Study Of Hematite Ore As A Source Of Iron For The Degradation Of Ether Amines Contained In Mining Wastewaters By The Fenton Reaction

Abstract

. In 2015 and 2019, Brazil witnessed two accidents of rupture of iron mining dams (in the Brumadinho and Mariana districts), causing environmental and social damages. Among the principal causes of ruptures, are dams where the water volume accumulates in these systems. Water accumulated in tailings dams can be recuperated to reuse or discharged on rivers, but for this, it is necessary for previous treatment. The current methods developed to degrade ether amine flotation reactants consume additional reactants as Fe ions or yet can take 28 days to achieve satisfactory results as in biodegradation. The heterogeneous Fenton can be an alternative that uses the iron already available in mining wastewaters This study used Fenton heterogeneous to investigate the degradation of an ether amine flotation reactant present in wastewaters from iron mining operations. For this, Fe ore from the mining industry was used as the catalyst. The catalyst was characterized by x-ray diffraction (XRD), and Fenton tests were conducted to evaluate the influence of H 2 O 2 (0.5g.L -1 – 6.3g.L -1 ) and ore concentrations (0.7g.L -1 – 14g.L -1 ) on degradation. The influence of Fe leached on the solution was also evaluated. The monitorization of the reaction was done by total organic concentration (TOC), iron concentration with atomic absorption (AA), and ether amine by bromocresol green method. The results showed that Fe ore could be used as Fenton heterogeneous catalyst degrading 96% of ether amine in 240 minutes, and with this, the technique could be explored to be applied to real wastewater treatments in mining operations.