Enrichment of anammox sludge by using an Internal Circulation Reactor innoculated with anaerobic granular sludge and old landfill leachate

Abstract

In recent years, anammox has not only economic benefits but also potential for wastewater treatment containing ammonium and low organic carbon. Along with breakthroughs ammonium treatment in the world, anammox process in internal circulation reactor (IC) is a new technology being researched and developed in high-load ammonium treatment. There In this study, an laboratory scale IC was used to enrich anammox sludge by seeding anaerobic granular sludge and feeding old leachate from the Go Cat municipal solid waste landfill. The seed sludge, which was anaerobic granular sludge taken from an UASB reactor of an industrial wastewater treatment plant was innoculated to IC at MLSS and MLVSS concentrations of 55.1 g.L-1 and 45 g.L-1, respectively, equivalent to the MLVSS:MLSS ratio of 0.82. Since 80 days of operation, the sludge in the IC was divided into two separate zones: a granular zone at the IC bottom part and the floc zone in the upper part. The average total nitrogen (TN) removal efficiency was 45% at nitrogen loading rate 0.4 – 0.6 kg N. m-3.day. The SAA of floc sludge and granular sludge on day 61, increased 6 and 8 times compared to thosed on day 27. The study illustrated that the enrichment of anammox sludge took a long time and granulation in the IC reactor was an important operating factor for anammox growth.