A Study: Removal of Cu(II), Cd(II), and Pb(II) Ions from Real Industrial Water and Contaminated Water Using Activated Sludge Biomass

Abstract

Abstract This study aims to remove of Cu 2+ , Cd 2+ , and Pb 2+ ions from solution and to investigate the adsorption isotherms, adsorption kinetics, and ion‐exchange affinities of these metals using waste activated sludge (AS) biomass. The adsorptions of the metals on biomass were optimal at an acidic pH value of 6.0 based on its monolayer capacities. Maximum monolayer capacities of AS biomass ( q max ) were calculated as 0.478, 0.358, and 0.280 mmol g −1 for Cu 2+ , Cd 2+ , and Pb 2+ , respectively, and the adsorption equilibrium time was found as 60 min for each metal. The adsorbed amount of metal rose with increasing of initial metal ion concentration. The equilibrium adsorption capacity of AS for initial 0.25 mmol L −1 metal concentration was determined as 0.200, 0.167, and 0.155 mmol g −1 for Cu 2+ , Cd 2+ , and Pb 2+ ions, respectively. These relevant values were determined as 0.420, 0.305, and 0.282 mmol g −1 for Cu 2+ , Cd 2+ , and Pb 2+ ions, respectively, when initial metal concentration was 0.50 mmol L −1 . In the multi‐metal sorption system, the adsorption capacity of AS biomass was observed in the order of Cu 2+ > Cd 2+ > Pb 2+ . In the presence of 100 mmol L −1 H + ion, the order of ion‐exchange affinity with H + was found as Cu 2+ > Cd 2+ > Pb 2+ . The adsorption kinetics were also found to be well described by the pseudo‐second‐order and intraparticle diffusion models. Two different rate constants were obtained as k i1 and k i2 and k i1 (first stage) was found to be higher than k i2 (second stage).