Risk Factor Analysis of Liquid Ammonia Cross-Border Air Pollution

Abstract

Research into cross-border air pollution caused by the continuous leakage of liquid ammonia has been carried out based on the standard allowable concentration of short-term exposure to ammonia of 30 mg/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and the more strict maximum allowable concentration of harmful substances in residential areas of 0.2 mg/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , assuming that the cross-border distances are 5 km, 10 km, 15 km and 20 km. The atmospheric stability classes, the range of wind speeds and the time required for the pollution to reach a border were studied for source intensities ranging from 3 to 20 kg/s. The results of the study show that the D and E stability classes are the most likely to trigger cross-border pollution events. The range of crossborder wind speeds leading to exceedance of the maximum allowable level narrows as the distance to the boundary increases. Irrespective of the source intensity, the travel time for the pollution to reach the same distance of boundary is similar under the same wind speeds which are in the range of transboundary wind speeds, and the duration of the pollution event is longer with increasing source intensity for the same wind conditions. The pollution arrives faster and the duration of the event becomes shorter with increasing wind speed, for the same source intensity.