Oil Shale, Vol.17, No.2, 113-128, 2000
Balance of alkaline and acidic pollution loads in the area affected by oil shale combustion
Field measurements of concentrations of SO2 and NO2 in the air and deposition of Ca2+, Mg2+, K+, Na+, SO42-, NO3- and Cl- in northeastern Estonia were carried out in the end of winter 1998/99, Concentrations in the air were measured by passive sampling method (Palmes tubes): snow samples were used to quantify the deposition lends. The measurement domain covered entire Ida-Viru County, eastern part of Laane-Viru County and a few sites in Jogeva County. These measurements and comparison with earlier investigations show that in wintertime most of sulfate over the area affected by oil-shale industrial complex appears to be deposited with fly ash particles. The regression formulae for wintertime sulfate and calcium deposition loads for oil-shale region are derived. The inhomogenous chemical composition of fly ash and influence of other (domestic, traffic) emissions are suggested as possible factors affecting the ratio of sulfate and calcium deposition loads.