ASSESSMENT OF HEAVY METAL POLLUTANTS IN DOWNSTREAM VAM THUAT RIVER

Abstract

Heavy metals in the downstream sediments of the Vam Thuat River pose many potential risks to the ecology of the Saigon River. Therefore, this study was conducted to evaluate the residual heavy metal pollutants, such as Cd, Cr, Cu, Pb, and Zn, in the downstream area of this River. Evaluation methods were based on QCVN, United State Environmental Protection Agency - US EPA recommended threshold, and the indexes, including Enrichment Factor (EF), contamination factor (CF), Geoaccumulation Index (Igeo), Pollution Load Index (PLI), 7 sediment samples were collected in March 2022 at low tide period. The results showed that heavy metals Cd, Cr, Cu, Pb, Zn content ranged from 1.08 - 1.93 mg/kg, 32.4 - 66.2 mg/kg, 2.3 - 10.5 mg/kg, 289 – 703 mg/kg of the sediment samples, respectively. The content of Cd, Cr, Cu, Pb of the samples was within the allowable limit according to QCVN 43/2017, except Zn. According to the recommended threshold of US EPA, Cd, Cr and Zn were exceeded. The EF has confirmed that heavy metal pollution in sediments is mainly anthropogenic. The Cf, Igeo indexes have also confirmed that Cd, Zn, and Pb are contaminated at a high level or need to be considered. The PLI has shown that the pollution level in the downstream Vam Thuat River has progressed towards the trend of high pollution. tand the status of heavy metal residues and their risks in river sediments.