Journal of Water Process Engineering
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2020
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IF 3.465
Xuerui Bai,Maiqian Nie,Zhenjun Diwu,Hongyun Nie,Yan Wang
Pseudomonas stutzeri N2 and Rhodococcus qingshengii FF were combined to enhance phenol degradation, and the interaction mechanism of microorganisms was investigated. The cells in the culture of mixed strain degrading 1000 mg/L phenol exhibited a rapid growth and proliferation, and the maximum cell density of mixed strain was 34.6 ± 0.3% and 60.8 ± 0.2% higher than the single strain N2 and strain FF respectively. The degradation of phenol by mixed strain was completed within 24 h, and the phenol mineralization efficiency was up to 84.9 ± 0.4%. In addition, two ring-cleavage products of catechol accumulating from the culture of mixed strain were markedly reduced. Through the analysis of intermediates and functional groups, the enhanced phenol degradation by mixed strain was found to mainly depend on the synergistic effect of strain N2 served as an oxidant and strain FF acted as a reductant. Based on the synergic mechanism, the mixed strain might be used as a promising bacterial agent for removing phenolic compounds from the industrial wastewater.
研究领域:
环境生物学
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微生物学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2017
·
IF 6.216
Wenjuan Shen,Bingning Wang,Falong Jia,Zhihui Ai,Lizhi Zhang
In general, the final product of atrazine (ATR) degradation by reactive oxygen species is cyanuric acid bearing a stable s -triazine ring, which is not further oxidized under mild conditions. In this study, we demonstrate that the presence of Ni(II) can increase the aerobic ATR degradation rate of core–shell Fe@Fe 2 O 3 nanowires (CSFN) by 6 times and also achieve the cleavage of recalcitrant s -triazine ring. The cleavage of s -triazine ring in this novel system was confirmed by the measurements of formic acid and nitrite acid. On the basis of experimental results, a feasible mechanism was proposed to account for the promoted aerobic ATR degradation and the facile s -triazine ring cleavage as follows. First, Ni(II) adsorbed on the surface of CSFN was reduced to nickel metal, which favored the generation of active hydrogen (•H). The in-situ generated •H then reduced ATR to 4-ethylamino-6-isopropylamino-1,3,5-triazine intermediate of easy ring opening property, rather than the recalcitrant cyanuric acid. Finally, this ATR degradation pathway change promoted the aerobic ATR degradation and benefited the s -triazine ring cleavage. This study clarifies the importance of degradation pathway on the ring-opening of organic pollutants, and also provides a mild method to remove s -triazine herbicides with molecular oxygen and zero-valent iron.
研究领域:
环境科学
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化学
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2014
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IF 1.552
Zhongkui Zhao,Renzhi Li,Yu Li
A clean and highly efficient synthesis of 1-amino-2-acetylanthraquinone via reductive isoxazole ring cleavage of 3-methylanthra[1,2- c ]isoxazole-6,11-dione catalyzed by trace copper using hydrazine hydrate as a clean reducing agent and water as a green reaction medium under mild reaction conditions was investigated. Various transition-metal catalysts were screened for the reductive ring-opening reaction, and Cu(NO 3 ) 2 was shown to be an excellent catalyst. A conversion of 97.2% and 1-amino-2-acetylanthraquinone selectivity greater than 95% were obtained in the presence of 2.6 mol% Cu(NO 3 ) 2 (turnover number 38) with 1.3 equiv. of hydrazine hydrate for 2 h in water. The structure of the product was confirmed by 1 H nuclear magnetic resonance spectroscopy and mass spectrometry ; the main byproduct was hydroxyl-substituted 1-amino-2-acetylanthraquinone. A possible reaction mechanism for the copper-catalyzed ring cleavage of 3-methylanthra[1,2- c ]isoxazole-6,11-dione with hydrazine hydrate was proposed.
