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-NH2) 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.