One-stage partial nitrification/anammox system with short sludge retention time and low mixed liquor suspended solids long-term control: Establishment, performance and sludge characteristics.

Anammox is a green, economical and efficient nitrogen removal process. Most successful anammox studies are based on biofilm- or granule-based systems, but pure floc sludge partial nitrification (PN) and anammox (A) systems that are not inoculated with anaerobic ammonia oxidizing bacteria (AnAOB) are rarely reported. If the anammox process occurs in floc-based systems, the large specific surface areas provide more efficient nitrogen removal, and are much more economical in terms of construction and investment.