Effect of Salinity Variation on the Autotrophic Kinetics of the Start-up of Membrane Bioreactor and Hybrid Moving Bed Biofilm Reactor-Membrane Bioreactor at Low Hydraulic Retention Time

A membrane bioreactor (MBR) and a hybrid moving bed biofilm reactor-membrane bioreactor (hybrid MBBR-MBR) for municipal wastewater treatment were studied to determine the effect of salinity on the nitrogen removal and autotrophic kinetics. The biological systems were analyzed during the start-up phase under regular and variable salinities, with a hydraulic retention time (HRT) of 6 h. The variable salinity affected the autotrophic biomass, which caused a reduction of the nitrogen degradation rate and an increase of time to remove ammonium from municipal wastewater.