Management of aquatic ecosystems and planning of their protection needs good knowledge about their conditions. Mathematical modeling becomes one of the basic things in that processes. Last decades was attain important progress in quality at the beginning relative modest models of aquatic ecosystems. During the analysis of existing experiences to forced a conclusion that a quality model in one's own structures needs proportional representation of hydrodinamic and ecology background.

The sampling of Crnojevica river has been carried out, because of estimation the correlation between main water quality parameters and precipitation impacts, as well as adequate hydrological parameters. An appropriate dynamic sampling has been applied. Continuous pollution of river water has been confirmed, as well as source of the pollution. It is estimated strong correlation of water quality parameters from precipitation quantity and water level, especially for sanitary pollution. Change of quality parameters value is discrete and accidental.

In recent works enzymatic phosphatase activity state as a new potential good indicator for water saprobity and trophic state in water. On water reservoir 'Grliste' reinstated monitoring on the base physico-chemical, microbiological and biological analysis from beginning works water factory 1990 but, from 1998 use of this new biochemical method in monitoring as reliable additional indicator in fast preliminary water quality and the ecophysiological state of water. According to the results obtained for index of phosphatase activity (IFA) (Matavulj, 1986) water of 'Grliste' water accumulation belongs to category 3-A (polluted water).

The examined period is characterized by small floristic variety and well advanced eutrophication process. By the phytoplankton qualitative analysis it has been noted the domination of Bacillariophyta algal division. The values of density on phytoplankton population and their biomass show the domination of bluegreen algae, before each other, that of the species Gomphosphaeria lacustris Chod. As the consequence of the eutrophication, these algae develop intensively, up to the degree of water blossoming. The very high concentrations of the primary and secondary nutrients have also been noted. The trophic status of the reservoir on the basis of OECD classification can be defined as eutrophic.

Dutch classification system for sediment pollution was applied at the Begej canal in Serbia (Serbia and Montenegro). The method used calculates the class of the sediment on the basis of the sediment composition, organic matter fraction and mineral clay fraction as well as data on ecological risks. Results obtained showed that sediment is heavily polluted and urgent remediation is necessary. The contamination consists of heavy metals, especially cadmium, copper and chromium (class 4). Regarding organic micropollutants some high levels of PCB's and organochlorine pesticides like DDT/DDD/DDE were found (class 3).

This paper presents general characteristics of water source Mareza, which has been used for water supply of the town of Podgorica, as well as potential risks that can affect water quality of this source. Measures for the source protection in order to maintain existing high quality of the source water are presented.

The paper presents the results of a pilot study of the combined process of ozonation and filtration through biologically activated carbon to remove residual organic matter in the process of drinking water production. It was established that the application of these procedures resulted in the removal in average of 74% PB, 50% TOC, 60% of total aldehydes, and 54% PFTHM, the result being a consequence of the adsorption/biosorption processes involved.

In this study, the possibility of application of agricultural lignocellulosic waste materials as adsorbents of different heavy metals ions from water was investigated. As adsorbents, wastes of widely cultivated plant cultures in our country were used. They were wheat straw, cornstalk, corn cob and soybean straw. These materials were showed as good adsorbents in most cases. But, leaching of organic matters from them during adsorption was observed. It was unfavourable. Because of that, adsorbents washed and dried. After that leaching of organic matters was significantly decreased, but also adsorption efficiencies slightly decreased, too.

Until recently, the wetlands have been destroyed as worthless areas due to the ignorance of their role in the processes that take place in the stream corridors. The paper presents an overview of their roles in the hydrologic cycle, biogeochemical cycling and supporting biodiversity. In addition, their significance in the stream corridor preservation, protection and restoration is discussed. Both, the knowledge of their role in and their significance for the stream corridors, is essential for preventing further imprudent destruction thereof, successful planning and preparation of the stream restoration projects, and the recognition of their possible usage in satisfying human needs.