Dye removal in steady-state continuous countercurrent liquid–solid adsorber

Mass transfer studies have been carried out in a continuous countercurrent liquid–solid adsorber to remove methylene blue from wastewater using activated carbon under steady-state conditions. Experimental data on axial concentration profile and overall removal efficiency has been obtained using a pilot plant set-up. The overall colour removal efficiency of the adsorber increases with increase in solid velocity, and a decrease in liquid velocity and initial dye concentration. A mathematical model has been developed to predict the axial concentration profiles, which compare with the experimental data satisfactorily. The overall mass transfer coefficient has also been evaluated using this model.