npj Clean Water
·
2020
·Vol. 3
·期 1
·1-10
·
IF 4.87
Zou Chunzhen,Guo Beibei,Zhuang Xuming,Ren Liying,Ni Shou-Qing,Ahmad Shakeel,Qiao Zhuangming,Cui Zhaojie,Hong Jinglan
The effects of FeS on nitrogen removal performance and microbial community of anammox process were studied. During the start-up period, the removal efficiencies of nitrite and total nitrogen were significantly improved by FeS. The addition of FeS increased the content of iron ions in the reactor and promoted the synthesis of heme c , which was involved in the formation of various enzymes. Compared with the control, the abundance of anammox bacteria in the FeS reactor was increased by 29%, and the expression level of the nirS gene (encoding cd 1 type nitrite reductase containing heme) was nearly doubled. The content of nitrite reductase (ammonia-forming) in the community was increased by 26.4%. The difference in functional bacteria and enzyme contents in the microbial community resulted in a difference in nitrogen removal rate (NRR) between the two reactors. High-throughput results indicated that FeS increased the richness and diversity of microbial community and enhanced the metabolic function of the microbial community. The addition of FeS did not change the dominant position of Ca. Kuenenia in both reactors. But the relative abundance of heterotrophic denitrifying bacteria was reduced with FeS, which may be related to the inhibition effect of S 2− produced by FeS.
研究领域:
环境微生物学
·
污水处理
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DOI
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
·
微生物学
·
生物技术
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产品关联
DOI
PubMed
高影响因子
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 Chemical Engineering
·
2024
·
IF 7.4
Lingjie Liu,Shaoqing Mo,Shaopo Wang,Jing Chang,Jianhui Zhao,Jingjie Yu
Low temperatures were a critical factor that inhibited anaerobic ammonium oxidizing bacteria (AnAOB) activity. This study demonstrated the effect of exogenous zero-valent iron (ZVI) on Anammox-hydroxyapatite (HAP) system at 17°C. The results showed that long-term addition of ZVI increased the system nitrogen removal efficiency by 8.59% and alleviated the inhibition of AnAOB by low temperature. After addition of ZVI, the activity of AnAOB and the heme c content increased by 58.20% and 4.83%, respectively. Moreover, the functional enzyme activities of NIR, HZS, and HZO increased by 94.12%, 36.36%, and 16.67%, respectively. The concentrations of quorum sensing molecules, i.e., C 6 -HSL and C 8 -HSL, increased by 191.17% and 41.54%, respectively, after ZVI addition. Metagenomic analysis revealed that the addition of 5 g/L ZVI stimulated the relative abundance relative abundance of Fe(II) metabolism-related genes in AnAOB at 17 °C, thereby contributing to the uptake, transport, utilization, and storage of Fe(II). The addition of ZVI could improve the nitrogen removal performance of the anammox-HAP system at the low temperature.
研究领域:
环境工程
·
微生物学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2020
·Vol. 43
·期 5
·851-861
·
IF 2.419
Ma Shu,Wang Jing,Han Ying,Yang Fan,Gu Chen,Wang Fengbo
Conductive magnetite (Fe 3 O 4 ) has been applied into some anaerobic bioprocesses to accelerate direct interspecies electron transfer (DIET), however, Fe 3 O 4 is usually dissolved by iron-reducing bacteria under anaerobic conditions, resulting in the loss of magnetite. Therefore, submicron magnetite particles were added to the sequencing batch reactor (SBR) to build a Fe 3 O 4 /SBR system, which could alleviate magnetite dissolution and simultaneously remove tribromophenol (TBP) effectively. The average removal efficiencies of chemical oxygen demand (COD) and TBP in Fe 3 O 4 /SBR system were 81% and 91%, respectively, which were 51% and 18% higher than those of the control group without Fe 3 O 4 (SBR system). The enhanced TBP biodegradation was likely related to potential DIET, which was supported by the scanning electron microscopy (SEM) analysis, the increase of dehydrogenase and heme c (fivefold and 1.7-fold), and the enrichment of iron-redoxing bacteria ( Geobacter and Thiobacillus ). Furthermore, magnetite mainly remained intact in structure as indicated by X-ray diffraction (XRD), which might be ascribed to in situ iron redox cycle and magnetite biosynthesis via Magnetospirillum . Notably, the content of hydrogen peroxide (H 2 O 2 ) and hydroxyl radical (⋅OH) in Fe 3 O 4 /SBR system was 4–5 times higher than that of SBR system. These findings could provide insights into the development of cost-effective strategy for the removal of refractory organic pollutants.
研究领域:
环境工程
·
生物技术
·
废水处理
✓ 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）