Nitrogen mineralization in mine waste-contaminated soils

Abstract

In this study, the effect of mine wastes on nitrogen 7 mineralization was investigated at two different depths of soil (0-5 cm and 5-15 cm) in waste sites in the surroundings of the Etibank Wolfram Mine Work, Bursa, Turkey. Due to the disorder of the distribution of mining wastes, the pH, CaCO3% and element content (Fe, Mn, Zn, Mg) in the soils around the mine were enriched by mining activity. The investigation was carried out in soils taken from waste-removal pools (WRPs) and from selected sample sites which differed in their distances from the mine works. Waste materials resulted by mining were discharged with water and, they were fall down on two waste removal pools which were constructed as primitive terraces around the mine work. For this reason, elements were most enriched on sandy ground of abandoned pools. Both N-mineralization and nitrification were determined by a standard incubation method under laboratory conditions at 20 degrees C and 60 % WHC. Mineral nitrogen was analyzed at the initial, the 21(st) and the 63(rd) day by micro-distillation method. The net mineral N production was estimated for 21 and 42 days. It was calculated as the potential mineralization rate of organic nitrogen. N-mineralization and net production were the highest at the site furthest from the mine waste site. Significant negative correlations between nitrification and element contents (Fe, Zn, Mn, Mg) of soils were also found. This shows that the mine wastes have a negative effect on the nitrogen mineralization, especially nitrification.