PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2022
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IF 7.926
Junyuan Guo,Jianying Jiang,Yihua Chen,Xiaoying Wen,Wenjing Chen,Yifan Wang,Lin Su,Jing Cao
In order to achieve efficient adsorptive and oxidative removal of pyrene, a persulfate oxidation system with composite nZVI-BC prepared by loading nano-zero-valent iron on coconut shell biochar as an activator was established and applied. The results of adsorption experiments showed that at pH 3, when the dosages of BC, nZVI and nZVI-BC were all 1.5 g/L, the removal efficiency of pyrene reached 64.9%, 19.0%, and 61.2%, respectively after 120 min of adsorption. The best performance of nZVI-BC-persulfate system was achieved at pH 3, nZVI-BC 1.2 g/L and persulfate concentration 6 mM, and after 60 min of degradation, the removal efficiency of pyrene reached 99.4%. The pre-adsorption process was a promoting-step for pyrene degradation. The conversion of nZVI to Fe 2+ and Fe 3+ played an important role in the activation of persulfate to produce SO 4 •− and • OH, both of which were responsible for non-selectively oxidization pyrene. The support of BC could improve the dispersibility and activity of nZVI and improve of the above conversion. The intermediates with relatively lower toxicity were identified during pyrene degradation, and they were successively oxidized into CO 2 and H 2 O finally. In summary, nZVI-BC can be a promising catalyst for persulfate activation to degrade PAHs in wastewater.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2024
·Vol. 31
·期 17
·25659-25670
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IF 0
Ge Huanying,Liu Xinghao,Lu Denglong,Yang Zhaoguang,Li Haipu
Polycyclic aromatic hydrocarbons (PAHs) were typical environmental contaminants that accumulated continuously in sediment. Microbial degradation is the main way of PAH degradation in the natural environment. Therefore, expanding the available pool of microbial resources and investigating the molecular degrading mechanisms of PAHs are critical to the efficient control of PAH-polluted sites. Here, a strain (identified as Xanthobacteraceae bacterium ) with the ability to degrade pyrene was screened from the rhizosphere sediment of Vallisneria natans . Response surface analysis showed that the strain could degrade pyrene at pH 5–7, NaCl addition 0–1.5%, and temperature 25–40 °C, and the maximum pyrene degradation (~ 95.4%) was obtained under the optimum conditions (pH 7.0, temperature 28.5 °C, and NaCl-free addition) after 72 h. Also, it was observed that the effect of temperature on the degradation ratio was the most significant. Furthermore, eighteen metabolites were identified by mass spectrometry, among which (2Z)-2-hydroxy-3-(4-oxo-4H-phenalen-3-yl) prop-2-enoic acid, 7-(carboxymethyl)-8-formyl-1-naphthyl acetic acid, phthalic acid, naphthalene-1,2-diol, and phenol were the main metabolites. And the degradation pathway of pyrene was proposed, suggesting that pyrene undergoes initial ortho-cleavage under the catalysis of metapyrocatechase to form (2Z)-2-hydroxy-3-(4-oxo-4H-phenalen-3-yl) prop-2-enoic acid. Subsequently, this intermediate was progressively oxidized and degraded to phthalic acid or phenol, which could enter the tricarboxylic acid cycle. Furthermore, the pyrene biodegradation by the strain followed the first-order kinetic model and the degradation rate changed from fast to slow, with the rate remaining mostly slow in the later stages. The slow biodegradation rate was probably caused by a significant amount of phenol accumulation in the initial stage of degradation, which resulted in a decrease in bacterial activity or death. Graphical Abstract
研究领域:
环境科学
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微生物学
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DOI
PubMed
BIODEGRADATION
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2024
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IF 3.1
Sun Shanshan,Wei Ran,Hu Siyi,Yang Meiyu,Ni Jinzhi
