Gobal Advanced Research Journal of Environmental Science and Toxicology (GARJEST) ISSN: 2315-5140
August 2012 Vol. 1(5), pp. 115-131
Copyright © 2012 Global Advanced Research Journals

Full Length Research Paper

Environmental geochemistry of Aq-Darreh Bala abandoned Sb mine and its impacts on water, sediment, and soil pollution in the Aq-Darreh River Watershed, Takab, NW Iran

Y. Rahimsouri^1*, A. Yaghubpur ² and S. Modabberi³

¹Department of Geology, Faculty of Sciences, Urmia University, Urmia 57153- 165, Iran
²Department of Geology, Faculty of Sciences, Tarbiat Moalem University, 49, Tehran 15614, Iran
³School of Geology, Faculty of Sciences, University of Tehran, Iran*

*Corresponding Author E-mail: rahimsouri@yahoo.com; Telfax: +984412753172

Accepted 18 August, 2012

Abstract

The abandoned antimony mine of Aq-Darreh Bala is located 42 km northwest of Takab city in northwest Iran. The host rocks of the stibnite-bearing silica veins are calcareous marl and a black shale unit rich in toxic elements such as As, Sb and Hg. Toxic elements are released through weathering and oxidation of this black shale unit into the surface water, and also in sediments, surface and agricultural soils causing contamination in plant, fruits and crops. The contaminated waters of Aq-Darreh Bala abandoned Sb mine area mix with unpolluted main tributary of Aq-Darreh river and the As and Sb concentrations in the downstream of confluence point rise to 9 (29.2 μg/l) and 4 (5.96 μg/l) times repectively and the As, Sb and Hg concentrations in river bed sediments rise to 0.1 (73.4 mg/kg), 4.3 (16.65 mg/kg) and 1.8 (1477 μg/kg) times respectively relative to unpolluted parts of the river. Toward the downstream, the runoff from the Aq-Darreh Au-Hg mining area flows in to the middle parts of Aq-Darreh river and incomparison to the upstream, the concentrations of As and Sb in water samples increase 13 (385.0 μg/l) times and decrease 0.15 (5.10 μg/l) time respectively. The concentrations of As, Hg and Sb in bed sediments of Aq-Darreh river(in middle parts) increase 6 (445.1 mg/kg) and 4 (6174  μg/kg) times for As and Hg respectively and decrease 3.3 (4.95 mg/kg) times for Sb. In this paper, it is attempted to illustrate that Sb contamination of Aq-Darreh river is affected by Aq-Darreh Bala abandoned Sb mine, while As and Hg contamination are due to the effects of Aq-Darreh Au-Hg active mine and its waste piles.

Keywords: Environmental geochemistry, abandoned Sb mine, water and soil pollution, Aq-Darreh mining district, Takab, Iran