No abstract

For the hydrocarbons methane through heptane, ethylene, and carbon monoxide anodic potential/current density curves were measured in a galvanostatic half‐cell arrangement. Raney platinum proved to be an active catalyst for the conversion of the hydrocarbons. In 3N H2SO4 at 100°C a stationary current density of 200 ma/cm2 was measured for ethane, propane, butane, ethylene, and carbon monoxide, and 100 ma/cm2 for methane and pentane. By coulometric analyses the conversion of methane, ethane, and propane to CO2 was found to be 100%. Complete conversion of butane, pentane, hexane, and heptane apparently requires conditions different from those employed here. In 5N H2SO4 potential oscillations with time were observed, which were caused by partial poisoning of the electrode on reduction of H2SO4 to H2S and the subsequent self‐regeneration of the electrode.

A hydrodynamic equation for the mixing of two miscible solutions in a porous media has been combined with the Gouy theory for ion distribution in soil pores in order to examine the effect of flow velocity and ion distribution in the pores on the breakthrough curves. The model considers zones of mobile and immobile solution in the porous media, and the extent these zones are affected by the total concentration of the solution and the pore water velocity.Miscible displacement experiments of 36Cl and 3H through Panoche clay loam at 0.1, 0.01, and 0.001N total salt concentration using CaCl2 were performed on the same column at a fast and slow flow velocity. It was shown that the exclusion volume for isotope and the separation volume for 36Cl and 3H increased as flow velocity decreased and these changes were related to the total ion concentration, the thickness of the diffuse double layer, and the zones of mobile and immobile solution.

A series of miscible displacement experiments was conducted in an unsaturated glass bead medium maintained at a constant average water content during each displacement. The variation in the form of the breakthrough curve with decreasing water content was not large and was not related in a simple way to the water content; however, there was a consistent shift of the breakthrough curve to the left of the relative concentration value of 0.5 and 1 pore volume and a long tail or slow approach to the final relative concentration of 1.0. Some of these effects may be attributed to the presence of ‘stagnant’ liquid in the pores.