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Wpływ paliwa zanieczyszczonego chlorem na trwałość elementów kontroli emisji NOX w silniku o zapłonie samoczynnym

Faber J., Sala R., Krasowski J.

Autobusy : technika, eksploatacja, systemy transportowe

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2018

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R. 19, nr 6

414--420, CD

PL

W artykule podjęto temat oceny wpływu paliwa, celowo zanieczyszczonego chlorem, na elementy kontroli emisji tlenków azotu NOx w silniku z zapłonem samoczynnym. Jakość stosowanego paliwa ma kluczowe znaczenie dla bezawaryjnej pracy silnika. Do zanieczyszczenia paliwa może dojść głównie na etapie transportu lub przechowywania. Główną uwagę zwrócono na wymiennik ciepła (chłodnicę spalin) EGR, służący recyrkulacji spalin, będąc jednym ze sposobów ograniczenia emisji szkodliwych tlenków azotu. Badania prowadzono w warunkach laboratoryjnych (testy stanowiskowe) w cyklach badawczych składających się z czterech faz. Zastosowano paliwo celowo zanieczyszczone chlorem. Czas trwania badania wyniósł 250 godzin i został przerwany momencie wystąpienia awarii silnika i pojawienia się osadów na wymienniku ciepła EGR. W artykule przedstawiono wyniki badań składu chemicznego osadów, zastosowane metody analizy chemicznej oraz zidentyfikowano źródła i przyczynę pojawienia się osadów.

EN

In paper the impact of intentionally chlorine-contaminated fuel on nitrogen oxides emission control elements in compression engine was described. The quality of fuel used is of key importance for the failure-free operation of the engine. Fuel contamination can occur mainly at the transport or storage stage. The main attention was paid to the EGR heat exchanger, which is used for exhaust gases recirculation, being one of the ways to reduce the emission of harmful NOx. The tests were conducted under laboratory conditions (research engine stand tests) in cycles consisting of four phases. The fuel used was intentionally contaminated with chlorine. The test was interrupted after 250 hours at the engine failure and deposits appearance at the EGR heat exchanger. Test results of chemical composition of deposits, analytical methods used and sources and the cause of deposits appearance were described in present paper.

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Assessment of physical, chemical and energetic properties of sludge in industrial and municipal sewage treatment plant

Iżewska A., Wołoszyk Cz., Sienkiewicz S.

Zeszyty Naukowe. Inżynieria Środowiska / Uniwersytet Zielonogórski

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2013

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nr 152 (32)

94--104

EN

The work presents physical, chemical and energetic properties of sludge from industrial and municipal sewage treatment plant in West Pomeranian Voivodeship. Among many macronutrients, sludge contains much of the following: nitrogen, phosphorus, calcium and magnesium, but little potassium. Total content of heavy metals (Cd, Cr, Cu, Mn, Ni, Pb, Hg, Zn) was lower than norms admitting sludge for natural, including agricultural use, presented in the Order of Ministry of the Environment14. Much content differentiation of particular sludge components indicates on the necessity to analyze each portion before its use. The kind of sludge (municipal, industrial) and the way of processing (thickening, drainage, drying) is embodied in differentiation in the content of organic dry matter and total organic carbon. Heat of combustion and calorific value of analyzed sludge oscillates in a very wide scope and the lowest value of indexes were achieved for dried municipal and industrial sludge, whilst higher for thickened municipal sludge and drained one. Sludge, the one after initial thermal processing (i.e. drying) can be used as renewable source of energy. Pearson's linear correlation analysis of sludge has show significant positive linear dependence between calorific value and organic dry matter content as well as total content of carbon and nitrogen for all analyzed kinds of sludge.

PL

W pracy przedstawiono właściwości fizyczne, chemiczne i energetyczne osadów pochodzących z oczyszczalni ścieków przemysłu spożywczego i komunalnych województwa zachodniopomorskiego. Spośród makro-składników osady ściekowe zawierały dużo: azotu, fosforu, wapnia i magnezu, a mało potasu. Całkowita zawartość metali ciężkich (Cd, Cr, Cu, Mn, Ni, Pb, Hg, Zn) była mniejsza od norm dopuszczających osady do przyrodniczego, w tym rolniczego wykorzystania, przedstawionych w Rozporządzeniu MŚ. Znaczne zróżnicowanie zawartości poszczególnych składników w osadach wskazuje na konieczność analizowania każdej partii przed ich wykorzystaniem. Rodzaj osadów (z przemysłu spożywczego, komunalne) i sposób ich przerobu (zagęszczanie, odwadnianie, suszenie) znajdowało odzwierciedlenie w zróżnicowaniu zawartości suchej masy organicznej i węgla całkowitego. Ciepło spalania i wartość opałowa analizowanych osadów ściekowych wahała się w bardzo szerokim zakresie i najniższe wartości tych wskaźników uzyskano w przypadku osadu przemysłowego i komunalnego po suszeniu, a wyższe dla osadu komunalnego zagęszczonego oraz odwodnionych. Osady, te po wstępnej termicznej przeróbce (np. suszeniu) mogą być wykorzystywane jako odnawialne źródło energii. Analiza korelacji prostoliniowej Pearsona osadów ściekowych wykazała istotne dodatnie prostoliniowe zależności między wartością opałową a zawartością suchej masy organicznej oraz całkowitą zawartością węgla i azotu dla wszystkich badanych rodzajów osadów ściekowych.

