Compost from poultry hatchery waste as a biosorbent for removal of Cd(II) and Pb(II) from aqueous solutions

Abstract

Abstract Compost from poultry hatchery waste (CPHW) was used as an efficient biosorbent for the removal of heavy metals from aqueous solutions. Single and competitive adsorption of Cd(II) and Pb(II) onto CPHW were studied. The optimum pH of the aqueous solution for Cd(II) and Pb(II) adsorption was found to be in the range 3 to 5. The pseudo‐second order model enabled a better description of the adsorption kinetics. Equilibrium data obtained at 25, 35, and 45 °C were better described by the Sips isotherm than by the Freundlich and Langmuir models. The maximum adsorption capacities calculated by applying the Sips isotherm were 32.3 mg/g for Cd(II) and 142.6 mg/g for Pb(II) at 25 °C. In binary metal ion solutions, a decrease in the adsorption capacity for both heavy metals was observed. The single and competitive adsorption tests revealed that the adsorption affinity was higher for Pb(II) than for Cd(II). Thermodynamic parameters such as ΔG 0 , ΔH 0 , and ΔS 0 indicated that the adsorption was feasible, spontaneous, and endothermic. FTIR spectroscopy characterization showed that carboxyl and hydroxyl groups were involved in the adsorption of the metals. SEM‐EDX analysis confirmed that Cd(II) and Pb(II) may replace Ca(II) from biosorbent surface. Therefore, the results suggest that CPHW can be used as an economical biosorbent for Pb(II) and Cd(II) removal from aqueous solutions.