Microbial and Physicochemical Characteristics of Compact Anaerobic Ammonium-Oxidizing Granules in an Upflow Anaerobic Sludge Blanket Reactor

Abstract

Anaerobic ammonium oxidation (anammox) is a promising new process to treat high-strength nitrogenous wastewater. Due to the low growth rate of anaerobic ammonium-oxidizing bacteria, efficient biomass retention is essential for reactor operation. Therefore, we studied the settling ability and community composition of the anaerobic ammonium-oxidizing granules, which were cultivated in an upflow anaerobic sludge blanket (UASB) reactor seeded with aerobic granules. With this seed, the start-up period was less than 160 days at a NH 4 ؉ -N removal efficiency of 94% and a loading rate of 0.064 kg N per kg volatile suspended solids per day. The formed granules were bright red and had a high settling velocity (41 to 79 m h ؊1 ). Cells and extracellular polymeric substances were evenly distributed over the anaerobic ammonium-oxidizing granules. The high percentage of anaerobic ammonium-oxidizing bacteria in the granules could be visualized by fluorescent in situ hybridization and electron microscopy. The copy numbers of 16S rRNA genes of anaerobic ammonium-oxidizing bacteria in the granules were determined to be 4.6 ؋ 10 8 copies ml ؊1. The results of this study could be used for a better design, shorter start-up time, and more stable operation of anammox systems for the treatment of nitrogen-rich wastewaters.

Identification of the release and effects of AHLs in anammox culture for bacteria communication

“…Real-time PCR assays were conducted as follows. The primers for anammox and eubacteria were 694F (forward primer)-960R (reverse primer) [27] and 314F (forward primer)-518R (reverse primer) [28], respectively. Each PCR working solution (20 lL) contained 12.5 lL of SYBR Green PCR master mix (Applied Biosystems, USA), 1 lL each of forward and reverse primers, 3 lL of template DNA (the DNA extraction was diluted 100 times) and 2.5 lL of ddH 2 O. PCR amplification and detection were performed with an ABI Prism 7000 sequence detection system (Applied Biosystems, USA).…”

Anaerobic ammonium oxidation (anammox) under realistic seasonal temperature variations: Characteristics of biogranules and process performance

“…For example, both the settling velocity and the EPS are affected by external conditions such as the presence of multivalent metals or toxic compounds (Ni et al, 2010;Sheng et al, 2010), and the diameter distribution is dependent on (nitrogen loading rate) NLR and (nitrogen removal rate) NRR, which express the performance of anammox reactor. However, little research has focused on the influence of variable lower temperatures on the quality or physico-chemical characteristics of anammox granules.…”

“…The granule characteristics are important for the design and monitoring of bioreactors. According to Sheng et al (2010) and Ni et al (2010), the characteristics of granules, such as settling velocity and extracellular polymeric substances (EPS) content, play important roles in the fast start-up of granule-based processes. The significant increase in settling velocities contributes to great biomass accumulation in the reactor, and the EPS have a significant influence on some physicochemical properties of the sludge.…”

Analysis of Microbial Community Structure for Effective Removal of Mixed Wastewater in Biological Wastewater Treatment

“…FISH법은 다양한 종류의 probe들을 사용하여 전체적인 박 테리아 군집에 대한 해석이 용이하며, 또한, 목적으로 하는 특정 박테리아 군집들에 대해 정성·정량적인 평가가 가능하 기 때문에 환경시료 내의 박테리아 군집 구조 분석과 모니터 링에 다양하게 적용되고 있다 [18][19][20]. 특히, 수처리 분야에서 하·폐수처리 공정내의 생물학적 처리공정의 박테리아 군집 분석 [15,16,[19][20] DAPI법에 의한 총 세균수 측정은 고정된 시료 2 µL를 gelatin으로 코팅된 slide glass에 놓고, DAPI (4',6-diamidino 2-phenylindole 1 µg/mL, Sigma, USA)로 5분 동안 염색하였 다.…”

“…특히, 수처리 분야에서 하·폐수처리 공정내의 생물학적 처리공정의 박테리아 군집 분석 [15,16,[19][20] DAPI법에 의한 총 세균수 측정은 고정된 시료 2 µL를 gelatin으로 코팅된 slide glass에 놓고, DAPI (4',6-diamidino 2-phenylindole 1 µg/mL, Sigma, USA)로 5분 동안 염색하였 다. 염색된 시료는 멸균 증류수로 세척한 후 confocal laser scanning microscopy (LSM 510, ZEISS, Germany)를 이용하 여 직접 형광을 띈 박테리아를 계수하였다 [25].…”