Aerobic granular SBR systems applied to the treatment of industrial effluents

Four lab scale sequencing batch reactors (SBRs) were operated to remove organic matter and nitrogen from four different industrial wastewaters. The biomass grew in the reactors in the form of aerobic granules characterized by good settling properties. The high biomass concentrations achieved inside the reactors allowed reducing the solids concentration in the effluent down to 0.2 g VSS L−1. The organic loading rates (OLR) applied to reactors ranged between 0.7 and 5.0 g COD L−1 d−1 with removal efficiencies of 60–95%. The nitrogen loading rates (NLR) applied varied between 0.15 and 0.65 g NH4+-N L−1 d−1 with variable removal efficiencies in the four systems (between 15% and 76%).