Successful startup of one-stage partial nitritation and anammox system through cascade oxygen supply and potential ecological network analysis

The effects of adding organic carbon on the performance of different partial nitrification‐anammox (PNA) process (the activated sludge process and biofilm process) were studied, especially nitrogen removal, functional microbial activity, and microbial community structure. The potential influences of quorum sensing (QS) on the nitrogen metabolism were also analyzed. The results showed that the addition of organic carbon in biofilm systems could reduce total nitrogen (TN) removal percentages, while in activated systems it could increase TN removal percentages. The TN removal percentages in SBBR‐CN (the biofilm system with addition of organic carbon) and SBR‐CN (the activated sludge system with addition of organic carbon) were 15% and 45%, respectively, and those in SBBR‐N (the biofilm system without addition of organic carbon) and SBR‐N (the activated sludge system without addition of organic carbon) were 75% and 21%, respectively. Batch experiments have proved that organic carbon inhibited the activities of nitrite‐oxidizing bacteria (NOB) and anaerobic ammonia oxidation (anammox) bacteria, and organic carbon could promote the activity of denitrifying bacteria in activated sludge systems. Compared with activated sludge systems, biofilm systems could protect the activity of anammox bacteria. The relative abundances of ammonia oxidizing bacteria (AOB) and anammox bacteria were decreased, while the relative abundances of denitrifying bacteria (Thauera) were increased with the addition of organic carbon. The biofilm systems were more conducive to the growth of anammox bacteria. Metagenomics revealed that the same bacteria might be involved in different nitrogen metabolism, and nitrogen metabolism was achieved through the complex cooperation among functional bacteria. Besides, functional bacteria involving in the nitrogen metabolism had genes related to QS, indicating that QS might affect the nitrogen metabolism by regulating the functional bacteria activity. Practitioner points PNA was achieved through SBBR and complete nitrification was achieved through SBR under the low ammonia nitrogen concentration condition. The effect of organic carbon on biofilm and activated sludge PNA process was different under the low ammonia nitrogen concentration condition. QS and QQ may affect the nitrogen removal performance by regulating the expression of nitrogen metabolism‐related genes.

Section: Resultssupporting

confidence: 85%

Section: Resultsmentioning

confidence: 99%

Analyzing the effect of organic carbon on partial nitrification‐anammox process based on metagenomics and quorum sensing

Xing

Liu

Zhang

et al. 2020

“…Previous studies proved that C6-HSL and C8-HSL widely exist in Anammox systems and may affect nitrogen removal and sludge activity (Feng et al, 2019;Zhang, Miao, et al, 2020;Zhang, Fan, et al, 2020). This study further confirmed that C8-HSL plays an important role in the stability of Anammox granules, while C6-HSL and 3OC8-HSL affected the activity of Anammox granules.…”

Section: Effects Of Exogenous C6-hsl C8-hsl and 3oc8-hsl On Granule Activitysupporting

confidence: 82%

Effects of AHLs inhibitors and exogenous AHLs on the stability and activity of Anammox granules at low temperatures

Zhang

Zhang²,

Sun³

et al. 2021

This study investigated the relationship between acyl homoserine lactones (AHLs)based quorum sensing (QS) and the properties of Anammox granular sludge at low temperatures (11-23°C). Results indicated that adding different concentrations of AHLs inhibitors reduced the content of N-hexanoyl-dl-homoserine lactone (C6-HSL) and N-octanoyl-dl-homoserinelactone (C8-HSL) in Anammox granules on different degrees at different operation temperatures, which led to the deterioration of granules stability and activity. The important role of endogenous C6-HSL and C8-HSL signals in maintaining Anammox granular sludge stability and activity in low-temperature conditions was revealed. In addition, in the process of reducing operation temperatures, another type of AHL signal (N-(3-oxooctanoyl)-l-homoserine lactone, 3OC8-HSL) was released by Anammox granules. The effects of exogenous C8-HSL on the strength, average diameter, and density of Anammox granules were closely related to the operation temperature. When the operation temperature ranged from 11°C to 16°C, the stability of granules could be significantly improved by exogenous C8-HSL. In addition, the addition of C6-HSL and 3OC8-HSL promoted the activity of Anammox granules when the operation temperatures of the reactors were 11-23°C. This study proposed a novel approach to improve the properties of Anammox granules at low temperatures from the perspective of QS. • Practitioner points• Endogenous AHLs played an important role in maintaining the activity and stability of Anammox granules at 11-23°C. • Exogenous C8-HSL improved the granules stability at the low temperature of 11-16°C. • Exogenous C6-HSL or 3OC8-HSL promoted the granules activity at 11-23°C.• Supply a novel way to improve the Anammox granules performance at low temperatures.

“…The relative abundance of the microbial community changed significantly during the operation of the single‐stage PN/A reactor. Nitrosomonas was a typical bacterium which was mainly responsible for ammonia oxidation (Feng et al, 2019). The relative abundance of Nitrosomonas was 1.9% when the reactor was started.…”

Section: Resultsmentioning

confidence: 99%

Performance of single‐stage partial nitritation and anammox reactor treating low‐phenol/ammonia ratio wastewater and analysis of microbial community structure

Ren

et al. 2021

Phenol and ammonia are common pollutants in many industrial wastewaters. The partial nitritation and anammox process is a very promising technology for treating phenol–ammonia wastewater. This study was the first time to rapidly achieve the start‐up and operation of the single‐stage partial nitritation /anammox reactor treating phenol–ammonia wastewater. The optimized ratio of phenol and nitrogen (phenol/NH4+‐N=0.3) was set to start‐up the reactor. After 60 days of operation, the total nitrogen and COD removal efficiencies were around 73.0% and 79.5%, respectively. The activity of ammonium‐oxidizing bacteria was291.1 ± 3.0 mg NH4+‐N g−1MLVSS d−1 and the specific anammox activity was 20.9 ± 1.0 mg NH4+‐N g−1MLVSS d−1. The results indicated that the anammox bacteria had adapted to phenol condition and remained stable activity after the 60 days’ operation in the reactor. The sequence analysis of 16SrRNA showed that the microbial community structure evolved to a balanced distribution that the removals of phenol and ammonia could be achieved simultaneously. Practitioner Points Phenol/N ratio of 0.3 was set to start up the single‐stage partial nitritation/anammox reactor. The single‐stage partial nitritation /anammox reactor was rapidly started up when treating the phenol‐ammonia wastewater. Total nitrogen removal rate and COD removal efficiencies could achieve to 73.0% and 79.5%, respectively. Microbial community structure evolved to stable distribution of which AOB, anammox bacteria, denitrification bacteria and heterotrophic nitrification bacteria coexisted.