Desorption kinetics of chosen organochlorine compounds (pentachlorobenzene, lindane and pentachloroaniline) mediated by solid absorbent, XAD-4 macroporous ion-exchange resin, was studied for two different contact times of organic compounds and sediment (15 and 90 days) in order to determine the potentiality of using this sample and fast method for the assessment of (bio)availability of organic pollutants in sediment-water system.

The aim of this work is to present the trophic state of water at the pelagic zone of lake Prespa, reviewing the result of defined parameters of physico-chemical and algological aspect. Investigations are done according to standard limnological methods and the samples for analysis were collected from one vertical profile (0, 5, 10 and 15 m) monthly during 2008 year. Water categorization, on the basis of gathered data from analyses of the sampling localities was done according to the OECD-regulations, positive law regulations of the Republic of Macedonia and Nürnberg classification system. Data from this investigating period point out that this area of the lake Prespa is by great influence of the anthropogenic factor and intensive eutrophication.

The aim of this work is to present the water quality of littoral zone of lake Prespa, based on defined physico-chemical parameters (NO3, NO2, NH3, total nitrogen). Samples for analysis were collected with a monthly dynamics during 2007 year (April-December). This period is not chosen by chance, in regard to that the lake basin is constantly under the anthropogenic influence and climate changes that have been registered by this time. According to the obtained results of the performed analyses, basis of the water act of RM and OECD regulation, a categorization of the after was made in the respective measuring points.

Researches of the Zelengora natural lakes during 2008 were performed in Orlovacko, Kotlanicko and the Lake Donje Bare. Water quality analysis of natural lakes of Zelengora were based on preliminary examination of basic physical and chemical parameters, as well as microbiological parameters. In the scope of biological examinations, phytoplankton, zooplankton and benthic fauna were determined. Due to the lack of data on biodiversity of examined natural lakes and whole area of National park Sutjeska results obtained in this research could only represent the first step toward further examinations, as well as the nature and biodiversity preservation in the Republic of Srpska.

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).

Research of phytoplankton is conducted in different seasons during 2004 and 2005. River Bojana and Ada Bojana are analyzed on several locations. The objective of research is based on algae as reliable indicator of water quality and ecological condition of water. We would like to show the need for protection of these water ecosystems from permanent contamination, basically sewage waste. Saprobiotic index is determined by Gulyas Pal method. Pantle Buck method is used to calculate saprobiotic level. Chlorophyll A is analyzed by spectrophotometer. Presence of Cyanophytae was established.