engleski

Levels of Fluoride Mass Concentrations in the Air in the Vicinity of an Aluminium Factory

Before the Yugoslav agression in Croatia, the annual production of aluminium in Šibenik was 71,000 tones. After wet purification of gases with the efficiency of 90-95%, the emission of fluorides in the air was 0.4-0.9 kg/t Al. During the agression the aluminium plant was completely destroyed and production of aluminium stopped. For two years before it stopped, mean daily mass concentrations of gaseous fluorides, mean weekly mass concentrations of particulate fluorides, and monthly levels of mass concentrations of fluorides in deposited matter had been continuously monitored at three sites located at different distances from the source of fluoride emission (1st stage measurement). The monitoring was repeated when the production stopped and has been carried at ever since (2nd stage measurement). The results show decreasing trends for all parameters. Mean annual concentrations of gaseous fluorides ranged from 0.34 to 2.55 μg/m3 with daily maximum of 58.83 μg/m3 in the 1st stage and from 0.37 to 0.50 μg/m3 in the 2nd stage with daily maximum of 3.46 μg/m3. Mean annual concentrations of particulate fluorides ranged from 0.35 to 1.20 μg/m3 with weekly maximum of 7.92 μg/m3 in the 1st stage and from 0.0129 to 0.0207 μg/m3 with weekly maximum of 0.1596 μg/m3 in the 2nd stage. Mean annual amounts of fluorides in deposited matter ranged from 0.88 to 9.04 mg/m2 d with monthly maximum of 15.74 mg/m2 d in the 1st stage, while in the 2nd stage the range was from 0.02 to 0.04 mg/m2 d with monthly maximum of 0.06 mg/m2 d. During the 2nd stage fluorides were also determined in soil and vegetation.

air pollution; monitoring; vegetation; soil; measuring sites

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