WATER RESEARCH
·
2020
·
IF 9.13
Da Kang,Yiyu Li,Dongdong Xu,Wenji Li,Wei Li,Aqiang Ding,Ru Wang,Ping Zheng
The red color is the most striking character of anaerobic ammonium-oxidizing bacteria (AnAOB) which has been used to estimate the anammox activity roughly. However, the quantitative relationship between the color and activity of anammox sludge still remains unknown. In this study, the chromaticity, activity and their correlation were systematically investigated at different steady-state nitrogen loading rates. The chromaticity of anammox sludge was digitalized by the CIE L*a*b* color space. The results revealed that the average chroma value was found to be significantly correlated with specific anammox activity ( r = 0.940, p < 0.01) and the cluster centers of chromaticity coordinates (a*, b*) of anammox sludge were established to define the typical working states of anammox system. The visible spectra of anammox sludge were proved to originate from the cytochrome c. The correlation between chroma and heme c concentration of anammox sludge was consistent with the fully-reduced cytochrome c and the chroma was determined by both content and redox ratio of cytochrome c. The chromaticity of anammox sludge was able to be linked with the anammox activity via reduced cytochrome c content. The gene abundance of cytochrome c synthetase linked the chromaticity with AnAOB quantity via total cytochrome c content, while the enzyme activity of octaheme hydrazine dehydrogenase linked the chromaticity with AnAOB activity via reduced cytochrome c ratio. Moreover, the redundancy analysis proved that heme c, as the key component of cytochrome c, was the most important explanatory variable accounting for the maximum 69.6% of the total variation of the anammox community, which correlated positively with the relative abundance of dominant AnAOB ( Candidatus Kuenenia). This work aimed at demonstrating the chromaticity of anammox sludge could be developed as an alternative intuitive anammox activity indicator which will promote the monitoring and optimization of anammox process.
研究领域:
环境工程
·
微生物学
·
生物技术
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2024
·
IF 8
Xun Weng,Meng-Jiao Gao,Zheng Mao,Hui-Min Fu,Shi-Jun Li,Peng Yan,You-Peng Chen
Iron nanoparticles (FeNPs) generated from industrial activities could end up into the sewer system, and potentially affect wastewater treatment processes. The impact of FeNPs on anammox process is getting increasing attention. However, the resistance mechanism of anammox granular sludge (AnGS) to FeNPs has not been fully elucidated. The current study investigated the metabolic and morphological response of AnGS to acute and chronic FeNPs exposure. Results showed that nitrogen removal efficiencies were elevated at 1–4 mM FeNPs concentrations compared to 0–0.5 mM FeNPs. Extracellular protein and tyrosine-like and tryptophan-like fluorophore secretions of AnGS were stimulated by FeNPs, which largely contributed to the adsorption of FeNPs on AnGS surface. FeNPs exposure triggered higher necrotic fraction of AnGS compared with no FeNPs condition. Highly absorbed particles appeared inside the bacterial cells of AnGS, soft X-ray imaging illustrated that anammox bacteria maintained intact cellular and anammoxosome structures whereas non-anammox bacterial structures were damaged under FeNPs exposure. Anammox bacterial abundance increased from 4.84% to 20.64%, when FeNPs concentrations increased from 0 mM to 4 mM, and anammoxosome membrane ensured anammox bacterial metabolism under FeNPs exposure. This study extended fundamental understanding of AnGS resistance mechanisms to FeNPs.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Yu Feng,Xingyu Zhang,Caiwei Zhang,Haozhe Xu,Xiaoming Ji,Jianfang Wang,Peng Wu,Feiyue Qian,Chongjun Chen,Yaoliang Shen,Wenru Liu
In this study, waste iron scraps (WIS) were exerted to alleviate sulfide inhibition on anammox bacteria and promote anammox nitrogen removal from sulfide-containing wastewater. Short-term batch experiments showed that WIS-addition led to the anammox bacteria activity increasing by 124.8 % at an initial sulfide concentration of 40 mgS/L. During the long-term experiments, the nitrogen removal rate (NRR) reached to 8.76 kg/(m 3 ·d) in the WIS-added reactor, while the maximum NRR was only 3.77 ± 0.31 kg/(m 3 ·d) in the non-WIS reactor. In contrast to anammox bacteria development in the non-WIS reactor, the relative abundance of Candidatus Kuenenia (1.4–3.7 %) declined significantly in the WIS-added reactor, but novel potential anammox bacteria Brocadiaceae_unclassified (60.1 %-78.6 %) were highly enriched. Overall, the experimental evidence suggested that WIS-addition not only mitigated the sulfide inhibition on anammox bacteria, but also promoted novel anammox bacteria proliferation. The findings of this work provide a promising solution for wide engineering applications of anammox treating sulfide-containing wastewater.
