Arsenic Pollution Characteristics and Variation Trends in Yangzonghai Lake, China

Abstract

In order to ascertain the status quo and variation trend of arsenic pollution in Yangzonghai Lake, China, the water samples of Yangzonghai Lake, sediment and interstitial water were collected and the total amount and morphological composition of arsenic were determined. The spatial distribution of arsenic was analyzed and the variation trends of arsenic pollution was evaluated. The results showed that the arsenic content of lake water in December 2016 was between 0.029-0.036 mg/L. The arsenic content in interstitial water is generally lower than 0.005 mg/L. The average content of arsenic in 0-2, 2-4, 4-6, 6-8 cm sediments are 50.5 mg/kg, 40.1 mg/kg, 33.6 mg/kg and 32.5 mg/kg, respectively. The high arsenic area is mainly distributed in the north and south shores, and gradually decreases from the coastal areas to the lake center. As the depth increases, arsenic content in the sediment gradually decreases. The arsenic in the sediment is still mainly in residual fraction, followed by organic fraction and oxide fraction. With the passage of time, the arsenic in the sediment gradually transforms from oxide fraction and organic fraction to residual fraction. The release of arsenic in the sediment is limited and the ecological risk is minimal.