Response of an ozone indicator plant before and after installation of a desulphurization device at a thermal power plant

Abstract

The main goal of the research was to compare the plant response to air pollutants in the rural environment (Zavodnje village) before and after the installation of a desulphurisation device at unit 5 of the Šoštanj Thermal Power Plant (Slovenia). The installation of the cleaning device for SO2 in the year 2001 caused very significant reduction of annual average SO2 emission and immission, while concentrations of dust particles, O3, NOx, and CO2 in Zavodnje remained unchanged. On the other hand the average concentrations of ozone during seasonal experimental period increased after 2001, but there were no significant differences in AOT40. The impact of O3 in combination with other air pollutants was studied at Zavodnje in the period 1996–2003 using white clover (Trifolium repens ‘Regal’) on the basis of visible ozone injuries of leaves, biomass reduction and by analysis of chosen biochemical stress parameters in leaves – the content of plant pigments and antioxidants. The effects of reduction of SO2 after 2001 were observed in the biochemical responses of white clover plants, which showed better vitality. Despite of that, there was no significant difference in the level of plant injury by ozone between the period 1996–2000 and period 2001–2003. Biomass ratio CN-S/CN-R was also unaffected.

Keywords

• air pollution
• desulphurization devices
• Trifolium repens ‘Regal’
• ozone
• sulphur dioxide
• plant pigments and antioxidants