During several years of hydrobiological investigation of the Zapadna Morava river the Medjuvrsje and Stancici localities stood out; the most favourable water quality was registered with the Medjuvrsje reservoir (being constantly of the class 2), whilst, according to all the data obtained over the years, water quality of the Zapadna Morava at Stancici locality was the worts. The Medjuvrsje reservoir is in stable eutrophic phase. The saprobic index value points to a certain water quality improvement. Floristic diversity in the locality of Stancici increased over the years. An increase in the percental share of the oligosaprobity indicator indicates a certain organic load decrease and an improving water quality trend was recorded as indicated by lower saprobic index values.

Water samples for chemical and microbiological analyses as well as material of the water community to be considered in the assessment of qualitative and quantitative composition of phyto- and zooplankton, and bottom fauna were take on 30 May 2001 at two profiles. Judging by the most of the analyzed chemical parameters, with the exception of BOD5 and oxygen saturation values indicating class 2, water of the Bovan lake accumulation belongs to the 1st class of water quality. According to the presence of heterotrophic bacteria, water was characterized as class 1-2 (after Kohl). Also, 6 groups of phyto- and 4 groups of zooplankton were recorded. Relative abundance and qualitative composition values of plankton show that saprobic index ranged from 1.54 to 1.98 pointing out oligo-beta, namely beta-mesosaprobic character of the accumulation. Saprobic index when oligochaetes were considered amounted up to 3.6 (alfa-mesosaprobic water).

In this paper, there were discussed the results of ecological investigation of the Montenerin part of the Adriatic sea during the period 1996-2003. Evaluation of the sea-water quality was done in the coastal sea. The importance of multiannual ecological investigations was emphasized, too.

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.

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.

The research of phytoplankton in water of Hydrosystem DTD in Banat region (canal complex and the rivers Zlatica, Old Begej) has been carried out seasonally i.e. in the spring, summer, autumn and winter of 2003 and 2004. According to guidance of Anon (2003) we selected biological element - phytoplankton in establishing referral body of water with maximum ecological potential (MEP) of the Danube-Tisza-Danube Hydrosystem also classified as artificial/heavily modified water. Classification was made according to Sorensen indices of similarity. Reference conditions with MEP were assigned to the HS DTD, canal Banatska Palanka - Novi Becej, Novi Becej - Melenci stretch. As determined by phytoplankton analyses, investigated canals and rivers could be classified as waters of good ecological potential, except the rivers Zlatica, Stari Begej (Old Begej) and some sections of the Canal Plovni Begej (Navigable Begej) what was designated to moderate ecological potential.

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.

In this paper modern instrumental techniques for monitoring, control and determination of water and waste water quality parameters are presented. The efficient and reliable control of quality of water can be achieved by integrating the central, referee laboratory, the laboratory on-field for quick and adequate responses, and in-field laboratory, as well as the measurements enabled with the use of chemical sensors that are installed on the places with the highest contamination. Beside equipped laboratories every monitoring system has to be connected with the latest informational systems which beside data base provide adequate response when the water is exposed to higher contamination.

This paper presents the results of water quality analysis of the rivers Tamis, Plovni and Stari Begej, using the WQI method, for the time periods 1987-1991 and 1998-2002. It also show the trend of water quality of these water streams for two characteristic time periods, through trend of WQI index.

The sampling of Crnojevica river has been carried out, because of estimation the correlation between main water quality parameters and precipitation impacts, as well as adequate hydrological parameters. An appropriate dynamic sampling has been applied. Continuous pollution of river water has been confirmed, as well as source of the pollution. It is estimated strong correlation of water quality parameters from precipitation quantity and water level, especially for sanitary pollution. Change of quality parameters value is discrete and accidental.