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The chemistry of atmospheric precipitation serves as an important proxy for discriminating the source(s) of air contaminants in urban environments as well as to discuss the dynamic of atmospheric chemistry exchanges. This approach can be undertaken at time scales varying from single events to seasonal and yearly time frames. Here, we characterized the chemical composition of two single rain episodes (18 July 2018 and 21 February 2019) collected in Wrocław (SW Poland). Our results demonstrated inner variations and seasonality (within the rain event as well as between summer and winter), both in ion concentrations as well as in their potential relations with local air contaminants and scavenging processes. Coupling statistical analysis of chemical parameters with meteorological/synoptic conditions and HYSPLIT back trajectories allowed us to identify three main factors (i.e., principal components; PC) controlling the chemical composition of precipitation, and that these fluctuated during each event: (i) PC1 (40%) was interpreted as reflecting the long-range transport and/or anthropogenic influences of emission sources that included biomass burning, fossil fuel combustion, industrial processes, and inputs of crustal origin; (ii) PC2 (20%) represents the dissolution of atmospheric CO2 and HF into ionic forms; and (iii) PC3 (20%) originates from agricultural activities and/or biomass burning. Time variations during the rain events showed that each factor was more important at the start of the event. The study of both SO42− and Ca2+ concentrations showed that while sea spray inputs fluctuated during both rain events, their overall impact was relatively low. Finally, below-cloud particle scavenging processes were only observed for PM10 at the start of the winter rain episode, which was probably explained by the corresponding low rain intensity and an overlap from local aerosol emissions. Our study demonstrates the importance of multi-time scale approaches to explain the chemical variability in rainwater and both its relation to emission sources and the atmosphere operating processes. [ABSTRACT FROM AUTHOR]

This paper presents the construction of a numerical three-dimensional model of the area of the Żelazny Most Mining Waste Storage Facility (MWSF). In the study area, the difficult geological conditions associated with glaciotectonics are accompanied by a complex hydrotechnical system of sediment deposition and sedimentary water drainage. In order to effectively reflect the water flow paths, a detailed schematization was carried out, using 700,000 boreholes and more than 300 hydrogeological cross-sections. In addition, numerous drainage sections, streams, and ditches were included to reliably assess the amount of saline water entering the underlying aquifers. This research was supported by magnetic resonance sounding (MRS) studies of the reservoir's sediments. The MWSF is currently being expanded, so the work primarily focuses on illustrating changes in the hydrodynamic field resulting from the inclusion of the new southern section. Models of similar facilities have been implemented before, but in the current one, the combination of meticulous analysis of the hydro-structural system, the water balance, a significant amount of data, the size of the facility, and the use of an unstructured discretization grid in the calculations is undoubtedly innovative and will be an important contribution to the development of analogous solutions around the world. [ABSTRACT FROM AUTHOR]

Propylene glycol (PG), one of the most important raw chemical materials, has many properties of interest to the industry like: low viscosity, negligible toxicity, odorlessness and low freezing point. Because of this, it is often used in food, pharmaceutical and cosmetic industries. A new way of PG obtaining was developed in Lodz University of Technology in cooperation with the Polish National Sugar Company Ltd. This method involves catalytic reduction of lactic acid (LA) obtained on the route of microbiological transformation of hydrolysates of sugar beet pulp. Sugar beet pulp, firstly in the enzymatic form hydrolyzed into hexose and pentose feedstocks, was used in the fermentation process. The obtained medium enriched with nutritients was fermented by selected lactic acid bacteria. After the removalof the biomass, broth was purified on active carbon and silica, and finally used as a substrate in catalytic hydrogenation to propylene glycol. Hydrogenation of LA was performed in a 50 ml autoclave at the temperature of 130˚C, under 3.5 MPa of H2 pressure. 5 % Ru/C catalyst was used with equal amounts (mcat = 0.5 g) in all reaction runs.

In this paper, studies on transformation of various types of waste biomass into furfural by acidic hydrolysis were presented. Among the studied groups of biomass, agro-food industry waste, brewing, sugar, mill industry as well as greenery and municipal bio-waste can be distinguished. Furfural in the form of water solution was obtained by the addition of concentrated H2SO4. The amount of obtained furfural was 0.12-4.20 %(w/w),based on the dry weight of the sample subjected to hydrolysis. The yields of furfural strongly depended on the type of biomass used in the processes. Water solutions of furfural, condensates without any purification, were used in the catalytic reduction processes over 5 %Pd/Al2O3 catalyst. Furfuryl alcohol and tetrahydrofurfuryl alcohol were the only products of reactions of furfural reduction carried out at the temperature of 90 °C and under the pressure of 20 bar of H2. Furthermore, it was concluded that the presence of other compounds in condensates inhibited the reduction of the double bond in the ring of furfural and that the main product of the reaction was furfuryl alcohol.

