Removal of binary dyes mixtures with opposite and similar charges by adsorption, coagulation/flocculation and catalytic oxidation in the presence of CeO/HO Fenton-like system.

In this study, the removal of binary mixtures of dyes with similar (Orange II/Acid Green 25) or opposite charges (Orange II/Malachite Green) was investigated either by simple adsorption on ceria or by the heterogeneous Fenton reaction in presence of HO. First, the CeO nanocatalyst with high specific surface area (269 m/g) and small crystal size (5 nm) was characterized using XRD, Raman spectroscopy and N physisorption at 77 K. The adsorption of single dyes was studied either from thermodynamic and kinetic viewpoints.

Capabilities of laser ablation mass spectrometry in the differentiation of natural and artificial opal gemstones.

The potentialities of laser ablation coupled to ion cyclotron resonance Fourier transform mass spectrometry are evaluated to distinguish natural and artificial opals. The detection of specific species in both ion detection modes leads us to obtain relevant criteria of differentiation. In positive ions, species including hafnium and large amounts of zirconium atoms are found to be specific for artificial opal.

Low-pressure argon adsorption assessment of micropore connectivities in activated carbons.

Low-pressure argon adsorption has been used to study the energetic distribution of microporous activated carbons differing by their burn-off. The collected isotherms were analyzed using the derivative isotherm summation method. Some oscillations on the experimental curves for very low partial pressures were detected.

Water vapor adsorption on activated carbon preadsorbed with naphtalene.

The adsorption of water vapor on a microporous activated carbon derived from the carbonization of coconut shell has been studied. Preadsorption of naphthalene was used as a tool to determine the location and the influence of the primary adsorbing centers within the porous structure of active carbon. The adsorption was studied in the pressure range p/p0=0-0.