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Reactivity of nano zero-valent iron in permeable reactive barriers

100%

Pawluk K., Fronczyk J., Garbulewski K.

Polish Journal of Chemical Technology

2015

vol. 17

issue 1

7-10

In this paper, the ability of nZVI to remove heavy metals (Cd, Cu, Ni, Pb, Zn) from multicomponent aqueous solutions was investigated through batch experiments. The experimental data were fitted to a second-order kinetic model based on solid capacity. The data for copper and lead fitted well into the second-order kinetic model, thus suggesting that the adsorption had a physical character. The values of the removal ratio and the second-order rate constant indicated that the order of adsorption priority of nZVI was as follows: Pb>Cu>Zn>Cd>Ni. The adsorption isotherm data were described by the most conventional models (Henry, Freundlich, and Langmuir). Equilibrium tests showed that copper and zinc were removed from the solution by adsorption processes, i.e., complexation and competitive adsorption. The test results suggested that the removal processes using nZVI are more kinetic than equilibrium. The study demonstrated that nZVI is favorable reactive material; however, comprehensive investigation should be performed for further in situ applications in PRB technology.

Assessment of the control rods shadow effect in the VENUS-F core

88%

Cetnar J., Domańska G., Gajda P., Janczyszyn J.

Nukleonika

2014

vol. 59

issue 4

137-143

The partitioning and transmutation (P&T) of spent nuclear fuel is an important field of present development of nuclear energy technologies. One of the possible ways to carry out the P&T process is to use the accelerator driven systems (ADS). This technology has been developed within the EURATOM Framework Programmes for several years now. Current research in this field is carried out within the scope of 7th FP project FREYA. Important parts of the project are experiments performed in the GUINEVERE facility devoted to characterising the subcritical core kinetics and development of reactivity monitoring techniques. The present paper considers the effects of control rods use on the core reactivity. In order to carry out the evaluation of the experimental results, it is important to have detailed core characteristics at hand and to take into consideration the differences in the effect of control rods acting separately or together (the so-called shadow effect) on both the reactivity value and the measured neutron flux. Also any core asymmetry should be revealed. This goal was achieved by both MCNP simulations and the experimental results. However, in the case of experimental results, the need for calculating respective correction factors was unavoidable.

Chemical reactivity of quinclorac employing the HSAB local principle - Fukui function

88%

Mendoza Huizar L. H., Rios-Reyes C. H., Olvera-Maturano N. J., Robles J., Rodriguez J. A.

issue 1

In the present work we have calculated several DFT reactivity descriptors for quinclorac at the B3LYP/6- 311++G(2d,2p) and MP2/6-311++G(2d,2p) levels of theory in order to analyze its reactivity. Reactivity descriptors such as ionization energy, molecular hardness, electrophilicity, condensed Fukui function and total energies were determined to predict the reactivity of quinclorac. The influence of the solvent was taken into account employing the PCM model. The results indicate that the solvation modifies the values of quinclorac reactivity descriptors. The Fukui function values predict that an electrophilic attack on quinclorac might cause a dechlorination, while a nucleophilic attack might lead to a decarboxylation and a free radical attack would cause a hydrogen substitution on the quinoline ring. Quinclorac in deprotonated form would be susceptible to decarboxylation through an electrophilic attack while nucleophilic and free radical attacks would cause an attack on the hydrogens of the ring.

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1 Nukleonika

1 Open Chemistry

1 Polish Journal of Chemical Technology

2 2015

1 2014

1 Cetnar J.

1 Domańska G.

1 Fronczyk J.

1 Gajda P.

1 Garbulewski K.

1 Janczyszyn J.

1 Mendoza Huizar L. H.

1 Olvera-Maturano N. J.

1 Pawluk K.

1 Rios-Reyes C. H.

1 Robles J.

1 Rodriguez J. A.

Search results

Reactivity of nano zero-valent iron in permeable reactive barriers

Assessment of the control rods shadow effect in the VENUS-F core

Chemical reactivity of quinclorac employing the HSAB local principle - Fukui function