Over the last three decades, many scientist, national and international agencies were concerned about pollution of the Romanian environment, especially water and its impact on human health. This research includes studies and interpretations resulting from chemical and bacteriological analyzes of water samples collected from wells or underground springs from central north-western part of Romania. The water parameters were determined using standard analytical methods: pH, turbidity, oxidability, ammonium, nitrates, nitrites, chlorides, total hardness, conductivity, mesophilic heterotrophic microorganisms, coliforms, E. coli, intestinal enterococci. Regarding non-compliant samples, the main problem is the bacterial load of water, confirming domestic pollution sources of water. More than 50% of the analyzed samples, which had concentrations of nitrate over 10 mg/L were also found bacteriological inappropria

This paper presents a study of the physico-chemical properties of geothermal fluids, coming from some wells in Sacuieni, Bihor County, Romania. The thermal energy of the geothermal waters studied is used for heating some industrial buildings, greenhouses, and administrative buildings. Continuous monitoring of physical and chemical characteristics of geothermal waters is needed. Based on this fact, a classification of these waters has been made according to their chemical composition. Using a silica-enthalpy thermodynamic model, it was possible to estimate the deep reservoir temperature, and compare it with the temperatures at depth, calculated by the silica (quartz and chalcedony) and Na+/K+ geothermometers. The WATCH program is used to estimate the mineral deposits that may accumulate due to boiling and cooling of the geothermal fluid when it is used in heat exchangers The results are confirmed by XRD spectrometric and thermogravimetric analyses.

In this paper presents ternary diagrams for geothermal waters from two wells in Săcuieni: ternary diagram Na-K-Mg, ternary diagram Cl-SO4-HCO3 and calculation model, which allows location of geothermal fluids in these diagrams. Classification of geothermal water with the two diagrams, involving knowledge of their chemical composition. Thus, it was the chemical composition of geothermal water coming from drillings: 1704 Săcuieni and 752 Săcuieni, situated in Bihor county. Location of geothermal water on the two diagrams we will establish the type of water, depending to the presence in their content of major anions and cations, what is of great importance for use in various purposes of the geothermal fluids.

This paper presents a study of the physico-chemical properties of geothermal fluids, coming from some wells in Sacuieni, Bihor County, Romania. The thermal energy of the geothermal waters studied is used for heating some industrial buildings, greenhouses, and administrative buildings. Continuous monitoring of physical and chemical characteristics of geothermal waters is needed. Based on this fact, a classification of these waters has been made according to their chemical composition. Using a silica-enthalpy thermodynamic model, it was possible to estimate the deep reservoir temperature, and compare it with the temperatures at depth, calculated by the silica (quartz and chalcedony) and Na+/K+ geothermometers. The WATCH program is used to estimate the mineral deposits that may accumulate due to boiling and cooling of the geothermal fluid when it is used in heat exchangers The results are confirmed by XRD spectrometric and thermogravimetric analyses.