Phytoplankton composition of the Hydrosystem Danube-Tisza-Danube (HS DTD) and isolated peaks of chlorophyll a in summer months of 2003 and 2004 revealed moderate ecological potential in Banat and Backa region (Serbia). Investigated HS DTD water pointed out to a slighty better ecological potential in 2004.

Microbiological and saprobiological characteristics of river Moraca and Skadar lake for period of 2004/2005 are done at localities: Pernica, Moraca estuary and Vranjina (Skadar Lake). The objective of the research is to establish quality of water of these aquatic ecosystems based on microbiological and saprobiological analyses, as well as, to show need for protection of these water ecosystems from permanent contaminations, mainly by sewage should be pointed out. Saprobiological index is determined based on Gulyas Pal, and Pantle Buck is used to determine saprobiological level.

Within the pollutant analysis in sediments the total organic carbon (TOC) content is determined, as well as nutrients such as nitrogen and phosphorus. In addition to this form carbon may be present as elemental or inorganic ones, as the crucial issue for sample preparation. Total phosphorus content was determined after sample digestion with sulphuric and perchloric acid. Organic nitrogen values were determined according the Kjeldahl method. Concentrations of TC, TOC, TIC, total P, organic N and total N in river Tisza sediment samples from sites Martonos, Novi Becej and Titel during 2004 and 2005 were presented.

In the course of implementation of project Ecological Significance Evaluation of River Moravica Basin with Pollutants Identification, supported by REC and DRP, chemical and physical water analysis were done, as well as slime analysis. Heavy metals presence in water, herb Mentha aquatica and slime was analysed at six relevant locations downstream river Moravica. Heavy metals test results in slime and herb Mentha aquatica points out the presence of Zn, Cu, Fe, Mn, with heavy metals concentration rise from spring to mouth of river Moravica to river Juzna Morava. Chemical and physical analysis of water content, and detection of heavy metals presence in herb Mentha aquatica - as bioindicator and in slime, shows on water contamination with heavy metals as the inflow result of waste waters from numerous polluters.

In the frame of the project Water Supplying of the Cities and Protection of the Groundwater Quality in the Velika Morava Valley, was obtained the analysis of potential polluters of groundwater sources of town Velika Plana - Livade. This paper presents results of water physical, chemical and microbiological characteristics of soil. According to the results of research and way of usage of the soil, it was concluded that agricultural production does not have negative influence on quality of the groundwater source.

In the frame of the project Water Supplying of the Cities and Protection of the Groundwater Quality in the Velika Morava Valley, was obtained the analysis of potential polluters of groundwater source of city Smederevska Palanka - Trnovce. This paper presents results of water physical, chemical and microbiological characteristics of soil. According to the results of research and way of usage of the soil, it was concluded that agricultural production does not have negative influence on quality of the groundwater source.

The EU Water Framework Directive imposes special requirements for transboudary groundwater bodies, and thereby emphasizes their significance. The management of a common resource calls for an integrated approach to monitoring and status assessment, as well as implementation of improvement measures. Serbia, Hungary and Romania share a water body in the Pannonian Basin, for which cooperation has already been established within the framework of the ICPDR and at the bilateral level.

In this paper, results of phytoplankton investigations were performed in June 2005. The investigated positions are located near the entrance of Boka Kotorska Bay: two positions in the outer part (Zanjica and Mamula island) and two positions in the inner part of the Bay (Njivice and Tivat bay). In this area the influences of the open sea and the land are expressed to the phytoplankton community. As a consequence of that quantities of phytoplankton are lower in the outer part and higher in the inner part. The most dominant species is diatom Pseudo-nitzschia delicatissima which is very frequent in the eutrophic area.

During the study we recorded narrow margins between zooplankton distribution and the ecological characteristics of water in Bokakotorska Bay (Adriatic sea, Montenegro). Various species show different vulnerability to environment quality. Some are defined as indicators, with low tolerance for the ecological variation of environment, and their distribution is limited to the particular type of water masses within the sea. The limiting factors are different for various species, and their indicator status is determined by their distribution. The indicator type, based on monitoring of particular species, may define a biotope, with the help of statistical analyses that identify the main time and spacial behavior patterns of a species, and my allow future ecosystem changes to be anticipated. In this paper we paid particular attention to the indicator species Oithona nana (Giesbrecht).

In this paper two different combinations for wastewater treatment are proposed for specific problems that Vojvodina (Serbia) has with arsenic. Both proposed technologies take into account treatment of water and treatment of waste. In this paper the concrete solution for water treatment is proposed for water that contains arsenic (the concentration is around 100 microgram/L) in Obrovac and Palic. With these water treatment plants the removal of ammonia (measured concentration was above the maximum allowed value, from 1.35-2.5 mg/L) is also included in case of Obrovac wastewater plant, and for Palic the proposed treatment plant the removal of iron (measured concentration was above the maximum allowed value, from 1.35-2.5 mg/L) is also included. With both treatment plants and with both proposed technologies the overall treatment of water is planned.