[Investigation of nitrogen removal performance with membrane sequencing batch reactor process].
Nitrogen removal performance was investigated using synthetic wastewater as feed without sludge discharge in an anaerobic/aerobic membrane sequencing batch reactor (MSBR) during 300 days operation. The results showed that MLSS in reactor was retained up to about 18 g x L(-1), sludge size larger than 100 microm was 96%, and aerobic granular sludge was developed. The bacterial community observation of AOB and NOB by FISH-CLSM for sludge revealed that they were existed in larger numbers. When influent NH(4+) -N concentration was about 50 mg x L(-1), effluent NH(4+) -N concentration was lower than to 1 mg x L(-1), and nitrification could complete in 180-210 min. There was a good correlation between nitrification reaction and aeration strength. When aeration strength was 100 m3 x (m2 x h)(-1), NH(4+) -N degradation rate 24.25 mg x (L x h)(-1), and nitrification reaction in MSBR was stable. The main factor determining nitrogen removal of the system was denitrification rate, which was optimal at aeration 69 m3 x (m2 x h)(-1), when the nitrification rate of NO(3-) -N 10.98 mg x (L x h)(-1), effluent NO(3-) -N 4.4 mg x L(-1), and NO(3-) -N in the beginning of anaerobic phase 3.5 mg x L(-1). The denitrification performance was not benefited by excessive aeration or deficient aeration. Bigger volumetric exchange ratio was helpful for nitrogen removal and the system treatment capacity. The C/N ratio 2 was suitable to good denitrification rate, while there was a NO(2-) -N accumulation if C/N ratio was larger than 2.
Zhang
Sheng
S
School of Environment, Beijing Normal University, Beijing 100875, China. zhangsheng9082@sina.com
Zhang
Ming-Chuan
MC
Xu
Li-Rong
LR
Zhu
Jian-Rong
JR
Liu
Hong-Liang
HL
D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D041841:Bradyrhizobiaceae / Q000378:metabolism; D008567:Membranes, Artificial; D009584:Nitrogen / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
D008567:Membranes, Artificial; D000644:Quaternary Ammonium Compounds; D009584:Nitrogen