Showing papers by "Manuel Rendueles published in 2006"
TL;DR: In this article, the equilibrium and kinetics in the loading stage using a strong base resin, Bayer Lewatit MP500, have been studied in the context of the recovery of copper cyanide complexes from wastewater.
Abstract: The use of an ion exchange resin in the recovery of copper cyanide complexes from wastewater and the recycling of the cyanide used in cyanidation to the gold cyanidation step is an economically interesting process. The equilibrium and kinetics in the loading stage using a strong base resin, Bayer Lewatit MP500, have been studied in this work. Two theoretical models were applied to the interpretation of these data. Experimental data on copper concentration were fitted to well known models. The constant separation factor isotherm was used to fit the equilibrium results, high values of the equilibrium constants being obtained at different pH. Two theoretical models were applied. Both the film mass transfer and the pore diffusion models give good fitting of the experimental results providing Kf and Dp for different pH. The Helfferich criteria allowed to establish control of the process in the liquid film surrounding the resin particles.
16 citations
TL;DR: In this article, the behavior of 1,2,4-trichlorobenzene in the saturated zone was investigated using two natural porous media, and the experiments were carried out with different configurations to simulate natural media with several stratigraphic units.
Abstract: Subsurface contamination by nonaqueous phase liquids, such as 1,2,4-trichlorobenzene, is a widespread problem at numerous sites. In this work, the behaviour of 1,2,4-trichlorobenzene in the saturated zone was investigated using two natural porous media. To this end, cylindrical columns were packed with different materials and the initial water saturation was displaced by loading a constant level of trichlorobenzene on top of the porous bed. The experiments were carried out with different configurations to simulate natural media with several stratigraphic units. Also, the effect of pressure gradient on nonaqueous phase liquid flow was investigated. Both the pressure gradient and the configuration of the layers of porous media have shown a strong effect on water recoveries and fluxes through the column.
9 citations
TL;DR: The sensorial assessment tests and determinations of stability and volume yield enabled us to verify that the addition of ovalbumin at an amount of 1.3% hardly alters the stability, resistance to shear stress, or the texture and improves the degree of foaming, therefore the product with additive is of good commercial quality.
6 citations
TL;DR: In this article, an ion exchange operation in a fixed bed column is tested as a method to recover copper cyanide complexes from gold extraction process waste effluents, and the breakthrough curves are obtained using the anionic resin Lewatit MP500.
Abstract: An ion exchange operation in a fixed bed column is tested as a method to recover copper cyanide complexes from gold extraction process waste effluents. With this aim in mind, load and elution breakthrough curves are obtained using the anionic resin Lewatit MP500. A good performance of the resin in the load stage can be deduced from the breakthrough curves obtained in all the assays at two different pHs (12, 8.5). After load step operation, column elution was carried out using NaSCN 1.25 M as eluent. A good elution peak is obtained in all cases, indicating a good performance of the resin and the eluent in this stage. With the aim of testing the design of the industrial operation, a phenomenological model is tested by fitting experimental data to theoretical equations. The model used for the simulation of both steps incorporates axial dispersion, ion exchange equilibrium, and diffusion inside particles described by the linear driving force approximation, as well as taking into account the fact that...
4 citations
TL;DR: In this article, a new polymeric material was developed and used in the chromatographic separation of ovalbumin at preparative scale and an application of the purified Ovalbumin was subsequently studied in the elaboration of yogurt mousse.
Abstract: Egg white contains high-quality proteins. Some processes using eggs produce egg white as by-product. These egg white proteins may be recovered for use as additive in food products. In the first part of this study, a new polymeric material was developed and used in the chromatographic separation of ovalbumin at preparative scale. Ovalbumin is the major component of egg white and thus, it has the greatest weight in terms of its functional effects. An application of the purified ovalbumin was subsequently studied in the elaboration of yogurt mousse. The results obtained showed that the poly(glycidil methacrylate-co-ethylene dimethacrylate) resin that was manufactured enabled the separation of ovalbumin with good efficiency. This study also showed that the formulation obtained from the yogurt mousse with ovalbumin had a greater yield in volume than the commercial product used as a benchmark, improving the majority of its organoleptic qualities without appreciably affecting its stability and organoleptic properties.
2 citations