研究领域:
环境工程
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Water Research X
·
2024
·
IF 7.2
Dongdong Xu,Aqiang Ding,Yang Yu,Ping Zheng,Meng Zhang,Zhetai Hu
Magnetite (Fe 3 O 4 ) particles have been widely reported to enhance the anammox's activity in anammox granular sludge (AnGS), yet the underlying mechanisms remain unclear. This study demonstrates that both Fe 3 O 4 microparticles (MPs) and nanoparticles (NPs) at a dosage of 200 mg Fe 3 O 4 /L significantly increased the specific anammox activity (SAA) of AnGS. Additionally, the transcriptional activities of the hzs and hdh genes involved in the anammox process, as well as the heme c content in AnGS, were also notably enhanced. Notably, Fe 3 O 4 NPs were more effective than MPs in boosting anammox activity within AnGS. Mechanistically, Fe 3 O 4 MPs released free iron, which anammox bacteria utilized to promote the synthesis of key enzymes, thereby enhancing their activity. Compared to MPs, Fe 3 O 4 NPs not only elevated the synthesis of these key enzymes to a higher level but also induced a nanofluids effect on the surface of AnGS, improving substrate permeability and accessibility to intragranular anammox bacteria. Moreover, the nanofluids effect was identified as the primary mechanism through which Fe 3 O 4 NPs enhanced anammox activity within AnGS. These findings provide new insights into the effects of nanoparticles on granular sludge systems, extending beyond AnGS.
研究领域:
环境工程
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微生物学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Xingyao Ye,Xiaojun Niu,Ling Li,Mengyu Lv,Dongqing Zhang,Deye Chen,Yu Line,Zhiquan Yang
N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) is an antioxidant commonly used in tire manufacturing, and its release into the environment has significantly increased due to rapid urbanization. When subjected to ozonation, 6PPD converts into the harmful pollutant 6PPD quinone (6PPDQ). These substances enter wastewater treatment plants (WWTPs) via stormwater runoff and pipelines, posing significant risks to the functional microorganisms. Anammox, a strictly controlled and sensitive microbial nitrogen removal process, is especially susceptible to the effects of the pollutants. This study investigates the comprehensive impact of 6PPD-Q and 6PPD on anammox communities based on characterization analysis and metagenomics. At environmental concentrations, 6PPD-Q at 200 ng/L-1000 ng/L led to the disintegration of anammox granules. Extended exposure to both 6PPD-Q and 6PPD significantly reduces the population of anammox bacteria (AnAOB). By utilizing organic matter from dead cells and incoming carbonate as a carbon source, the system evolved into a nitrogen metabolism network primarily focused on denitrification and dissimilatory nitrate reduction to ammonium (DNRA). This transformation was accompanied by a reshuffling of the microbial community and associated genes, resulting in an accumulation of NH 4 + -N. These findings underscore the toxicity of 6PPD-Q and 6PPD to anammox and stress the importance of incorporating 6PPD into regulatory and preventive strategies.
研究领域:
环境科学
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微生物学
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
·
IF 10.753
Yong-Ze Lu,Jing Han,Wei-Jia Zhang,Ji Sun,Xin Li,Zhong-lian Yang,Jun-Ling Yang,Shu-Ping Li,Guang-Can Zhu
At high altitude, wastewater aeration efficiency is low, which is detrimental to nitrification in conventional biological nitrogen removal. The combined partial nitritation and anaerobic ammonium oxidation (CPNA) process requires little oxygen and can be appropriate in low-pressure conditions. As such, in this study, we investigated the effect of air pressure on CPNA using a laboratory-scale reactor. We found that low air pressure promoted the removal of total inorganic nitrogen (TIN), achieving a TIN removal rate of 43,000 mg·N/(kg·VSS·d). The secretion of extracellular polymeric substances under low air pressure was not significantly different from that under ordinary air pressure, indicating no adverse effects on microbial aggregation ability, stability, or settleability. The abundance of aerobic ammonia-oxidizing bacteria (AeAOB) increased from 0.2% to 5.6%, and the activity of anaerobic ammonia-oxidizing bacteria (AnAOB) enhanced, giving AeAOB and AnAOB a competitive advantage over nitrite-oxidizing bacteria, thus forming a microbial community structure favorable to the CPNA process. Our further analysis of the results of batch tests in serum bottles confirmed the positive effect of low air pressure on the anaerobic ammonium oxidation (anammox) process, with a 28.5% ± 1.9% improvement in the specific anammox rate at 70 kPa compared with 100 kPa. AnAOB activity increased, which was reflected in the intracellular heme content increasing from 0.56 ± 0.18 μmol/(g·VSS) at 100 kPa to 2.56 ± 0.20 μmol/(g·VSS) at 70 kPa. We clarified the CPNA-process-promoting effect of low air pressure, which shows potential for nitrogen removal in high-altitude regions.
