Adsorption Characteristics of Four Acid Dyes on Reaming Functionalized Mesoporous Material

The present paper is aimed to investigate and develop renewable adsorption methods for four dyes removal from wastewater using pore-expanding mesoporous material. The sorption kinetics, sorption thermodynamic and the renewable adsorption test were evaluated. The adsorption process attained equilibrium within 60min, which show that the adsorbent can remove of the dye in a short time. It was shown that the process best described by the pseudo-second-order equation. Various thermodynamic activation parameters such as enthalpy of sorption △H, Gibbs energy change △G and entropy △S were estimated. The negative values of △G indicate that adsorption of dye with the adsorbent was spontaneous, while positive △H values indicative of endothermic nature of the adsorption. The negative △S values for the adsorbents show decreased randomness at the solid solution interface during the adsorption of dye. The adsorbent, washed by NaOH, can be reused by regeneration decolorizing process.

Diffusion Characteristics of Toluene into Natural Rubber/Linear Low Density Polyethylene Blends

The sorption and diffusion of toluene through blends of natural rubber (NR) and linear low density polyethylene (LLDPE) of varying compositions were studied at 35, 55, and65°Cby conventional weight-gain experiments. The effects of blend ratio on the diffusion, sorption, and permeation coefficients were determined. The sorption data were used to estimate the activation energies of diffusion and permeation, parameters which were found to show a decrease when the amount of NR or LLDPE was increased. The transport of toluene through most of the blends was anomalous, althouh at35°C, the transport of toluene through the 60/40 blend was Fickian and at35°C, pseudo-Fickian. The enthalpy of sorption of toluene obtained is positive and suggests a Henry's type sorption.