Enhanced removal of Congo red dye from aqueous solution by surface modified activated carbon with bacteria

Aims The adsorption behaviour and mechanisms of the surface modified activated carbon with bacteria was evaluated. Methods and Results 16S rRNA was employed to identify the hydrocarbon-degrading bacteria. The bacteria was characterized by TEM and electron microscope. The surface modified activated carbon with bacteria was characterized by SEM. The adsorption behaviour was tested by static adsorption and dynamic adsorption. Conclusion The adsorption efficiency of the modified activated carbon was high when pH was weak acidic, and the adsorption capacity increased with the increase of temperature ranging from 20 to 35 degrees C. The adsorption capacity peaked at 234 center dot 6 mg g(-1) at 25 degrees C, which was sixfold higher than that of activated carbon. The pseudo-first-order kinetic can more accurately assess Congo red adsorption on the two adsorbents. The adsorption of Congo red by bacteria surface modified activated carbon fitted well with the Langmuir's model. The adsorption process was endothermic, and the biological floccules were formed during the adsorption. The physical adsorption is the main driving force. Significance and Impact of the Study The results indicate that the bacteria surface-modified activated carbon can be used effectively as an adsorbent to eliminate Congo red from aqueous solutions.

Automated summary

The study evaluated the adsorption behavior and mechanisms of surface modified activated carbon with bacteria. Results showed that modified activated carbon had high adsorption efficiency under weakly acidic pH, with adsorption capacity increasing with temperature. The adsorption of Congo red by bacteria surface modified activated carbon fitted well with the Langmuir's model, and the process was endothermic with physical adsorption as the main driving force.