The aim of this study was to determine, by use PCA analysis, the impact of meteorological elements on the PM10 concentration on the example of the mountain valley. Daily values of selected meteorological elements, measured during a ten-year period in the spring, summer, autumn and winter, obtained from the meteorological station in Nowy Sącz, were adopted as variables explaining PM10 concentration. The level of PM10 was significantly affected by the maximum, minimum and average temperature in autumn, winter and spring. In summer the average and maximum temperature was significant. In winter, the first principle component mainly consisted of the combination of the average and maximum wind speed. The second principal component in spring, summer and autumn was the combination of the wind speed (average and maximum), but in winter humidity and atmospheric pressure seemed to be significant. The third principal component, in terms of strength of impact, was humidity in spring, the combination of humidity and minimum temperature in summer, and precipitation in autumn. In winter, the highest PM10 concentrations were observed during the non-directional, anticyclonic wedge conditions. Three principal components were distinguished in this situation: temperature (average, maximum and minimum); the combination of humidity and wind speed and precipitation.
The paper presented the methodology for the construction of a soft sensor used for activated sludge bulking identification. Devising such solutions fits within the current trends and development of a smart system and infrastructure within smart cities. In order to optimize the selection of the data-mining method depending on the data collected within a wastewater treatment plant (WWTP), a number of methods were considered, including: artificial neural networks, support vector machines, random forests, boosted trees, and logistic regression. The analysis conducted sought the combinations of independent variables for which the devised soft sensor is characterized with high accuracy and at a relatively low cost of determination. With the measurement results pertaining to the quantity and quality of wastewater as well as the temperature in the activated sludge chambers, a good fit can be achieved with the boosted trees method. In order to simplify the selection of an optimal method for the identification of activated sludge bulking depending on the model requirements and the data collected within the WWTP, an original system of weight estimation was proposed, enabling a reduction in the number of independent variables in a model—quantity and quality of wastewater, operational parameters, and the cost of conducting measurements.
The aim of the study was to assess the possibility of using polyurethane foams (PUF) as a filling of a foam-sand filter to directly treat domestic sewage with increased content of ammonium nitrogen and low organic carbon to nitrogen ratio (C/N). The study compared performance of two types of flexible foams: new, cylinder-shaped material (Novel Foams, NF) and waste, scrap foams (Waste Foams, WF). The foams serving as a filling of two segments of a foam-sand filter were assessed for their hydrophobic and physical properties and were tested for their cell structure, i.e., cell diameter, cell size distribution, porosity, and specific surface area. The study accounted also for selected application-related properties, such as hydrophobicity, water absorption, apparent density, dimensional stability, amount of adsorbed biomass, and the possibility of regeneration. Cell morphology was compared in reference foams, foams after 14 months of the filter operation, and regenerated foams. The experimental outcomes indicated WF as an innovative type of biomass carrier for treating domestic sewage with low C/N ratio. SEM images showed that immobilization of microorganisms in NF and WF matrices involved the formation of multi-cellular structures attached to the inner surface of the polyurethane and attachment of single bacterial cells to the foam surface. The amount of adsorbed biomass confirmed that the foam-sand filter made up of two upper layers of waste foams (with diameters and pore content of 0.50–1.53 mm and 53.0–63.5% respectively) provided highly favorable conditions for the development of active microorganisms.
ABSTRAKT Cel pracyCelem pracy było określenie wpływu struktury pianek PUR, stanowiących wypełnienie filtra gąbczasto-piaskowego, na proces oczyszczania ścieków bytowych charakteryzujących się podwyższoną zawartością azotu amonowego i niskim stosunkiem C/N. Materiał i metodyWielowarstwowe filtry oceniono po 120, 150 i 330 dniach pracy pod względem jednoczesnego usuwania węgla organicznego i azotu amonowego ze ścieków wstępnie oczyszczonych w osadniku gnilnym. W tym celu określono wpływ: (1) mikrostruktury gąbczastego wypełnienia, (2) kolejnych jego warstw oraz (3) obciążenia filtrów ładunkiem zanieczyszczeń organicznych OLR i azotowych NLR na efektywność ich pracy. Dokonano również oceny poszczególnych warstw filtrów w zakresie usuwania bakterii grupy coli. Wyniki i wnioskiZaobserwowano, że filtry wypełnione fabrycznie nowymi piankami o średnicy porów 0,44 mm i 77,6%-owej ich zawartości uległy kolmatacji podczas oczyszczania ścieków bytowych o niskim stosunku C/N. Filtr skonstruowany z dwóch górnych warstw odpadowych pianek (o średnicach i zawartości porów odpowiednio 0,50--1,63 mm i 63,3%) oraz z warstwy piasku osiągnął wysoką średnią efektywność zatrzymania zanieczyszczeń organicznych i azotowych. Skuteczność filtra z wypełnieniem w formie odpadów umieszczonych w osłonkach w zakresie usuwania ChZT i N-NH 4 + wynosiła odpowiednio 82,4 i 79,2%. Stwierdzono, że usuwanie azotu amonowego ze ścieków bytowych z podwyższoną jego zawartością i niskim stosunkiem C/N, zachodziło na we wszystkich warstwach gąbczastego materiału. Wypełnienie filtrów odpadami pianek umieszczonych w osłonkach, zapewniło najbardziej korzystne warunki dla rozwoju zarówno tlenowych bakterii heterotroficznych, jak i bakterii usuwających azot amonowy. Zastosowana dodatkowo dolna warstwa piasku pozwoliła na całkowite usunięcie bakterii Escherichia coli oraz bakterii grupy coli w stopniu 96,4%.
In the paper we present the evaluation of the effectiveness of the removal of biogenic compounds and indicator bacteria from domestic sewage in a vertical flow filter with a variety of fillings. The research was carried out on expanded clay, zeolite, calcined siliceous limestone, and crushed PET flakes. Based on the study of raw and treated wastewater, the effectiveness of removal of ammonium nitrogen, orthophosphates, Escherichia coli, and coliform bacteria was determined according to the selectivity, porosity and grain size of the fill. In the case of removing biogenic compounds, the most effective fillers were found to be of natural porous selective materials, such as zeolite and calcined siliceous limestone. They produced a very high removal rate of ammonium and orthophosphate, amounting to 75.34%, and over 79%, respectively. It has been demonstrated that the filter that was filled with natural porous material of fine particle size (the zeolite) was the most suitable for the removal of indicator bacteria. A very high degree of the Escherichia coli (99.98%) and coliform bacteria (99.94%) reduction was obtained.
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