The effect of nitrate on phosphorus release from phosphorus-rich waste activated sludge

The effect of nitrate on phosphorus release was investigated with 3 groups brown anaerobic reactors by the additions of nitrate. The investigated object comes from a sewage treatment plant in which the A/O process ( a enhanced biological phosphorus removal process) was used. A series of indicators of sludge were measured every certain time during experimental period. The results indicated that: The phosphorus release was inhibited obviously at the presence of nitrate. The accumulation of SCOD under anoxic conditions exceeds that under anaerobic conditions probably due to the methane production actions under anaerobic conditions; The relationship between the consumption of nitrate and intake of phosphorus in this work was shown as ΔP= 0.069×ΔN, which indicated strongly that nitrate were used to not only denitrifying phosphorus removal action, but also others.