Considerable efforts that isolate and characterize degrading bacteria for polycyclic aromatic hydrocarbons (PAHs) have focused on contaminated environments so far. Here we isolated three distinctive pyrene (PYR)-degrading bacteria from a paddy soil that was not contaminated with PAHs. These included a novel Bacillus sp. PyB-9 and efficient degraders, Shigella sp. PyB-6 and Agromyces sp. PyB-10. All three strains could utilize naphthalene, phenanthrene, anthracene, fluoranthene and PYR as sole carbon sources, and degraded PYR in a range of temperatures (27–37 °C) and pH (5–8). Strains PyB-6 and PyB-10 almost completely degraded 50 mg L −1 PYR within 15 days, and 75.5% and 98.9% of 100 mg L −1 PYR in 27 days, respectively. The kinetics of PYR biodegradation was well represented by the Gompertz model. Ten and twelve PYR metabolites were identified in PYR degradation process by strains PyB-6 and PyB-10, respectively. Chemical analyses demonstrated that the degradation mechanisms of PYR were the same for strains PyB-6 and PyB-10 with initial dioxygenation mainly on C-4,5 positions of PYR. The degradation of 4,5-phenanthrenedicarboxylic acid was branched to 4-phenanthrenecarboxylic acid pathway and 5-hydroxy-4-phenanthrenecarboxylic acid pathway, both of which played important roles in PYR degradation by strains PyB-6 and PyB-10. To our knowledge, Shigella sp. and Agromyces sp. were found for the first time to possess the capability for PAHs degradation. These findings contributed to upgrading the bank of microbial resource and knowledge on PAH biodegradation.
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
BIORESOURCE TECHNOLOGY
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2024
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IF 9.7
Xing Zhang,Xiao Liu,Shuhuan Lin,Xiaoli Zhu,Ziye Zhang,Baoshou Shen,Shi Zhou
Immobilization technology is a promising way to improve effectiveness and stability of microbial remediation for polycyclic aromatic hydrocarbons (PAHs), in which carrier material is one of key factors restricting removal efficiency. In this study, fulvic acid-wheat straw biochar (FA/WS) composites were applied for immobilization of an efficient PAHs degrading bacterium Stenotrophomonas maltophilia (SPM). FA/WS&SPM showed superior degradation capacity than free bacteria and biochar-immobilized bacteria, with the removal efficiency of pyrene (20 mg L -1 ) reaching 90.5 % (7 days). Transcriptome analysis revealed that FA in the carrier materials can promote transportation and degradation of pyrene, and cell growth, as well as inhibit cell apoptosis. Enzyme activity and degradation products detection showed that SPM utilized both phthalic acid and salicylic acid metabolic pathways to degrade pyrene. Practicality of FA/WS&SPM for different kinds of PAHs remediation had been verified in contaminated soil, demonstrating a great potential in the field of PAHs polluted sites remediation.
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
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2016
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IF 3.13
Fucai Deng,Zhengfang Zhang,Chen Yang,Chuling Guo,Guining Lu,Zhi Dang
Biotechnology is considered as a promising technology for the removal of polycyclic aromatic hydrocarbons from the environment. Free bacteria are often sensitive to some biotic and abiotic factors in the environment to the extent that their ability to effect biodegradation of organic pollutants , such as polycyclic aromatic hydrocarbons, is hampered. Consequently, it is imperative to carry out investigations into biological systems that will obviate or aid tolerance of bacteria to harsh environmental conditions. Chitosan/alginate bio-microcapsules produced using layer-by-layer (LBL) assembly method were tested for pyrene (PYR) biodegradation under harsh environmental conditions. Morphology observation indicated that the flake bio-microcapsules could be successfully prepared through LBL assembly method. Surface analysis showed that the bio-microcapsules had large fractions of mesopores . The results of the biodegradation experiments revealed that the 95% of 10 mg L −1 PYR could be removed by the bacteria encapsulated chitosan/alginate bio-microcapsules in 3 days, which was higher than that of the free bacteria (59%). Compared to the free cells, the bacteria encapsulated chitosan/alginate bio-microcapsules produced 1–6 times higher PYR biodegradation rates at a high initial PYR concentration (50 mg L −1 ) and extremely low pH values (pH =3) or temperatures (10 °C or 40 °C), as well as high salt stress. The results indicated that bacteria in microcapsules treatment gained a much higher tolerance to environmental stress and LBL bio-microcapsule could be promising candidate for remediating the organic pollutants.
