NITROGEN AND PHOSPHORUS POLLUTION OF THE RIVER MOUTHS AROUND THE BOHAI BAY

摘要

Twelve water samples and 24 sediment samples at 19 river mouths were collected and analyzed around Bohai Bay, including Jiyun, New Yongding, Haihe, Dagu, Duliujian, Ziya, Qikou, Majia, Tuhai and the Yellow. This paper reports the analytical results of nitrogen and phosphorus pollution in the water and sediment at the river mouths around the Bay. The nitrogen and phosphorus pollution in water and sediment was evaluated by employing China's Environmental Quality Standard for Surface Water (GB3838-2002) and the standards of specific pollutants in sediment of the Technical Rules of the Second Baseline Investigation on Chinese Ocean Pollution (TRSBI), respectively. The results show that the water and sediment at most of the river mouths are severely polluted by nitrogen and phosphorus, especially near the Haihe River mouth. The nitrogen concentration has been increasing since 1990s while the phosphorus concentration is decreasing. The high concentrations of nitrogen and phosphorus cause eutrophication of the waters. Analysis indicates that the terrestrial pollutants and nutrients are the main cause of red tides frequently occurring in the Bohai Sea.