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EN
This paper deals with the numerical simulation of a pilot-scale axial cyclone separator. The main purpose of this paper is to develop a numerical model that is able to foresee the cyclone separator cut-off point. This is crucial in blast furnace gas installation to capture large particles containing carbon and iron, while allowing smaller particles such as zinc and lead to pass through. The cut-off point must be designed to give a sufficiently high zinc and lead content in the sludge created after the second cleaning stage. This allows the sludge to become a commercial product. To design this cut-off point, an investigation of the influence of inlet gas velocity, temperature, and the angle of guiding vanes at the inlet was done. The developed CFD model was validated against experimental data on the fractional efficiency of the cyclone separator. The results were in good agreement with the experimental data for all parameters tested. The behavior of the particles inside the cyclone was also physically correct.
EN
This article focuses on discussing the adsorption process of phenol and its chloro-derivatives on the HDTMA-modified halloysite. Optimized chemical structures of phenol, 2-, 3-, 4-chlorophenol, 2,4-dichloro-, and 2,4,6-trichlorophenol were obtained with computational calculation (the Scigress program). Charge distributions and the hypothetical structure of the system HDTMA-modified halloysite are among their key features. The above-mentioned calculations are applied in order to explain adsorption mechanism details of chlorophenols on the HDTMA-modified halloysite in aqueous solutions. The results of electron density distribution and solvent accessible surface area calculations for phenol and chlorophenols molecules illustrate the impact of chlorine substitution position in a phenol molecule, both on the mechanism and the kinetics of their adsorption in aqueous solutions. Experimental adsorption data were sufficiently represented using the Langmuir multi-center adsorption model for all adsorbates. In addition, the relations between adsorption isotherm parameters and the adsorbate properties were discussed. This study also targets at explaining the role of meta position as a chlorine substituent for mono-chloro derivatives. Given the above findings, two possible mechanisms were utilized as regards chlorophenol adsorption on the HDTMA-modified halloysite, i.e., electrostatic and partition interactions when the chlorophenols exist in a molecular form.
EN
Rising carbon dioxide emissions are driving climate change and there is growing pressure to find alternative energy sources. Co-combustion of waste with fuels is still occurring in some regions of the world, and it is important to know the compounds emitted from such combustion. This study investigated the emissions from the combustion of wood pellets with waste. The wood pellet was combusted with different additions of polyethylene terephthalate plastic and medium-density fiberboard (10 and 50%), in a low-power boiler (18W). Phenols, alkylphenols, phthalates, biomass burning markers, and polycyclic aromatic hydrocarbon emissions were determined. Gas chromatography coupled with a mass spectrometry detector was used to analyze these compounds after extraction and derivatization in the particulate matter and gas phase. The emissions of biomass burning markers and phthalates were the highest among all the compounds determined for MDF addition. The total emission of these compounds was 685 mg/h and 408 mg/h for 10% addition and 2401 mg/h and 337 mg/h for 50% addition, respectively. For the co-combustion of biomass with PET, PAHs and phenols had the highest emission; the emission was 197 mg/h and 114.5 mg/h for 10% addition and 268 mg/h and 200 mg/h for 50% addition, respectively. In our opinion, the obtained results are insufficient for the identification of source apportionment from household heating. After further study, tested compounds could be treated as markers for the identification of the fuel type combusted in households.
PL
Rosnąca emisja dwutlenku węgla powoduje zmiany klimatyczne przez co rośnie presja na poszukiwanie alternatywnych źródeł energii. Współspalanie odpadów z paliwami nadal występuje w niektórych regionach świata, dlatego istotna jest wiedza na temat związków emitowanych z takiego spalania. W niniejszej pracy zbadano wpływ dodatku odpadów na emisję ze współspalania z biomasą. Pelet drzewny współspalano z różnymi dodatkami plastiku z politereftalanu etylenu i płyty pilśniowej średniej gęstości (10 i 50%), w kotle małej mocy (18 W). Oznaczono emisję fenoli, alkilofenoli, ftalanów, markerów spalania biomasy oraz wielopierścieniowych węglowodorów aromatycznych. Do analizy tych związków po ekstrakcji i derywatyzacji w fazie pyłowej i gazowej zastosowano chromatografię gazową sprzężoną ze spektrometrem mas. Emisja znaczników spalania biomasy oraz ftalanów była najwyższa spośród wszystkich związków oznaczonych dla dodatku MDF. Całkowita emisja tych związków wynosiła odpowiednio 685 mg/h i 408 mg/h dla 10% dodatku oraz 2401 mg/h i 337 mg/h dla 50% dodatku. Dla współspalania biomasy z PET największą emisję miały WWA i fenole; emisja wynosiła odpowiednio 197 mg/h i 114,5 mg/h dla 10% dodatku oraz 268 mg/h i 200 mg/h dla 50% dodatku. Naszym zdaniem uzyskane wyniki są niewystarczające do identyfikacji źródeł zanieczyszczeń z ogrzewania gospodarstw domowych. Po dalszych badaniach, badane związki mogłyby być traktowane jako markery do identyfikacji rodzaju paliwa spalanego w gospodarstwach domowych.
EN
The pesticide persistence, in particular in soils, often significantly exceeding the declarations of their manufacturers is surprising. There are many publications devoted to the explanation of this phenomenon in the fi eld literature, but the diverse research methodologies used may lead to the ambiguous conclusions. On the basis of the collected literature, the attempt was made to systematize the available information on the interactions of commonly used groups of pesticides with individual soil components. The complex mechanisms of interactions between pesticides and soil based on van der Waals forces, ionic and covalent bonding, ligand exchange and charge transfer complexes formation were demonstrated. It was also proved that the nature of interactions is strictly dependent on the structure of the pesticide molecule. The conclusion of the review may contribute to the choice of plant protection products that, in addition to their effectiveness, are as little ballast for the environment as possible.
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