Impact of High-Nitrogen Leachate on Microfauna of Aerobic Granular Sludge

The microfauna communities present in aerobic granular sludge reactors (e.g., granule sludge batch reactor or GSBR) that are used to treat landfill leachate were studied to determine which taxons are useful as process performance indicators. Communities were analyzed during four periods: a stable reactor operation period at a temperature of 29 degrees C, a transitional period of biomass adaptation at a temperature of 25 degrees C, an additional period of stable reactor operation at 25 degrees C, and at 25 degrees C after a period of lowered dissolved oxygen concentration. The results indicate that Vorticella infusionum and telotrochs were the taxons most sensitive to environmental changes in the GSBR, showing potential as biological indicators of ammonium overload and process destabilisation. Other taxons had similar abundance, despite changing environmental conditions in the bioreactor.