Nội dung bài viết trình bày kết quả nghiên cứu cho thấy, các thông số thủy lý, hóa học của nước tại cửa Ba Lạt có giá trị thay đổi theo mùa: Nhiệt độ trung bình của nước mùa mưa cao hơn 2,5oC so với mùa khô; pH trung bình mùa mưa (7,45 ± 0,36) cao hơn so với mùa khô (7,01 ± 0,17). Các thông số như độ dẫn điện, độ muối, NO3-N, NH3-N, PO4-P, dầu mỡ tổng số, Fe và Zn trong mùa khô đều cao hơn so với mùa mưa từ 1,22 đến 2,92 lần. Nồng độ một số muối dinh dưỡng (NO3-N; NH3-N; PO4-P; SiO3-Si), kim loại nặng (Fe, Zn) và dầu mỡ tổng số ở mức cao. | Vietnam Journal of Marine Science and Technology Vol. 20 No. 1 2020 51 59 DOI https 1859-3097 20 1 12892 http jmst Water quality of Ba Lat estuary Bui Thi Hoa1 2 Nguyen Xuan Huan1 2 Nguyen Thanh Nam1 2 Le Thu Ha1 2 1 Faculty of Biology VNU University of Science Hanoi Vietnam 2 Center for life Science Research VNU University of Science Hanoi Vietnam E-mail hoatb82@ Received 24 December 2018 Accepted 12 June 2019 2020 Vietnam Academy of Science and Technology VAST Abstract Ba Lat estuary is the large mouth of the Red river every year the Ba Lat estuary receives million cubic meters of water before the water is dissolved in the sea. Therefore polluted materials in the water from the continent are also transported to the sea through the estuary. However the volume of the water pouring into the sea varies with the season. In this paper the water quality at Ba Lat estuary Red river was surveyed in July 2017 representing the Southwest wind season rainy season and in October 2017 representing the Northeast wind season dry season . The research results show that the values of chemical parameters of water at Ba Lat estuary changed according to the season the average temperature of water in the rainy season was higher than in the dry season average pH in the rainy season was higher than that in the dry season . Parameters such as conductivity salinity NO 3-N NH3-N PO4-P total grease Fe and Zn in the dry season were times higher than in the rainy season. Concentration of some nutrition including NO3-N NH3-N PO4-P and SiO3-Si heavy metals Fe Zn and total grease in the water were high in which NO3-N ranged from mg l to mg l NH 3-N ranged from mg l to mg l to times higher than the standard of Vietnam. PO 4-P ranged from mg l to mg l which was 2 to times higher than the standard. SiO 3-Si ranged from mg l to mg l. Iron concentration in .
