EMECAP Deliverable 5.3. Sensitivity studies.

As part of Work Package 5 of the EU FP5 EMECAP project, dispersion model calculations have been carried out in order to determine the concentration and deposition of Mercury in the region surrounding 3 selected Mercury Cell Chlor-Alkali (MCCA) plants. In order to study the sensitivity of Mercury deposition in the local region surrounding the MCCA plants a number of sensitivity tests are carried out to determine local deposition around the plant as a function of dry deposition velocities, wet scavenging ratios and the percentage of Mercury emitted in the formof RGM. Sensitivity runs have been carried out at the Bohus plant in Sweden for a 5 day period. The results indicate that uncertainty in the deposition parameters, particularly the wet scavenging ratio, is significant in determining the total deposition. They also show that RGM is the most important species contributing to deposition despite its low representation, < 1% of TGM.