天津港南部海区水体中活性磷酸盐的分布特征

Distribution of active phosphate content in the southern sea area of Tianjin Harbor

根据2006年3月天津港南部海域水体活性磷酸盐的调查数据,对该区水体中活性磷酸盐的分布特征进行了分析,并与2003年4月的调查数据进行了对比,研究了该海域磷营养元素的地球化学特征及其反映的环境意义。结果表明,磷酸盐超标率2003年4月为23.8%,2006年3月为60%,2006年3月的活性磷酸盐含量总体上高于2003年4月的,虽然在第一类环境功能区站位2006年超标率有所降低,但第二类、第三类环境功能区站位在2006年3月均出现超标现象。超标可能是由于陆源废水和养殖废水的排放使该区域营养盐结构发生变化所致。活性磷酸盐的浓度由岸向海递减,等值线几乎与海岸线平行,这与调查海域受潮汐和陆源河流输入有很大关系。

The present paper is concerned with the measurement and analysis of the actual phosphate content distribution in the air of the southern sea area of Tianjin Harbor during March, 2006. The paper also analyze and contrast the analysis results with the data of the content distribution measured in April, 2003. Based on its findings, the paper analyzes the geochemical features and the environmental significance of the phosphate in the area. The above comparison and contrast results show that the excessive ratio of the phosphate content in April, 2003, was 23.8% whereas that of March, 2006 was 60%. Thus, it can be inferred that the distribution of the active phosphate content in March, 2006, is much higher than that in April 2003. Although the content in the first environment function area falls, the content both in the second and the third environment function area are beyond the state standard. The likely reason for the difference is that the nutrient distribution in these areas has been disturbed by wastewater discharge from the terrestrial industries and breed aquatics. Due to the tidal current and the fiver water interference, the concentration of the phosphate content can be lowered from the alongshore to the sea, and the isoline of the active phosphate distribution still remains almost parallel to that of the coastline.