L.M. Yang

Heavy Metal Ion Sorption Properties of Porous Glass Beads with a Core‐Shell Structure

Porous glass beads with a core‐shell structure have been successfully prepared through subcritical water treatment. The product has high capacity and fast mass transfer property due to its structure, and may serve as an inorganic adsorbent. Accordingly, the kinetics, the equilibrium isotherm, and the column breakthrough curve of this material were measured using Cu(II) as a model target ion. The results indicate that the material has an advantage over some other adsorbents, such as kaolinite and clinoptilolite, in both adsorption capacity and kinetics. The adsorption capacity for Cu(II) is almost twice as much as that of the Na‐mordenite. The pseudo‐second order kinetic and the Langmuir isotherm fit the experimental data. An adsorption mechanism was hypothesized in which the non‐bridging oxygen ions in the glass network were hypothesized to be the functional site.

Visual study of mass transfer characterization in the process of biological catalytic hydration of acrylonitrile using pendant drop method

In this work, a pendant drop method was utilized to observe visually the mass transfer process of an acrylonitrile droplet during bio-hydration. At a temperature of 293 K, the droplet radius was reduced from 100 μm to 49.8 μm within 55 seconds and the value of the diffusion coefficient of acrylonitrile in water was 9.51 × 10−10 m2 s−1. The reduction of the droplet radius is conducive to the acceleration of the mass transfer rate. Cells without enzyme activity to some degree decrease the mass transfer rate of acrylonitrile. At the same temperature, the droplet radius is reduced from 100 μm to 50.4 μm within 135 seconds at a cell concentration of 0.204 g L−1. The bio-hydration reaction can greatly strengthen the mass transfer process, with the intensifying factor ranging from 1.70 to 4.78. The increase of acrylamide concentration shortens the critical droplet radius of acrylonitrile, and hence also strengthens the mass transfer process.