| 摘要: |
| 珠江口是生态敏感的典型河口区，也是富营养化和赤潮多发区。为了搞清楚该区域沉积物中营养物质的含量及平面分布特征，进一步研究营养盐在沉积物-水体间的循环机制,同时也为珠江口污染防治和生态环境保护提供科学依据，对珠江口16个站位的表层沉积物中氮、磷的形态、含量及分布特征进行了研究。其中总氮用凯氏定氮法测定，无机氮提取后直接测定各形态含量,各种形态的磷采用化学分步提取法进行。提取液中硝酸盐氮用锌-镉还原法，亚硝酸盐氮用重氮-偶氮比色法，氨氮用靛酚蓝法，无机磷酸盐用磷钼蓝法测定。沉积物中TOC的测定用重铬酸钾氧化-还原滴定法。在测定结果的基础上采用单项指标标准指数法对沉积物中氮和磷的污染程度进行了评价。研究结果表明：沉积物中总氮的含量较高，平均值高达1649 mg/kg；有机氮所占的比例很高，平均达83.17%，平均含量为1374 mg/kg；氨氮是无机氮的主要形式，平均占无机氮的98%，平均含量为209.64 mg/kg；硝酸盐氮和亚硝酸盐氮在沉积物无机氮中比例很低，平均值为54.87 mg/kg。表层沉积物中总磷的含量平均值为455.94 mg/kg；有机磷占总磷含量的39.41%，平均含量为179.69 mg/kg；铁结合磷和铝结合磷平均含量为94.97 mg/kg。在平面分布上，各站间不同形态氮、磷的含量差异与陆源输入、沉积物粒径及水动力条件等因素有关。单项指标标准指数法对沉积物中氮和磷的污染评价结果表明：珠江口沉积物中总磷含量较低，标准指数都小于1；而总氮的含量较高，其标准指数变化范围为1.96-3.86， 说明珠江口沉积物环境质量受氮的污染相对严重。 |
| 关键词: 氮 磷 形态 分布特征 沉积物 珠江口 |
| DOI： |
| 分类号: |
| 基金项目:中国科学院知识创新工程项目,KSCX2-SW-102号;广东省重大科技项目,A200099F01号、A3050301号 |
附件 |
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| DISTRIBUTION AND POLLUTION OF NITROGEN AND PHOSPHORUS IN SURFACE SEDIMENTS FROM THE PEARL RIVER ESTUARY |
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YUE Wei-Zhong, HUANG Xiao-Ping, SUN Cui-Ci
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The LED,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou,510301
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| Abstract: |
| The Pearl River Estuary is a typical estuary with susceptibility in environmental ecological factors, suffering frequently from eutrophication and red tide. To understand the spatial distribution of nitrogen and phosphorus, and the mechanism of nutriment cycle from sediment to seawater, 16 samples were collected from the estuary surface sediments, for determining the concentration and forms of the nutrients and other metals. Single standard index method was used to assess the pollution of nitrogen and phosphorus in sediment. The results indicate that the content of total nitrogen was relatively higher in the surface sediment in average of 1649 mg/kg, in which 83.17% was organic nitrogen that averaged at 1374 mg/kg. NH4-N was the main form of inorganic nitrogen in average of 209.64 mg/kg, with minor NO3-N and NO2-N together at 54.87 mg/kg. The mean content of total phosphorus was 455.94 mg/kg in surface sediment, in which organic one took 39.41% at 179.69 mg/kg. The mean content of Fe-P and Al-P was 94.97 mg/kg. The contents of different forms of nitrogen and phosphorus in different sites were mainly influenced by terrigenous inputs, sediment grain size and hydro-dynamics. All the single standard indexes of total phosphorus were below 1, indicating that the content of the total phosphorus was relatively low. However, the content of total nitrogen was high, the standard indexes ranged from 1.96 to 3.86, which indicated that the nitrogen pollution was relatively serious. |
| Key words: Nitrogen, Phosphorus, Form, Distribution characteristic, Sediment, The Pearl River Estuary |