研究领域:
环境生物学
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微生物技术
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DOI
高影响因子
Industrial Chemistry & Materials
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2023
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IF 0
Jun Han,Wenrou Tian,Ye Miao,Najun Li,Dongyun Chen,Qingfeng Xu,Hua Li,Jianmei Lu
Coupling the effects of flexoelectricity with piezoelectricity has been proved to effectively harvest mechanical energy. In this study, a composition-graded core–shell structure (HAP@FAP) was prepared by surface-gradient F-doping in hydroxyapatite, which could introduce flexoelectricity by a built-in strain gradient. A flexoelectric-boosted piezoelectric response was demonstrated by piezoresponse force microscopy (PFM) characterization, showing that the piezoelectric constant of HAP@FAP was increased by 2.25 times via a lattice strain gradient induced by chemical heterogeneities derived from the unique composition-graded core–shell structure. Thus, the piezocatalytic activity of HAP@FAP for phenanthrene (PHE) degradation in soil was enhanced. This work provides a new strategy for the modification of piezoelectric catalysts for the remediation of organics-contaminated soils on industrial land.
研究领域:
材料科学
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环境科学
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物理化学
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DOI
Environmental Technology & Innovation
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2024
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IF 6.7
Shiyuan Liu,Qin Qiu,Hong Yang,Lai Zhou,Xueqiang Zhu
Polycyclic Aromatic Hydrocarbons (PAHs) are persistent organic pollutants known for their carcinogenic, teratogenic, and mutagenic properties. A considerable amount of PAHs has been released into groundwater. Persulfate-based advanced oxidation processes (PS-AOP) are commonly employed to remediate such contamination. However, traditional in-situ chemical oxidation (ISCO) faces challenges such as concentration rebound and tailing. To address these issues, sodium persulfate sustained release materials (PDS@SA) and ferrous sulfate sustained release materials (FeSO 4 @SA) were developed using stearic acid (SA) as a binder. Batch and column experiments were conducted to evaluate the efficacy of pyrene degradation through PDS@SA activated by FeSO 4 @SA. The batch experiments showed that the optimal mass ratio of FeSO 4 @SA to PDS@SA was 1:2, achieving degradation efficiencies over 95 % for pyrene with various concentrations (5, 10, 15, 20 mg⸱L −1 ) within 2 h. The column experiments showed that sustained release materials (FeSO 4 @SA and PDS@SA) with a particle size of 5 mm achieved an average removal rate of 89.3 % during days 7–15, while those with particle sizes of 7.5 mm and 10 mm achieved average removal rates of 68.5 % and 74.6 % during days 15–23, respectively. Additionally, electron paramagnetic resonance (EPR) analysis confirmed sulfate radicals SO 4 - ⸱ and hydroxyl radicals ⸱OH as the primary oxidative species during pyrene degradation. These findings suggested that the sustained activation of PDS by sustained release Fe 2+ represents a viable method for degrading PAHs in groundwater.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2022
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IF 7.968
Maofeng Shi,Lei Song,Yihong Wu,Chuhan Gu,Jiaxian Zhang,Jingyu Lv
Pyrene (PYR) is a typical high molecular weight polycyclic aromatic hydrocarbon (HMW-PAH) with potential biotoxicity and resistance to biodegradation, and the accumulation of PYR in sediments increases the risk to ecosystems. Therefore, this study evaluated the catalytic performance of nitrogen-doped magnetic biochar-activated peroxymonosulfate system (NMBC/PMS) on PYR in sediments and elucidated its mechanism. The results showed that the degradation rate of PYR in sediments by the NMBC/PMS system reached 87% at PMS= 1 × 10 −4 M, NMBC= 3.0 g/L and pH= 9, which conformed to the pseudo-first-order rate law, and the rate constant(K obs ) was 7.3 × 10 −2 h −1 . The high adsorption performance of NMBC was attributed to π-π electron donor-acceptor interactions (π-π EDA). The high degradation performance of NMBC/PMS system was attributed to the active sites generated by graphitization , magnetism, and electronegativity of NMBC, which were the key to activate PMS to degrade PYR. The results of X-ray photoelectron spectroscopy (XPS), quenching experiments and electron paramagnetic resonance (EPR) analysis indicated that N-doping and Fe 3 O 4 -loading on NMBC synergistically promoted the degradation of PYR. In addition, the mechanism of PYR degradation by NMBC/PMS system was investigated, indicating that SO 4 · - , HO·and 1 O 2 were the main reactive oxygen species . The excellent recoverability of NMBC showed its application potential. The NMBC/PMS system developed in this study provided a theoretical basis for a future multi-pathway synergistic degradation mechanism of PYR in sediments.
