Introduction
Bimonthly, started in 1957
Administrator
Shanxi Provincial Education Department
Sponsor
Taiyuan University of Technology
Publisher
Ed. Office of Journal of TYUT
Editor-in-Chief
SUN Hongbin
ISSN: 1007-9432
CN: 14-1220/N
Administrator
Shanxi Provincial Education Department
Sponsor
Taiyuan University of Technology
Publisher
Ed. Office of Journal of TYUT
Editor-in-Chief
SUN Hongbin
ISSN: 1007-9432
CN: 14-1220/N
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Effect of FA,FNA and pH on Partial-nitrificationUnder Micro-aerobic Conditions
DOI:
10.16355/j.cnki.issn1007-9432tyut.2019.05.005
Received:
Accepted:
| Corresponding author | Institute | |
| DUAN Yun | College of Environmental Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China |
abstract:
The sequencing batch reactor(SBR)combined with microporous aeration and mechanical agitation was used to study the effect of free ammonia(FA),free nitrous acid(FNA)and pH on partial-nitrification under micro-oxygen conditions(dissolved oxygen at 0.3~0.5 mg/L).The results show that stable partial-nitrification occurred at temperature of(28±2)℃,pH of 7.8~8.3,with influent FA concentration from 16 to 120 mg/L.The nitrite accumulation rate(NAR)reached the maximum at FA concentration of 40 mg/L,which was 95%.During the reaction,as FA concentration decreased,FNA concentration increased accordingly,which benifited inhibiting the growth of nitrite oxidizing bacteria(NOB).No additional NaHCO 3 was required to maintain constant pH,thus NaHCO 3 was saved by about 40%.After 94 days of operation,the ammoxidation rate in the reactor increased from 40 to 115 mg/(L·h).By high-throughput sequencing technology the proportion of nitrosomonas was found to increase from 32%to 39%.When FA was higher than 40 mg/L,the growth rate of ammonia-oxidizing bacteria(AOB)was significantly reduced,resulting in an increase in the number of Nitrospira.
Keywords:
partial-nitrification;free ammonia;free nitrous acid;pH