Danube and Sava river sediment monitoring in Belgrade and its surroundings.

Belgrade is the largest city in Serbia located at the confluence of river Sava to the Danube river. The quality of water and sediments of rivers which run through Belgrade is of a significant importance, since water from these rivers is a source of Belgrade drinking water supply system and probable anthropogenic contamination is related to industrialization and inputs of sewage water. In order to follow the sediment quality of river Sava (km 62-1) and river Danube (km 1193-1124) in Belgrade and its surroundings, the content of As, Cd, Cr, Cu, Zn, Ni, Pb and Hg were measured in the period 2001--2005. The content of 16 polycyclic aromatic hydrocarbons (PAHs) was measured in 2005. The results have shown that, due to the metal content, examined Danube sediment quality varies from class 1 to class 3, predominantly nickel being the class determining parameter. Elevated copper, zinc and mercury concentrations were measured at some profiles, as well. Typically due to the nickel content, Sava sediment quality belongs to class 3 in the period 2001--2004. Elevated concentrations of cadmium, zinc and mercury were observed in 2001, as well. Moreover, in 2005, sediments from three profiles were extremely polluted with nickel, leading the Sava sediment to class 4, when highest urgency measures are needed. Total PAH concentration in the sediments from Danube (213.1-575.4 microg kg(- 1)) was lower than total PAH concentration from Sava sediments (416.2-595.3 microg kg(- 1)). Nevertheless, according to the Dutch regulatory system, it has been concluded that river sediments in Belgrade and its surroundings were not polluted with PAHs in 2005.