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 indicate which plants are well hyperaccumulators and test species for remediation, in order of protection, regeneration and conservation of the Gruza lake as reservoir that is important for water supply and as particular natural ecosystem.

Aquatic macrophytes are exceptional accumulations of heavy metals and they are very important in phytoremediation of the pollutants. The aim of the survey was to show according to content of heavy metals in aquatic macrophytes DTD (Danube-Tisza-Danube) canal complex, at localities under great human influence indicate the situation of chemical contamination these localities and to define test species, actually the ones that have the greatest accumulation. Plant material was prepared according to the Standard Methods for Examination of Water and Wastewater of the American Health Association. Analysis of heavy metals in the plant tissue samples was done by standard methods using atomic absorption spectrophotometry. The best accumulator of majority of heavy metals is Ceratophyllum demersum. The results show that mentioned species can be used for removal of heavy metals from water, what means that it has the ability of phytoremediation of pollutants.

Seasonal dynamics of plankton in DTD hydrosystem in Backa region (Serbia) was estimated during the period June 2002-March 2003. More irregular cycles of the phosphorus level and plankton activities in DTD canal network gradually downstream (Northern Western - Southern Eastern channel direction) was observed. The plankton group of total coliforms was developing in early spring in the period of beginning of vegetation season and in summer, when the phosphatases of pH 5 and pH 9 have the highest activities, in all DTD sectors. In the assessment of trophic condition of DTD canal network, sectors of canals were corresponded with bacteriological analyses and level of phosphatase enzyme activities.

A monitoring program was organized with the aim of assessing the quality of sediment and water in Nadela canal regarding metal content (Cr, Cd, Cu, Ni, Pb, Zn, Hg). Water was the 1st/2nd class according to national requirements. The Canadian probable effect guideline value for sediment quality is occasionally or constantly exceeded for different metals. Mercury and zinc contents are in elevated concentrations and nickel shows a tendency for accumulation. The results obtained give a preliminary overview of watercourse imperilment.

In this study we analyzed the water quality of the Danube-Tisza-Danube (DTD) canal network (Serbia) in October of 2006. Selected number of microbiological parameters showing lowering of ecological potential was in accordance with quantitative plankton analyses and water phosphatase activity. Obviously, the high presence of coliform bacteria, diatoms indicating water high salinity (Cyclotella meneghiniana, Entomoneis paludosa) pointed to the considerable problems of canal water usage of the middle and southern irrigation/drainage DTD hydrosystem for agricultural watering purposes.

This paper presents the results of the Danube river water quality analysis, using the data set for the period of 2001-2005, provided by the Hydrometeorological Service of Republic of Serbia. Main input parameters - data on water quality resulting from sampling performed generally once per month for relevant parameters, are used according to Water Quality Index (WQI) methodology. Data grouped on a sampling site basis, averaged on a yearly level, resulting with a median WQI of each sampling station are employed to create a synthesized quality indicator. Final result of such an analysis shows a general deterioration of quality expressed using WQI for the observed period.

Region of Banat (Serbia) could solve a problem concerning drinking water by construction of a regional water supply system. These issues are elaborated in the Pre-feasibility Study for the construction of regional water supply system Dubovac-Zrenjanin-Kikinda, which is based on a concept of centralized water supply system, providing water from the unique source to the municipality centers. Some solutions concerning these issues with feasibility analysis are presented in this paper.

Iron-related well-screen encrustation and aquifer biofouling has decreased the specific capacity of RB-7 well. This paper describes the role of iron-related bacteria in the encrustation process and relates their occurrence to chemical conditions in the well.

Water wells are among the oldest hydraulic engineering structures in the world. Today, hundreds of water wells service water supply systems in Serbia, and groundwaters are widely used for public water supply. Extensive practical engineering experience in water well operation has identified a number of problems which affect well service life and capacity (i.e. reduce specific yield). Some of the encountered problems are, also, a result of microbial activity in groundwater. Products of life processes of groundwater specific microbial community cause biocorrosion, blockage, closure, plugging, deposition, and biofouling of well screens and collectors. We applied BART biodetectors as a reliable tool in monitoring well rehabilitation effectiveness. This paper presents several process assessments based on BART biodetector tests conducted at Belgrade groundwater source.

Filamentous bacteria are commonly found in activated sludge. If numerous, they can cause bulking problems. In order to control their number in a system detailed identification of filaments is necessary. In Subotica Wastewater Treatment Plant (WWTP) daily analyses of filamentous bacteria were performed from January 2006 till March 2007. The dominant and constantly abundant was Thiothrix sp. The filaments of Haliscomenobacter hydrosis and Type 1863 were also common (moderately numerous with periods when develop massively). Nostocoida limicola was frequent, but not numerous. Sphaerotilus natans was numerous in some periods when even dominant. Type 1701, Beggiatoa sp. and nocardioform actinomycetes were rarely found and were not abundant.