Sharif Digital Repository

Most sulfide oxidizing bioreactors are based on pure cultures or artificial mixes of microorganisms with strict requirements for growth, which make the system unstable and do not guarantee their long term performance. The ultimate goal of this study is to develop a natural mix of chemotrophic bacteria that may be applied anaerobically for the treatment of sour gas. Activated sludge from local municipal wastewater treatment plant that was maintained in endogenous anaerobic conditions for one year was used in this study. Total suspended solids (TSS) and volatile suspended solids (VSS) of the sludge was 22 gl-1 and 14.3 gl-1, respectively. A glass culture vessel had a volume of 0.65 L was used... 

Interactions of chemically exfoliated graphene oxide (GO) nanosheets and Escherichia coli bacteria living in mixed-acid fermentation with an anaerobic condition were investigated for different exposure times. X-ray photoelectron spectroscopy showed that as the exposure time increased (from 0 to 48 h), the oxygen-containing functional groups of the GO decreased by ∼60%, indicating a relative chemical reduction of the sheets by interaction with the bacteria. Raman spectroscopy and current-voltage measurement confirmed the reduction of the GO exposed to the bacteria. The reduction was believed to be due to the metabolic activity of the surviving bacteria through their glycolysis process. It was...