程中,厌氧细菌将硝酸盐转化成可溶性亚硝酸盐,最终以N2形式排放到大气.为理解自然湿地生态系统的脱氮机理,以日本千叶县的越智小流域为例开展研究.沿地下水流动方向取原状土,包括2个非饱和带点和2个饱和带点.用乙炔抑制法和带ECD检测器的气相色谱仪于0,2,6,12,2 4h测定土壤反硝化能力.同时分析土壤全碳、全氮和反硝化细菌.结果发现,饱和带的反硝化能力高于非饱和带.乙炔抑制后,N2O排放从0-l.17 g Nm-2h-1,前6h增至最大,随后降低.
지표수화지하수중초산염오염이성위중요적배경문제지일.수착대전구변난적공헌증가,N2O(양화아담)야득도IPCC월래월다적관주.반초화재수생생태계통담순배과정중기착겁위중요적작용.반초화과정중,염양세균장초산염전화성가용성아초산염,최종이N2형식배방도대기.위리해자연습지생태계통적탈담궤리,이일본천협현적월지소류역위례개전연구.연지하수류동방향취원상토,포괄2개비포화대점화2개포화대점.용을결억제법화대ECD검측기적기상색보의우0,2,6,12,2 4h측정토양반초화능력.동시분석토양전탄、전담화반초화세균.결과발현,포화대적반초화능력고우비포화대.을결억제후,N2O배방종0-l.17 g Nm-2h-1,전6h증지최대,수후강저.
Nitrate contamination has become one of the most important issues for surface water and groundwater.N2O,with an increasing contribution to global warming,has been more and more attention by the IPCC recently.As well known,denitrification plays a major role in nitrogen cycle of aquatic ecosystems and operates at rates far below its potential under proper conditions.Sediments are the single largest pool of nitrogen in wetland ecosystems.During this process,facultative anaerobic bacteria transform nitrite into nitrogen gas which dissolves in the groundwater and diffuses into the atmosphere finally when it shows up with seepage or spring in the wetland.To seek a mechanistic understanding of N removal in natural wetland ecosystem,a case study was carried in terms of denitrification rate at the Ochi catchment,Chiba,Japan.In this study,samples of intact soil cores in 0-20cm were taken along the groundwater flow path,which including 2 samples in the unsaturated zone and 2 in saturated wetland ecosystem.Denitrification capacity of soil was quantified using acetylene (C2H2) inhibition/gas chromatography ECD method with time intervals of 0,2,6,12,24 h.Total-N and Total-C contents and amount of denitrifying bacteria were also analyzed.It is found that denitrification ability is low for all 2 samples in the unsaturated zone and high in saturated zone.Results show that N2O emission flux after C2H2-inhibition ranges from 0 to 1.17 gN m-2h-1,with an increase value prior 6 hours and slow down after that.