Abstract-Textile effluent is rich in hydrolyzed dyes that need to be removed. This study presents an evaluation of the potential of the enzyme horseradish peroxidase to remove the hydrolyzed dyes Reactive Blue 21 (RB 21) and Reactive Red 195 (RR 195) from cotton fiber and the effluent of the dyeing process. The parameters pH, dye concentration and temperature were evaluated to determine the optimal conditions to remove the dyes. The studies of removal of the dyeing effluent led to an increase of degradation for all tested colors. The use of the enzyme horseradish peroxidase as a biocatalyst can be a viable technological alternative to remove some hydrolyzed dyes.

A study was carried out to evaluate the leaf gas exchange relations and water-use efficiency (WUE) of ungrafted Carménère (Vitis vinifera L.) grapevines growing under field conditions and different levels of water stress. Stomatal conductance (g s), transpiration (E), net CO2 assimilation (A N) and stem water potential (i*s) were measured at midday in a drip-irrigated commercial vineyard located in the Maule Valley (Chile) during three growing seasons (2005 to 2009). In addition, the instantaneous (A N/E) and intrinsic (A N/g s) water-use efficiencies and stomatal sensitivity factor (k) were estimated for the own-rooted grapevines. In this study a significant non-linear relationship was observed between A N and g s (r² = 0.82), with values of A N decreasing from 14.9 to 3.5 pmol/m2/sec as g s diminished from 0.5 to 0.05 mol/m²/sec. This resulted in a progressive increase in WUEi (intrinsic water use efficiency). A significant linear relationship was observed between i*s and g s (r² = 0.39) for measurements taken before and after véraison, with an increasing scattering from -1.6 to -0.4 MPa. Finally, k decreased as water stress increased, with values of 234 and 120 for no and severe water stress respectively, while k ranged from 264 to 480 and 255 to 297 for the measurements taken before and after véraison respectively. Based on the results obtained in the present study, the cultivar Carménère could be classified as drought tolerant at low water potentials, with a large range of physiological parameters changing in response to water stress.

This work presents an analytical modelling of mass transfer in spheroidal solids using a liquid diffusion model. The diffusion equation, written in cylindrical coordinates, is solved using the Galerkin method with a constant diffusion coefficient and an equilibrium boundary condition at the surface of the solid. Results on the drying kinetics, and moisture content distribution in the solids are presented and analysed. The iso-concentration lines for moisture content show that the drying process is faster in sharp areas,. It was verified that solids with a larger area/volume ratio dry faster. The results obtained are consistent so the model presented can be used to solve diffusion problems such as drying, wetting, heating and cooling of solids with a shape that varies from a circular disk to an infinite cylinder, including a sphere and ellipsoids.