The experimental research has highlighted the variety of possibilities of combustion of animal fat from bovine and swine mixed with liquid hydrocarbons. Previous research has established that the upper limit for an efficient combustion was 30 %. For a perfect mixing, the lower temperature limit was set to 40 °C. In the fuel laboratory, at the department TMETF was determined the viscosity of the mixtures for different proportions. The values obtained for various concentrations and preheating temperatures were close to the values for liquid hydrocarbons. The experimental researches have studied the combustion of the mixture using a mechanically spraying burner with constant pressure between 14 and 18 bar. The aspiration of the mixture is done from a specially designed tank; this tank is equipped with an electric heater, in order to maintain the mixture at a constant temperature between 40 °C to 50 °C. After that, the burner heats again the mixture with an integrated heating device up to 75 °C. The burner is also equipped with an air blower, pump and a calibrated nozzle. The combustion resulted from the experimental boiler with a power rated to 55 kW were monitored with a thermal vision camera and an exhaust gas analyser. This research has demonstrated the viability of using this type of mixtures in energetic burning equipment designed for liquid hydrocarbons.

In Romania, the hydropower is the main form of renewable source with an important share in energy mix. Despite their valuable advantages on supplying energy and balancing the energy system, public acceptance, environmental, social and economic impact has become a common challenge in development of hydropower projects. Increasing of water consumption and raising awareness regarding available water resources leads to an integrated management approach of them. In this paper the water footprint is estimated for one of the largest Romanian hydropower project, namely Hydropower Plant Vidraru. The water footprint from hydroelectricity is evaluated considering electricity production of the hydropower plant, water footprint of dam construction and three different approaches to quantify water footprint of the reservoir: gross water consumption, net water consumption and water balance. Also, water footprint is assessed based on economic value of the reservoir using allocation coefficients for various purposes of the reservoir. It is estimated that economic benefit of the reservoir is 81.92·106 €/y, with hydroelectricity major contributor.

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The aim of this paper is to predict the energy consumption of a wastewater treatment plant from Romania, taking into account the flowrate, concentration of BOD, TSS, COD and the energy consumption. For the mathematical model the logistic regression was applied. The input data used were from a waste treatment plant in Romania, for a period of 2 years 2015 and 2017, a total of random 403 dataset. The treatment technologies of WWTP consist of advanced biological treatment SBR (nitrification, denitrification, and phosphorus removal), aerobic sludge stabilization, dewatering, storage and chemical disinfection. Octave software was used to build the model. The answer of the model refers to the fact that for a given situation there will be high energy consumption or low energy consumption in the wastewater treatment plant (WWTP). Performance of the model was compared with real value.