Authors: Ngoc Nguyen*, University of Denver
Topics: Water Resources and Hydrology, Urban Geography, Asia
Keywords: heavy meal pollution, To Lich river, sediment, multivariate statistics
Session Type: Virtual Poster
Start / End Time: 9:35 AM / 10:50 AM
Room: Virtual 52
Presentation File: Download
In this research, concentrations of seven typical heavy metals were investigated in 19 sediment samples along To Lich River, Hanoi, Vietnam. Multivariate statistics and comparison to four previous studies were conducted. The Geo-accumulation Index and Enrichment Factor orders of seven heavy metals are similar: Cd > Zn > Pb > Cu > Cr > As > Ni, with less than 50% of the samples showing uncontaminated level in terms of Cd, Zn, Pb, and Cu, and all samples have been impacted by anthropogenic sources except for Ni and As in some locations. A majority of locations are not free of toxicity in terms of these metals, with 42.1% and 47% of locations are above the PEC value for Cr and Zn respectively. Hierarchical Cluster Analysis and Principal Component Analysis allocate these metals into two categories with group 1 is Cu and group 2 is the other metals. It is still not clear why Cu shows an unusual pattern with others. 165 pollution point sources were detected evenly along the river, and an abnormal high in concentrations of all metals was observed in locations with a high factory density. Compared to previous studies, the river sediment has shown signs of toxicity during the last 20 years. More studies with frequent measurements should be conducted to better track the toxicity of sediments, especially when the city population and numbers of factories have increased dramatically over time.