Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "polychlorinated biphenyls" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Kinetyka przemian polichlorowanych bifenyli w czasie kompostowania
Kinetics of polychlorinated biphenyls transformation during composting
Autorzy:
Siebielska, I.
Powiązania:
https://bibliotekanauki.pl/articles/1819826.pdf
Data publikacji:
2009
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
kompostowanie
kinetyka
osady ściekowe
polichlorowane bifenyle
composting
kinetics
polychlorinated biphenyls
Opis:
Systematycznie rosnąca ilość wytwarzanych osadów ściekowych w oczyszczalniach stanowi poważny problem ekologiczny. Według danych GUS z 2006r., w Polsce powstaje rocznie około 501,3 tys. ton s.m. osadów ściekowych [6]. Bezpośrednie ich wykorzystanie w rolnictwie jest ograniczone, zarówno ze względów sanitarnych (wysoka liczebność bakterii chorobotwórczych oraz jaj pasożytów), jak i ze względu na obecność wielu substancji toksycznych, do których należą także polichlorowane bifenyle [2].
Polychlorinated biphenyls (PCBs) is a group of chlorine derivative of hydrocarbon with two, joint with bond, phenyl rings. Isomers differing with the degree of chlorination are called congeners [5]. PCBs show high chemical resistance, they do not undergo oxidation, hydrolysis, they are resistant to acids, bases and other chemical reagents. Presence of polychlorinated biphenyls in the environment is first of all connected with theeconomic development. Results of investigations conducted in Brazil show, that kontent of PCBs (above 300 žg/kg d.m.) in composts, obtained from sewage sludge, is several times smaller than in industrialized Europe (about 1000 žg/kg d.m.) [7]. Because of industrialization of Poland it is advisable to examine content of those organic contaminants In sewage sludge, coming from municipal wastewater treatment plant and in composts obtained from them. The composting is one of many methods to dispose biodegradable waste like sewage sludge. Among many organic compounds present in composted sewage sludge, can be a lot of toxic substances, which can be hazardous to living organisms and because of that they make biochemical transformation harder, and less efficient. Such substances are polychlorinated biphenyls. During the research, sewage sludge with addition of green waste was composted. In samples taken from piles of frequency 14 days, 6 densities of PCB congeners, were measured. Final analysis was executed using gas chromatography equipped with ECD detector. Purpose of the research was to checkthe kinetic of polychlorinated biphenyls transformation during time of composting. The change of content of determined congeners depended on quantity of chlorine atoms. In the case of compounds containing small number of chlorine atoms, increase of their concentration could be caused by biodegradation of polychlorinated biphenyls with higher number of chlorine atoms. Exponential function illustrates the best changes of concentrations of polychlorinated biphenyls for PCB 52 and 101, during composting of the mixture of sewage sludge and green wastes. Logarithmic function describes conversions of remaining compounds. Linear character of the function V(C) for congeners 138, 153 and 180 in both cycles are compatible with the Michaelis-Menten model of biodegradation. The process of biodegradation of examined substances has the primary character. Calculated constatnt of process rate was about 0.03 day-1.
Źródło:
Rocznik Ochrona Środowiska; 2009, Tom 11; 473-483
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Usuwanie PCB i jonów metali ciężkich z wody powierzchniowej w procesie koagulacji
Removal of PCBs and Heavy Metal Ions from Surface Water by Coagulation
Autorzy:
Dąbrowska, L.
Rosińska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1819026.pdf
Data publikacji:
2013
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
usuwanie PCB
proces koagulacji
polychlorinated-biphenyls pcbs
organic matter
polyaluminum chloride
optimization
adsorption
Opis:
The aim of the presented research was to analyse the pollution of the Warta River (Poland) with coplanar PCBs (77, 126 and 169) and heavy metals (Ni, Cd, Pb). Aluminum sulfate and pre-hydrolyzed polyaluminum chloride (PAX-XL10, PAX-XL60, PAX-XL69, PAX-XL1905) were used as coagulants, and the following parameters were analysed in water samples from the Warta River: turbidity, colour, TOC and concentrations of PCBs and heavy metals (Ni, Cd, Pb). Composition of water was modified in order to obtain concentrations of each heavy metal of ca. 0.3 mg/L with implementation of particular amounts of cadmium-, lead nitrate (Cd(NO3)24H2O, Pb(NO3)2) and nickel chloride (NiCl26H2O). In order to obtain concentration of 300 ng/L in case of each congener, a standard mixture PCB MIX3, which consisted of indicator congeners, was added to water. After application of PAX-XL1905, polyaluminum chloride with the highest alkalinity, the best results (among the investigated coagulants) for chosen contaminants removal were obtained; 92% decrease of turbidity and 63% TOC concentration was acquired. In case of heavy metals, best effects were obtained for lead and cadmium removal using PAX-XL1905. Concentration of these metals was reduced from 0.3 mg/L to 0.07 and 0.12 mg/L, respectively. Good results of lead removal were also obtained with use of the other coagulants: PAX-XL60 and aluminum sulfate; its concentrations were decreased to following values: 0.09, and 0.12 mg/L, respectively. When PAX-XL1905 was applied, the residual aluminum concentration in purified water was below 0.05 mg/L, whereas, when aluminum sulfate was used the concentration was below 0.3 mg/L. The highest removal rates for indicator PCBs were obtained with use of aluminum sulfate. Total concentration of PCBs was reduced by 65%. Removal efficiency for particular congeners amounted from 54% (PCB 77) to 72% (PCB 126).
Źródło:
Rocznik Ochrona Środowiska; 2013, Tom 15, cz. 2; 1228-1242
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies