According to the Programme of systematic examination of surface water quality of the Republic Hydrometeorological Service of Serbia the examinations of Medjuvrsje water reservoir have been carried out during October 2002 and August 2003. The examinations have been carried out at the dam, in central part and at the entrance of the water reservoir, on three depths. This paper shows the results on phytoplankton composition, chemicophysical properties and the trophic status of water reservoir. The qualitative analysis of the phytoplankton shows the presence of 96 taxa from six divisions of algae. Following the standard of Swedish Agency for Environmental Protection, the high concentrations of primary nutrients belong to the fifth class, by the categorization. According to OECD classification trophic status of water reservoir may be characterized as eutrophic and hypereutrophic.

Thermal waters represent an unused natural potential of Serbia. A possible way of utilizing this resource is to carry out the initiative that has been underway over the past several years to use certain thermal waters for the rearing of some allochthnous thermophilic fish species, the most famous among them being the group Tilapia (fam. Cichlidae), authochthonous in Africa and Asia. The analysis of basic physico-chemical properties of the Ovcar Banja (Ovcar Spa) thermal waters (the bed of the Zapadna Morava river, Western Serbia) indicates the possibility of their utilization for this purpose.

There are presented the results of investigations carried out in the Kotor Bay (Adriatic Sea), Montenegro (Serbia and Montenegro) during the winter months of 2004. The highest value of microphytoplankton as a greater size-fraction of phytoplankton is found in the surface layer during March (1.4 x 10**7 cells/cubic dm). The main edificator was diatomic species Skeletonema costatum with relative percentage about 100%. Obtained results point out that Kotor Bay belongs to the highest eutrophic or extreme eutrophic area. Similar result is found in the same period twenty years ago.

The paper presents the seasonal overview of horizontal distribution and abundance for the species of genus Oithona in Bokokotorski Bay. Three species have been recorded. Oithona helgolandica and Oithona plumifera have a wide horizontal distribution within the Adriatic Sea, while Oithona nana is a typical euritherm and eurihaline form that occupies shallow and closed coastal areas along the eastern coast of Adriatic. Also presented are seasonal oscillations and quantitative presence of these species in the Copepoda population during 2002.

The aim of this study was to determine the content of heavy metals, cadmium and lead, in drinking water, spring and well water from rural part of south Serbia, as in water of river Jablanica and in the top water. The content of cadmium and lead, a very toxic metals, were studied simulataneously by potentiometric stripping analysis (PSA) in water samples using thin mercury film electrode, as a working electrode, by standard addition method in the presence of supporting electrolyte. The results of content of examined heavy metals obtained in examined water samples by PSA method, are compared with results obtained by using AAS and GF-AAS spectrometry.

Potentiometric stripping analysis (PSA) is highly sensitive electroanalytical method for determination of traces of heavy metals. In this paper detection limit and linearity of potentiometric stripping analysis for lead was investigated. Method was successfully used for determination of traces of lead ion (detection limit 5 microgram/cubic dm) in stream water of river Ibar, before and after joint of potential pollutant.

Organic matter of various composition is present in soils and sediments ranging from simple compounds to the very complex proteins, etc. Within the pollutant analysis in soils and sediments the total organic carbon (TOC) content is determined. In addition to this form carbon may be present as elemental or inorganic ones. TOS identification and quantitation methods may be qualitative or quantitative with prior sample preparation. It is recommended catalytic combustion of samples at high temperatures with Pt catalyst and IR detection of evolved CO2.

New type of ozone generator based on barrier discharge was applied for removal of phenol from water under laboratory conditions. Three water samples with initial concentration of phenol of 6.0 mg/L were studied. In the experiment with distilled water containing phenol, 98.9% of phenol was removed (93.3% during the ozonization). Under similar conditions two different water samples from river Danube were used. In these cases, 76.7% and 80.0% of phenol were removed, respectively. In all experiments, water samples containing phenol passed only once through the ozonizer. It is reasonable to assume that better purification could be obtained with several passes of water through ozonizer and/or by optimization of the process (adjusting concentration of ozone, ozonization time, water flow, etc.).

The paper contains description of potential approaches to better defining of distribution curves parameters for low water levels on water courses that sporadically dry up, also including additional information on the length of dry period. Computed results are given for the example of minimum annual discharge on several rivers in the Velika Morava basin, Serbia (Serbia and Montenegro).

During the 2004 research of Moraca river water quality was conducted onto six localities: Pernica, Zlatica, Gradska plaza, Kolektor, Grbavci and Vukovci. Physical, chemical and microbiological properties were analyzed. Physical and chemical analyses done were: water temperature, air temperature, pH, electro-conductivity, KMnO4 consumption, dissolved O2 and BCO5 (biological consumption of oxygen in five days). Microbiological analysis included determination of the total number of aerobic mezophyll bacteria, oligotrophic and heterotrophic bacteria, as well as the most probable number of colliform bacteria. In addition to distribution and population dynamics, identification of the bacteria was also done. Microbiological water analysis were performed using standard bacteriologic methods and identification of the bacteria using INVIC or, when needed, using API diagnostics.