Aerobic granular sludge sequencing batch reactor: study of granule formation and the cycle time effect in the carbon, nitrogen, and phosphorus removal from domestic wastewater

In this work, the formation of aerobic granules in a sequencing batch reactor fed with domestic wastewater was studied and the reactor's performance, in terms of carbon, nitrogen, and phosphorus removal, during operational cycles of 3 and 4 h, was evaluated. After 150 days of operation, the reactor's biomass predominantly consisted of compact mature granules, with a suspended solids concentration around 1.5 g.L^-1. The reactor presented a high capacity for removing carbon, nitrogen, and phosphorus, mainly when operated in successive cycles of 4 h. Average removal efficiencies of 82±5% for soluble chemical oxygen demand, 69±19% for NH₄ ⁺-N, and 30±10% for PO₄ ^3--P were obtained.

aerobic granules; sequencing batch reactor; nutrients removal; domestic wastewater treatment