Enhancement Of Hydrolysis And Acidification Effect Of Starch By Habitat Oxidation

Hydrolysis and acidification process has been widely used in the wastewater treatment field. It can improve the biodegradability of refractory wastewater through using mixed fatty acids as typical acidogenic end products. Oxidation-reduction potential (ORP) can reflect the habitat redox condition, affect the types and yield of metabolic products. In this experiement, FeCI3was used as habitat ORP regulator. Through comparative analysis and research, the enhancements of starch hydrolysis and acidification rates were investigated, and the distribution rule of starch acidogenic end products were discussed. Through high-throughput sequencing, the succession change of hydrolysis and acidification bacteria community induced by babitat ORP regulation was demonstrated.When ORP increased from-250mV (natural anaerobic condition) to-50mV, the starch hydrolysis and acidification rates were higher than that under natural anaerobic condition. Under the condition of-100mV, the hydrolysis rate of the starch was the fastest and the hydrolysis rate constant reached the maximum, namely,0.732min-1; the Specific DHA was the highest with the highest acidification rate of380mg/(L·h), which was the optimal habitat ORP condion for starch acidification. The fermentation type was converted from acetae fermentation to propionate fermentation, but TVFA productions were slightly affected by ORP regulation.Parabacteroides was the dominant population under natural anaerobic condition. When habitat ORP rised, it evolved to Bacteroides and the microbial abundance and complexity increased. The ecological succession of hydrolysis and acidification bacteria community is the micro mechanism for why hydrolysis and acidification effect could be strengthed by habitat ORP regulation.