Denitrifying phosphorus removal by anaerobic/anoxic sequencing batch reactor

Denitrifying phosphorus removal was verified in a laboratory anaerobic/anox ic Sequencing Batch Reactor (A/A SBR) for a period of 18 months. The result s obtained demonstrated the ability of the anaerobic/anoxic strategy to enr ich the growth of denitrifying phosphorus bacteria (DPB) capable oi taking up phosphate under anoxic conditions by using nitrate as the electron accep tor. Phosphorus removal efficiency ranging from 40-100% could be attained i n an A/A SBR system. Simultaneous anoxic phosphate uptake and biological de nitrification under anaerobic/anoxic condition occurred in this system. Bat ch tests showed, however, that simultaneous presence of carbon and nitrate would be detrimental to denitrifying phosphorus removal. Results of bacteri a studies suggested that three denitrifying isolates had aerobic phosphorus removing ability.