This work shows the effects of opening the Itebej sluice gate on the metals content of the water and sediment of the Begej canal. A deterioration in water quality resulted, in particular on the first day after opening of the sluice gate, when high concentrations of Zn, Cr, Cu and Pb were detected. The metals content of the surface sediments across the canal at Klek had significantly higher concentrations of Pb, Cr, Zn, Cu and Hg five days after the opening, whereas there were no obvious changes at Itebej. From the metals content of the suspended sediment it can be concluded that the increase in metals contents occurred one day after opening the sluice gate.

This paper presents the results of assessment of dredging activities at the Romanian side of the channel on the quality of water and sediment in the Begej channel (in Serbia). Sediment monitoring results have pointed to the increasing content of metals in surface sediments, as well as increased concentrations of some metals (Cd, Ni and Cr) compared to the period from 2008. Results of the water quality after the dredging at the Romanian side shows low metal concentrations, which is probably caused by coprecipitation of metal in the iron in forms of amorphous and hydrated oxide. Monitoring of water and sediment should be conducted continously through the year in order to follow the trend of sediment and water quality and targeted when we know the exact time of some of the activities in the channel.

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.

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).

The objective of the paper is establishing of eco-chemical characterization of the river system by investigating and distribution heavy metal content in the river sediments using sequential extraction and total digestion. Heavy metals toxicity and bioavailability in the Danube river sediment are defined according to their distribution between different phases. Sediments samples were taken from 9 sites and analysed for cadmium (Cd), iron (Fe), manganese (Mn), lead (Pb), copper (Cu), zinc (Zn) and chromium (Cr), and the results about cadmium and iron presented in this paper.

Investigation in this study should indicate to importance of aquatic macrophytes in accumulation of toxic metals in aquatic ecosystems and control of their pollution, as well as to establish which plants are well hiperacumulators and test species for remediation, in order to protection, regeneration and conservation of the Gruža lake as reservoir that is important for water supply and as particular natural ecosystem. Obtained results showed that species Lemna gibba L. was reliable indicator of surrounding conditions (environment), as well as good accumulator of heavy metals, so it could be used to remediate aquatic ecosystems.

The paper presents the results of different methods of sequential extraction of metal in sediment of the Great Backa canal in order to obtain data on the total, available and potentially available contents of heavy metals as well as risk assessment in aquatic systems. Based on the results of sequential extraction of metals was found that sediment does not have the risk to the environment in terms of Cr, Cu and Pb concentration while the contents of Ni, Zn and Cd sediment indicates a moderate risk. Results of sequantial extraction of metals indicate that the risk to the aquatic ecosystems decreases in risk assessment based on the pseudo total metal content in the sediment. Thus the results suggest that not all detected metals are bioavailable and that not only on the basis of total metal content of the actual risk may be overestimated.

This study investigates the possibilities of using Lagenaria vulgaris biomass as a biosorbent for removal of heavy metals from wastewater and natural water. The experiments were carried out with model solutions of Pb2+, Cd2+, and Zn2+, in batch system. The effects of contact time, temperature, initial metal concentration and adsorbent doses, on the adsorption of heavy metals have been studied. Results show that biosorbent based on Lagenaria vulgaris represent efficient and low-cost means for pretreatment of heavy metals contaminated waters.

In this work, the horizontal and vertical distribution of metals in the sediment of the DTD canal was studied, in a 6 km long polluted section between Vrbas and Bezdan. The assess sediment quality and the bioavailability of heavy metals, sediment samples were analyzed for total metal content, acid volutile sulphides (AVS) and simultaneously extracted metals (SEM). A high total metals content was determined (mainly Cu, Ni and Zn), which indicates that the sediment requires remediation. The AVS and SEM results show that in almost every profile, the molar concentration of metals is less than the molar concentration of sulphides, which suggests that in practice, the metals are not bioavailable. The high metals content of the sediment means that drudging of the canal will be necessary, during which, attention will have to be paid to avoid causing negative effects from the metals present in the sediment.

Stable complexes formation caused by usage of complexing agents as additive in plating solutions, made waste water treatment aggravated and expensive. The investigation results of samples that contain some cations expected in waste waters from this type of facilities, are presented in this paper. The precipitation of disolved heavy metals by neutralization, in the presence of strong chelators, do not give requested results. The dithiocarbamates are effective in complexing heavy metal ions forming insoluble compounds, with solubility far below that of the corresponding hydroxides. Inductively Coupled Plasma Optical Emission Spectroscopy is used for wastewater samples analysis. After the reduction of Cr6+ into Cr3+ ions and homogenization, dithiocarbamate is added. Modified neutralization process with unchanged retention time and pH 9.0 +/- 0.2 results the Law permitted wastewater quality.