Relationship analysis of anaerobic fermentation parameters exposed to elevated chromium (VI)

Heavy metals may affect anaerobic fermentation processes, which could result in variations in anaerobic fermentation parameters. In the present study, the impact of changing hexavalent chromium (Cr 6+ ) concentrations on different anaerobic fermentation parameters was investigated. The results showed that adding Cr 6+ affected fermentation efficiency since it elicited changes in enzyme activity as well as metabolic pathways. Adding Cr 6+ (30 mg/L) resulted in significant positive correlation between coenzyme F 420 activities, CH 4 contents, and cumulative biogas yields. The results suggested Cr 6+ enhanced biogas production by promoting the activity of coenzyme F 420 . Increasing the concentration of Cr 6+ to 100 mg/L resulted in a significant correlation ( P < 0.01) between the CH 4 contents and cumulative biogas yields and oxidation–reduction potential and pH. At high concentrations, Cr 6+ (500 mg/L) elicited parametric relationships dissimilar to those obtained using low Cr 6+ concentrations, particularly on the hydrolysis stage. This study comprehensively demonstrated the influence of Cr 6+ stress during the anaerobic fermentation process from a new insight and could provide critical references for further experimental design and data monitoring investigations. © 2019 American Institute of Chemical Engineers Environ Prog, 38: e13212, 2019