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The dynamics of phosphorus in lacustrine sediments : contents and fractions in relation to lake trophic state and chemical composition of bottom deposits

Rzepecki M.

Polish Journal of Ecology

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2010

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Vol. 58, nr 3

409-427

EN

Phosphorus is still recognized as the element driving the matter cycling in freshwater ecosystems. It is the key nutrient in productivity and eutrophication process of lakes and reservoirs. The bottom sediments cumulatively formed inside and in-shore of lakes play a crucial role in accumulation/sorption of phosphorus organic compounds, as well as in release/desorption of the compounds available for uptake by producers and microbial heterotrophs. These two opposite processes are dependent on the chemical composition of sediments and on the site conditions (like oxygen, pH) in over-bottom layers. About three hundred of the sediment surface layer samples were taken from the lacustrine habitats in a variety of lakes typical for postglacial landscape (Masurian Lakeland, Poland): profundal and littoral zones in lakes forming a trophic gradient including a humic lake, river/lake ecotone zone and wetland sites adjacent to lake shoreline. The contents of Ca, Fe, Mg, Mn and Al were analysed as well as the amount of total P (TP) and its three basic groups i.e. easily exchangeable, hardly exchangeable and non-exchangeable fractions. It was found that the sediments of humic lake had the most different, distinct chemical composition and contained very small amounts of Fe, Mn, Mg and Ca - nearly 30 times less than sediments of other, non-humic lakes. These sediments contained the most of organic matter and similar (as in non-humic lakes) amounts of TP whose dominant part (80%) consists of hardly exchangeable organic fraction. Sediments of lakes forming the trophic gradient along the small (15 km long) river (Jorka River) showed consistent changes in the chemical composition. Sediments of lakes situated up the river system (meso- and meso-eutrophic lakes) had higher content of organic matter and Ca but lower content of TP, Fe and Mg than sediments of lakes in the lower part of the river system (eutrophic and hypertrophic lakes). The content of these elements was also higherin profundal than in littoral sediments. Significantly higher content (40-70%) of non-exchangeable P was found in sediments of eutrophic and hypertrophic lakes than in sediments of meso- and meso-eutrophic lakes (30-60%) in both the littoral and profundal zones. Sediments of the river-lake-river ecotones (Krutynia River) showed also the consistent changes of element content along the river flow through the lake. The amount of TP was lower in riverine sediments down and upstream the lake than in lake sediments. Organic matter and Fe contents were lower and Ca, Mg, Mn and Al contents were higher in river-lake-river ecotones or similar to those in sediments of the lakes from the trophic gradient. Easily exchangeable phosphorus prevailed in lake sediments; TP in riverine sediments was dominated by hardly exchangeable and non-exchangeable forms and was similar to that found in littoral sediments of lakes from the trophic gradient. Inshore wetland sediments were characterized by a highcontent of organic matter - higher than in littoral and profundal sediments of lakes forming the trophic gradient. The content of Ca, Mg, Mn and Fe was two to five times lower than in sediments of lakes from the trophic gradient but similar to sediments of humic lake. They also contained less TP than profundal sediments from the trophic gradient and humic lakes but had similar content to littoral and riverine sediments. As in the case of profundal and riverine sediments, non-exchangeable and hardly exchangeable P fractions dominated TP content in wetland inshore sediments. Almost all phosphorus a ccumulated in these sediments is associated with a high organic matter deposition. The study results concern the basic types of lake and lacustrine habitats representative for the postglacial landscape of north and north-east Europe. A significant diversity of sediment origin, chemical composition and phosphorus amount and its potential mobility was found among the sediment types. The wetland and humic sediments appeared to be active in cumulation and stabilisation of P resources while sediment of nonhumic, trophic lakes (especially in profundal zoners) are the active sites for P release and sorption processes.