研究领域:
环境工程
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微生物学
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污水处理
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 53
·32249-32258
·
IF 3.119
Fengli Liu,Huosheng Li,Dandan Liao,Yanhong Xu,Mingxia Yu,Shengwen Deng,Gaosheng Zhang,Tangfu Xiao,Jianyou Long,Hongguo Zhang,Yuting Li,Keke Li,Ping Zhang
Carbon quantum dots (CQDs) were synthesized via a hydrothermal method, in which extracellular polymeric substance (EPS) from anaerobic ammonium oxidation (anammox) granular sludge was used as a carbon precursor, while citric acid and ethylenediamine were applied as auxiliary carbon source and passivation agent, respectively. The synthesized CQDs, with orderly spherical shape and mean size of 7.15 nm, emitted blue fluorescent light under UV radiation of 365 nm. The CQDs had a high fluorescence yield (40.84%), with good water solubility and excellent spectroscopic properties. In addition, the CQDs exhibited selective, sensitive and distinctive fluorescence quenching behaviors for Cr(VI) and Mn(VII) in a PBS buffer solution (NaH2PO4–Na2HPO4) of pH 7, with a detection limit of 5.8 nM for Cr(VI) and 2.3 nM for Mn(VII). Owing to the nitrogen components from the EPS of anammox granules, the CQDs were well nitrogen-doped, promoting electron-transfer and leading to reduction between the CQDs and Mn(VII)/Cr(VI). These results indicate that CQD-based chemical sensing is a simple and efficient means for the fluorescence detection of Mn(VII) and Cr(VI).
研究领域:
环境科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2023
·
IF 8.7
Xun Weng,Hui-Min Fu,Zheng Mao,Peng Yan,Xiao-Wei Xu,Yu Shen,You-Peng Chen
Iron nanoparticles (FeNPs) are commonly used in various industrial processes, leading to their release into the environment and eventual entrance into wastewater treatment plants (WWTPs). FeNPs undergo dissolution, migration, and transformation in WWTPs, which can potentially affect the stable operation of anaerobic ammonia oxidation (anammox) systems and may be discharged with wastewater or biomass. To better understand the fate of FeNPs in anammox systems, exposure experiments were conducted using anammox granular sludges (AnGS) and FeNPs. Results demonstrated that FeNPs released Fe 2+ upon contact with water, with a portion being bound to functional groups in extracellular polymeric substances (EPS) and the rest entering the bacteria to form highly absorbable substances. A significant amount of FeNPs was observed to cover the surface of AnGS or aggregate and deposit at the bottom of the reactor, eventually converting into Fe 3 O 4 and stably existing within the anammox system. The findings of this study clarify the fate of FeNPs in anammox systems and provide important insights into the stable operation of anammox systems under FeNPs exposure.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2022
·
IF 7.34
Ying Wang,Haoyu Chen,Chao Chen,Zikun Zhang,Yin Xu,Guangjiao Chen,Yanlong Zhang
The anammox-HAP coupling process can simultaneously achieve high-efficiency nitrogen removal and phosphorus recovery from sewage. The composition and physical properties of the byproducts (aHAP) collected in the anammox-HAP process were analyzed. In addition, the application potential and mechanisms for Cd(II) adsorption by aHAP in wastewater were investigated. The results show that aHAP is mainly composed of hydroxyapatite and calcium carbonate , having granular structure with honeycombs and pores. The aHAP shows an adsorption capacity of 21.10–34.80 mg/g for Cd(II) removal, and the adsorption behavior is consistent with pseudo-second-order and intra-particle diffusion models, showing that the rate-limiting step is controlled by the chemical reaction of surface complexation, ion exchange, and precipitation. In addition, the remaining anammox biomass in aHAP can bind Cd(II). The aHAP also shows a pH buffer capacity when the initial pH ranges between 4.10 and 8.46, and the final pH can be stabilized in the range of 6.3 to 8.3, which is suitable for anammox reactions. Collectively, the anammox-HAP coupling process can not only be used to achieve high-efficiency nitrogen and phosphorus removal, but its aHAP byproduct shows good adsorption properties and pH buffering capacity, which meets the requirements of green chemistry and has high economic and environmental benefits.
