Immobilizing of zero-valent iron in mono- and bi-metallic systems on the bentonite clay surface as new nanocatalyst were synthesized and used to degrade model acidic dyes from aqueous media. The Fourier-transform infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analysis were ...

A complete thermo-hydro-mechanical model is presented to tackle the complex coupling problems encountered in clay barriers. A detailed formulation coupling the heat, moisture (liquid water and water vapour) and, air transfer in a deformable unsaturated soil is given. The formulation of the AlonsoGens’s mechanical model for unsaturated soil is also incorporated. The sensitivity to some parameter...

Tightening legislation on the emission of hazardous pollutants is driving chemical industries towards the implementation of innovative “clean technology” including the use of alternative heterogeneously catalyzed processes. This prompted us to examine the catalytic potential of Indian clays for fine chemical synthesis. Catalytic activity of clay minerals from India was only less studied. In the...

−− The kinetics of the gas-phase isomerization of β-pinene over an acid-activated bentonite clay has been investigated in a fixed-bed continuous flow reactor, at atmospheric pressure between 58 and 90 C. The major isomers produced were camphene, α-pinene and limonene. The reaction rates of β-pinene conversion and the apparent activation energy were determined. The kinetics of β-pinene isomeriza...

The paper examines the interaction between host rock and a clay-based engineered barrier in the context of deep underground disposal of high-level radioactive waste. A large scale ‘‘in situ’’ heating test currently under way in the underground Grimsel Rock Laboratory (GRL; Switzerland) is adopted as a representative case for study. The main features of the behaviour of the rock/barrier system h...

An array of pioneering research, dealing with various aspects of soil chemistry, has appeared in Soil Science for the past 90 years. In this review, two papers that have shaped the field forever are featured and discussed. The paper by Mattson (1931) and the many others that he published in Soil Science established the importance of variable or pHdependent surface charge on colloids and soils a...

A model for the simulation of gas flow in clayey rocks and clays is described. Gas migration is associated with the development of preferential paths along existing or pressure-dependent discontinuities. The model handles the combined phenomena of two-phase (air and liquid) flow and the generation of discrete paths. Aperture of discrete paths is the main variable to account for permeability and...