Comparaison de divers adsorbants naturels pour la récupération du plomb lors de la décontamination de chaux usées d'incinérateur de déchets municipaux

The objective of this research was to compare the efficiency of different natural adsorbents for lead recovery from basic leachate produced during municipal incinerator used lime decontamination. Shake flasks adsorption tests have shown that cedar barks, pine barks, cocoa shells, and peat moss are efficient and cheap adsorbents for lead removal from this type of leachate. Peanut skins are less efficient than other tested natural materials. The use of a hot-acid treatment (H 2 SO 4 0.75 M) allows to slightly increase lead removal performance of the adsorbents. However, this gain does not justify, from an economical point of view, the utilization of the chemical treatment. Tests done with different cedar and pine bark concentrations (2–30 g/L) have revealed that heavily lead-contaminated (approximately 130–140 mg/L) used lime leachate can be efficiently treated by addition of a small adsorbent concentration (e.g. 2 g/L). Finally, elution tests (HCl 0.5 M) with reuse of adsorbents have demonstrated that some natural materials, like cedar barks and cocoa shells, can be used for many adsorption–elution cycles without loss of lead removal efficiency. Key words: lead, adsorption, used lime, leaching, peat, bark.[Journal translation]