研究领域:
有机化学
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环境化学
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DOI
高影响因子
Journal of Water Process Engineering
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2025
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IF 6.7
Caiyun Zhang,Jin Qian,Jiajie Wang,Xinyan Zhang,Zhuqiu Sun,Bairen Yang
Herein, a microbial consortia directed domestication approach based on degradation pathways was proposed. This approach employs intermediates capable of promoting ring-opening and dechlorination of m -dichlorobenzene ( m -DCB), in conjunction with m -DCB itself, as substrates for stepwise domestication, with the aim of overcoming the limitation of microbial activity due to the high toxicity of m -DCB. The microbial community analysis for the directed domestication of consortia domesticated that microorganisms responsible for ring-opening and dechlorination were predominant. Meanwhile, the removal efficiency (RE) of m -DCB by directed domestication microbial consortia was significantly higher than the original microbial consortia and abiotic control. To further improve the ring-opening and dechlorination performance of m -DCB, electrical stimulation was introduced as a means of enhancing the directed domestication. Performance tests showed that the highest RE and elimination capacity (EC) of m -DCB were 95.23 % and 23.77 mg/m 3 /h, at an electrical stimulation of 0.7 V, respectively. The microbial community analyses revealed that electrical stimulation led to an increase in the relative abundance of key functional genera (e.g., Rhodanobacter and Pseudomonas ) and functional genes (e.g., catE and dhaA), thereby facilitating the oxidation ring-opening and reductive dechlorination of m -DCB. Metagenomic sequencing further revealed the potential and mechanisms for enhanced biodegradation of m -DCB by the coupled approach of electrical stimulation and directed domestication. The study demonstrates that the biodegradation potential of m -DCB can be enhanced through electrical stimulation based on directed domestication, providing a strategic pathway for microbial construction and improved m -DCB removal from exhaust gases.
研究领域:
环境科学
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微生物学
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高影响因子
Nature Communications
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2021
·Vol. 12
·期 1
·1-10
·
IF 14.919
Liu Gongquan,Zhao Yi-Lei,He Fangyuan,Zhang Peng,Ouyang Xingyu,Tang Hongzhi,Xu Ping
Biodegradation of aromatic and heterocyclic compounds requires an oxidative ring cleavage enzymatic step. Extensive biochemical research has yielded mechanistic insights about catabolism of aromatic substrates; yet much less is known about the reaction mechanisms underlying the cleavage of heterocyclic compounds such as pyridine-ring-containing ones like 2,5-hydroxy-pyridine (DHP). 2,5-Dihydroxypyridine dioxygenase (NicX) from Pseudomonas putida KT2440 uses a mononuclear nonheme Fe(II) to catalyze the oxidative pyridine ring cleavage reaction by transforming DHP into N -formylmaleamic acid (NFM). Herein, we report a crystal structure for the resting form of NicX, as well as a complex structure wherein DHP and NFM are trapped in different subunits. The resting state structure displays an octahedral coordination for Fe(II) with two histidine residues (His 265 and His 318 ), a serine residue (Ser 302 ), a carboxylate ligand (Asp 320 ), and two water molecules. DHP does not bind as a ligand to Fe(II), yet its interactions with Leu 104 and His 105 function to guide and stabilize the substrate to the appropriate position to initiate the reaction. Additionally, combined structural and computational analyses lend support to an apical dioxygen catalytic mechanism. Our study thus deepens understanding of non-heme Fe(II) dioxygenases.
研究领域:
生物化学
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结构生物学
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环境微生物学
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
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2021
·Vol. 46
·期 2
·592-598
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IF 3.591
Rui Wang,Wei Zhang,Ying Tang,Ze-Hui Qi,Yuan-Hui Yu,Hong-Bo Tan,Dian-Yong Tang,Zhi-Gang Xu,Zhong-Zhu Chen
An efficient one-pot four-component reaction for the synthesis of a new family of novel bridgehead nitrogen-containing pyrido[1,2-d][1,4]diazepines has been described and its mechanism has been proposed, which follows a ring-closure and ring-cleavage pathway. The protocol involved a cyclization through γ-selective C–C bond formation, an intramolecular Michael addition and a ring-opening of a pyranone ring under refluxing conditions with high to excellent yields. The advantages of this methodology, including the use of easily available raw materials and an inexpensive catalyst, an open-air reaction setup, wide functional group tolerance, and gram-scale synthesis, make the developed methodology a practical way to access novel pyrido[1,2-d][1,4]diazepines and functionalized tricyclic or polycyclic fused 1,4-diazepines as well as novel analogs of important biologically active molecules.
