Modeling the atmospheric concentration of secondary steel-plant emissions

Abstract

A model is proposed for calculating the spatial distribution of secondary gaseous emissions around steel plants. The model is based on the maximum-risk principle. The following are the basic factors determining the maximum risk of exceeding the permissible concentration of the secondary emission: the formation of the emissions, the propagation of the emissions; and the falloff in concentration. Fundamental differences in the methods of calculating the propagation of primary and secondary gas emissions are noted. In particular, secondary emissions are generated not by point sources but over the whole region where the concentration of the primary emission exceeds its background value in the atmosphere. The concentration field of secondary sulfuricacid emissions is analyzed for a spatially distributed source on the basis of data from OAO Magnitogorskii Metallurgicheskii Kombinat. The H₂SO₄ concentration is plotted as a function of the distance from the source of the primary emission, for different wind speeds. The functional dependence of the H₂SO₄ concentration on the distance has a clear maximum. The position of the peak and the corresponding H₂SO₄ concentration may be determined for any wind speed if the mean power of the primary emission is known over the specified time interval.