FE-SEM Study of Microbially Formed Jarosites by Acidithiobacillus ferrooxidans

In this study, we investigated the morphological characteristics of jarosite minerals formed by biogenic oxidation of Fe(III) using Acidithiobacillus ferrooxidans through field emission scanning electron microscopy (FE-SEM). The objective was to understand how different populations of A. ferrooxidans affect the formation and morphology of jarosite minerals. Our methodology involved culturing A. ferrooxidans at varying densities, followed by FE-SEM imaging to characterize the morphology of the resulting jarosite minerals. The results indicated that a higher population of A. ferrooxidans led to more distinct shapes of jarosite and enhanced Raman intensities indicative of potassium jarosite, ammoniojarosite, and argentojarosite. We noted that the morphology of jarosites is likely influenced by the iron-oxidizing activity of A. ferrooxidans. Additionally, FE-SEM proved effective in identifying jarosite compounds formed during the microbial dissolution of arsenopyrite, which can be challenging using traditional X-ray diffraction due to low amounts and poor crystallization. Our findings suggest that examining the morphology of jarosites can provide valuable insights into the identification and geological history of these minerals.