Precipitation composition and wet deposition temporal pattern in Central Serbia for the period from 1998 to 2004.

Bulk samples collected on a daily basis at three principal meteorological stations in central Serbia were analyzed on chloride (Cl(-)), nitrate (NO(3)(-)), sulfate (SO(4)(2-)), sodium (Na(+)), ammonium (NH(4)(+)), potassium (K(+)), calcium (Ca(2+)), and magnesium (Mg(2+)) in addition to precipitation amount, pH and conductivity measurements over the period 1998-2004. The data were subjected to variety of analyses (linear regression, principal component analysis, time series analysis) to characterize precipitation chemistry in the study area. The most abundant ion was SO(2-)(4) with annual volume weighted mean concentration of 242 microeq L(-1). Neutralization of precipitation acidity occurs both as a result of the dissolution of alkaline compounds containing Ca(2+), Mg(2+), and K(+) as well as the absorption of ammonia. The ratio of SO(4)(2-)/NO(3)(-) was above 5, which indicated that the combustion process of low-grade domestic lignite for electricity generation from coal-fired thermal power plants was the main source of pollution in the investigated area. A considerable mean annual bulk wet deposition of SO(4)-S determined by precipitation amount and concentrations of sulfate in the precipitation was calculated to be 12-35 kg ha(-1).

An evaluation of residues at an oil refinery site following fires.

Soil pollution at the oil refinery at Novi Sad following destruction of crude oil and its products in storage tanks during the Kosovo conflict was investigated. More than 100,000 t of crude oil and its products were destroyed, and about 90% of these were burnt off, 10% leached and 130 t recovered. The acute injection of polycyclic aromatic hydrocarbons (PAHs) to the air of the town was widespread depending on the weather conditions and ranged from 1-431,000 ng/m3. The presence of PAHs, polychlorinated biphenyls (PCBs), and elements in the surface zone and soil core samples taken from various sites were determined up to a depth of 100 cm. Concentrations of PAHs were in the range between 0.75 and 86.19 microg/g dry soil. The contaminated soil can be expected to act as a permanent pollution source, while the mobile constituents are likely to cause groundwater pollution.

AN EVALUATION OF RESIDUES AT AN OIL REFINERY SITE FOLLOWING FIRES.

Soil pollution at the oil refinery at Novi Sad following destruction of crude oil and its products in storage tanks during the Kosovo conflict was investigated. More than 100, 000 t of crude oil and its products were destroyed, and about 90% of these were burnt off, 10% leached and 130 t recovered. The acute injection of polycyclic aromatic hydrocarbons (PAHs) to the air of the town was widespread depending on the weather conditions and ranged from 1-431, 000 ng/m3. The presence of PAHs, polychlorinated biphenyls (PCBs), and elements in the surface zone and soil core samples taken from various sites were determined up to a depth of 100 cm. Concentrations of PAHs were in the range between 0.75 and 86.19 µg/g dry soil. The contaminated soil can be expected to act as a permanent pollution source, while the mobile constituents are likely to cause groundwater pollution.

Environmental tritium of the Danube basin in Yugoslavia.

An overview of environmental distribution of tritium in the Danube basin in Yugoslavia during the period 1976-1990 is presented. Temporal and regional variations of environmental tritium in the Danube along its flow (1425-847 km from the confluence) and its tributaries (the Sava, the Tisa, the Velika Morava and the Timok) at various locations, as well as in alluvial groundwaters, are given. In Belgrade, monthly values of tritium in rainfall ranged from 1.1 to 18.3 Bq litre(-1), with a maximum in the late spring and early summer months. The half-life for decline in concentration was estimated as 8.3+/-1.0 years. The total amount of tritium deposited in the first 6 months during 1976-90 was 35% larger than in the second 6 months for the same period. Seasonal variations were noticeable in rivers and groundwaters, but these were greatly attenuated and smoothed for the latter. Tritium content in the monthly composite samples from the river in the Belgrade region varied between 2.5 and 18.2 Bq litre(-1) for the Danube and from 1.5 to 16.8 Bq litre(-1) for the Sava. The yearly mean values along the Danube and its tributaries ranged from 2.4 to 15.9 Bq litre(-1) with individual measurements 1.0-30.2 Bq litre(-1). The half-lives were between 6.9+/-1.7 for the Velika Morava and 9.4+/-0.9 for the Danube. Groundwaters, particularly ones in the Ranney wells, followed changes of tritium content in the rivers with a time lag from a few days to a month. During the period of observation, tritium content decreased in alluvial waters with half-lives from 9.9+/-1.6 (Belgrade area) to 7.3+/-1.8 (the Velika Morava).