This paper presents the results of chemical analyzes of water and sediment of the River Tisza, in the section from the Hungarian border to the mouth of the Danube. According to local legislation, water quality in the Tisza is acceptable, i.e. does not exceed the maximum allowable values for Class II watercourses for most parameters at almost all sampling locations. by using the Dutch methodology, it was concluded that the sediments of the Tisza at all profiles is categorized as polluted due to the high mercury and/or nickel contents, except for the profile downstream of Senta, which is partially contaminated. All the sediments are partially polluted in terms of copper content, and the sediment in the profile downstream of the dams is also partially polluted with zinc. The results of this analysis can be used to obtain a preliminary picture of the vulnerability of the Tisza River over its course in Serbia to the large number of industrial pollutants that are present in wastewaters discharged into the river or in the lateral canals that empty into the Tisza.

In the year 2010 ichthyological research on some Vrbas River tributeries located on wider area of Banjaluka city (Bosnia and Herzegovina) was carried out and the occurrence of 14 fish species was recorded. On the basis of the occurrence and abundance of fish species indicators as limnosaprobic parameter, water quality of the analyzed watercourses variated from oligosaprobic to beta mesosaprobic (I and II class of bonity) with saprobic index from 1.27 for Švrakava River to 1.81 for Vrbanja River. The obtained results indicate that water quality of this Vrbas River watershed was on satisfactory level for multiple purposes (in order to sustain ichthyofauna diversity and production and as potential protected areas and spawning zone for some endangered domestic fish species).

In this work, the results of preliminary study of stomach content in brown trout (Salmo trutta L. 1758) of the Gradac in autumn are presented. The fishes were collected by the end of September of 2011 at three sampling sites along the course. A total of 12 fish specimens were examined. By examination of trout stomach content have been found members from macrozoobentho-groups – Trichoptera, Ephemeroptera, Diptera (fam. Ceratopogonidae), Oligochaeta, Coleoptera. At the same time, investigations of bottom fauna composition and structure have been done also. Our study showed that the diet of brown trout is dependent of bottom fauna availability and abundance.

The aim of this study was to assess the water quality of the Gradac, near the town of Valjevo, on an analysis of DNA damage in different tissues of trout (Salmo trutta L. 1758) and barbel (Barbus meridionalis R. 1827). For the detection of genotoxic potential of alkaline comet assay were used three types of tissue, blood liver and gills. Among the parameters available the Olive tail moment was chosen as the most reliable to estimate the damage to DNA molecules. In all tested tissues was detected damage in DNA molecule, where the gills showed the highest sensitivity.

The aim of this work is to present preliminary results of the Sava River investigation at five sites within the reach from Martinska Ves (Croatia) to Šabac (Serbia). A total of 70 macroinvertebrate taxa from 13 groups were recorded, with domination of molluscs and oligochaetes. Among them 7 alien species were registered. Invasive clam Corbicula fluminea was recorded at all five sites, while invasive amphipod Dikerogammarus haemobaphes was not recorded only at locality Šabac. It is expected that the taxa list of aquatic macroinvertebrates within investigated reach will contain more species, after the identification of the rest of biological material and more detail identification of certain taxonomic groups.

The Rapid Small Scale Column Test (RSSCT) was developed to predict the adsorbtion of organic compounds in activated carbon adsorbers. In the RSSCT, a small column, which is loaded with an adsorbent ground to small practicle sizes, is used to simulate the performance of a pilot or full scale system. Due to the similarity of mass transfer processes and hydrodynamic characteristics between the small, pilot and full-scale columns, the breakthrough curves are expected to be similar. Due to its small size, the RSSCT requires a fraction of the time and water volume compared to pilot column testing. Recently the RSSCT has been used successfully in simulating the performance of metal-oxide based arsenic adsorbers. The adsorptive-filtration column was scaled down to mimic the performance of continuous flow, full and pilot scale arsenic treatment systems using the RSSCT approach. This paper investigates the application of the RSSCT method for assessing arsenic removal by unconventional adsorptive media such as waste materials.

On the base of monitoring of water quality for aquaculture, performed since 2010, it is noticed that two positions are showing increased level of trophicity and bacteriological contamination. Changes in sanitary quality of farms are especially intensive during the summer months, so the results of basic physical, chamical and biological parameters, measured during periods June-September 2010 and 2011 are presented and compared.

In this paper the results of preliminary investigations of microbiological quality of seawater and sediment are presented. Analyses are performed by membrane filtration. The samples were collected near the sawage outfalls in Bokakotorska bay. It is noticed much higher number of bacteria – indicators of fecal pollution in sediment surface that seawater overlaying the sediment. Concentrations of bacteria diminished in layers of sediment laying deeper that sediment surface. Influence of wastewater is the most evident on 1 and 3 positions.

The microbiological quality of the groundwater was monitored by determining relevant physiological groups of bacteria (organotrophic bacteria) which are indicators of water organic pollution. Standard high nutritive medium (Nutrient Agar) and low nutritive medium (R2A agar) were used. The enzymatic activity was also estimated based on IFA determination (index of phosphatase activity). According to the number of organotrophic bacteria and categorization by Kohl (Kohl, 1975) water is generally classified in category II. IFA showed variation of water quality, which varied from polluted to very pollute. The results showed organic pollution of groundwater and confirmed the sensitivity of enzymatic methods. In addition, cultivation methods confirmed superiority of low nutritive media.

The aim of this work is to present the trophic state of water at the pelagic zone of lake Prespa, reviewing the result of defined parameters of physico-chemical and algological aspect. Investigations are done according to standard limnological methods and the samples for analysis were collected from one vertical profile (0, 5, 10 and 15 m) monthly during 2008 year. Water categorization, on the basis of gathered data from analyses of the sampling localities was done according to the OECD-regulations, positive law regulations of the Republic of Macedonia and Nürnberg classification system. Data from this investigating period point out that this area of the lake Prespa is by great influence of the anthropogenic factor and intensive eutrophication.