Physico-chemical parameters and bio-contamination assessment through protozoan cysts and helminths eggs were carried out from the period of June to September 2010 in order to appreciate the pollution of the Danube River Basin in Romania. It recorded a higher tenor in Magnesium ion (60 mg/L) with respect to the calcium ion (20 mg/L). Other ions identified at substantial proportions were iron (1.459 mg/L), manganese (6.583 mg/L), phenol (12.780 mg/L) and Aluminium (0.0441 mg/L). Twenty one ciliated protozoa were identified in our analysis of water in the Danube River. Prominent was the presence of Caenomorpha medusula and Metopus ovatus which are indicators of polysaprobity. Resistant forms of enteropathogenic protozoa were present in our samples. These are Cryptosporidium sp (65 oocysts/l in August), Entamoeba histolytica (22 cysts/L in September), Giardia sp with 30 cysts/L in August. The helminths identified were Ascaris lumbricoides, Clornochis sinensis, Diphyllobothium latum, Enterobius vermicularis, Heterophrys heterophrys, larva of strongiloides stercoralis and Taenia sp. There is a low impact of natural depollution mechanisms which can functionally reduce the impending effect of the communicable diseases that are being transmitted by humans who constantly explore this aquatic medium during their leisure or economic activities.

In order to contribute with date to the Danube River Basin which is a prime European waterway, this analysis was carried out on the one hand to investigate the possibilities of sanitary risks that are incurred by the riverside population as they are engaged in professional recreational activities that impose a direct contact between man and water, that is intensely developed along the aquatic system and on the other hand to indicate a clear cut picture of the final level of coliforms and Escherichia coli that is actually present in the Galati industrial segment of the Danube River. Total coliforms, faecal coliforms and E. coli could attain values reaching 1.5×10 3 , 9.5×10 2 and 6.4×10 3 CFU/ml, respectively for the aquatic ecosystems analysed. A variation of these parameters with respect to the ecodynamical characteristic of the Danube water quality such as temperature, pH, total dissolved solids, salinity and hydrogen sulphite reveal the preponderant role that abiotic factors play in the dispersion of biocontaminants in a broad basin ecosystem. While the persistence of E. coli during the sampling period from June to September confirm the fact that there is a continuous faecal pollution of this medium. The high presence of organic pollutants in this medium, combined with the presence of coliforms and E. coli, could be related to an accumulation of waste matter all along the ecosystem, also due to the lack of wastewater treatment plants for domestic and industrial discharges, the high impact of human activities across the international river basin and the difficulties encountered in the natural operational processes of self purification.

The slags are an important waste and by-products of metallurgical industry. The present paper summarizes results obtained from physical and chemical analyses on metallurgical slag provided from S.C. "Mittal Steel Galati" S.A. The physical structure and gradation of granulated slag depend on the chemical composition of the slag, its temperature at the time of water quenching, and the method of production. The following mineralogical components were noticed through bypowder X-ray diffraction analysis (XRD) and the chemical analysis of metallurgical slag: cristobalite (SiO 2 ); gehlenite (2CaO•Al 2 O 3 •SiO 2 ); corundum (Al 2 O 3 ); sillimanite (Al 2 O 3 •SiO 2 ); pyrope (3MgO•Al 2 O 3 •3SiO 2 ); dicalcic ferrite; calcium orthosilicate. It is very important to analyze the content of the free calcium oxide and free magnesium oxide. The chemical reaction between blast furnace slag and water is slow, but it is greatly enhanced by the presence of free calcium oxide and free magnesium oxide getting on calcium and magnesium hydroxide which would make the aggregates obtained through slag processing disintegrates. These alkalis can modify the mechanical properties of slag. The elimination of this problem is effected through controlled cooling of the slag and through its aging, meaning, and the continuous watering of it. Blast furnace slag is mildly alkaline and exhibits a pH in solution in the range of 10 to 12. Processed slag exhibits favorable mechanical properties for aggregate use including good abrasion resistance, and high bearing strength. By our assessments it was proved that the blast furnace slag from S.C. "Mittal Steel Galati" S.A. have comparable properties of granite. The presence of Fe (+2) and Fe (+3) →Fe (total) oxides in the metallurgical slag composition makes its gross density be greater thus being possible to compare it to natural rocks. During the determination of the resistance to frost-defrost (chemically and physico-mechanically) very similar values were obtained through both processes due to the slow cooling process of metallurgical slag and implicitly to the formation of its crystalline structure.

The natural depollution mechanisms often reach a low impact level in the case of lakes situated close to major urban settings. We are presenting the assessment of the eutrophication potentialities of Lake Brates, situated in Galati County (Romania). The results may be considered a case study, as the Lake Brates receives an estimated 800 visitors/month for recreational, aquacultural, domestic and industrial purposes. Experimental measurements in order to determine the contamination of Lake Brates, which incurs an enormous social and economic potential. Low oxygenation, high alkalinity, water hardness, organic content, and increasing values of the nitrate and phosphate ions place this endorheic lake in a eutrophic-hypertrophic limnic ecosystem. The presence of Metopus ovatus, Caenomorpha medusula, and Vorticella campanula reveal a high pollution status, while the high abundance of the resistant forms of Cryptosporidium spp

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