Anionic clays (layered double hydroxides) comprise positively charged layers with at least two different metal cations, octahedrally coordinated by hydroxyl groups. The positive charges of layered double hydroxides are counterbalanced by interlayer anions. The interlayer anions and water, which fill the interlayer space, are often labile. Therefore, anionic clays exhibit anion exchange capacity (AEC). Anionic clays which have a high surface area and a high anion exchange capacity, are potential adsorbents for anionic contanimants, such as the oxyanion of chrome. The adsorption study of chromium (VI) from aqueous solutions by natural cationic clay mineral (kaolinite, montmorillonite, etc.) was not given much attention, perhaps due to the fact cationic clays have negatively charged layers and clay mineral surface shows no affinity for oxyanion of chrome.

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.

In the present paper it is presented application of Daily Egg Production Method (DEPM) to the anchovy (Engraulis encrasicolus L. 1758) stock in the open part of Montenegrin coast. This article is based on the research done within the frame of AdriaMed Project.

A batch adsorption test was conducted to examine the adsorption characteristics of cadmium and copper on bed sediments of the Sava river and its relation to the concentration of dissolved metals. The adsorption of ions were studied using equilibrium technique as a function of adsorbate concentration. The adsorption data, over the whole range of concentrations used, follow the Langmuir adsorption isotherm. Cu2+ and Cd2+ adsorption isotherms were measured on some sediment samples obtained from 3 different sites.

Water quality conditions of the Tatarnica canal are considered in this paper. Tatarnica is also the main canal of Begec drainage system, which is situated about twenty kilometers from Novi Sad on the west. Water quality of this canal is important, beside others, because its inflow into Danube is near Begecka Jama, which is representative of natural garden with special ecological asset. Results of investigation on this locality during three years are analyzed and presented. According the most relevant water quality parameters from predominant number of samples, water belongs to required category. Sometimes, a bad water quality are recognized, usually when organic pollution was appear, which influence higher value of BOD5.

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 allochthonous aquatic macroinvertebrates and fish species represent a potential danger to the autochthonous diversity. Hydrobiological research conducted during 2008 under the development of medium-term programmes for fishery improvement in Serbia, showed that some of the allochthonous aquatic macroinvertebrates and fish species have expanded their areals to a new water habitats. Artificial lakes (reservoirs) proved to be very suitable for the population of allochthonous species, where they become numerous most of the time. New habitats were found for allochthonous aquatic macroinvertebrates species: shells (Dreissena polymorpha, Sinanodonta woodiana) and American crab (Orconectes limosus), and for fish species for Micropterus salmoides. It was also determined that fish populating is a good way to inhabit and expand new habitats with allochthonous species of aquatic organisms.

Barje reservoir, established by damming of Veternica river, 30 km upstream from Leskovac town (Serbia), was intended for water supply of communities of Leskovac and Lebane. From its final formation and attaining of maximal volume (1995), long-year investigations have performed, and they included morphometric, chemical and biological parameters (phytoplankton, zooplankton, benthic fauna and ichthiofauna). The results of these hydrobiological investigations have showed that the reservoir Barje is unstable. In according to recommendation for continual following of condition of Barje reservoir, investigations of phytoplankton were repeated in spring and autumn aspects in 2005, and quality of the water was determined on the base of algae. The results of saprobiotic investigations show that the type of water is oligo-beta saprobic, but dense populations of eutrophic species (Fragilaria crotonensis and Closterium aciculare) indicate on deterioration of trophic conditions in this reservoir.