Pilot-scale aerobic granular sludge in the treatment of municipal wastewater: Optimizations in the start-up, methodology of sludge discharge, and evaluation of resource recovery.

This work evaluated the formation, maintenance, performance, and microbiology of a pilot-scale aerobic granular sludge reactor treating low-strength municipal wastewater under tropical climate conditions. Additionally, different resource recovery possibilities (phosphorous, tryptophan, and alginate-like exopolysaccharides) were investigated from the produced sludge. Granulation occurred after 35 days without external carbon source supplementation (COD ≈ 461 mg/L; COD/DBO ≈ 3.

Effects of carbon source on the formation, stability, bioactivity and biodiversity of the aerobic granule sludge.

Three aerobic granular sludge systems were operated as sequencing batch reactors (SBR) with acetate, ethanol and glucose as carbon source. The SBR cycle was 6 h, with an anaerobic phase followed by an aerobic phase. The acetate granules (>1.