研究领域:
有机化学
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药物化学
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生物活性分子合成
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DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2024
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IF 3.3
Wenxian Liu,Liting Xu,Haina Cheng,Zhu Chen,Hongbo Zhou,Yuguang Wang
BACKGROUND The potential for the efficient conversion of lignocellulosic biomass has been extensively explored to produce a wide range of bioproducts. Many approaches have been sought for the deep conversion of lignin to generate products that are toxin-free and beneficial for processing into high-value-added components. RESULTS This study reported a fungus isolated from the deep sea with strong synthesis of multiple lignocellulases, conversion of lignin and guaiacol (0.1%) by 71.6% and 86.1% within 9 days at 30 °C respectively, and outstanding environmental adaptability (20–50 °C and pH 3–8). Metabolic pathway profiling showed that this fungus utilized lignin to rapidly activate multiple ring-opening reactions including the 2,3- and 3,4-cleavage pathways, with the 2,3-cleavage pathway predominating after 5 days. Conversion of metabolic intermediates confirmed the superb potential of this strain for lignin treatment. Meanwhile, its shikimic acid pathway was metabolically active under lignin. CONCLUSION This further expands the potential to produce valuable bioproducts during lignin treatment, especially under ambient conditions, which can significantly enhance high-value precursor compound production. © 2024 Society of Chemical Industry.
研究领域:
生物技术
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环境科学
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微生物学
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生物化学
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DOI
PubMed
高影响因子
Journal of Cleaner Production
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2022
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IF 11.072
Xinxin Meng,Zhun Liu,Xubin Qian,Shaoyu Tang,Cheng Fang,Junfeng Niu,Lei Xu
The effect of low-frequency ultrasound (US, 20 kHz, 104 W) on the degradation of anticancer drug irinotecan (IRI) using reactive electrochemical membrane (REM) was investigated. Results demonstrated that higher k value (0.103 min −1 ) and mineralization efficiency (94.6%) as well as lower energy consumption (0.906 Wh L −1 ) were observed in US-REM system. The effects of influence factors including US power, volume flow rate, current density and initial IRI concentration on the degradation of IRI were studied in US-REM system. The relative contributions of • OH, SO 4 •− and O 2 •− (indirect oxidation) to IRI degradation using REM were all increased with the assistance of US. The production rate of • OH using US-REM increased by 19.7% compared with that using REM. Seven intermediates of IRI degradation using both REM and US-REM were identified, and the main degradation pathways of IRI were hydroxylation , oxidation and ring cleavage. The enhanced degradation and mineralization of IRI in US-REM system could mainly be attributed to higher • OH production and higher contribution of free radicals.
研究领域:
环境工程
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药学
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化学工程
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2019
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IF 7.65
Lei Xu,Xiao Ma,Junfeng Niu,Jie Chen,Chengzhi Zhou
The kinetics and mechanisms of naproxen (NPX) degradation with the concentration of 20–200 μg/L were investigated by using reactive flow-through membrane anode. The electrochemical degradation of NPX followed pseudo-first-order reaction kinetics. The kinetic rate constant ( k ) of 0.649 min –1 and energy consumption ( E EO ) of 0.744 Wh/L were found under optimal conditions with the initial NPX concentration of 50 μg/L. Higher current density benefited •OH production and NPX degradation. Faster rotational speed of pump and lower pH were in favor of electrochemical degradation of NPX, in which k and E EO were 3.9 and 0.27 times when rotational speed was increased from 100 to 600 rpm, and 4.9 and 0.21 times when pH was decreased from 11.0 to 3.0, respectively. The degradation efficiency and energy consumption were both maintained at a narrow range when the initial concentration of NPX was changed from 20 to 200 μg/L, and even under the addition of humic acid (1.0–10.0 mg/L). The major degradation pathways of NPX were demethylation and decarboxylation, followed with the further ring cleavage reactions. The flow-through membrane electrode is proved to be effective for the elimination of trace NPX from aqueous solution.
研究领域:
环境工程
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水处理
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电化学
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制药废物管理
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2021
·
IF 10.588
Mengqi Zheng,Hongjun Han,Jingxin Shi,Zhengwen Zhang,Wencheng Ma,Chunyan Xu
In current study, nano-Fe 3 O 4 @activated coke enhanced bio-system (FEBS) under limited-oxygen condition was applied for efficient treatment of aromatic organics in coal pyrolysis wastewater. Metagenomic analyses revealed functional microbiome linkages and mechanism involved in aromatic ring-cleavage. Based on biodegradation efficiency in different reactors, FEBS supplementation conferred the best organic removal (avg. 92.29%). It also showed a remarkable advantage in biodegradability maintenance (> 40%) over control reactors. Metagenomics profiling revealed the degradation processes were driven by Fe 3 O 4 redox reactions and microbial biofilm, while the suspended sludge was the principal force for aromatic mineralization . Based on the analysis of functional species and genes, most bacteria cleaved the benzene ring preferably through the aerobic pathways, mediated by catechol 1, 2-dioxygenase, catechol 2, 3-dioxygenase and protocatechuate 3, 4-dioxygenase (66−84%). Ecological network showed that Comamonas testosterone -centered microbiome and Azotobacter linked to the nitrogen (N)-heterocyclic ring-cleavage. Network linkage further demonstrated that Alicycliphilus and Acidovorax were the key tone taxa involved in benzene ring-cleavage. Finally, combined with analysis of degradation products , bacteria degraded N-heterocyclic ring containing organic aromatic compounds (quinoline) mainly through anaerobic processes , whereas cleavage of benzene ring preferred aerobic pathways. The enriched functional species were the primary reason for the enhanced biodegradation in FEBS.
