珠江口水域化学耗氧量(COD)的分布特征

Distribution Feature of COD in the Waters of Pearl River Estuary

2002年5月和8月对珠江口伶仃洋水域水质化学耗氧量(COD)进行了调查研究,结果表明:该水域近期COD含量变幅在0.41～2.72mg/L之间,平均值为1.21mg/L;区域分布呈北部向南部水域逐渐递减以及近岸水域含量大于远岸的变化趋势;夏季COD的含量高于春季;以我国Ⅰ类海水水质COD含量≤2mg/L标准评价,超标率为15%;COD含量与同期(春、夏季)的悬浮物含量呈正相关性,与无机氮和活性磷酸盐含量在夏季呈负相关性。

The survey on the contents of COD in the waters of Pearl River estuary was carried out.in May and August of 2002, The result showed the content of COD in the waters ranged from 0.41 to 2.72mg·L^-1 with an average of 1.21mg·L^-1. The spatial distribution showed that COD was gradually decreased from north to south, with a content in the coastal waters was higher than in the offshore waters. Evaluated by the standard of first class seawater quality in the nation （COD〈2mg/L）, the exceeding rate reached to 15%.The content of COD in summer was higher than that in spring, and the positive correlation with the content of the suspending substance in the corresponding period, but in summer it showed a negative correlation with the contents of inorganic nitrate and active phosphate. As viewed from the content of COD, the water quality in the waters of Pearl River estuary was in the second class for the seawater quality set by the national standard.