Removal of heavy metals by electrocoagulation generates substantial amount of electrocoagulated metal hydroxides sludge (EMHS). This paper reports calcined EMHS as an effective adsorbent for removal of PO43-from aqueous solutions. Cumulative % removal Of PO43- is investigated in a batch adsorber with different initial adsorbate concentrations, adsorbent dose, pH of the solution and adsorption temperature. Adsorption of PO43- is due to ligand exchange between the OH group on oxide surface and PO43- in the aqueous medium with formation of inner surface complex. Removal of PO43- is found to be high at lower pH values and higher temperatures indicating strong positively charged metal oxide surface at acidic pH (< pH(zpc)) and the endothermic nature of adsorption. The experimental results preferably fitting the Langmuir isotherm suggest monolayer coverage of adsorbed molecules. Pseudo-second-order kinetic model provides the best fitting to experimental results at different adsorbent dose and adsorption temperature. The magnitude of the activation energy (10.33 kJ/mol) is calculated based on pseudo-second-order rate constants from Arrhenius equation indicates removal of PO43- corresponds to activated chemisorption. (c) 2006 Elsevier B.V. All rights reserved.