长江口南槽水域污染物迁移和分布规律

Study on the distribution and transport of pollutants in the South Channel of the Yangtze River Estuary

经对长江口南槽水域水质指标监测表明 ,在近岸带 ,水体中悬浮颗粒吸附态磷和各种重金属的浓度较低 ,而氨氮、硝氮和总溶解态磷的浓度明显偏高 ;在南槽主航道至九段沙水域 ,水体中悬浮颗粒吸附态磷和各种重金属的浓度明显增加。水体中溶解态磷的浓度很低 ,磷的赋存形态以悬浮颗粒吸附态磷为主 ,水体中重金属元素的赋存形态也以悬浮颗粒吸附态为主。落潮时的悬浮颗粒、TP、悬浮颗粒吸附态磷和重金属总浓度明显高于涨潮。

The water quality of the South Channel of the Yangtze River Estuary was monitored. The results are as follows: (1) The water in the alongshore area contains low contents of particular phosphorus (PP) and heavy metals, but high contents of ammonium nitrogen, nitrate nitrogen and total soluble phosphorus (TSP). However, in the area between the main sea-route and the Jiuduan Shoal, the water contains high contents of PP and heavy metals. (2) With low content of soluble reactive phosphorus (SRP), PP is the main form of phosphorus in the water. Most of heavy metals in the water are also adsorbed by suspended particulates (SS); moreover, there are significant correlations between the heavy metals in the water, indicating their similar geochemical behaviours. (3) Contents of SS, total phosphorus (TP), PP and heavy metals in the ebb tides are significantly higher than those in the flood tides. It is because the South Channel mainly accept the currents with high contents of SS and pollutants from the Yangtze River during the ebb tide period; during the flood tide period, however, the pollutants in the water are diluted and partially deposited with SS because of the invasion of the tides from the outside sea.