TY - JOUR N2 - The study investigates chemical modifications of coal fly ash (FA) treated with HCl or NH4HCO3 or NaOH or Na2edta, 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-NH4HCO3 > FA > FA-Na2edta > 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 pseudofirst 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. L1 - http://www.journals.pan.pl/Content/85141/PDF/04-paper-Soco.pdf L2 - http://www.journals.pan.pl/Content/85141 PY - 2016 IS - No 2 June EP - 234 DO - 10.1515/cpe-2016-0018 KW - heavy metals KW - coal fly ash KW - adsorption KW - kinetics KW - thermodynamics A1 - Sočo, Eleonora A1 - Kalembkiewicz, Jan PB - Polish Academy of Sciences Committee of Chemical and Process Engineering VL - vol. 37 DA - 2016 T1 - Comparison of adsorption of Cd(II) and Pb(II) ions on pure and chemically modified fly ashes SP - 215 UR - http://www.journals.pan.pl/dlibra/publication/edition/85141 T2 - Chemical and Process Engineering ER -