Effects of charcoal air filtration and ozone generation on concentrations of some N and S compounds in open-top field chambers

Concentrations of nitric acid (HNO3), nitrous acid (HNO2), ammonia (NHA sulfur dioxide (SO2), as well as particulate nitrate (NOD, sulfate (SO42−), and ammonium (NH4+) were determined with annular denuder systems in open-top chambers (charcoal-filtered [CF] ; ambient air [AA] ; and ambient air with ozone [O3] added [2 × O3]) and the outside chamberless plot. Concentrations of HNO3 were the highest in the outside plot, followed by the 2 × O3, AA, and the CF chambers. Substantial increases of HNO2 were noticed in the CF chambers compared with other chambers and the outside plot. No changes in concentrations of NH3 were recorded for the studied filtration regimes. As expected, concentrations of SO2 were drastically reduced for the CF treatment. No clear effects of air filtration on concentrations of the particulate pollutants were determined. Possible consequences of the observed chemical changes of the open-top chambersʹ environment on plants are discussed.