Preliminary results on some heavy metal contents in the Red river system

Abstract

Environment quality, especially aquatic environment is increasingly being interested. This paper presents the initial results of dissolved heavy metal of the monthly observations for the period from January to October 2012 at Yen Bai, Ha Noi, Hoa Binh and Vu Quang stations in the Red River system. The monitoring results showed that the heavy metal concentrations in the Red River water varied in a high range: Cu: 10 - 80 pg/1; Zn: 2 - 88 ^g/1; Cr: 0.2 - 5.1 p.g/1; Pb: 2-107 pg/l; Cd: : 2 - 12 |jg/l; Mn: 2 - 35 pg/l; Fe: 160 - 950 pg/l. Most of the mean values of heavy metal contents at the four monitoring sites were lower than the ones of the Vietnamese standard limits for surface water quality, QCVN 08:2008/BTNMT. However, at several time during the observation period, the contents of some heavy metals such as Fe, Cd and Pb exceeded the Vietnamese standard limits. The results showed that the water quality of the Red River needs more be frequently and systhematically observed.