Water
·
2023
·Vol. 15
·期 24
·4272
·
IF 3.4
Xueyuan Bai,Jianwei Li,Sheng Chang
Amidst rapid urbanization, municipal wastewater treatment plants remain a significant source of nitrogen compounds, which stems from their effluents. Constructed wetlands, employing denitrification processes, have been proven effective at nitrogen removal. Variations in influent nutrient concentrations are often seen as limiting factors affecting nitrogen removal and influencing microbial communities. This study evaluates the impact of nutrient limitation on nitrogen removal by analyzing changes in microbial communities within constructed wetlands under different influent water C/N ratios. The findings indicate that both excessively high and low C/N ratios constrain nitrogen decomposition, with optimal nitrogen removal observed at C/N ratios of 6 or 7. Moderate C/N values (6–7) support diverse and stable microbial networks, ensuring treatment system stability. Microorganisms play a pivotal role in nitrogen transformation, with thenirkgene being crucial for NH4+−N conversion, while theAOAgene dominates NO2−−N and TN conversion. This study offers practical guidance for identifying a suitable C/N ratio for wastewater treatment and establishes a theoretical foundation for regulating nitrogen removal by microbial communities in constructed wetlands within nitrogen removal systems.
研究领域:
环境科学
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微生物学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2023
·
IF 11.4
Ze-Tong Feng,Xin Ma,Ying-Jun Sun,Jia-Min Zhou,Zu-Gang Liao,Zhi-Cong He,Fei Ding,Qian-Qian Zhang
The nitrogen removal efficiency and distribution of microbial community in a denitrification process aided by zero-valent iron (ZVI) under low carbon-to-nitrogen ratio (C/N) were assessed in this study. Experimental results demonstrated that the nitrogen removal efficiency (TNRE) increased to 96.4 ± 2.72% and 63.3 ± 4.02% after continuous addition of ZVI with molar ratio of ZVI to nitrate (NO 3 – -N) (ZVI/N) of 6 at C/N of 3 and 2, respectively, which was 4% and 7.7% higher than the blank one. Meanwhile, extracellular polymeric substance (EPS) could be used as electron transfer medium and endogenous carbon source for denitrification system and also the production of which increased by 28.43% and 53.10% under ZVI stimulation compared to the control group. Finally, a symbiotic system composed by autotrophic and heterotrophic denitrification bacteria was formed by aid of ZVI. This study proposed new insights into denitrification process improved by ZVI.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Zheng-Zhe Zhang,Jia-Jia Xu,Zhi-Jian Shi,Yu-Hui Bai,Ya-Fei Cheng,Hai-Yan Hu,Ren-Cun Jin
Given the increasing use of nanoscale zero-valent iron (NZVI) particles for environmental remediation and wastewater treatment, their potential impact on anaerobic ammonium oxidation (anammox) bacteria was investigated in this study using anammox sludge. Batch assays showed that NZVI concentrations up to 200 mg L −1 did not affect anammox activity, reactive oxygen species production, and cell membrane integrity. The nitrogen removal efficiency of the continuous-flow reactor fluctuated in the presence of 20 or 50 mg L −1 NZVI, but it could return to normal over time, even at 200 mg L −1 NZVI. 16S rDNA-based high-throughput sequencing indicated that although the presence of 10, 20, 50, and 200 mg L −1 NZVI to some extent affected microbial composition, the anammox bacteria ( Candidatus Kuenenia ) never lost its dominance. The abundance of gene families that are related to the assimilation and utilization of iron was down-regulated in response to the stress of high-level NZVI.
研究领域:
环境科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Qiong Wang,Yuqi Li,Na Chen,Xiaojing Zhang,Yongpeng Ma,Yali Song
Ibuprofen (IBU), a commonly used non-steroidal anti-inflammatory drug, is frequently detected in wastewater treatment systems, where it can interfere with nitrogen removal. This study investigated the effects of IBU on nitrogen removal performance and its biotransformation in a coupled sulfur autotrophic denitrification and anammox (SAD/A) system. Moreover, key parameters, such as nitrogen removal efficiency, microbial activity, community structure, and IBU degradation products, were carefully monitored. While IBU concentrations of up to 1 mg/L had negligible impacts on nitrogen removal efficiency due to the counteracting effects of slight inhibition on anammox and enhancement of sulfur autotrophic denitrification, a significant inhibition of ammonia removal occurred when the concentration increased to 10 mg/L. Quantum chemical analyses revealed that IBU underwent biotransformation through decarboxylation and hydroxylation pathways, leading to the formation of two biotransformation products with high ecological toxicity. This study is the first to elucidate the mechanisms by which IBU influences microbial communities and metabolic activities in SAD/A systems. In addition, it highlights the resilience of these systems in maintaining nitrogen removal efficiency under varying IBU concentrations, as well as the environmental risks posed by the biotransformation products of IBU.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 5
·1216-1223
·
IF 2.372
Wu Lian-Kui,Shi Yi-Jie,Su Cheng,Cao Hua-Zhen,Zheng Guo-Qu
