- Tytuł:
- Comparison of adsorption of Cd(II) and Pb(II) ions on pure and chemically modified fly ashes
- Autorzy:
-
Soco, E.
Kalembkiewicz, J. - Powiązania:
- https://bibliotekanauki.pl/articles/185273.pdf
- Data publikacji:
- 2016
- Wydawca:
- Polska Akademia Nauk. Czytelnia Czasopism PAN
- Tematy:
-
heavy metal
coal fly ash
adsorption
kinetics
thermodynamics
popioły lotne z węgla kamiennego
adsorpcja
kinetyka
termodynamika - Opis:
- The study investigates chemical modifications of coal fly ash (FA) treated with HCl or NH4 HCO3 or NaOH or Na2 edta, based on the research conducted to examine the behaviour of Cd(II) and Pb(II) ions adsorbed from water solution on treated fly ash. In laboratory tests, the equilibrium and kinetics were examined applying various temperatures (293 - 333 K) and pH (2 - 11) values. The maximum Cd(II) and Pb(II) ions adsorption capacity obtained at 293 K, pH 9 and mixing time 2 h from the Langmuir model can be grouped in the following order: FA-NaOH > FA-NH 4 HCO 3 > FA > NaOH2edta > FA-HCl. The morphology of fly ash grains was examined via small-angle X-ray scattering (SAXS) and images of scanning electron microscope (SEM). The adsorption kinetics data were well fitted by a pseudo-second-order rate model but showed a very poor fit for the pseudo- first order model. The intra-particle model also revealed that there are two separate stages in the sorption process, i.e. the external diffusion and the inter-particle diffusion. Thermodynamics parameters such as free energy, enthalpy and entropy were also determined. A laboratory test demonstrated that the modified coal fly ash worked well for the Cd(II) and Pb(II) ion uptake from polluted waters.
- Źródło:
-
Chemical and Process Engineering; 2016, 37, 2; 215-234
0208-6425
2300-1925 - Pojawia się w:
- Chemical and Process Engineering
- Dostawca treści:
- Biblioteka Nauki
Artykuł