Authors:Magdalena Janus, Ewelina Kusiak-Nejman, and Antoni Waldemar Morawski
Company, Poland) was used as photocatalyst. At different temperatures (20, 30, 40, 50, and 60 °C), the amount of produced • OH radicals was measured using the fluorescence technique described by Ishibashi et al. [ 3 ]. This fluorescence technique is also
) fabric [ 3 , 16 ] may loose their dimensional stability under the processing condition of temperature and pressure if the evolution of such heat exotherm is excessively high. Therefore, from the practical viewpoint, the quantity of epoxy resin in bulk to
Authors:Jozef Martinka, Danica Kačíková, Emília Hroncová, and Juraj Ladomerský
Fire emissions from smoke are the cause of death for more than 80% of all fire victims [ 1 ]. The quality and quantity of generating fire emissions depend on the combustion temperature, material, and oxidizing
Authors:Lei Chen, Bin Gao, Songsheng Lu, and Yunhui Dong
Sorption of radionickel on attapulgite is studied as a function of contact time, ionic strength, pH and temperature. The results
indicate that the sorption of Ni(II) on attapulgite is strongly ionic strength-dependent at pH <8, and independent of ionic
strength at pH >8. Outer-sphere surface complexation or ion exchange contributes to Ni(II) sorption on attapulgite at pH <8,
whereas the sorption of Ni(II) is mainly dominated by inner-sphere surface complexation at pH >8. The sorption of Ni(II) on
attapulgite increases with increasing temperature, and the thermodynamic parameters (ΔH0, ΔG0 and ΔS0) calculated from the temperature dependent sorption isotherms suggest that the sorption of Ni(II) on attapulgite is a spontaneous
and endothermic process. The high sorption capacity of attapulgite suggests that attapulgite is a suitable material for the
preconcentration and solidification of radionickel from large volumes of aqueous solutions.
Effects of pH, Eu(III) concentration, ionic strength, temperature and humic acid (HA) on Eu(III) sorption to iron oxides were
investigated in detail. The sorption of Eu(III) to iron oxides was significantly dependent on pH and weakly dependent on ionic
strength, and higher temperature was gainful to Eu(III) sorption. In the presence of HA, Eu(III) sorption was enhanced significantly
at low pH; whilst obvious negative effect was observed in higher pH range. Below 12 mg/L HA, HA could obviously enhanced Eu(III)
sorption to iron oxides, nevertheless Eu(III) sorption decreased steeply with increasing HA while HA exceeded 12 mg/L. The
results were helpful for understanding radionuclides behaviors in natural environment.
The interaction of uranium(VI) with carbonate ions was studied with absorption spectroscopy and time-resolved laser-induced
fluorescence spectroscopy due to the importance of these complexes in environmental relevant waters. In the pH range from
2 to 11 the influence of the temperature on the spectra was studied to check changes in the abundances of several binding
forms. It was found that several binding forms are predominant at different temperatures and pH values. This observation can
be explained by speciation changes due to the dependence of chemical equilibria on the temperature. Furthermore photoluminescence
spectra of aqueous solutions of uranyl carbonate complexes were observed at ambient temperatures for the first time and single
component absorption spectra of the uranyl carbonate complexes UO2(CO3)34− and UO2(CO3)22− were derived.
Authors:Qian Lijuan, Zhao Jianing, Hu Peizhuo, Geng Yanxia, and Wu Wangsuo
Sorption of Th(IV) on Zr2O(PO4)2 as a function of contact time, reaction temperature, pH, ionic strength and solid-to-liquid ratio (m/V) is studied under ambient condition by using batch technique. Effects of fulvic acid (FA), phosphate, sulfate and citrate
on Th(IV) sorption are investigated in detail. A pseudo-second-order rate equation is used to simulate the kinetic sorption.
The removal of Th(IV) increases with increasing pH and hardly depends on ionic strength. Sorption of Th(IV) increases with
increasing m/V and reaction temperature. The presence of FA and phosphate enhances the sorption of Th(IV) on Zr2O(PO4)2 while sulfate and citrate decrease the sorption. The Langmuir and Freundlich models are used to simulate the sorption isotherm
of Th(IV) on Zr2O(PO4)2 at different temperatures. The thermodynamic data (i.e., ∆H0, ∆S0, ∆G0) are calculated from temperature dependent sorption isotherms. The results suggest that the sorption process of Th(IV) on
Zr2O(PO4)2 is spontaneous and endothermic.
Authors:Kan Li, Zhengjie Liu, Tao Wen, Lei Chen, and Yunhui Dong
In this paper, the sorption of Co(II) from aqueous solution to Ca-montmorillonite was studied under ambient conditions by
using batch technique. The effects of contact time, solid content, pH, ionic strength and temperature on the sorption of Co(II)
to Ca-montmorillonite was also investigated. The results indicated that the sorption of Co(II) was strongly dependent on pH
values. The sorption was dependent on ionic strength at low pH values, but independent of ionic strength at high pH values.
Outer-sphere surface complexes were formed on the surface of Ca-montmorillonite at low pH values, whereas inner-sphere surface
complexes were formed at high pH values. The Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models were used to simulate
the sorption isotherms of Co(II) at three different temperatures. The thermodynamic parameters (ΔH0, ΔS0 and ΔG0) were calculated from the temperature dependent sorption isotherms, and the results indicated that the sorption reaction
of Co(II) to Ca-montmorillonite was an endothermic and spontaneous process. The high sorption capacity of Co(II) on Ca-montmorillonite
suggests that the Ca-montmorillonite is a suitable material for the preconcentration and solidification of radiocobalt from
Authors:Y. Wang, Q. Fan, P. Li, X. Zheng, J. Xu, Y. Jin, and W. Wu
The sorption of Eu(III) on calcareous soil as a function of pH, humic acid (HA), temperature and foreign ions was investigated
under ambient conditions. Eu(III) sorption on soil was strongly pH dependent in the observed pH range. The effect of ionic
strength was significant at pH < 7, and not obvious at pH > 8. The type of salt cation used had no visible influence on Eu(III)
uptake on soil, however at low pH values, the influence of anions was following the order: Cl− ≈ NO3− > ClO4−. In the presence of HA, the sorption edge obviously shifted about two pH units to the lower pH, whilst in range of pH 6–7,
the sorption of Eu(III) decreased with increasing pH because a considerable amount of Eu(III) was present as humate complexes
in aqueous phase, then increased again at pH > 11. The results indicated that the sorption of Eu(III) on soil mainly formed
outer-sphere complexes and/or ion exchange below pH ~7; whereas inner-sphere complexes and precipitation of Eu(OH)3(s) may play main role above pH ~8.