[Effect of electron acceptors on anoxic phosphorus uptake of DPB]

The test of anoxic phosphate uptake of denitrifying phosphorous removal bacteria (DPB) which was cultivated during the anaerobic/ anoxic/aerobic processes was conducted at the various situations of electron acceptors. The various concentrations of nitrate or nitrite were added during the anoxic stage respectively. The conclusions stated that the anoxic phosphate uptake of DPB was rarely influenced by the concentration of nitrate with the adequate nitrate as electron acceptors. It takes 1 mg PO4(3-) -P when the consumption of NO3(-) -N is 1 mg. The nitrite could be regarded as the electron acceptor to participate into the activities of denitrifying phosphorous removal. Compared with the nitrate, the phosphorous uptake rate of DPB with nitrite was rather higher at a low concentration (NO2(-) -N with the concentration range of 5 - 20 mg/L). Furthermore, the rate of anoxic phosphorous uptake was increased with the decreased concentration of NO2(-) -N. The restraining effects related to the anoxic phosphors uptake of DPB was increased as the increase of nitrite concentration. Hence, the anoxic phosphorous uptake of DPB was entirely inhibited when the concentration of NO2(-) -N was higher than 35 mg/L.