Effects of chemical and physical properties of influent on copper sorption onto activated carbon fixed-bed columns

Experimental studies were carried out to determine the effects of influent pH, ionic strength, metal concentration, and empty-bed contact time (EBCT) on copper sorption in the activated carbon fixed-bed columns. As the influent pH was increased, the column performances significantly improved. An overshoot of the effluent concentration was observed at pH 3.0 due to desorption of copper from the surface-metal complexes. The uptake enhanced as the ionic strength was increased; however, this role was much weaker than that of pH. An increase in metal concentration resulted in a decrease in the bed volumes at the breakthrough. In the beginning of all the experiments, the effluent pH increased dramatically and then dropped and approached lower values. Less sorption was observed when prewashed columns were used, in which the pH in the columns was kept constant. Modelling of the metal sorption in the prewashed columns was performed using a metal ion transport model HYDROGEOCHEM and a fixed-bed model. (C) 2003 Elsevier Science Ltd. All rights reserved.