A strategy to reduce sulphur dioxide emissions from the Hornby industrial estate

Abstract

AUSPLUME, a Gaussian plume dispersion model, is evaluated for operational performance in the medium scale, multiple point source area of Hornby, Christchurch. The evaluation is conducted using a 1 hour averaging period for a month of meteorological data, an emission inventory of industrial sources in the suburb and observed sulphur dioxide (SO₂) concentrations from the Canterbury Regional Council's air quality monitoring station at South Hornby Primary School. The evaluation process uses five statistical parameters, the confidence limits of which parameters are obtained using bootstrap resampling techniques, and four qualitative criteria. The model is shown to significantly over-predict at the 95% confidence level. However, when compared to other models and criteria set by the American Meteorological Society for dispersion model evaluation AUSPLUME is shown to perform to an acceptable standard.

AUSPLUME is then used to predict the ground level concentrations (GLCs) of sulphur dioxide at the monitoring site if a district heating system was to replace the individual boilers that currently supply the process and space heating demands of the industries in the area. A comparison is made between the GLCs from current discharges of SO₂ and those predicted by AUSPLUME under the emissions from the district heating scheme. The district heating system is shown to significantly reduce SO₂ concentrations experienced at the Hornby monitoring site at the 95% confidence level. It is therefore concluded, that the introduction of such a scheme would improve air quality in the Hornby area.