Estudo do comportamento do chumbo em latossolos brasileiros tratados com fosfatos: contribuições para a remediação de sítios contaminados

Abstract

Recebido em 14/5/07; aceito em 17/8/07; publicado na web em 26/2/08 STUDY OF LEAD BEHAVIOUR IN BRAZILLIAN LATOSOILS TREATED WITH PHOSPHATES: CONTRIBUTIONS TO THE REMEDIATION OF CONTAMINATED SITES. Phosphates have been used for lead immobilization in soils but the influence of soil type is not fully understood. In this work, lead chemical behaviour in two Brazilian latosoils (LA and LV) was studied via treatment with phosphates. The Pb concentration in Toxicity Characteristic Leaching Procedure (TCLP) solutions was decreased in all treatments. After treatment with H 3 PO 4 the Pb concentration in the LA remained within the regulatory limit established by EPA. The ecotoxicological results with Daphnia pulex showed that this treatment reduced the lead bioavailability. Sequential extraction analyses showed that the lead was transferred from the most available to the residual fraction. Relevant decrease of soluble lead was observed in all phosphate treatments.