Assessment of the sorption of toxic elements after addition of vermicompost used in remediation of contaminated soil

• Grant number: 11/14383-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2011
• End date: November 30, 2012
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Maria Olímpia de Oliveira Rezende
• Grantee: Luis Felipe Peres Bucater
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Among the various methods remediation of contaminated soils include isolation, immobilization, toxicity reduction, physical separation and extraction. In this context, there is vermicomposting, which uses earthworms to break down the organic matter recently, transforming it into a chemically more stable, able to retain metal ions making them unavailable to the environment. These elements will be determined by atomic absorption spectrometry. To understand the transport of these elements in soil is necessary to know how the dynamics in their environment acts. To this end, a detailed study of adsorption / desorption, evaluating the influence of added organic matter and thus able to assess the risk that these elements provide to the environment and human health. The vermicompost is produced from cattle manure. The curves of adsorption of toxic elements in soils will be determined from a solution of salts of metals in different concentrations, which will be added to the soil and taken to the centrifuge. The concentrations of adsorbed elements will be considered as the difference between those initially added and the remaining balance after the period. Desorption will be evaluated by adding solution of 0.01 mol L-1 to CaCl2.2H2O soil samples where metal ions were adsorbed. Following the same procedure, measure the concentrations desorbed.