Abstract
Acidithiobacillus ferrooxidans (A. ferrooxidans) was applied in coal biodesulfurization and coal's pyrite bioleaching. The result showed that A. ferrooxidans had significantly promoted the biodesulfurization of coal and bioleaching of coal's pyrite. After 16 days of processing, the total sulfur removal rate of coal was 50.6%, and among them the removal of pyritic sulfur was up to 69.9%. On the contrary, after 12 days of processing, the coal's pyrite bioleaching rate was 72.0%. SEM micrographs showed that the major pyrite forms in coal were massive and veinlets. It seems that the bacteria took priority to remove the massive pyrite. The sulfur relative contents analysis from XANES showed that the elemental sulfur (28.32%) and jarosite (18.99%) were accumulated in the biotreated residual coal. However, XRD and XANES spectra of residual pyrite indicated that the sulfur components were mainly composed of pyrite (49.34%) and elemental sulfur (50.72%) but no other sulfur contents were detected. Based on the present results, we speculated that the pyrite forms in coal might affect sulfur biooxidation process.
Highlights
Coal has the most abundant reserves and is always the most important energy on earth, which accounts for more than 24% in energy production in the world [1]
A. ferrooxidans was isolated by our laboratory, and it was cultured in basal medium supplemented with 44.5 g⋅L−1 ferrous sulfate
The result showed that the bacteria significantly promoted the biodesulfurization of coal and bioleaching of coal’s pyrite
Summary
Coal has the most abundant reserves and is always the most important energy on earth, which accounts for more than 24% in energy production in the world [1]. Sulfur is present in coal mainly in three forms: pyritic, organic, and sulfate; in addition, a small amount of sulfur may be associated with coal in elemental form [4, 5]. Compared to the conventional physical and chemical desulfurization method, biodesulfurization can selectively oxidize organic sulfur and inorganic sulfur in coal and even remove the finely disseminated pyrite in coal matrix [6, 7]. Mesophilic, moderately thermophilic, and extremely thermophilic microorganisms exhibit the ability to enhance pyrite oxidation and its conversion to soluble, washed-out compounds [6, 8]. The mesophilic Acidithiobacillus ferrooxidans (A. ferrooxidans) is the most frequently applied bacterium to remove pyrite from coal [6, 9, 10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
