a mathematical model of sorption of zirconium and hafnium cations mixture and elution of these ions from a cation exchange resin bed is developed. sulfuric acid is selected as the eluent for selective separation of zr and hf in a packed bed of dowex cation exchange resin. the column model is a dispersed plug flow model,and assumed to consist of randomly packed synthetic and spherical resin bead...

The adsorptive removal of Cr(VI) by alginate beads containing Cr(VI)-adapted Acinetobacter junii, Escherichia coli and Bacillus subtilis in batch and continuous packed bed column reactors was investigated. Under optimized conditions (pH 3.0; contact time, 180 min; 30 °C; initial Cr(VI) concentration of 100 mg/L), 65.86 mg/g adsorption capacity was recorded in the batch study. When an adsorbent ...

A high-fidelity DEM-CFD model is newly proposed for process intensification of packed bed reactors. The discrete element method (DEM) is employed for simulating random packing under gravity with hundreds of spheres in a cylindrical tube. It is verified that the DEM is capable of constituting a packed bed whose voidage well agrees with the literature according to particle-to-tube diameter ratio....

The treatment of perchlorate-contaminated groundwater was examined using two side-by-side pilot-scale fixed-bed bioreactors packed with sand or plastic media, and bioaugmented with the perchlorate-degrading bacterium Dechlorosoma sp. KJ. Groundwater containing perchlorate (77microg/L), nitrate (4mg-NO(3)/L), and dissolved oxygen (7.5mg/L) was amended with a carbon source (acetic acid) and nutri...

Investigation of turbulency on the rate of induced liquid circulation, gas hold-up, mixing time and overall gas–liquid volumetric oxygen mass transfer coefficient. The various types of surfactants (containing Brij58, TritonX-405, Tween40, HCTBr) with various concentrations of 1-5 ppm were examined on the operational characteristics of the reactor. In surfactant solutions (in comparison with pur...