Institute for Development of Water Resources Jaroslav Černi and the Republc Hydrometeorological Service of Serbia carried out detailed processing and analysis of available hydrometeorological data within the amendments of the draft for Water Management Master Plan of Serbia in 2009. In this particular case, the most important characteristics of time series of hydrological and meteorological parameters on key sections of hydrological and meteorological stations, their conventional processing and analysis was completed and updated. The final goal of amendments of the draft of Water Management Master Plan is to provide elements to define the balance of available water resources in the territory of the Republic of Serbia, necessary for defining the strategy of water use and defining the conditions for integrated and rational management. This paper presents the most important elements of water balance using modern GIS technology.

Microbiological monitoring of river water quality is obligatory for use-related aspects such as drinking water production, irrigation and recreation. Assessment of the microbiological quality of water and sediment at the Velika Morava River was performed at five sites, during 2010 and 2011. By applying standard procedures for sanitary correctness and organic load assessment, total of 16 parameters were analyzed. Results of analysis indicated that microbiological water quality of the Velika Morava River is unsatisfactory.

The paper presents the results of preliminary study of the intestinal content in bream (Abramis brama L. 1758) of the Danube River through the Belgrade Region. The fishes were collected in May and October during the period 2007-2009 at two sampling sites along the course. A total of 42 fish specimens of different age (2+ to 6+) were examined. By examination of compositing of intestine of bream have been found members from macrozoobentho-groups – Oligochaeta, Gastropoda (Lithoglyphus naticoides), Bivalvia, Amphipoda (Gamaridae). Our investigation showed that the diet of bream is dependent of bottom fauna composition and structure.

In the spring/summer and autumn season of 2010 dynamics of macrozoobenthos structure of Moravica River was investigated after the changes in habitat caused by floods. It was found that macroinvertebrates are represented with 13 groups and 64 taxa from 54 genera. Trichoptera fauna was represented by 11 species, Diptera 10, 8 Ephemeroptera, Odonata 5, 6 Oligocheata, Gastropoda 5, Crustacea 3, 2 Hirudinea, Bivalvia 2 and Turbellaria 1. In average 11 taxa was identified in samples. Most abundant were Gammarus pulex fossarum, Grammarus balcanicus, Asellus aquaticus and Chironomus thumma. Abundance of macroinvertebrates at the downstream direction was increasing and was correlated with decreasing number of taxa especially in the spring season. Species are equal in number to the initial sites, and downstream a smaller number of species dominated. Average value of N-index was 2.1 which points to relatively favorable structure of macroinvertebrates. Average value of C of 0.32 indicates increased dominance of individual species. Saprobity index ranged from 1.6 to 3.5 at average of 2.3.

Physico-chemical and microbiological analysis of Brvenica River water was conducted in period 2006-2010 and showed seasonal variations of water quality. The results of correspondence analysis indicated that the year 2006 regarding the physical and chemical characteristics of water, was different from the rest of the examined period. This year was characterized by the absence of ammonia, low contents of nitrite, iron and chlorine, and increased concentrations of KMnO4 consumption. In 2007 and 2008 presence of manganese in water, low concentration of KMnO4 consumption was detected as well increased turbidity and electrical conductivity. And the third distinguish period are years 2009 and 2010 when water was characterized by low concentration of NO3, and the presence of ammonia, NO2, and iron in the water, while turbidity was low and conductivity was average. In Brvenica River water Escherichia coli, Citrobacter sp., Enterococcus sp., Klebsiella sp. are detected. In year 2006 number of aerobic bacteria and total coliforms were rather low, while their number in 2008 is relatively high. Over the whole period, only in 2008 fecal streptococci were not detected. Other years are characterized by growth of aerobic bacteria and total coliforms and the occasional presence of fecal streptococci. Throughout the whole examination period fecal coliform bacteria were present in the water.

This paper presents the results of the Danube River water quality analysis based on the calculated SWQI index values, using the data set provided by the Hydrometeorological service of the Republic of Serbia for the year 2009. The relevant parameters are sampled once a month on average, at 16, measuring stations of the River Danube along the flow through Serbia. Data grouped on the sampling site basis, averaged on a yearly level, resulting in a median SWQI for each sampling station, are employed to obtain a synthesized quality indicator. Research shows that the overall quality of the water of the Danube in Serbia, SWQI = 85 for the given one-year period and to match the descriptive indicator very good water quality.

The paper presents results of microbiological quality of three drinking water sources – Ratno ostrvo, Petrovaradinska ada and Strand. The following analyses were carried out in 2010: total count of aerobic mesophilic bacteria at 37 deg C, count of organotrophs (categorization according to Kohl), aerobic facultative organotrophs, lipolytic and hydrocarbon oxidizing bacteria. Organotrophic count was determined on low nutritive R2A medium. Enzymatic activity of water was also determined and water was categorized according to index of phosphatase activity (IFA).

In this paper the size-frequency distribution by sexes and for the whole sample of Norway lobster Nephrops norvegicus (Linnaeus, 1758) as well as the sex raio have been analyzed. Representative subsamples were collected during the four sesonally trawl surveys (summer 2009 – spring 2010) at depths from 330 to 350 m. Total number of analyzed individuals was 303. The carapace length (CL) of the all individuals ranged from 20 to 58mm while the female carapace length-range was 20-56mm and 22-58mm for males. in all seasons males were larger than females and highly represented in the catch in bigger size classes. The overall sex ratio during the investigation period was in favor of females (1.3:1).

The paper presents results of studies of biology and fisheries of red mullet (Mullus barbatus, L.) which was done within the frame of AdriaMed Trawl survey Project 2007/08. The Project encompassed monthly research of several target species in trawl fisheries of Montenegrin waters during one year in three most important fisheries ports in Montenegro (Bar, Budva and Herceg Novi). Total length of red mullet ranged from 9.1 to 21.5 cm with an average value of 15.1 cm. Length frequency distribution, length-weight relationship and sex ratio were analyzed.

In this study we examined the possibility of conventional electrokinetic treatment of electroplating sludge as well as the application of galvanic instead of electrochemical cell. The following efficacies were achieved by using the electrochemical and galvanic cell, respectively: 45 and 43% for Ni, 43 and 16% for Cu, 30 and 27% for Zn and 46 and 38% for Cr. Although sludge is hazardous after treatment, significant metal contents were removed so the metal recycling can be accomplished. It can be also concluded that similar efficacies were accomplished after using galvanic and electrochemical cell for EK treatment.