ARSENIC AND OTHER METALS CONTAMINATION IN GROUND WATER RESOURCE IN DAK NONG PROVINCE, VIETNAM

Abstract

This study aimed at understanding the concentrations of selected heavy metals including arsenic, iron, manganese, cadmium and mercury in groundwater used for domestic purposes in Dak Nong Province of Vietnam. A total number of 572 groundwater samples including 61 duplicates were collected during October, 2018 – April, 2019. The collected samples were measured onsite for pH and preserved with 2% HNO3 before being analyzed in the laboratory for heavy metals by inductively coupled plasma mass spectrometry. The relative percent differences of all duplicate samples were less than 30%, indicating that the analytical results were within acceptable ranges. The average concentrations of As, Fe, Mn, Cd, Hg and Pb in groundwater were 9.53±46.36, 307.1±1,178, 166±478, 4.66±6.2, 1.0±1.8 and not detected, respectively. Amongst all the analytical results, however, some values on the concentrations of studied metals exceed the Vietnamese regulation values for groundwater quality and for domestic use requirements. The research results therefore suggest that groundwater containing rather high concentrations of heavy metals at the studied area should not readily be used for domestic purposes without proper treatments.