Water and sediment pollutions and their changes at the Yellow River mouth

In this paper, the authors report the analysis results of the 3 water samples and 3 sediment samples at the Yellow River mouth and compared them with the historical data. The water quality was evaluated by employing China's Environmental Quality Standard for Surface Water (GB3838-2002). The sediment quality guidelines for waters by the National Oceanographic and Atmospheric Administration (NOAA) of USA are employed to evaluate degree of sediment contamination by the heavy metals and arsenic, and the standards of specific pollutants in sediment of the Technical Rules of the Second Baseline Investigation on Chinese Ocean Pollution (TRSBI) are used to evaluate the sediment contamination by the concentrations of organic material, total nitrogen and total phosphorus. It is found that the waters near the Yellow River mouth are seriously polluted by mercury and nitrogen. The sediment at the Yellow River mouth has not seriously been polluted since the 1970s, but the increased rates of the pollutants are noticeably high. High concentration of nitrogen in waters and high increase rate of nitrogen in sediment at the Yellow River mouth may cause eutrophication and contributes to the frequently occurred red tides events in the Bohai Bay.