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[en] Formaldehyde is considered a carcinogen compound because causes DNA damage, mutations in microorganisms and mammalian cells. Therefore, treatment of effluents containing HCHO prior disposal into waterways is an important target from the environmental point of view. In the present study liquid-phase catalytic oxidation of 50 mg dm-3 HCHO with NaOCl at mild conditions was studied using nanosized Co-oxide system as catalyst. CoOx was synthesized by non-conventional ultrasound assisted precipitation-oxidation method with reverse order of precipitation. The synthesis’ conditions favour the formation of catalytic systems with desired structure, morphology and surface properties typical of environmental catalysts. The catalyst was characterized by XRD, FT-IR spectroscopy, thermal and chemical analyses. The catalytic activity of CoOx was evaluated through both the rate constant (k, min-1) and the overall degree of HCHO conversion (α, %). The effect of main operational parameters influencing HCHO degradation efficiency such as catalyst loading, temperature, and oxidant concentration was investigated. The method of the planned experiment has been applied for determination of the optimal technological parameters of the process. Results obtained show that the optimal conditions for achieving complete conversion of HCHO are temperature 30℃, catalyst loading 1.5 g dm-3, and NaOCl concentration 15 ml dm-3. Keywords: CoOx catalyst, HCHO complete oxidation, NaOCl, wastewater treatment
[en] In this paper we evaluate the greenhouse gas emissions based on a critical analysis of the existing literature and the calculations made by the authors in the USA and Europe. The study examines the European legislation applicable to hydraulic fracturing activities and provides recommendations for further work. It addresses potential gas resources and future availability of shale gas in relation to the current supply of conventional gas and the likely evolution. Keywords: hydraulic fracturing, gas resources, pollution, unconventional hydrocarbons, resources
[en] In this study our goal was to select the variety of Z. hybrida that shows the best growth in oil contaminated soils and the highest remediation of contaminated soil. We chose ‘Profusion White’, ‘Profusion Cherry’ and ‘Profusion Orange’ in Z. hybrida cultivars and cultivated the plants under 18,597 mg diesel/Kg soil condition. The dry weights of shoot and root of ‘Profusion White’ were more than ‘Profusion Cherry’ and ‘Profusion Orange’. Soil total petroleum hydrocarbons (TPH) concentration decreased in all three varieties throughout the study period and no significant differences could be observed among the varieties. Dead cells of plant roots and rotten roots after plant death are nutrient sources for microorganism in soil. We propose that ‘Profusion White’, whose root growth was the greatest among the three varieties, is the best suitable variety for the remediation of oil-contaminated soil under the initial soil TPH concentration of 20,000 mg/kg. Keywords: oil-contaminated soil, phyto remediation, varietal differences, zinnia hybrid
[en] In Belarus thermal and electric power facilities do not contribute a lot to the total pollutant emissions in the atmosphere. But in case of greenhouse gas emissions their impact together with oil refineries is significant. The article shows the ways to decrease pollutant emissions from energy facilities.
[en] The article analyses the mechanisms of ecological control in Ukraine, their development in recent years. The citizens’ participation in public environmental control is the exercise of their constitutional right to a safe environment for life and health. The ecological status of Ukraine was assessed from the point of view of realization of a citizen’s ecological and legal status.
[en] In this proceeding, the production process of methyl ethers of unrefined cottonseed, corn and sunflower vegetable oils by using amine containing compounds like diethylamine, triethylamine and phenylendiamine as catalyst, with 1:6 ratio of oil to methanol, at 65-70°C, in 15-45 mTl induction of magnetic field has been investigated. As a result of the process which had been done in 25mT induction of magnetic field for 30-45 minutes, it has been determined that the production yield is 97.1- 98.8 % (by mass). The content of the flue gases of the compositions those are produced by adding 5 and 10% of the manufactured methyl ethers to petroleum based diesel fuel has been determined. It has been revealed that when 5% of methyl ethers of vegetable oils are added to diesel fuel, the amount of the carbon monoxide and the sulfur oxides in the flue gases decreases by 23.4-25.2% and 5.2-6.9% respectively. Keywords: biofuel, catalyst, magnetic field, combustion products, flue gases, carbon monoxide, sulfur oxides, nitrogen oxides, dsc spectra
[en] Mesoporous titanium–zirconium and titanium- cerium oxide materials with different composition (Ce(Zr)=25, 50 and 80 mol %) were prepared by homogeneous precipitation with urea and further calcination at 773 K. The obtained materials were characterized by low temperature nitrogen physisorption, XRD, UV–Vis, FTIR and Raman spectroscopy. Their catalytic activity was tested in methanol decomposition to CO and hydrogen with a potential application as alternative fuel. All binary oxides possess higher specific surface area and higher dispersion as compared to the individual oxides. For the Ti-Zr binary materials the BET surface area passed through a maximum for the sample with equimolar Zr/Ti ratio, while it permanently increased with the decreased of Ce content in Ti-Ce samples. The Raman and XRD data indicated significant structure and morphology changes with the variation of Ce and Zr content due to the formation of mixed oxides. The catalytic behavior of the binary materials in methanol decomposition was in a complex relation with the improved textural characteristics of binary materials and to the specific interaction between the individual oxides, which could be successfully controlled by their composition.
[en] The new version of the Concept of Energy Security of the Republic of Belarus was adopted by Government in December 2015. This document defines the main indicators of clean energy development in the country until 2035: nuclear energy and renewable energy sources. Currently, both these areas are under implementation. Keywords: energy security, environment, nuclear power, renewable energy sources
[en] Radiological investigations have been performed in Bansko-Razlog region, Bulgaria by means of high-resolution gamma-spectrometry of soil samples. The activity concentrations of the natural radionuclides 238U, 232Th and 40K as well as of the fission product 137Cs have been determined. The spatial distributions of the activity concentrations of the radionuclides are mapped and discussed. The comparison between spatial distributions of the activity concentrations of the 40K and 137Cs shows good negative correlation between activity concentrations of the two radionuclides. The high resolution map of spatial distribution of the ratio of the activity concentrations of 238U and 232Th shows a clearly visible increase in activity of 238U in east, adjacent to the former uranium mines. It has been shown that the continuous spatial distributions of the activity concentrations obtained by using the kriging interpolation allows us to obtain a more detailed picture of activity concentrations of the radionuclides compared with other statistical methods such as linear regression, etc. Keywords: radioactivity, gamma-spectrometry, U-238, Th-232, K-40, Cs-137, activity concentration
[en] Water from tailing ponds of mineral processing plants can be discharged to natural water bodies if the concentration of xanthates is below 1 mg/L. The paper presents the removal of potassium ethyl xanthate from model wastewater by silver nanoparticles-zeolite composite. The impact of adsorbent dose, initial pH value of polluted water and initial pollutant's concentration was investigated. The process kinetics is fast. The kinetics of the xanthate immobilization is best described by the pseudo second order model and the equilibrium - by the Langmuir adsorption isotherm. The material exhibits high capacity with respect to the pollutant when the latter is spiked into natural waters. Even more, over 75 % of the pollutant present in clarified real wastewater from zinc-lead ore flotation experiment have been removed in 120 min at adsorbent dose of 0.2 g/L.