Incineration of sewage sludge produces every year huge amounts of sewage sludge ash. Due to its porosity and composition, sewage sludge ash can be used as an adsorbent for heavy metal ions removal. The present paper discusses the efficiency and feasibility of its use as an adsorbent for Pb (II) and Cu (II) removal in single and binary systems. Sewage sludge ash dosage, pH influence, equilibrium and kinetic studies were examined. The results show that sewage sludge ash is an effective and environmentally friendly adsorbent. The maximum adsorption capacity was 25.0 mg/g for Pb (II) and 7.5 mg/g for Cu (II). The presence of the competitive metal led to lower adsorption rate. The study concludes that sewage sludge ash is a promising adsorbent for Pb (II) and Cu (II) removal from wastewater presenting both economic and environmental benefits.
Keywords: adsorbent; adsorption; copper; lead; sewage sludge ash.