摘要
通过分级浸取的方法获得了胶州湾沉积物中不同形态的氮,将可转化态氮分为离子交换态(IEF-N)、弱酸浸取态(WAEF-N)、强碱浸取态(SAEF-N)和强氧化剂浸取态(SOEF-N),讨论了其地球化学特征和控制因素,并结合210Pb测年计算了不同年代氮的埋藏通量。在此基础上,分析了胶州湾沉积物中氮给出的环境信息。结果表明,强氧化剂浸取态氮是胶州湾沉积物中可转化态氮主要赋存形态,NO3-N是胶州湾沉积物中氮的优势形态,氮的含量及埋藏通量的分布受到pH、盐度、温度、生物扰动、沉积物粒度、沉积速率等多种因素的影响。受人为活动的影响,目前每年排入胶州湾的固体垃圾和污水中的悬浮颗粒物的量已超过河流来沙,成为胶州湾主要的沉积物来源。在20世纪初由于污染情况较轻,并且受人为活动的影响较小,胶州湾沉积物各形态氮的埋藏通量较低,但自从20世纪80年代开始,环胶州湾地区的工农业迅猛发展,氮的埋藏通量急剧增加,胶州湾地区的环境一度恶化,但由于近年来采取的较为得力的治污与排放措施,胶州湾的环境状况已有明显改观。
Nitrogen plays an important role in global biogeochemical cycle and may serve as an efficient proxy for marine sedimentary environmental changes. The biogeochemical cycle of nitrogen is a very complicated process and affected by many physical, geochemical, and biological factors. Up till now, the research about nitrogen is mainly focused on the early diagenisis cycle （including mineralization, nitrification, denitrification, and so on） and the benthic flux of nitrogen of sediment-water interface. This research has resulted in a systematic understanding about the nitrogen cycle. However, nitrogen forms, distributions, and its relationship with other biogenic elements in nitrogen cycle have seldomly been involved. This paper presents the nitrogen species employing sequential extraction technique. The transferable nitrogen in Jiaozhou Bay sediments can be divided into four species, namely the ion exchangeable form （IEF-N）, the weak acid extractable form （WAEF-N）, the strong alkaline extractable form （ SAEF-N）, and the strong oxidant extractable form （SOEF-N） according to their different bonding strength to sediments. The geochemical characteristics of nitrogen in Jiaozhou Bay sediments as well as the controlling factors and the environmental significances were given in the paper associated with ^210Pb chronological studies. The results show that the SOEF-N is the primary form of transferable nitrogen and the NO3-N is the dominant form in Jiaozhou Bay sediments. The SAEF-N is the dominant form of inorganic nitrogen. The IEF-N is the most active transferable nitrogen and the WAEF-N accounted for least part of nitrogen in Jiaozhou Bay sediments. The concentrations and burial fluxes of nitrogen were controlled by many environmental factors including pH, salinity, temperature, particle size and etc. Also, nitrogen has some correlation with the phytoplankton and their spatial distributions are similar. Results also present sedimentation rate changes in the past hundred years and the corresponding years
出处
《第四纪研究》
CAS
CSCD
北大核心
2007年第3期347-356,共10页
Quaternary Sciences
基金
国家重点基础研究发展规划项目(批准号:2007CB407305)
中国科学院"百人计划"项目(批准号:科人2003-202)
青岛市科技将才专项计划(批准号:04-3-JJ-03和05-2-JC-90)
中国科学院知识创新重要方向性项目(批准号:KZCX3-SW-214)资助
关键词
氮形态
地球化学特征
环境意义
胶州湾沉积物
nitrogen form, geochemical characteristics, environmental significance, Jiaozhou Baysediments
