The paper presents the results of a pilot study of the combined process of ozonation and filtration through biologically activated carbon to remove residual organic matter in the process of drinking water production. It was established that the application of these procedures resulted in the removal in average of 74% PB, 50% TOC, 60% of total aldehydes, and 54% PFTHM, the result being a consequence of the adsorption/biosorption processes involved.

In this study, the possibility of application of agricultural lignocellulosic waste materials as adsorbents of different heavy metals ions from water was investigated. As adsorbents, wastes of widely cultivated plant cultures in our country were used. They were wheat straw, cornstalk, corn cob and soybean straw. These materials were showed as good adsorbents in most cases. But, leaching of organic matters from them during adsorption was observed. It was unfavourable. Because of that, adsorbents washed and dried. After that leaching of organic matters was significantly decreased, but also adsorption efficiencies slightly decreased, too.

The role of forest belts for surface water protection has great importance in two geomorphological ambiances: plains and hilly-mountainous. Plains ambiances are concerned to regions where dominates wind erosion: Backa, Banat, Macva, sandy terrains (Deliblatska, Suboticko-Horgoska, Ramsko-Golubacka, Kladovska), spacious surfaces in surroundings of hydrosystem DTD, natural and artificial reservoirs, river beds. Hilly-mountainous ambiance is related to regions where dominates pluvial erosion: catchment areas of reservoirs for water supply south from Sava and Danube, Fruska Gora mountain and Vrsac mountains.

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.

Faculty of Science, University of Kragujevac (Serbia, Serbia and Montenegro), has developed SeLar Information System (Serbian Lake and Reservoirs Information System) which provides all the information of Serbian lakes and water reservoirs. Information system is needed for transfer of knowledge and informations, cooperation among participant in management and support of sustainable using of water resources. The paper presents the basic system components and some applications examples.

Consequently to eutrophication, from the beginning of July to the end of November there was a water bloom in reservoir Celije generated by three cyanobacterial species. Monitoring of that phenomenon indicates that cyanobacteria have become phytoplanktonic dominant residents in the course of significant part of the year.

In this paper we have presented the results of the investigations of phytoplankton carried out in the river Old Begey, from April 2003 till February 2004. The presence of 116 algal taxa of which 10 Cyanobacteria, 20 Euglenophyta, 50 Bacillariophyceae, 3 Chrysophyceae, 30 Chlorophyta and 3 Dinophyta was recorded. In the river Old Begey some rarer brackish species Entomoneis alata and Bacillaria paradoxa have also been found. The index of saprobity given on the basis of Pantle-Buck method indicated that the quality of water of the river Old begey belonged to beta-alfa-mesosaprobic category.

One of major direction of algology development in Serbia is completing data about bioindicating values for saprobic system based on the existing list of bioindicators. This work shows the results of several year's investigation of macroalgae in streams that belong to the Danube river watershed. Altogether, 72 taxa belonging to six divisions were found in the investigated streams. They were as follows: Cyanophyta (34 taxa), Rhodophyta (8), Xanthophyta (6), Chrysophyta (1), Chlorophyta (22) and Charophyta (1). Analysis of the list of species found in streams of highland regions of Serbia and the List of Indicatory Species reveals that 50% (36) of the species found have definite indicatory values. This work presents the data obtained for species that are not on the existing lists of indicators.