Effect of Sulfate-Reducing Bacteria on the Production of Iron Sulfides

Abstract

Using Fourier transform infrared spectroscopy (FTIR) to identify the sulfate-reducing bacteria (SRB) in Daqing Oilfield sewage. The growth curve of SRB and the adsorption ability of extracellular polymeric substances (EPS) to the Fe²⁺ were combined to explore iron sulfide generation. X-ray diffraction (XRD) results showed that different species of SRB produce iron sulfides, mainly composed of mackinawite. The growth characteristics of SRB affected the formation of iron sulfides and had a negative charge. Various SRB growth trends were different. The growth of the bacterium in an exponential phase or log phase can be described by the greater concentration of inoculation. And smooth growth trends were contributed to the formation of FeS. At the same time, sulfur-rich, like FeS₂, was easily formed when S²⁻ (or S₂²⁻) played a major role compared with the protein and polysaccharide functional groups in the negatively charged EPS at the process of Fe²⁺ adsorption.

Keywords:

• Extracellular polymeric substances
• Fourier transforms infrared spectrometer
• iron sulfides
• sulfate-reducing bacteria

Acknowledgments

Thanks are due to Pro. Zhou for assistance with the article proofreading.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.