ẢNH HƯỞNG pH ĐẾN QUÁ TRÌNH GIẢI PHÓNG KIM LOẠI NẶNG (Cu, Pb, Zn) TRONG TRẦM TÍCH CỬA SÔNG SOÀI RẠP, SÔNG SÀI GÒN- ĐỒNG NAI

Tóm tắt

The Soai Rap estuary of the Sai Gon - Dong Nai river systemis located at the intersection of Can Gio,Can Giuoc, and Go Cong Dong districts and is one of the bigest rivers in Vietnam. Soai Rap estuary isconsidered to have the high biodiversity, especially commercial activities of oysters. However, pH levelcan be changed in the Soai Rap estuary due to human activities and climate change. Therefore, thisstudy investigated the effect of pH levelson mobilzation of Cu, Pb and Zn from sediments at the studiedsites of Soai Rap estuary. The results showed that the Zn, Cu and Pb releases significantly increased atvery low pH level (pH = 2) (44% for Zn; 23.6% for Cu and 10.2 % for Pb) and decreased at high pH(pH = 6-9). The results also recommended that the oysters farming in Soai Rap might be adverselyaffected by Cu and Zn contamination in sediment, especially for early life stage of oysters. Zn may alsohave effects on the development of oyster larvae only when pH level decreased suddenly to the lowerthan 4. The distribution coefficients,(Kd) showed higher the mobility potential of Cu and Zn than thatof Pb.Keywords: sediment, pH, Cu, Pb, Zn