The paper presents the results of orthophosphate concentration trends in waterflows in Serbia, using the method of non-parametric Mann-Kendal test. Data used for these purposes were provided by Republic Hydrometeorological Service of Serbia (RHMZ), sampled on average once a month for the period 1998-2007. Measuring places are shown on the waterflow map by adequate symbol for the various kind of trend and colour of symbol for the intensity of orthophosphate concentration. Statistical analysis of trends is discussed within the comparative review of methods of linear regression and Mann-Kendall test.

Water quality monitoring of surface waters encompasses the watercourses of the river basins of Una, Vrbas, Bosna, Drina, Ukrina and the direct Sava basin. Apart from comprehensive analyses which demand determinations of physical - chemical characteristics, as well as the ihtiofauna composition, special emphasis is given to the analysis of the macrozoobenthos. As a part of all water ecosystems, benthic invertebrate serve as a reliable indicator of the quality and changes of the environment, due to a series of advantages in relation to other communities. Most of the aquatic habitats, especially flowing waters of good quality of water and benthic state, enable various of benthic invertebrates communities with moderate formation of species within the overall number of the present individual species. This kind of communities react to possible changes in the community composition (abundance and macroinvertebrata composition).

The results of sediment quality monitoring gathered during the period 2002-2008 were processed and shown in the current work to assess the overall sediment quality in Vojvodina watercourses regarding heavy metals content. Since Serbia does not have legislation for sediment quality, Canadian and Dutch sediment criteria were used for evaluation of sediment quality. The elevated concentrations of heavy metals in Vojvodina watercourses are a consequence of the discharge of untreated or partially treated industrial and municipal wastewaters, but also of the corosion of metal structures and constructions (Cu, Zn) as well as the influence of difussion sources, principally agriculture (Cd, Cr, Hg) and transport (Pb).

Water quality analysis of Zelengora natural lakes, were included researches of Kotlanicko, Orlovacko and Lake Donje Bare. Apart from comprehensive analyses which demand determinations of physical-chemical characteristics, special emphasis is given to the analysis of the makrozoobenthos. As a part of all water ecosystems, benthic invertebrate serve as a reliable indicator of the quality and changes of the environment, due to a series of advantages in relation to other aquatic communities. Most of the aquatic environments of good quality of water and benthic state, enable various of benthic invertebrates communities with moderate formation of species within the overall number of the present individual species. This kind of communities react to possible changes in the community composition (abundance and macroinvertebrata composition).

The aim of this paper is to present the use data of aquatic macro-invertebrates community, beside abiotic parameters, to define typology and type of specific reference conditions and index of ecological status, to contribute to the establishment of the system of ecological status/potential of surface waters in Serbia. The investigation involves macroinvertebrates as biological elements that have been widely used in implementation of the Water Framework Directive.

Arsenic is inorganic spread out in nature. Toxicity of arsenic is different, depending on its form. However, current international and Serbian legislation in drinking water regulate maximum allowed concentration of 0.010 mg/l (of total arsenic), regardless of its form. Concentration of total arsenic in water of springs of mountain Avala (Serbia) is higher than 0.010 mg/l. This paper present determination of inorganic arsenic in drinking water of spring Sakinac (Avala), also determination which form is more represented, relation of As(III) and As(V) and implementation of legislation. We used stripping voltametry method and gain value of total arsenic-62.87 microgram/l, in which 3.97 microgram/l is As(III) and residue of 58.90 microgram/l is As(V). It is obvious that value of 62.87 microgram/l is higher than MAL, but the most abundant arsenic form is less toxic, so the question is whether the water from spring Sakinac can or cannot be used.

Groundwater from the middle Banat region (Serbia) which is used as a drinking water supply for Zrenjanin town contains a high amount of natural organic matter and a high content of arsenic. In this study a pilot-scale system was used to investigate the influence of different ozone doses (0.4-0.9 mg O3/mg DOC) during a pre-ozonation process on NOM removal by coagulation. Ferric chloride coagulant was chosen at a dose of 100 g/cubic meter, as a traditional coagulant which can also help in arsenic removal. The obtained results indicate that an ozone dose of 0.4 mg O3/mg DOC has the best influence on structural changes of NOM. The coagulation process with ferric chloride as coagulant had a significant influence on the arsenic content of the water, with the measured values in the water after coagulation in all three investigated treatment trains being below 10 microgram/l, which is the standard MCL in Serbian legislation.

In the paper is presented the microbiological quality of groundwater of drinking water supply Strand which is important water source for the city of Novi Sad (Serbia). The examinations were carried out using high and low nutritive media. The count of physiological groups, that are relevant from the aspect of organic pollution and phosphatase activity were also monitored. The results indicate potential organical pollution and need for protection of the water supply Strand.

This paper presents the concentration of Pb, Cd, Zn, Cu and Ni in the surface sediment samples, determined by EDPXRF. Also, a horizontal distribution of these metals is given for seven investigated sites in the coastal sea of Montenegro, from the entrace to the Bokakotorska Bay to the mouth of the river Bojana. A trend of increase in the concentration of metals with the distance from the coast is noticed in the studied area. The possible causes of this distribution should be sought in the direction of movement of sea currents in the Adriatic Sea as well as the fate of suspended material after entering the river Bojana.

Relatively dense network of irrigation channels in Vojvodina is exposed to various point and non-point pollutants impacts. Therefore, deposited channel sediments-sludges can be contaminated with high concentration of dangerous and harmful substances such as polycyclic aromatic hydrocarbons (PAH). These sediments could have long lasting harmful effects on environmental status, quality and usability of channel water, and especially on surrounding agricultural soil, where dredged sediments are deposited or scattered. In this paper above mentioned conclusions are illustrated by quality analysis of specific irrigation channels sediments in terms of PAH contents in them.