Improvement of nitrification efficiency by bioaugmentation in sequencing batch reactors at low temperature

• Published in: Frontiers of environmental science & engineering 2014-12, Vol.8 (6), p.937-944
• Main Authors: Cui, Di, Li, Ang, Qiu, Tian, Cai, Rui, Pang, Changlong, Wang, Jihua, Yang, Jixian, Ma, Fang, Ren, Nanqi
• Format: Article
• Language: English
• Subjects: Ammonia; Ammonia-oxidizing bacteria; Bacteria; Batch reactors; bioaugmentation; Bioreactors; Clostridium; Dechloromonas; denitrifying bacteria; Earth and Environmental Science; Efficiency; Effluents; Environment; Low temperature; Microorganisms; Municipal wastewater; Nitrification; Nitrifying bacteria; Nitrites; Nitrogen dioxide; nitrogen-fixing bacteria; Nitrospira; Oxidation; PCR-DGGE; Reactors; Research Article; Sequencing batch reactor; sequencing batch reactors (SBRs); temperature; Thauera; Wastewater treatment; 亚硝酸盐氧化细菌; 低温; 反应堆; 序批式; 氨氮浓度; 生物强化系统; 硝化
• ISSN: 2095-2201; 1673-7415; 2095-221X; 1673-7520
• DOI: 10.1007/s11783-014-0668-7

Bioaugmentation is an effective method of treating municipal wastewater with high ammonia concentration in sequencing batch reactors （SBRs） at low temperature （10℃）. The cold-adapted ammonia- and nitrite- oxidizing bacteria were enriched and inoculated, respectively, in the bioaugmentation systems. In synthetic wastewater treatment systems, the average NH4＋-N removal efficiency in the bioaugmented system （85%） was much higher than that in the unbioaugmented system. The effluent NH4＋ -N concentration of the bioaugmented system was stably below 8 mg. L1 after 20 d operation. In municipal wastewater systems with bioaugmentation, the effluent NH4＋- -N concentration was below 8 mg·L^-1 after 15 d operation. The average NH4＋ -N removal efficiency in unbioaugmentation system （about 82%） was lower compared with that in the bioaugmentation system. By inoculating the cold-adapted nitrite-oxidizing bacteria （NOB） into the SBRs after 10 d operation, the nitrite concentration decreased rapidly, reducing the NO2 -N accumulation effectively at low temperature. The func- tional microorganisms were identified by PCR-DGGE, including uncultured Dechloromonas sp., uncultured Nitrospira sp., Clostridium sp. and uncultured Thauera sp. The results suggested that the cold-adapted microbial agent of ammonia-oxidizing bacteria （AOB） and NOB could accelerate the start-up and promote achieving the stable operation of the low-temperature SBRs for nitrification.