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In the present study, a combined approach of ozone-based advanced oxidation and adsorption by activated char was employed for the treatment of a pharmaceutical industrial effluent. Ozone is a selective oxidant, but the addition of H 2 O 2 generated in situ hydroxyl radicals, which is a non-selective stronger oxidant than ozone. The effluent obtained from the pharmaceutical industry mainly contained anti-cancer drugs, anti-psychotic drugs, and some pain killers. The peroxone process had 75–88.5% chemical oxygen demand (COD) reduction efficiency at pH 5–11 in 3 h. Adsorption by activated char further reduced the COD to 85.4–92.7% for pH 5–11 in 2.5 h. All other water quality parameters were significantly decreased (>73% removal) during ozonation. The primary operational parameters (system pH and H 2 O 2 concentration) were also varied, and their effects were analyzed. The pseudo-first-order rate constants for ozonation were calculated, and they were found to be in the range of 1.42 × 10 –4 to 3.35 × 10 –4 s –1 for pH 5–11. The kinetic parameters for adsorption were calculated for the pseudo-first-order, pseudo-second-order, and Elovich models. The fit of the pseudo-first-order kinetic model to the experimental data was the best.

This study reports hydrodynamics and mixing characteristics for the single-phase flow through a millimetric multichannel packed bed device to meet the specific requirements of the small-scale transport systems. Residence time distribution studies were performed to characterize the velocity distribution for the internal flow inside the packed bed. The effects of the operating variables and the geometries on the hydrodynamics and mixing properties were enunciated. The experimental results were compared with the available correlations, and the new relationships were proposed on the basis of the experimental results. Copper adsorption with the parametric effects was studied in the same packed multichannel geometry with the amine-functionalized reduced graphene oxide (RGO-NH 2 ) coated glass beads. The experimental results were analyzed by the Thomas and Yoon−Nelson adsorption models. The adsorptive mass transfer rates were correlated to the hydrodynamic parameters of the said packed bed device, and the regeneration studies were also performed.

The present study depicts the hydrodynamics and the mixing characteristics in a millichannel‐based serpentine fixed‐bed device to attain the particular demands of the miniature adsorption devices' fabrication. Residence time distribution analyses were accomplished to analyze the velocity distribution inside the packed bed geometry. The effects of operating variables on the system hydrodynamics and mixing and their impact on the lead adsorption characteristics were enunciated. New correlations were proposed for the frictional resistance and axial dispersion of the fluid. The parametric effects on the lead ions [Pb(II)] adsorption were studied in the same millichannel geometry packed with the graphene oxide coated glass beads. The kinetics of the adsorptive removal process is assessed by the Thomas model and the Yoon–Nelson model. The regeneration study of the said millichannel‐based fixed‐bed device was also executed.