Coagulation and flocculation can be efficiency applied in drinkling water treatment, in order to remove natural organic matter (NOM). However, in the experiments presented in this paper, the water used is very rich in NOM, and required investigations of additional processes. In order to increase the efficiency of coagulation and flocculation processes in removing NOM from groundwater, the following processes were investigated: adsorption on powdered activated carbon (5-30 mg PAC/l) and preozonation with applied ozone doses of 1.1-6.3 mg O3/l. The parameters used to evaluated the changes in NOM content during the experiment were: KMnO4 consumption, UV absorbance at 254 nm, pH and turbidity.

One of the last stages in purification of waste water is by aquaculture pond using macro biological cells - fishes. In such outdoor ponds, oxygen depletion events can occur at anytime, but most likely to cause fish kills during summer hot weather. Aquaculture pond model can predict dissolved oxygen using small number of measurements and very simple numerical model. Alarm system can be activated urgently when the oxygen level drops below a certain concentration, depending on fish species. Such a model is realized for WWTP at Citluk coal mine, close to Sokobanja in Serbia, and explained in this paper.

The length - weight relationship of juvenile anchovy, Engraulis encrasicolus at Bokakotorska Bay (Adriatic sea, Montenegro) was analyzed. The better knowledge of juvenile growth needs more attention for the entire Adriatic, especial for the Montenegrin coast were this investigation made for the first time. The results obtained from this investigation were compared with the data obtained from the period 1989-1991 from the area of Novigrad Sea of the the eastern Adriatic coast (5).

In the beginning of 2008, on the Montenegrin coast is confirmed finding of new species, what was unknown until now in this part of Adriatic sea. The Sphoeroides cutaneus is tropical species with habitat in warm sea around Japan, China and Indonesia. Probably is one of the Lessepsian migrant. It tooks around 130 years for a fish to come through Suez Canal and Red Sea to Mediterranean, then through Otrant Strait into Adriatic sea. It is possible, also that this apparition has something with the global climate change and temperature rise in saltwater in Mediterranean as well as in Adriatic.

The red algae Womersleyella setacea is Indo-Pacific species but introduced to Mediterranean Sea were is now relatively widely distributed. During research of benthic communities in Ponta Veslo locality (Lusnica peninsula, Montenegrian coast, Adriatic sea) in summer 2007 dense assemblages on rocky substratum and on sea grass Posidonia oceanica (L.) Del. rhizomes were discovered. The impact on biocenosis structure is discussed.

In Boka Kotorska Bay there are two recorded species of Copepoda from family Temoridae: Temora stylifera and Temora longicomis. This paper presents the data on horizontal distribution and abundance of these species during 2007. Temora stylifera has a wide horizontal distribution in coastal and open waters of Adriatic sea, while Temora longicomis is a typical representative of estuary-neritic waters of northern Adriatic, Kvarner area and the Italian coats at the west. Their abundance was particularly high in spring and summer.

In this paper some results of investigations of physical, chemical and biological parameters were presented from the parts of Montenegrin coastal sea exposed to the impact of the open waters of the Southern Adriatic sea. As Herceg Novi area is simultaneously the part of the Boka Kotorska Bay (which goes deeply to mainland), eutrophication is more visiable there. Biological parameters were the most visiable indicators of eutrophication during these investigations.

Lake ecosystems determined by trophic conditions, accurately defined Ecological status of protected area. Trophic condition of water of Lake Skadar and two rivers, the inflow Moraca and the outflow Bojana was described via plankton data considering abundance of phytoplankton, seasonal dynamics of organotrophs, cyanobacteria, total coliforms, plankton biodegrading potential and nitrogen fixing bacterioplankton. The trophic potential for phytoplankton growth has been detected in late autumn throughout September-November 2004, contrary to early summer June-July 2005, and adverse growth of bacterioplankton in May, June and September 2005, respectively. The results of quantitative analysis of coliforms showed good relation of Lake Skadar and Ada Bojana, contrary to similarities between Moraca River and Ada Bojana estimates in accordance with the Pantle-Buck index. Nevertheless, investigation pointed out Lake Skadar beta-mesosaprobic level and moderate self-purification rate. In evaluating trophic conditions the good ecological potential of protected area has been proposed.