The studies presented in this paper concern the choice of an effective bimetallic catalyst for the reduction of furfural to furfuryl alcohol (FA) and tetrahydrofurfuryl alcohol (THFA) in the liquid phase. The way of furfural reduction greatly depends on the catalyst system used. In the studythe effect of the addition of metallic promoter (Au, Bi, Fe, In, Te, Tl) into 5 % Pd/SiO2 on the activity and selectivity in furfural reduction was investigated. Depending on the bimetallic catalysts used in the process, furfuryl alcohol, tetrahydrofurfuryl alcohol or condensation products were mainly obtained.

In the 2008 ablation season, subglacial springs discharge, flow rate and profiling of the proglacial river, physical-chemical parameters (pH, temperature, electrical conductivity) and chemical composition (HCO3-, SO42-, Cl-, NO3-, NO2-, PO43-, Ca2+, Mg2+, Na+, K+, Fetot, Mn2+, Al3+, Zn2+, Pb2+ and SiO²) of water in the Werenskiold Glacier forefield were measured. Chemical composition of groundwater as well as water of lakes, the main watercourse, subglacial outflows and water representing direct meltwater recharge were studied to determine their origin, the depth of circulation and recharge systems. The results indicate that the main source of water in the glacial river were the subglacial outflows in the central part of the glacier. They generated 77% of the total amount of water in the glacier forefield. Direct inflow of groundwater from glacier moraine to proglacial river was marginally low and the water circulation system was shallow, fast and variable. There were no evidences for an important role of deeper than suprapermafrost water circulation systems. The water temperature, especially in the lakes, exceeding the mean daily air temperature during the ablation period, is due to the heating of the ground moraine rocks. A clear difference between groundwater chemical composition and surface water as well as subglacial runoff in terms of major ions, together with the homogeneity of chemical composition of the proglacial river from spring to mouth confirmed the marginal role of groundwater runoff in the drainage of the catchment area. It was confirmed that the chemical composition of groundwater and moraine lakes in the glacier forefield was shaped by geological factors, i.e., mainly chemical weathering of sulphides, carbonates and secondary sulphates. The possibility of secondary iron hydroxide precipitation and a high probability of complex aluminosilicate transformations were also demonstrated. [ABSTRACT FROM AUTHOR]

This study investigates the effects of the addition of tungsten on the structure, phase composition, textural properties and activities of β-SiC-based catalysts in the aqueous phase hydrogenation of furfural. Carbothermal reduction of SiO2 in the presence of WO3 at 1550 °C in argon resulted in the formation of WxC-β-SiC nanocomposite powders with significant variations in particle morphology and content of WxC-tipped β-SiC nano-whiskers, as revealed by TEM and SEM-EDS. The specific surface area (SSA) of the nanocomposite strongly depended on the amount of tungsten and had a notable impact on its catalytic properties for the production of furfuryl alcohol (FA) and tetrahydrofurfuryl alcohol (THFA). Nanocomposite WxC-β-SiC catalysts with 10 wt % W in the starting mixture had the highest SSA and the smallest WxC crystallites. Some 10 wt % W nanocomposite catalysts demonstrated up to 90% yield of THFA, in particular in the reduction of furfural derived from biomass, although the reproducible performance of such catalysts has yet to be achieved. [ABSTRACT FROM AUTHOR]

Chemical composition of groundwaters was investigated in the region of the Hornsund fjord (southern Spitsbergen). The investigations were conducted during polar expeditions organized by the University of Wroclaw in two summer seasons of 2003 and 2006. Three zones of groundwater circulation: suprapermafrost, intrapermafrost and subpermafrost, were identified in areas of perennial permafrost in the region of Hornsund. The zone of shallow circulation occurs in non-glaciated (suprapermafrost) and subglacial areas. In this zone, the chemical composition of groundwater originates from initial chemical composition of precipitation, mineralogical composition of bedrock, oxidation of sulphides and dissolution of carbonates. The intermediate system of circulation is connected with water flow inside and below perennial permafrost (intrapermafrost and subpermafrost). In this zone, the chemical composition of groundwater is mainly controlled by dissolution of carbonates, ion exchange processes involving Ca2+ substitution by Na+, and oxidation of sulphides under oxygen-depleted conditions. The subpermafrost zone (deep groundwater circulation) occurs in deep-tectonic fractures, which are likely conduits for the descent of shallow groundwater to deeper depths. In this zone, the groundwater shows lower mineralization comparing to intrapermafrost zone and has a multi-ion nature Cl-HCO3-Na-Ca-Mg. [ABSTRACT FROM AUTHOR]

Information about the paper on the partition of sulfur and oxygen isotopes in sulfate crystalline formations of the Sudety Mountains discussed at the European Society for Isotope Research (ESIR) meeting is presented. These massifs are evidently contaminated by polluted precipitation from the combustion of fossil fuels. The acid rains generated in the Black Triangle have been suggested as the main cause of elevated sulfate content in surface waters and groundwater in Sudety Mountains.