ASSESSMENT OF AN DUONG LAKE WATER QUALITY IN HAI DUONG PROVINCE USING A WATER QUALITY INDEX AND WATER POLLUTION INDECIES

Abstract

This study was carried out to assess water quality of An Duong lake in Hai Duong province in the period from 2019 to 2020. 12 surface water samples were taken on the lake in rainy season (9/2019) and dry season (2/2020) to analyze water quality parameters. Water quality index (WQI), comprehensive pollution index (CPI) and organic pollution index (OPI) were used to assess water quality of the lake. Pearson, T-test and Cluster analysis were calculated to evaluate the correlation among concentration of pollutants in the lake water and the fluctuation in water quality of the lake over time and space. The results showed that: water quality of the lake in rainy season is still good for domestic use. However, in dry season, water quality is polluted by the parameters of TSS, PO₄^3-, NH₄⁺, COD and BOD₅. There is a difference in water quality of the lake over time and space. In which, the process of diluting concentration of pollutants in rainy season and increasing the waste of birds and storks in dry season are two factors that lead to water quality of the lake in the rainy season better than in the dry season. According to space, water quality of the lake is divided into points with little fluctuation and fluctuation. This division depends on the distribution of waste sources around the lake and the location of culverts that drain water into the lake.