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The correct management of municipal solid waste (MSW) is a critical factor in the protection of the environment, as well as a source for the recovery of valuable materials for a circular economy. The Principality of Asturias and the Region of Prague has developed a comprehensive waste management system for the correct treatment of the waste generated, to achieve also the recycling targets set by European policies. The research compares the generation and management policies in both regions. The influence of several characteristics such as the collection of MSW, population density, type of municipality, and presence of different waste disposal facilities was also analysed. As was expected, the presence of an extensive system of civic amenity sites and bulky facilities decreases the volume of mixed municipal waste disposed of, and apparently improves the recycling rate. On other hand, and on contrary to popular belief, the utilisation of MSW incineration systems and ash management, like in Prague, improves recycling rates.

Residual biomass is a valuable and growing by-product, but often underutilized. This research aims to investigate the possible strategies for the energetic valorisation of agri-food industry wastes: grape seed and chestnut shell. Pyrolysis thermal process was the selected for this work. Applied to biomass, pyrolysis is a promising method for the simultaneous production of biochar, bio-oil, and gas. Two different pyrolysis processes were conducted: conventional pyrolysis at 750 °C and flash pyrolysis at 750 °C and 850 °C. Flash pyrolysis yielded superior product properties compared to conventional pyrolysis. The gas obtained through flash pyrolysis presented a four-fold higher high heating value due to increased CH4 and H2 content. Bio-oil contains over 90% of polycyclic aromatic hydrocarbons, and calorific value reached up to 32 MJ kg−1 for grape seed, which is 7% more than bioethanol HHV. Biochar can be used both as fuel or as activated carbon precursor due to its high carbon content (91%). Calorific value of chestnut shell biochar (32.7 MJ kg−1), comparable to mineral coals, increased by 72% with respect to the value of this untreated raw material. This work approved the potential of flash pyrolysis as a method to process biomass wastes in a renewable energy scenario.

In the Czech Republic, coal-bearing siliciclastic sediments have been deposited during the Serpukhovian and Bashkirian (Carboniferous). Until now, no attention has been paid to inorganic geochemical assessment of the coals and associated non-coal rocks from the mixed shallow-marine to continental sediments (Ostrava Formation), and continental non-marine settings (Karviná Formation). Samples were collected from a 750 m deep coal exploration borehole at the ČSM Mine. The bulk parameters, total organic carbon TOC, total inorganic carbon TIC, total sulphur TS, major elements, trace elements, and REEs were measured on these samples, and their mineral associations have been investigated using microscopy combined with the principal component analysis (PCA). Common redox proxies V/Cr, U/Th, Ni/Co, Mo/U, and the ratio S/TOC have been tested on the samples to investigate their usefulness for studying anoxia. Research concludes that redox proxies such as U/Th, Ni/Co and V/Cr have been strongly influenced by the clastic input and carbonates, which it hinders for them to be reliable indicators of anoxia. On the basis of Eu anomaly and REEs distribution, the primary source of detrital elements comes from the parent rock, being governed more by physical than redox processes.

A kinetic approach was adopted to analyze the reaction mechanism of elemental mercury (Hg0) oxidation by HCl over three Mn-based low-temperature SCR catalysts, MnOx/TiO2, Fe-MnOx/TiO2 and CeMnO3. Experimental results validated that Hg0 oxidation efficiencies of the catalysts were promoted by HCl at different temperatures. The kinetic models for the heterogeneous Hg0 oxidation were established and verified based on the experimental data. The verification results demonstrated that Hg0 oxidation over the Mn-based catalysts follows Langmuir-Hinshelwood mechanism. The kinetic parameters of reaction rate constant and HCl adsorption constant were calculated from the model fitting equations. The reaction rate constant was raised with the increase of temperature, while the HCl adsorption constant presented the opposite trend. The Mn-based catalysts with the reaction rate constant of 84.17–335.77 s−1 showed the advantage over some other catalysts such as commercial V2O5-(WO3)/TiO2 and CeO2/TiO2. The kinetic parameters were further improved in the presence of O2. The apparent activation energy for Hg0 oxidation over the catalysts that was derived from the kinetic parameters was 4.13–12.53 kJ/mol, which was much lower than that of the other approaches. The advantageous kinetic parameters and apparent activation energy were favorable for the Mn-based catalysts to act as low-temperature SCR catalyst for synergistic Hg0 removal. The kinetic study results were of fundamental significance for designing the reactor according to the known flue gas conditions, used catalyst and required Hg0 oxidation efficiency.

Bio-derived magnetic activated carbons from industrial chestnut shell waste have been obtained through a novel, optimized and sustainable methodology where impregnation, pyrolysis, acid washing or other intermediate steps commonly used in the activation process were eliminated saving time, energy and costs. The resulting materials (MACs) were obtained at 220-800 °C showed interesting properties: textural (SBET up to 568 m2 g-1) and magnetic (different iron species developed), depending on the activation temperature employed. Data showed outstanding results when MACs were tested for Hg removal in pollution emissions at 150 °C in lab-scale device. In MACs obtained at 500-600 °C, where the highest concentration of magnetite was found, the best Hg adsorption capacity was achieved, while it decreased when metallic iron or iron carbides were present (MACs obtained at 800 °C). Moreover, the difference of Hg0 removal/adsorption in N2+O2 and Simulated Flue Gas atmosphere between MACs obtained at 500 and 600 °C pointed out the influence on Hg removal of additional parameters, as surface chemistry and the existence of sulfur or chloride. The determination of Hg species in post-retention solids confirmed the mercury oxidation by high-valence iron ions (Fe3+) and the involvement of physisorption and chemisorption processes for the gas-solid interaction mechanism.

Using SCR catalyst to oxidize and remove elemental mercury (Hg0) synergistically is a promising method for mercury emission control in coal combustion power plants and is currently attracting widespread interest. In this study, a developed mercury thermal desorption (Hg-TPD) approach, combined with other associated methods, was employed for identification of the mercury species in the Mn-based SCR catalysts that have been used for synergistic Hg0 removal. The analysis results demonstrated the Hg0 adsorption on the catalysts was a necessary process for the Hg0 removal, though the SCR catalysts removed Hg0 mainly through catalytic oxidation and the amount of the adsorbed mercury contributed only a little to the Hg0 removal efficiency. And the essential adsorption process was mainly in the way of chemisorption. HgO was the prime species that was identified to form in the catalysts, and a little amount of adsorbed HgCl2, Hg(NO3)2 and Hg-OM was detected as well in the samples spent in the simulated coal-fired flue gases. O2, HCl, NO and high concentration of CO2 in the flue gas all promoted the adsorption capacity and the generation of related Hg compounds so that they were conductive to Hg0 removal efficiency, while similar phenomenon was not emerged in the presence of SO2, NH3 and H2O and meanwhile the amount of adsorbed HgO was decreased so that the efficiency was inhibited. The mobility testing by sequential extraction procedure indicated most of the retained Hg belonged to the mobile fraction, which was in accordance with the identification results of the Hg-TPD analysis. The consequences of this research would create a better understanding of the Hg0 removal mechanism over the Mn-based SCR catalysts and provide additional information on the disposal of the retired catalysts in the environment.