The article notes an increase in the share of renewable energy use in European countries and the reasons for the lag of the Russian Federation in this area A promising area of application of non-traditional sources of thermal energy for heating using heat pumps is noted. Despite the constant growth in the use of low-potential geothermal systems in foreign countries, the share of geothermal energy in Russia is negligible. The analysis of climatic conditions and characteristics of aerothermal heat pumps allowed to note their low reliability in regions with a long heating season while reducing the temperature to –15 °C. The versatility and popularity of geothermal pumps has been pointed out. Calculations of thermal energy consumption of residential buildings with individual gas heating were carried out. Based on long-term observations, seasonal changes in the temperature of the soil mass at various depths have been determined. The results obtained were used in the design of a geothermal heating system with heat extraction from the soil mass. The required pump capacity and collector area for heat collection are defined. When calculating the parameters of a soil collector laid at a shallow depth, insufficient heat content of the soil was noted, which will lead to a gradual decrease in the temperature of the array and, accordingly, a decrease in heat extraction. High costs for purchasing heating equipment and installing a geofield reduce the interest of individual consumers in using alternative heat sources. The most realistic area of application of geothermal heat pumps is for heating apartment buildings and social facilities under construction with heat extraction at depths of more than 50 m.
Bentonite of which major mineral is montmorillonite will be used as a buffer material for the geological disposal of a high-level radioactive waste. It has been reported that the interlayer aperture of montmorillonite decreases with increasing salt water concentration. In this study, a model was improved based on a thermodynamic model to quantitatively analyze the effect of salinity on the number of hydration layers of Na-and Ca-montmorillonite. We calculated average interlayer distance as a function of montmorillonite partial density based on the specific surface area of montmorillonite, and calculated the change in montmorillonite partial density versus salinity based on the thermodynamic model. Furthermore, we considered the number of hydration layers versus salinity. In addition, in the analysis, the montmorillonite content in Kunigel-V1 was taken into consideration, and consistency with swelling stress and swelling rate was confirmed, before an empirical equation for the relationship between water content and the relative partial molar Gibbs free energy of interlayer water was revised. The number of hydration layers in the interlayer decreased with increasing salinity. This is qualitatively consistent with the measured data by X-ray diffraction (XRD).
Bentonite is used as a buffer material in the geological disposal of high-level radioactive waste, which is considered for co-location with part of TRU waste. Bentonite swells in contact with groundwater to fill gaps and resist rock pressure by swelling stress. Many studies have been conducted on swelling stress, including data acquisition so far. The authors have proposed a thermodynamic model in the past and are testing its practicality in parallel with the acquisition of thermodynamic data for various conditions. The application of the model also requires thermodynamic data for groundwater in contact. For example, if nitrate (NaNO3) contained in some TRU wastes or Ca(OH)2 in cement used as support material for tunnels excavated in the repository and as filling material around TRU wastes dissolve into groundwater, the eluate may come into contact with buffer material or bentonite mixed soil, etc., but thermodynamic data for those waters are scarce. In this study, the activity of water and the relative partial molar Gibbs free energy, which are necessary for the analysis of swelling stress of bentonite, were obtained as parameters of NaNO3 and Ca(OH)2 concentration and temperature, and the relative partial molar enthalpies were calculated. The results showed that the relative partial molar enthalpies were almost zero in NaNO3 solutions of 1–5 M and Ca(OH)2 solutions of pH 12.07–12.47 (equivalent to concentrations of 0.0017–0.005 M).
Petroleum sludge, a hazardous by-product derived from petroleum extraction and refining process, it may cause significant environmental risks and potential health hazards for humans because of its high content of petroleum hydrocarbons, heavy metals, and other toxic compounds if handled improperly. To extract residual oil from Tahe Oilfield sludge, an alkali-surfactant compound was employed in this study. The key parameters encompassing surfactant concentration, alkali loading, and washing temperature were investigated and optimized. After two washing cycles with a solution containing, cocamidopropyl hydroxysulfate betaine (CPSB) at 0.5 wt
The specific hydro-climatic conditions of the upper Yellow River are important for endemic plateau fish. Hydropower development alters water flows and habitats, with its long-term effects on native cold-water fish remaining unclear. This study examines the fish community's response in the Hukou–Erduo River section of the upper Yellow River before and after the Maerdang Hydropower Station’s impoundment. Utilizing a comprehensive 20-year dataset (2005–2024) that incorporates multi-season fishery surveys alongside plankton and benthic monitoring, this study analyzed temporal variations in species composition, abundance, and community dominance. The results indicate that the fish species richness increased from 15 to 21 after impoundment of Maerdang Hydropower Station, with assemblages consistently dominated by Schizopygopsis pylzovi and Gymnocypris eckloni, alongside other native cold-water taxa such as Triplophysa spp. The overall community structure remained stable, and no evident proliferation of exotic species was observed. Despite local transformations from rapid-flow to lentic habitats within the reservoir, tributary connectivity and fish passage facilities preserved essential ecological linkages. These findings demonstrate that, under conditions of intact tributary habitats and effective ecological management, early-stage hydropower operation exerts limited disturbance on fish community stability.
