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Abstract

The purpose of this study was to validate the applicability of specialized microbial consortium for the degradation of lipids in wastewater. An experimental model of the process is proposed that enables prediction of the required batch length. This model can be used for supervision of the process and to control cycles of the batch reactor. The study involved 4 reactors with microbial consortium obtained by inoculation from a commercially available biopreparate. Each reactor was fed a different load of lipid containing substrate. The biodiversity, settling characteristics and COD reductions were measured. The biodiversity of the microbial consortium changed within a range of ±15% depending on lipids concentration, as shown by the Shannon index and increasing amount of β-proteobacteria. Higher concentrations of lipids increased the biodiversity suggesting higher growth of microorganisms capable of utilizing lipids as energy and carbon source by producing lipid hydrolyzing enzymes. High lipid concentrations degrade the settling capabilities of the biomass. Higher lipid concentrations (0.5–2.0 [g/l]) increase the final COD (1445–2160 [mg O2/l]). The time necessary for substrate degradation changes with the initial concentration and can be predicted using the proposed model. The study showed that specialized microbial consortium is capable of reducing the lipids containing substrate and maintains its biodiversity suggesting that utilization of such consortia in multiple cycles of a batch reactor is possible. Future research should concentrate on assessing the biodiversity and effectiveness of substrate reduction after an increased number of batch reactor cycles.

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Authors and Affiliations

Witold Nocoń
1
ORCID: ORCID
Anna Węgrzyn
1
Mieczysław Metzger
1

  1. Silesian University of Technology, Gliwice, Poland
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Abstract

Quantifying and understanding global land use change and its spatial and temporal dynamics is critical to supporting international policy debates. The main area of transformation of spatial structures nowadays are suburban areas of the largest cities. Constant land development and urbanization, including such forms as urban sprawl, influence significant changes in land use. The aim of this study was to analyse a land use change pattern in a selected rural area which is under pressure of spatial development of a regional city. Data used for a land use change detection was based opensource Urban Atlas dataset for 2006, 2012, and 2018, enriched by recent update from 2021 orthophoto map. Spatial analyses presenting statistics of land use change were conducted in QGIS. Besides analysis of land use change, the paper discusses observed spatial patterns also taking into account changing social, environmental and economic conditions and spatial policies influencing land cover complexity. Understanding these dynamics would help better spatial management of real estates for more sustainable land development.
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Authors and Affiliations

Jan K. Kazak
1
ORCID: ORCID
Magdalena Błasik
1
ORCID: ORCID
Małgorzata Świąder
1
ORCID: ORCID

  1. Wrocław University of Environmental and Life Sciences, Institute of Spatial Management, ul. Grunwaldzka 55, 50-357, Wrocław, Poland
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Abstract

The paper presents the research data on structure, phase composition, defect substructure state, and microhardness of surface layers in the piston alloy Al-10wt%Si-2wt%Cu irradiated by an electron beam with various energy densities and pulse times. An important finding to emerge from the study is that the processing by an electron beam with an energy density of 10 J/cm2 brings about slight surface melting, whereas a weak thermal impact of an electron beam hardly changes the phase composition. Once an energy density of an electron beam is set 30 J/cm2, intermetallic compounds dissolve and numerous micropores arise. Irradiating by an electron beam with an energy density of 50 J/cm2, randomly located microcracks are detected on the treated surface with no regard to a pulse time. A structure of high-speed cellular crystallization with cells from 500 to 600 nm forms in the surface layer. A thickness of the modified layer is related to a beam energy density. As a beam energy density goes up, a thickness of a high-speed cellular crystallization layer increases. Atoms of Si, Cu, Ni, as well as a small quantity of Fe and Mg are detected in the surface, in thin layers surrounding crystallization cells. In a layer 60-80 μm below the irradiated surface, in material between high-speed crystallization cells, there are Si atoms and an insignificant number of Cu atoms. An analysis of a deeper material part has shown a structure similar to the as cast alloy. A drop of microhardness – if compared with the as cast material – is reported at an energy density of 10 J/cm2 because an energy amount supplied by an electron beam to the alloy surface is insufficient for melting of the material and dissolution of the intermetallic phase. A raise of a beam energy density up to 20-50 J/cm2 causes a max increase of microhardness up to 1.13 GPa for 40 J/cm2, 50 s, and up to 1.16 GPa for 40 J/cm2, 200 s.

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Authors and Affiliations

D. Zaguliaev
S. Konovalov
Y. Ivanov
A. Abaturova
A. Leonov

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