Abstract:
BACKGROUNDWith the rapid development of China's coastal economy, the intensity of human activity is increasing. The disturbance and damage to the marine ecosystem are becoming increasingly serious. In order to understand the water quality of the coastal waters of Haizhou Bay, the survey of surface seawater quality in Haizhou Bay was carried out in April and September, 2016. Hydrochemistry factors including temperature, salinity, pH, SS, DO, CODMn, NO2--N, NO3--N, NH4+-N, PO43--P, Cu, Pb, Zn, Cd and oils were surveyed.
OBJECTIVESTo explore the spatial and temporal distribution characteristics and pollution level in the coastal waters of Haizhou Bay.
METHODSThe indexes were analyzed by spectrophotometry and inductively coupled plasma-mass spectrometry. Based on the single factor method, evaluation mode of eutrophication and organic pollution index, the water quality has been evaluated.
RESULTSThe average value of CODMn in the surface seawater of the study sea area was 1.34mg/L in April and 1.22mg/L in September. The average value of petroleum in April was 0.031mg/L, and that in September was 0.034mg/L. The average value of active phosphate was 0.013mg/L in April and 0.012mg/L in September. The average value of dissolved inorganic nitrogen in April was 0.34mg/L and in September was 0.16mg/L. The concentrations of CODMn, petroleum, active phosphate and dissolved inorganic nitrogen showed the decreasing trend from the southwest to the northeast. Moreover, the overall concentration of inorganic nitrogen was higher, which was the main pollutant in the sea area.
CONCLUSIONSAccording to the eutrophication evaluation model and the results of organic pollution index calculation, this study demonstrates that the overall nutrient level of surface water quality in the coastal waters of Haizhou Bay is relatively high, and it reaches the potential eutrophication level of nitrogen limitation. The degree of organic pollution belongs to GradeⅡ, indicating the level of pollution in the water.