Study On The Characteristics Of Nitrogen And Phosphorus Removal In A Sequencing Batch Moving Bed Biofilm Reactor

Experiments carry out in a sequencing batch moving bed biofilm reactor (SBMBBR), which operates in the pattern of A/O. The factors which could affect the removal of phosphorus and nitrogen, such as different organic carbon, anaerobic time, aerobic time, COD concentration, NH3-N concentration and temperature, are studied. On the other hand, the denitrifying phosphorus removal performance in the SBMBBR, which operates in the pattern of A/A, is also investigated. The experimental results show that:(1) SBMBBR is operated with glucose and acetate sodium as carbon source. When glucose used as carbon source, the phosphorus release amount is 11.3 mg/L in 6 hours and 19.5 mg/L phosphorus is taken up in 8 hours. When acetate sodium used as carbon source, the phosphorus release amount is 45.2 mg/L in 2 hours and 54.4 mg/L phosphorus is taken up in 4 hours. It can shorten the cycle when acetate sodium as carbon source.(2) The experiments are performed at the concentration of COD varying from 200 to 800 mg/L. The results show that phosphorus release reach maximal amount, 61.2mg/L, at initial COD of 450 mg/L in the anaerobic period. When the COD concentration exceed the value, phosphorus release decreases. More than 30% of TN loss is observed in the initial of anaerobic stage, due to biological adsorption. Rather high losing of TN and phosphorus in the aerobic, TN could reach maximal removal, 87.8%, at 450mg/L of initial COD.(3) Good effect of TN removal rate is gained, about 400 mg/L of the COD concentration. When the ammonia concentration is lower than 600 mg/L, the TN removal rates exceed 97%. While the ammonia concentration is 800 mg/L, the TN removal efficiency is about 87%. Phosphorus release amount and phosphorus removal rate decrease wit the feed ammonia concentration rises.(4) The effects of two kinds of temperature condition (14±1℃and 24±1℃) on the removal of phosphorus and nitrogen are studied in SBMBBR. The results indicate that the phosphorus release amounts are 54.7 mg/L, 19.7 mg/L, the phosphorus removal rates are 98.3%, 83.4%, and the TN removal rates are 87.8%, 98.4%. It finds that PAOs (phosphorus-accumulating organisms) predominate in the biomass, however, the total nitrogen removal efficiency increases with the temperature increases.