In the period of 1993-1996 water quality of the Bajski canal (Serbia, Yugoslavia) was followed using certain chemical and biological parameters. Oxygen control ranged from its deficiency to its supersaturation recorded in spring and early summer which moved down in summer and early autumn. A smaller amount of suspended particles points to a sedimentation process provoked also in the canal bed, clearing the way for the development of macrophytes. A diverse zooplankton showed typical seasonal variations. A total of 73 species was recorded including 13 Protozoa (17.8%), 44 Rotatoria (60.3%), 10 Cladocera (13.7%), and 6 Copepoda (8.2%). In summary, the process of water quality deterioration is less evident in this section of the DTD (Danube-Tisza-Danube) hydrosystem (Serbia, Yugoslavia).

Owing to the habit of most of Yugoslavs to prepare coffee without filtering, the large part of used coffee comes to recipients. In this paper, the influence of coffee deposits reaching recipients in Yugoslavia is analyzed. Results of laboratory examination of the biodegradability and kinetic of biodegradability of coffee deposits are also presented.

The river Tara (Montenegro, Yugoslavia) is under the treatment of the international (UNESCO) and domestic legal protection, so the prescribed quality of its water is the 1st class. Permanent measurement of the water quality of this river shows that due to the influence of the human factor, its quality has been endangered. Examination of the data collected through many years at all the measurement station along its current shows that the quality of water and pollution estimate have changed.

In this paper, the results of statistical analysis of then years water quality data of Tamis river at the Romanian-Yugoslav border ("Jasa Tomic" Control Station) are presented. Following changes of analyzed water quality parameters at the Romanian-Yugoslav border a strong trend of deterioration has been observed during analyzed period. Because of periodical accidentally high organic content (COD, BOD) and concentration of ammonia and organic nitrogen in river water, it is concluded that upstream discharging of farm waste waters was the main reason of deterioration of water quality along the Yugoslav part of Tamis river.

The paper provides a report on the quality of water of the Kolubara river and its tributaries, the Ljig and the Pestan, for the period 1992-1996, on the basis of results obtained in the course of regular examinations carried out by the Republic Hydrometeorological Service of Serbia (Yugoslavia). The examination of the waters of the Kolubara river region is significant in view of the vinicity of developed industry, since the wastewater of such an industry represents a potential pollutant of the adjacent rivers. The paper also provides a separate review of the heavy metals contents of the examined rivers. The obtained results indicate to periodical deviations of the water from the required quality, that represents, without any doubt, the pollution of anthropogenic origin.

Drainage of industrial and communal effluents, directly into the water flow, as many hydrotechnical activities, significantly influence the schedule and balance of the processes that take place into water. In this paper, there are represented the results of systematic control of the water quality of the Danube river and DTD (Danube-Tisza-Danube) channel on the parts Vrbas-Bezdan and Becej-Bogojevo, at the control station network of the Republic Weather Bureau (the Republic of Serbia), for the period of 1991-1996. The results show that the most adverse influence of anthropogenic factor is on the part of the flow of the DTD (Danube-Tisza-Danube) channel from Vrbas to the flow into Tisza river.

The results of the determination of PCB (polychlorinated biphenyls) residues by gas chromatography, in the samples of underground water of one alluvial well of the river Danube (Serbia, Yugoslavia) have been presented. The residues of PCB (polychlorinated biphenyls) in examined samples (February-March period, 1997) were detected.

Spectrophotometric method for determination of inorganic phosphate liberated in hydrolysis of ATP catalyzed by ATPase was modified in order to obtain faster procedure, which could also be used in none laboratory conditions. The modification has some advantages compared to the most used Pennial method: a) the reagents are stable for several months; b) the 45 min procedure of phosphomolibdate extraction by isobutanole-benzene is ommited, and the method is not dangerous for the analyst; c) color develops after 20 min. The method was tested on the determination of inorganic phosphate in the presence of cadmium nitrate as inhibitor of ATPase activity. The results were compared to the results obtained by Pennial method. The results obtained have shown some good agreements.

The work is concerned with the possibility of inactivation of galvanic sludge formed in treatment of wastewaters of electroplanting plants by imbedding the waste in a glass material. Glass can be synthesized in contact with the waste by mixing and heating with glass constituents. The efficiency of inactivation was monitored by leaching the obtained materials. The results of leaching tests showed that the highest amount of electroplanting sludge (about 30%) can be inactivated by vitrification of the following mixtures: 26.3% of electoplanting sludge, 43.7% of sand, and 30.0% of Na2CO3 at 1000 deg C; 30% of galvanic sludge, 49% of sand and 21% of Na2CO3 at 1100 deg C.