STUDY OF MERCURY IMPACT FROM CLOSED CHLORALKALINE PLANT IN CROATIA ON NEARBY DRINKING WATER SUPPLY

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-27-0 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 33, 347-354 pp; DOI: 10.5593/sgem2017H/33/S12.043

ABSTRACT

A mercury-cell chlor-alkali plant operated 50 years in Kaštela Bay (situated in the middle of eastern Adriatic coast) near the town of Split. Even after 28 years the abundant cell house is still a hazardous source of the total gaseous mercury. Measured concentrations in the air (2.1 – 9.6 μg m-3) could possibly present Hg-pollution of 9 km distant source of Jadro River. This source is used as a drinking water supply for the town of Split.
The aim of the work was to find how far mercury is transported.
Total mercury was measured in the air, in soils near the factory and stream sediments of Jadro River. The overall study showed that mercury pollution is localized to specific sites, that concentrations are highly variable and that at 600 m from pollution source they are < 0.2 mg kg-1. At the source of Jadro River concentration of mercury in stream sediment was < 0.06 mg kg-1 in the year 2001. This result was confirmed later by Croatian Waters by monitoring mercury from years 2010 to 2015.
The reason that Hg pollution is not spread to the source of Jadro River, situated east from pollution source can be explained by local winds, measured by State meteorological and hydrological service. The rose of the winds shows that western winds are not predominating.
The conclusion is that nature itself prevented anthropogenic pollution of the precious drinking water supply.

Keywords: mercury, sediments, soils, Kaštela Bay (Croatia), Jadro River