研究领域:
环境工程
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微生物学
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宏基因组学
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废水处理
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Yu Liu,Linlin Qin,Yiming Qin,Tong Yang,Haoran Lu,Yulong Liu,Qiqi Zhang,Wenyan Liang
Nitrogen-containing heterocyclic compounds (NHCs) are hazardous, toxic, and persistent pollutants, thereby requiring urgent solutions. Herein, ZIF-67 was compounded with powder-activated carbon (PAC) to prepare Co/NC/PAC (NC i.e. nitrogen-doped carbon) particle electrodes for the electrocatalytic treatment of pyridine and diazines . Co/NC/PAC reflected the confinement of Co 3 O 4 /CoN/Co 0 into the N-doped graphitic-carbon layer to generate both pyrrolic-N and graphitic-N active sites. Under the optimal conditions (0.3 A, 12 mL min −1 , and initial pH 7.00), the degradation of four NHCs realized 90.2–93.7% efficiencies. The number and position of N atoms in NHCs directly affected the degradation efficiency. The following increasing order of facilitated degradation was recorded: pyridazine < pyrimidine < pyrazine < pyridine. The as-obtained Co/NC/PAC possessed the direct redox effect on NHCs, achieving fast electrocatalytic rate. Species like ·OH and H* were detected in Co/NC/PAC system with contributions to NHCs degradation estimated to 24% and 34%, respectively. Density functional theory (DFT) calculations revealed H* susceptible to attacking the N position, while the meta-position of C was subject to hydroxyl radical (·OH) addition. Overall, degradation of NHCs was achieved by hydro-reduction, oxidation , ring opening cleavage, hydroxylation, and mineralization. Ring-cleavage and mineralization of NHCs provided a novel electrochemical strategy to refractory wastewater treatment .
研究领域:
环境科学
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电化学
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材料科学
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废水处理
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 30
·75595-75609
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IF 5.8
Jiang Mengyun,Xu Zhongjun,Zhang Tingting,Zhang Xirong,Liu Ying,Liu Peng,Chen Xiaochun
In this work, FeS supported SBA-15 mesoporous silica catalyst (FeS@SBA-15) was synthesized successfully, characterized and first applied to persulfate (PS) activation for the degradation of imidacloprid in wastewater. The as-prepared 3.5-FeS@SBA-15 presented an impressive imidacloprid removal efficiency of 93.1% and reaction stoichiometric efficiency (RSE) of 1.82% after 5 min, ascribed to the synergetic effects of improved FeS dispersion and abundant surface sites by SBA-15. Electron paramagnetic resonance spectra and quenching experiments proved that both SO 4 ·- and ·OH were produced in FeS@SBA-15/PS system, and SO 4 ·- played a dominant role in the degradation process. The S 2- can accelerate the cycling of Fe(III)/Fe(II) during activation and increase the steady-state concentration of Fe(II). More importantly, the constructed heterogeneous system exhibited an efficient and stable catalytic activity over a wide range of pH (3.0-9.0), temperature (283K-313K), inorganic ion (NO 3 - ) and humic acid (1-20 mg/L). Moreover, the density functional theory calculations were conducted to predict the potential reaction sites of imidacloprid. Based on eighteen identified intermediates, four main degradation pathways were proposed: hydroxylation, dechlorination, hydrolysis, and the ring cleavage of the imidazolidine. ECOSAR analysis indicated hydroxylation and dechlorination played a key role in the detoxification of the formed compounds. These findings would provide new insights into the application of FeS@SBA-15 catalyst in wastewater treatment and the removal mechanism of imidacloprid from wastewater.
研究领域:
环境科学
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催化
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废水处理
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化学工程
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材料科学
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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）