Research of Physicochemical Environment and Water Quality in Miaodao Archipelago

Abstract

This study conducted four voyages of the surface of the waters of the Miaodao Archipelago in August 2018, October 2018, March 2019 and June 2019. In the seawater quality survey, 100 stations were set up to analyze the distribution of physicochemical parameters such as water temperature, pH, dissolved oxygen, chemical oxygen demand, dissolved inorganic nitrogen, PO4-P, total nitrogen, total phosphorus, petroleum hydrocarbons. The nutritional status and organic pollution status of the sea area were evaluated. The results showed that the mean value of water temperature was (16.8±5.69)℃, the average pH was 8.13±0.074, the average DO concentration was (8.62±1.46) mg/L, the average COD concentration was (0.85±0.29) mg/L, the average DIN concentration was (0.0706±0.0545) mg/L, the average PO4-P concentration was (0.0706±0.0545) mg/L, the average TN concentration was (0.255±0.148) mg/L, and the average TP concentration was (0.0133± 0.00639) mg/L, the average concentration of petroleum hydrocarbons was (0.0135±0.00755) mg/L. The physical and chemical parameters of the waters of the Miaodao Archipelago basically meet the Class II seawater quality standards. The water quality eutrophication index of the monitoring station in the sea area is basically < 1, and the nutritional status of the sea area is basically poor nutrition. The water quality of the sea area was evaluated by the organic pollution evaluation index method, and the water quality level of 96% of the monitoring stations in the four months was good.

Keywords

• miaodao archipelago
• physicochemical parameter
• nutrition status
• organic pollution