| 摘要: |
| 2018年7月对茅尾海主要入海河口区进行现场调查，分别采用二乙酰一肟法和分光光度法测定了表层海水中尿素和各种形态氮的浓度，分析了该海湾尿素的浓度变化、分布特征及溶解态氮的组成，并探讨其来源和分布的影响因素。结果表明：夏季茅尾海尿素的浓度（以N计）分布在0.40～1.13 μmol/dm3范围内，平均浓度为（0.51±0.18） μmol/dm3。钦江入海口区尿素的平均浓度高于茅岭江入海口区，尿素占茅尾海溶解有机氮（DON）的0.8%～10.3%。茅尾海尿素分布特征主要表现为由河口向外海逐渐降低的特点，高值区主要位于河流入海口，陆源输入和海域自身生物地球化学过程是控制茅尾海尿素来源分布的主要影响因素。 |
| 关键词: 海洋化学 溶解有机氮 尿素 分布 影响因素 茅尾海 |
| DOI：10.3969/J.ISSN.2095-4972.2020.02.011 |
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| 基金项目:国家自然科学基金资助项目（41706083，41466001）；广西自然科学基金资助项目（2017GXNSFBA198135，2018GXNSFDA281025）；广西“海洋生态环境”院士工作站能力建设资助项目（桂科AD17129046）；广西珊瑚礁研究重点实验室开放基金资助项目(GXLSCRSCS2018002) |
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| Distribution of urea and its influencing factors in major estuaries of Maowei Sea in summer |
| YANG Bin,NIU Bei-bei,LU Dong-liang,XU Cheng,LAN Wen-lu,NING Zhi-ming |
| (Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf， Beibu Gulf University， Qinzhou 535011， China; Guangxi Laboratory on the Study of Coral Reefs in the South China Sea， Guangxi University， Nanning 530004， China;Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf， Beibu Gulf University， Qinzhou 535011， China; College of Chemistry and Bioengineering， Guilin University of Technology， Guilin 541006， China;Marine Environmental Monitoring Center of Guangxi， Beihai 536000， China) |
| Abstract: |
| Based on the investigation in Maowei Sea area in July， 2018， concentrations of urea and different forms of dissolved nitrogen in surface seawater were determined with diacetyl monoximesemicarbazide hydrochloride method and spectrophotometric method. The concentration variations and distribution characteristics of urea and the components of dissolved nitrogen are studied. The source and influencing factors of urea are also discussed. The results show that the concentration of urea （calculated as nitrogen） in Maowei Sea in the summer ranges from 0.40 to 1.13 μmol/dm3 with an average of (0.51±0.18) μmol/dm3. In the study area， the average concentration of urea in the Qinjiang estuary is higher than that in Maolingjiang estuary. Urea accounts for 0.8%-10.3% of the dissolved organic nitrogen （DON） in Maowei Sea. The concentration of urea in the study area gradually decreases from the estuaries to open waters. High urea concentrations are located in waters near the river mouths. It shows that terrestrial input and biogeochemical process in the sea are the main factors controlling the urea distribution． |
| Key words: marine chemistry dissolved organic nitrogen urea distribution influencing factor Maowei Sea |
