Effect of long-range transport of sulphur and nitrogen oxides from large coal power plants on acidification of river waters in the Baikal region, East Siberia

Abstract

Research has focused on the effect of sulphate and nitrate atmospheric deposition on river water chemistry in the Baikal region. During long-term monitoring it was ascertained that anthropogenic SO2 and NOx in the plumes emitted from regional coal Power Plants (PPs) cause extra nitrate and sulphate deposition in the Pereemnaya River basin that is located 100–150 km away from the emission sources. As a result, average concentrations of sulphate and nitrate in the water of the Pereemnaya River are 2–3 times higher than those in Lake Baikal, whilst total mineralisation of the river water is approximately 3 times lower. Because of the acidity of atmospheric deposition in the Pereemnaya river basin, pH value of the snow cover and precipitation is about 4.7. That makes the river water pH significantly lower (=6.8) than that in the lake and other tributaries (=7.8). It is recommended to strengthen monitoring of the natural environment in the southern basin of Lake Baikal and to apply measures to reduce pollutant emissions from PPs.