Carmen Daniela Petcu

RESEARCH REGARDING THE BACTERIOLOGICAL PARAMETERS OF MUREŞ RIVER WATERS

The study followed the microbiological charge of Mures River on a flow of 10 km above and 10 km below Târgu Mures city. There were water samplings in January, April, July and October from seven points, respectively: above Târgu Mures (P1), city entrance (P2), city - Libertăţii quarter (P3), Cristesti above purification station (P4), Cristesti below purification station (P5), 8 km below the city (P6) and 10 km below the city (P7). From the samples there were done the following microbiologic determinations: total coliforms number, fecal coliforms number, fecal streptococcus and sulphites-reducing bacteria. The determination was performed in accordance with STAS 3001/1991 and the results interpretations were done in accordance with the Order of Ministry of Waters and Environmental Protection number 1146/2002. After the research we reached the following conclusions: - In all seven sampling points between 10 km above and 10 km below Târgu Mures city there were determined coliforms germs, enterococcus and sulphites-reducing bacteria during all seasons. - The lowest number of bacteria was recorded in sampling point no. 1, situated at 10 km above the city and the highest number at sampling point no. 2, from city entrance. - The level of values recorded at the city entry point is explained by one recreational area and also by the release of used waters from a mink farm. - It is obvious the seasonal evolution of bacteria from the four determined groups, with lower values during winter, slightly higher during spring and higher during summer and autumn. - The sulphites-reducing bacteria are present in all the analyzed samples but in sensible reduced number than the other groups. - According to the ratio between fecal coliforms bacteria and fecal streptococcus, the fecaloid pollution of Mures River waters is of human nature during summer in sampling point 3 (inside the city), of animal nature in point 1 and mixed in the other sampling points.