engleski

Airborne ammonia and ammonium within the northern Adriatic area, Croatia

Determination of airborne ammonia started in the early 1980s, as a part of air pollution monitoring of industrial plants. Due to high emissions, the city of Rijeka was one of the most polluted in Croatia in the mid-1980s. Considerable reductions in SO2 and NOx emissions led to lower airborne levels of these pollutants in the mid 1990s. In spite of the coke plant closure in 1994, there was only a weak decline in airborne ammonia over the period 1980e2005, with annual means in the range of 12e20 mg m3 at urban Site 1 and 6e28 mg m3 at suburban Site 2. Similar behaviour has been observed with ammonium in bulk rainwater samples since 1996. Higher and approximately equal deposition of nitrogen as ammonium (N-NH4þ ; ) were obtained for the urban Site 1 and the mountainous Site 4, but with different causative facts. Ammonium’ s contribution to total nitrogen (NO3 þ ; NH4þ ; ) deposition is approximately two thirds, even for a remote Site 3.

Air pollution; Ammonia; Ammonium; Precipitation; PM10

Reduced Nitrogen in Ecology and the Environment