Monthly sampling in the Grosnica water reservoir near Kragujevac, Serbia (Yugoslavia), was carried out in the period October 1996 - September 1998. Comparison of the results with those obtained in 1950-1952 revealed changes in the qualitative and the quantitative composition of zooplankton. The presence of a considerably greater number of species was recorded, including some that were registered for the first time in this reservoir and which represent a very significant component in the dynamics of its zooplankton. A multi-fold increase of zooplankton production was also observed. The number of recorded species fluctuated from 26 in the winter to 59 in the summer. Average total abundance of zooplankton ranged from 100.7 ind./l (late spring to 2508.6 ind./l (summer). The results indicate an intensive process of eutrophication in the Grosnica water reservoir, the oldest artificial lake in the this part of Yugoslavia.

In this paper there were given research results obtained during many years of investigation of hydrophytes of the Tisza river, Serbia (Yugoslavia), and their bioindicating values. The plant world of the Tisza river is characterized by floristical diversity, with three characteristics band: band of submerged, band of floating and band of emerged hydrophytes. Among submerged plants these are distinguished by abundance, covering values and occurrence degree: Ceratophyllum demersum, Elodea canadaensis, Potamogeton crispus, Potamogeton perfoliatus and Potamogeton pectinatus. In the floating band species of the fam. Lemnaceae: Lemna minor, Lemna gibba, Spirodela polyrrhiza and Potamogeton fluitans are most frequent. In the closest coastal band, these species are most frequent: Typha angustifolia, Typha latifolia, Phragmites communis, Sagittaria sagittifolia and Typhoides arundinacea. On the basis of determined floristical composition and bioindicating values there can be noticed the organic pollution increasing trend.

The present paper cites results of studying phytoplankton in the Grosnica Water Reservoir, Serbia (Yugoslavia). Seasonal investigations during 1997 and 1998 enabled us to establish composition and structure of the phytoplankton community, quality of the lake's water, and its trophic status. During the period of investigation, the phytoplankton community was characterized by forms of Cyanophyta, Pyrrophyta, Chrysophyta, Bacillariophyta, Euglenophyta and Chlorophyta. Qualitative analysis indicated that algae of the divisions Bacillariophyta and Chlorophyta are dominant in the phytoplankton, while saprobiological analysis using bioindicatory algal species showed that water of the Grosnica Water Reservoir during the given period was of the 1st and 2nd quality class.

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This paper presents some preliminary results on the implementation of a biodegradability batch test to fraction different types of wastewater samples to assess the variability of the WWTP influent composition.

[Departement_IRSTEA]GMA [TR1_IRSTEA]21 - TECHNEAU / EPURE | This paper presents some preliminary results on the implementation of a biodegradability batch test to fraction different types of wastewater samples to assess the variability of the WWTP influent composition.

Studies were conducted to assess factors that may influence the rate and extent of biodegradation of polyaromatic hydrocarbons (PAHs) in waters of Guayanilla Bay (latitude, 18°N; longitude, 66.45°W) Puerto Rico. Phenanthrene was used as a model PAHs compound. Both the rate and extent of phenanthrene degradation by natural microbial flora present in seawater samples from Guayanilla Bay were quite slow. Addition of KNO3 as a source of inorganic nitrogen (N) resulted in a 10-fold increase in the rate of phenanthrene degradation within a 125 h period, whereas, addition of K2HPO4 as a source of inorganic nutrient phosphorus (P) had no effect. Phenanthrene degradation was strongly inhibited when seawater pH was adjusted to 10.0. Phenanthrene in seawater samples degraded rapidly when first pretreated with hydrogen peroxide (H2O2) and then inoculated with a known indigenous phenanthrene degrading bacterium, Alteromonas sp. Pretreatment of phenanthrene with Triton-x-100 had little or no effect on its degradation by the same bacteria, whereas, degradation in samples preheated at 60°C was somewhat inhibited.

La pollution des ecosystemes terrestres par du cadmium d'origine industrielle (usine d'engrais phosphates) se traduit par des taches necrotiques au niveau des feuilles et par une accumulation importante de cet element dans ces feuilles et dans les horizons superficiels des sols. A proximite de la source d'emission, les taux de cadmium dans le sol depassent 10 fois les valeurs normales. Au niveau des feuilles, elles sont 10 a 30 fois plus elevees que chez les temoins et dependent de la nature de l'espece, de la distance (correlation negative) et des conditions topographiques