Investigation of the Critical Biomass of Acclimated Microbial Communities to High Ammonia Concentrations for a Successful Bioaugmentation of Biogas Anaerobic Reactors with Ammonia Inhibition.

This study aimed to investigate the role of the bioaugmented critical biomass that should be injected for successful bioaugmentation for addressing ammonia inhibition in anaerobic reactors used for biogas production. Cattle manure was used as a feedstock for anaerobic digestion (AD). A mixed microbial culture was acclimated to high concentrations of ammonia and used as a bioaugmented culture.

Advanced phosphorus recovery using a novel SBR system with granular sludge in simultaneous nitrification, denitrification and phosphorus removal process.

In this study, a novel process for phosphorus (P) recovery without excess sludge production from granular sludge in simultaneous nitrification-denitrification and P removal (SNDPR) system is presented. Aerobic microbial granules were successfully cultivated in an alternating aerobic-anaerobic sequencing batch reactor (SBR) for removing P and nitrogen (N). Dense and stable granular sludge was created, and the SBR system showed good performance in terms of P and N removal.

Inoculum and zeolite synergistic effect on anaerobic digestion of poultry manure.

Poultry manure is an ammonia-rich substrate due to its high content of proteins and amino acids. Ammonia is the major inhibitor of anaerobic digestion (AD) process, affecting biogas production and causing great economic losses to the biogas plants. In this study, the effect of different natural zeolite dosages on the mesophilic AD of poultry manure inoculated with a non-acclimatized to ammonia inoculum (dairy manure) was investigated.

Effect of ammonium and acetate on methanogenic pathway and methanogenic community composition.

Methanogenesis from acetate (aceticlastic methanogenesis or syntrophic acetate oxidation (SAO) coupled with hydrogenotrophic methanogenesis) is the most important step for the biogas process. The major environmental factors influencing methanogenesis are volatile fatty acids, ammonia, pH, and temperature. In our study, the effect of acetate and ammonia concentration on the methanogenic pathway from acetate and on the methanogenic communities was elucidated in two experiments: one where inocula were gradually exposed to increasing concentrations of acetate or ammonia, and another with direct exposure to different ammonia concentrations.

Biohydrogen production in granular up-flow anaerobic sludge blanket (UASB) reactors with mixed cultures under hyper-thermophilic temperature (70 degrees C).

Hyper-thermophilic hydrogen production without methane was demonstrated for the first time in granular up-flow anaerobic sludge blanket (UASB) system fed with glucose using mixed cultures. The maximum hydrogen yield in this study was 2.47 +/- 0.