This work aims to test the use of scales from the cones of the Araucaria angustifolia tree in the removal of chromium and iron encountered in the wastewaters from the galvanoplasty process. A comparison with other treatment methods was also performed for compliance with environmental legislation. The cone scales are obtained from "pinhão", which is consumed in the south Brazil. Some parameters were optimized for the best performance of metal removal, such as biosorbent particles size and dosage, pH, time of contact and initial metal concentrations. The results were compared with adsorption treatment using activated carbon and chemical precipitation with bisulfite. The cone scales are efficient for the removal of chromium(VI) (> 99%), while the iron concentration was 62% lower after 1 hour of the contact with 3 g.L-1 of the sorbent (particle size <250 mm). The scales showed to be competitive with the traditional processes, allowing also a more noble use a material that would be discarded.
Galvanoplasty wastewater; metals; biosorption; Araucaria angustifolia
