Resíduo de lodo galvânico: caracterização, tratamento, recuperação e reuso

Abstract

In this work we study the physico-chemical and toxicological properties of a galvanic sludge residue (GS), it’s recovery and reuse of recovered material. The GS was characterized by the techniques of X-ray fluorescence by dispersive energy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, determination of the basicity and thermogravimetric analysis. The toxicological characterization was performed using different leaching tests, and the germination test and also cytogenetic analysis employing Lactuca sativa (lettuce) as test organism. The recovery of heavy metals present in GS (Fe, Zn, Mn, Cr and Cu) was studied and the reuse of metals recovered in the new galvanizing steel parts. We tested the protective capacity of the layer formed by zinc recovered. The GS is composed mainly by oxides of Fe, Zn and Mn. The leaching of metals present in galvanic sludge was higher in dynamic medium and lower pH ranges. The presence of galvanic sludge in soil inhibited root growth of Lactuca sativa (lettuce) and even prevented germination. Increasing the percentage of galvanic sludge in soil increased the number of chromosomal aberrations and prevent duplication of various cells of the meristematic tissue of the Lactuca sativa seeds. The recovery and separation of metals was efficient. The use of recovered zinc in the galvanizing of nails ABNT 1030 steel was effective to form a layer of 1.80 m (±0,01). The mass loss in galvanized nails with recovered zinc were less than loss the mass in non-galvanized nails and galvanized with synthetic solution