Tratamento de resíduos sólidos perigosos e avaliação dos materiais estabilizados por solidificação.

Abstract

Stabilization/ solidification is a process used to reduce the toxicity of hazardous solid waste. The stabilization/solidification has been applied to treat solid waste disposal in order to landfills and storage sites, in addition it is a process that converts solid waste Class I (hazardous) for non-hazardous (Class HA or IIB). The present work was aimed at making the treatment of hazardous solid waste Class I and evaluate the acid neutralizing capacity of the materials stabilized or solidified. The research was conducted on the premises of the Laboratory of Environmental Management and Waste Treatment, belonging to the Academic Unit of Chemical Engineering, UFCG. Factorial design was adopted, with two factors and two replications. The factors used were synthetic percentage of hazardous solid wastes (20 %, 40 %) and age of the preparation of cement matrices equal to 14 and 28 days. The results showed that the synthetic hazardous waste had a lead content of 29.840 mg.kg"1 and a zinc content of 6300 mg.kg"1. The binder used in this work was the common Portland cement, which had in its composition 5.9 mg.kg"1 of 3 mg.kg"1chromium and magnesium-1. With respect to materials stabilized by solidification, the best results were for the percentage of 20 % of solid residue and synthetic 28 days of healing matrices, compressive strength obtained is 24.5 MPa and wetting / drying 1.49 %. For water absorption capacity for the best result was 40 % of solid residue and synthetic 28 days of curing the matrix-valued 10.85 %. The lead content for all treatments were those recommended in the leaching test, as presented below concentrations recommended by the ABNT NBR 10004 is a 20 mg.kg"1. The best result for the lead content was for the percentage of 20 % synthetic solid residue, thus, the residue was converted to the Class I to Class II. The materials stabilized by solidification showed high acid neutralization capacity of the results revealed that the material provides resistance to acid attack and hence integrity and resistance to pH variations. After stabilization for solidifying the cement matrices presented integrity and durability characteristics, efficiency of retention of lead and acid neutralization capacity of the environment when disposed.