研究领域:
环境科学
·
污水处理
✓ 已验证
DOI
高影响因子
Environmental Technology & Innovation
·
2025
·
IF 7.1
Zhenxin Wang,Qilin Yu,Zhiqiang Zhao,Ruicheng Zhang,Hongbo Zhang,Yaobin Zhang
Anammox is limited in practical application due to the need to control the influent ratio of NO 2 - to NH 4 + . Fe(III) (hydr)oxides have been confirmed to serve as electron acceptors and induce a so-called Feammox to anaerobically oxidize ammonia in Anammox systems via extracellular electron transfer, which however is also restrained by the low activity of Fe(III) (hydr)oxides. Heme, a Fe-containing compound with high redox activity, was introduced into the Anammox system to improve NH 4 + oxidation in this study. A removal rate of 46.32 mg N/(L·d) was achieved for nitrogen through the addition of heme, which was 43.85% higher than the maximum Feammox efficiency in documents (32.20 mg N/(L·d)). Continuous experiments showed that the added heme participated in the intracellular and extracellular electron transfer of Anammox. The contribution of Feammox to nitrogen removal was affected by the influent NO 2 - -N/NH 4 + -N ratio. Under a high NO 2 - -N/NH 4 + -N ratio (1.25:1), the contribution of Feammox to NH 4 + -N removal was 8.29%. This ratio increased to 31.49% under a low NO 2 - -N/NH 4 + -N ratio (0.80). Besides increasing the nitrogen removal efficiency, heme addition may significantly lower the nitrite requirement in this biological process, leading to improved adaptability in its application.
研究领域:
环境微生物学
·
污水处理
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Zheng-Zhe Zhang,Hai-Yan Hu,Jia-Jia Xu,Zhi-Jian Shi,Yang-Yang Shen,Man-Ling Shi,Ren-Cun Jin
The increasing use of engineered nanoparticles (NPs) poses an emerging challenge to biological wastewater treatment. The long-term impact of CuNPs on anaerobic ammonium oxidation (anammox) process was firstly investigated in this study. The nitrogen removal capacity of anammox reactor was nearly deprived within 30 days under the stress of 5.0 mg L −1 CuNPs and the relative abundance of anammox bacteria (Ca. Kuenenia ) was decreased from 29.59% to 17.53%. Meanwhile, copper resistance genes associated with the Cus, Cop and Pco systems were enriched to eliminate excess intracellular copper. After the withdrawal of CuNPs from the influent, the nitrogen removal capacity of anammox biomass recovered completely within 70 days. Overall, anammox biomass showed susceptibility, resistance and resilience to the stress of CuNPs. Therefore, the potential impacts of ENPs on anammox-based processes should be of great concern.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 25
·37266-37276
·
IF 5.19
Zhang Li,Lan Shuang,Dou Quanhao,Hao Shiwei,Wang Yueping,Peng Yongzhen
The zero-valent iron-anaerobic ammonium oxidation (ZVI-anammox) system has received widespread attention due to its excellent nitrogen removal performance and user-friendly operation. However, its disadvantages include a short service life, high ZVI consumption, and poor system stability. The use of ultrasound as a physical method is increasing in various water treatment processes. In this study, a series of batch tests were conducted to obtain the best ultrasonic parameter and explore the comprehensive effects of ultrasound on a ZVI-anammox system. The highest specific anammox activity of the ZVI-anammox system was found to be 2.88 mg total nitrogen/g of volatile suspended solids/h after ultrasonic treatment (0.2 w/mL, 5 min), which was 37.85% higher than a control group. Additionally, the service life of ZVI extended by 28.57% and the total nitrogen removal efficiency changed from 58.03–72.08 to 63.92–78.33% under ultrasonic irradiation. These phenomena were related to the mechanical force and cavitation of ultrasonic waves. Judging from the characteristics of sludge and ZVI, ultrasound can promote anammox sludge granulation, ease ZVI passivation, and enhance the stability of the entire system. This paper also briefly discusses the impact mechanisms of ultrasound on the ZVI-anammox system. In brief, ultrasound destroys the surface structure of ZVI and thus provides numerous attachment points for microorganisms that improve the performance of the entire system. The proposed ultrasound combined with ZVI is a novel method that has potential for use in large-scale engineering applications in actual sewage treatment after comprehensive analysis.
研究领域:
环境工程
·
水处理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）