Characterizations and Measurements on Biogenic Sludge Produced by Field SRB

摘要

Microbiologically influenced corrosion is not a distinct type of corrosion, but rather involves synergistic interaction of microorganisms with resulting biofilms and metabolic biogenic products that enhance corrosion processes. Therefore, it is important to obtain insights about the nature of the biogenic products resulting from microbial metabolic process. In this research, the biogenic products produced by sulfate reducing bacteria (SRB) cultivated from a sour oil field were characterized using X-ray photoelectron spectroscopy (XPS). Moreover, the zeta potential and magnetic susceptibility of SRB cells and biogenic products were evaluated using a microelectrophoretic apparatus and a magnetometer that is based on superconducting quantum interference methods, respectively. The results reveal that the biogenic sludge is mainly composed of different compounds of iron sulfides such as pyrrhotite and pyrite. Furthermore, it was found that the SRB consortium used in this investigation have negative surface charges of -53 mV as indicated by the zeta potential measurements and were able to generate paramagnetic sludge particles with an average calculated magnetic susceptibility of 1.4 × 10~(-6) m~3/kg Fe. The implications of biogenic products physical and chemical characteristics on MIC will be presented.