Mercury removal from water using activated carbons derived from organic sewage sludge.

Various types of activated carbons were developed from organic sewage sludge (SS) using H(2)SO(4), H(3)PO(4) and ZnCl(2) as chemical activation reagents, and the removal of Hg(II) from aqueous solution by these carbons was effectively demonstrated. The quality of the activated carbons was dramatically improved owing to chemical activation. ZnCl(2) activated carbon had the highest capability for Hg(II) adsorption, followed by H(3)PO(4) and H(2)SO(4) activated carbons. The adsorption was greatly affected by Hg(II) concentration, solution pH and carbon dosage, and followed Lagergren first order rate equation and Freundlich isotherm model. Desorption results indicated that around 60% to 80% of the adsorbed Hg(II) could be recovered from the carbons to 0.1 M HNO(3) solution by sonication treatment. Accordingly, it is believed that the activated carbons developed in this study are effective and practical for utilization in industrial wastewater treatment for mercury removal.