Abstract A combined anode, Ti/IrO 2 (0–3.5 h)–Ti/RuO 2 (3.5–7 h) is designed to promote the removal of high concentration of nitrate by a stepwise method. During the electrolysis process, Ti/IrO 2 is used as anode at the first stage to promote the generation of ammonia-N and then Ti/RuO 2 is switched as anode at the next stage to enhance the chlorine evolution. The generated Cl 2 will further react with H 2 O to produce ClO − , which will oxidize ammonia-N to N 2 , therefore improve the nitrate removal efficiency. Results shown that both of the reduction of nitrate and oxidation of the by-product of ammonia-N are enhanced and the total nitrogen removal efficiency is 85% when the initial nitrate concentration is 500 mg L −1 . The avoid using cation exchange membrane not only efficiently reduces the operation cost but also simplifies the operation and maintain procedure. Graphical Abstract
研究领域:
环境科学
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电化学工程
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Zongshuo Han,Ruijie Hu,Xiaoying Zheng,Zhilin Zhao,Wenfei Li,Haidong He,Tao Lin,Hang Xu
The long acclimation period and sensitivity to environmental conditions of Anammox are the bottlenecks for its promotion and application. An innovative strategy was adopted to accelerate functional microbial enhancement and improve nitrogen removal performance by inoculating cryopreserved Anammox sludge and activated sludge with intermittent dosing of nanoscale zero-valent iron (nZVI). The acclimation time was shortened by 76 days with nitrogen removal efficiency (NRE) reaching up to 91.07 %. Anammox, NDFO (nitrate/nitrite-dependent Fe(II) oxidation), Feammox (Fe(III) reduction coupled with anaerobic ammonium oxidation) and abiotic reactions were coupled in the system with nZVI, contributing to 69.79 %, 15.14 %, 9.84 % and 0.25 % of nitrogen removal, respectively. Further microbial analysis demonstrated significant enrichment of functional microorganisms, such as Candidatus Jettenia , Acidovorax and Comamonas . High-efficient nitrogen removal was attribute to the increase of functional genes involved in Anammox, electronic transfer, heme C synthesis and iron metabolism. This work provides an inspiring idea for the mainstream Anammox application.
研究领域:
环境工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Chuanqi Jian,Yanru Hao,Rentao Liu,Xiaochen Qi,Minmin Chen,Na Liu
Heterotrophic sulfur-based autotrophic denitrification is a promising biological denitrification technology for low COD/TN (C/N) wastewater due to its high efficiency and low cost. Compared to the conventional autotrophic denitrification process driven by elemental sulfur, the presence of polysulfide in the system can promote high-speed nitrogen removal. However, autotrophic denitrification mediated by polysulfide has not been reported. This study investigated the denitrification performance and microbial metabolic mechanism of heterotrophic denitrification, sulfur-based autotrophic denitrification, and mixotrophic denitrification using lime sulfur and butanediol as electron donors. When the influent C/N was 1, the total nitrogen removal efficiency of the mixotrophic denitrification process was 1.67 and 1.14 times higher than that of the heterotrophic and sulfur-based autotrophic denitrification processes, respectively. Microbial community alpha diversity and principal component analysis indicated different electron donors lead to different evolutionary directions in microbial communities. Metagenomic analysis showed the enriched denitrifying bacteria ( Thauera , Pseudomonas , and Pseudoxanthomonas ), dissimilatory nitrate reduction to ammonia bacteria ( Hydrogenophaga ), and sulfur oxidizing bacteria ( Thiobacillus ) can stably support nitrate reduction. Analysis of metabolic pathways revealed that complete denitrification, dissimilatory nitrate reduction to ammonia, and sulfur disproportionation are the main pathways of the N and S cycle. This study demonstrates the feasibility of a mixotrophic denitrification process driven by a combination of lime sulfur and butanediol as a cost-effective solution for treating nitrogen pollution in low C/N wastewater and elucidates the N and S metabolic pathways involved.
研究领域:
环境工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Weidong Xiao,Yaoguo Wu,Sihai Hu,Zherui Zhang,Lang Ran,Hongjian Luo,Ran Sun
Carbon sources as energy sources and electron donors are essential for the nitrogen removal efficiencies of heterotrophic nitrification and aerobic denitrification (HNAD) process. However, conventional carbon sources from the chemical industry face issues of low stability of biological treatment systems and increased indirect carbon emissions in practical applications. Encouragingly, wood vinegar, a by-product of biomass pyrolysis process, promises to address these concerns. Herein, we investigated the potential of wood vinegar for green composite carbon source in HNAD process from multiple perspectives by establishing different microcosms. Regular monitoring results showed that wood vinegar-fed microcosms had the optimal cost-effectiveness with a C/N ratio of 7, and total nitrogen and COD removal efficiencies of up to 85.0 % and 93.4 % respectively. Furthermore, wood vinegar significantly improved the species diversity and optimized the microbial community structure compared to traditional carbon sources, strengthening the stability and resistance of the microcosm. Meanwhile, the enrichment analysis of key genes and enzymes indicated that both carbon and nitrogen metabolism were enhanced obviously, and the wood vinegar as a composite carbon source was expected to overcome the defects of traditional carbon sources, better balance the nitrification and denitrification capabilities. Importantly, the introduction of wood vinegar does not present a risk of secondary contamination and contributes to carbon reduction in the water treatment field. All indications are that wood vinegar as a green composite carbon sources can enhance wastewater treatment system stability and efficiency, and provide a viable strategy for promoting more sustainable wastewater management.
