Biological Nitrogen Removal through Nitritation Coupled with Thiosulfate-Driven Denitritation.
A novel biological nitrogen removal system based on nitritation coupled with thiosulfate-driven denitritation (Nitritation-TDD) was developed to achieve a high nitrogen removal rate and low sludge production. A nitritation sequential batch reactor (nitritation SBR) and an anoxic up-flow sludge bed (AnUSB) reactor were applied for effective nitritation and denitritation, respectively. Above 75% nitrite was accumulated in the nitritation SBR with an influent ammonia loading rate of 0.43 kg N/d/m(3). During Nitritation-TDD operation, particle sizes (d50) of the sludge decreased from 406 to 225 um in nitritation SBR and from 327-183 um in AnUSB reactor. Pyrosequencing tests revealed that ammonium-oxidizing bacteria (AOB) population was stabilized at approximately 7.0% (calculated as population of AOB-related genus divided by the total microbial population) in the nitritation SBR. In contrast, nitrite-oxidizing bacteria (NOB) population decreased from 6.5-0.6% over the same time, indicating the effective nitrite accumulation in the nitritation SBR. Thiobacillus, accounting for 34.2% in the AnUSB reactor, was mainly responsible for nitrogen removal via autotrophic denitritation, using an external source of thiosulfate as electron donor. Also, it was found that free nitrous acid could directly affect the denitritation activity.
School of Architecture and Civil Engineering, Chengdu University, Sichuan 610106, China.|Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 00852, China.
Jin
J
Qian
School of Architecture and Civil Engineering, Chengdu University, Sichuan 610106, China.|Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 00852, China.
Junmei
J
Zhou
Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 00852, China.|State Key Laboratory of Heavy Oil Processing, Beijing Key Laboratory of Oil and Gas Pollution Control, China University of Petroleum, Beijing 102249, China.
Zhen
Z
Zhang
Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 00852, China.
Rulong
R
Liu
Advanced Water Management Centre (AWMC), The University of Queensland, QLD 4072, Brisbane, Australia.
Qilin
Q
Wang
D018533:Biomass; D019149:Bioreactors; D058440:Denitrification; D009566:Nitrates / Q000737:chemistry*; D009584:Nitrogen / Q000302:isolation & purification*; D010316:Particle Size; D012722:Sewage; D013885:Thiosulfates / Q000737:chemistry*
D009566:Nitrates; D012722:Sewage; D013885:Thiosulfates; D009584:Nitrogen