ANALYSIS OF HEAVY METALS IN SEWAGE SLUDGES AND THEIR ASH

RODRIGUEZ R., GAUTHIER D., UDAQUIOLA S., MARTINEZ O., MAZZA G. FLAMANT G.

Río de Janeiro

Congreso; ICHMET XIII INTERNATIONAL CONFERENCE ON HEAVY METALS IN THE ENVIRONMENT; 2005

Centro de Tecnologia Mineral - CETEM

This paper addresses the problem of heavy metals (HM) presence in sewage sludge (SS). Their concentration depends on the industrial activities in the collecting area, and they remain within the sludge during wastewater treatment processes since they are incorporated in its solid matter (Werther et al., 1999). The world production of SS is growing drastically, while the once classical sludge disposal outlets (fertilizer, land filling, ocean dumping?theoretically forbidden since 1998-) will doubtless decrease for environmental impact reduction. Incineration may be the solution for the future, but the fate of pollutants either created (dioxins) or included in them (HM) is of concern. Indeed, the high ash content of the sewage sludge may lead to very high ash concentration in the flue gas, particularly in the case of fluidized bed furnaces (Werther et al., 1999). In this study, we characterized both the sewage sludge from San Juan (Argentina) and its ash, in the objective of possible valuation by incineration. Seventeen classical metals of concern were analyzed, but the characterization was especially focused on 3 representative toxic metals: Cd, Pb and Zn.