Comparison of non-agitated and agitated batch, thermophilic anaerobic digestion of sugarbeet tailings.

Microbial Ecology in Anaerobic Digestion at Agitated and Non-Agitated Conditions

To investigate the distribution and dynamics of microbial community in anaerobic digestion at agitated and non-agitated condition, 454 pyrosequencing of 16s rRNA was conducted. It revealed the distinct community compositions between the two digesters and their progressive shifting over time. Methanogens and syntrophic bacteria were found much less abundant in the agitated digester, which was ma...

Inhibition of Thermophilic Anaerobic Digestion of Waste Food by Long Chain Fatty Acids and Propionate

Modeling of Anaerobic Digestion of Complex Substrates

A structured mathematical model of anaerobic conversion of complex organic materials in non-ideally cyclic-batch reactors for biogas production has been developed. The  model is based on multiple-reaction stoichiometry (enzymatic hydrolysis, acidogenesis, acetogenesis and methanogenesis), microbial growth kinetics, conventional material balances in the liquid and gas phases for a cyclic-bat...

Thermophilic Aerobic Digestion of Activated Sludge; Reduction of Solids and Pathogenic Microorganisms

In the temperature range of 10 to 80 ºC and in a batch digester, a typical activated sludge was digested aerobically. Reaction rate constants were determined by measuring the amounts of volatiles removed from the suspended solids at different time intervals during the process. The maximum value of the reaction rate constant (0.45 d-1) occurred in the temperature...

Polygalacturonase Production by Aspergillus sp. in Air-Lift and Agitated Fermentor

Polygalacturonase production under different shear stress environments by Aspergillus sp. was studied. It was found that the rate of enzyme production in the stirred tank fermentor decreased with increasing the stirrer speed in the range 300-750 rpm. On the other hand, in a split cylinder air-lift fermentor, the rate of polygalacturonase production slightly increased with increasing in air ...