Studies on Anoxic Aerobic Alternate Frequency of Oxidation Ditch for Removing Nitrogen and Phosphorus

摘要

Biological removal of nitrogen and phosphorus species from an artificial wastewater was investigated in a sequencing batch reactor (SBR) by changing operating mode which simulation oxidation ditch aeration realization of point and achieved alternate anoxic/aerobic, The results show that: the total control for 6 h reaction time, including aeration 3 h, stop aeration 3 h, four conditions under the condition of 30 min, 10 min, 5 min, 3 min anoxic/aerobic alternate of COD, ammonia nitrogen removal not too big effect, TN, TP influence is bigger. COD removal efficiency is above 89% for four modes and effluent COD is lower than 35 mg/L. Ammonia nitrogen average removal efficiency is above 90% for four modes and effluent ammonia is less than 5 mg/L. Total nitrogen removal rates was 68.71%, 67.70%, 60.36%, 37.27% respectively for four modes. In instantaneous influent, anoxic and aerobic alternating time should not be less than 5 min for TN removal. Mode I to IV removal efficiency of TP was 23.05%, -2.17%, 1.19%, 43.61% respectively.