研究领域:
环境科学
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微生物学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2021
·
IF 9.642
Jin-Jin Fu,Dong-Qi Huang,Zheng-Yang Lu,Yuan-Long Ma,Xian-Wen Xu,Bao-Cheng Huang,Nian-Si Fan,Ren-Cun Jin
Two types of anaerobic ammonium oxidation (anammox) seed sludge were selected to evaluate their responses to copper nanoparticles (CuNPs) exposure. Antibiotic-exposed anammox granules (R 1 ) were more likely to be inhibited by 5.0 mg L -1 CuNPs than the normal anammox granules (C 1 ). The nitrogen removal efficiency (NRE) of C 1 decreased by 9.00% after two weeks of exposure to CuNPs, whereas that of R 1 decreased by 20.32%. Simultaneously, the abundance of Candidatus . Kuenenia decreased by 27.65% and 36.02% in C 1 and R 1 under CuNPs stress conditions, respectively. Generally, R 1 was more susceptible to CuNPs than C 1 . The correlation analysis indicated that the horizontal transfer of antibiotic resistance genes and cop A triggered by int I1 facilitated the generation of multiresistance in the anammox process. Moreover, the potential multiresistance mechanism of anammox bacteria was hypothesized based on previous results. The results will generate new ideas for the treatment of complex wastewater using the anammox process.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Jiajia Xu,Chao Li,Nanwen Zhu,Yanwen Shen,Haiping Yuan
The nitrite (NO 2 − ) inhibition in anaerobic ammonium oxidation (anammox) process is widely reported. Here, the effects of three pyrolytic biochars (CS300, CS550 and CS800) were investigated to alleviate NO 2 − stress on anammox process under exposure of varied NO 2 − -N concentrations (70, 200, 400 and 600 mg L −1 ). No nitrite inhibition was observed at 70 mg N L −1 . However, the total nitrogen removal efficiency (TNREs) decreased with NO 2 − -N concentration increased, while the biochar-amended groups achieved higher TNREs than the control (CK). At 200 mg N L −1 , the TNREs were 60.2%, 99.0%, 98.5% and 86.6% for CK, CS300, CS550 and CS800, respectively. At 400 mg N L −1 , the TNREs were 23.3%, 56.0%, 37.1% and 29.7% for CK, CS300, CS550 and CS800, respectively. At 600 mg N L −1 in which severe inhibition was observed, the TNREs were increased by 231% ( p = 0.002), 149% ( p = 0.014), and 51.0% ( p = 0.166) for CS300, CS550 and CS800, respectively, as compared to CK, with the corresponding specific anammox activity increased by 3.1-, 2,0- and 1.1-folds, respectively. CS300 enriched the relative abundance of Candidatus Kuenenia and increased the gene copies of functional genes ( hzs A, hdh , nir S and nir K). Besides, CS300 effectively alleviated the suppression of three membrane-associated enzyme complexes for anammox electron transport chain, indicating the possible contribution of redox-active moieties of CS300 to energy conversion metabolism for mitigating the NO 2 − -N inhibition. This study provided an effective strategy for alleviating NO 2 − -N stress by applying an environmentally compatible material (biochar) on anammox process.
研究领域:
环境科学
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生物技术
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废水处理
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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
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微生物学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
ACS ES&T Water
·
2024
·
IF 4.8
Jianguo Li,Shikan Zheng,Wanli Yan,Chengsong Ye,Xin Yu
The membrane-aerated biofilm reactor (MABR) is emerging as a promising solution for future wastewater treatment owing to its remarkable proficiency in achieving concurrent nitrogen and carbon removal. The research addressed a new type of MABR (R2) equipped with a polytetrafluoroethylene membrane-wrapped hollow nylon rope module that was constructed to improve the carbon and nitrogen removal of conventional MABR (R1). Uninterrupted operation lasting 120 days was conducted to compare the performance of R1 and R2 in treating simulated municipal wastewater with varying chemical oxygen demand (COD)/nitrogen (C/N) ratios. The results showed that R2 outperformed R1, exhibiting over 15.9% and 27.9% higher COD and TIN removal rates, respectively. The nylon fillers promoted biofilm formation, mitigated membrane pore clogging by the extracellular polymeric substances, and maintained a stable transmembrane pressure. R2 consistently maintained stable ammonia removal efficiency across different C/N ratios, while R1 exhibited a notable decrease at a high influent C/N ratio. Utilizing nylon carriers on membranes offered a cost-efficient and convenient method for modifying and preparing membranes for treating wastewater with broader C/N ratios and scaling up MABR applications.
研究领域:
环境工程
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废水处理
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生物技术
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材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）