研究领域:
环境科学
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污染治理
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2025
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IF 11.3
Yibin Yang,Rui Chen,Zhiqiang Zhang,Yuke Qin,Attiqa Parveen,He Bai,Xiaoqiang Jia
Phenanthrene, a pervasive polycyclic aromatic hydrocarbon (PAH), poses significant environmental and health risks due to its persistence and bioaccumulation. This study presents the development of a synthetic bacterial consortium comprising three engineered Escherichia coli BL21(DE3) strains, each harboring distinct catabolic modules encoded by pET-28(a) plasmids for the complete mineralization of phenanthrene. The consortium was engineered by integrating 17 genes critical for phenanthrene degradation, organized into three distinct modules that harness the collective metabolic potential of separate strains to enhance the degradation process. Each module was tailored to a specific phase of phenanthrene catabolism, ensuring the coordinated and efficient breakdown of the pollutant. Following the identification of rate-limiting enzymes within the up- and downstream degradation modules, the eight corresponding genes were subjected to laboratory evolution using the SCRaMbLE method to bolster the degradation capabilities of the strains. The consortium was then tested in a minimal salt medium (MSM) containing 100 mg/L phenanthrene. Following their evolution, the two SCRaMbLE strains E. coli SCRPHE033 and E. coli SCRKA065 exhibited enhanced degradation rates of 11.5 and 25.18 % for their respective substrates. Finally, the comprehensive phenanthrene degradation system, which includes the two SCRaMbLE strains and E. coli CRSA, was subjected to comprehensive optimization, after which it achieved a significant degradation efficiency of 84.33 % for 100 mg/L phenanthrene within a 120-hour timeframe. This research demonstrates the potential of synthetic biology in constructing microbial consortia for environmental bioremediation based on the SCRaMbLE method, offering a promising strategy for mitigating PAH pollution.
研究领域:
合成生物学
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环境微生物学
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基因组工程
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生物修复
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DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
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2021
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IF 8.071
Manzoor Ahmad,Pandeng Wang,Jia-Ling Li,Renfei Wang,Li Duan,Xiaoqing Luo,Muhammad Irfan,Ziqi Peng,Lingzi Yin,Wen-Jun Li
Bio-stimulation of the indigenous microbial community is considered as an effective strategy for the bioremediation of polluted environments. This examination explored the near effects of various bio-stimulants on pyrene degradation, prokaryotic community compositions, and functions using 16S rRNA amplicon sequencing and qPCR. At first, the results displayed significant differences (p < 0.05) between the prokaryotic community structures of the control group, PYR (contains pyrene only), and bio-stimulants amended groups. Among the bio-stimulants, biochar, oxalic acid , salicylate , NPK, and ammonium sulfate augmented the pyrene degradation potential of microbial communities. Moreover, the higher abundance of genera, such as Flavobacterium, Hydrogenophaga, Mycobacterium, Rhodococcus, Flavihumibacter, Pseudomonas , Novosphingobium, etc., across the treatments indicated that these genera play a vital role in pyrene metabolism. Based on the higher abundance of GP-RHD and nidA genes, we speculated that Gram-positive prokaryotic communities are more competent in pyrene dissipation than Gram-negative. Furthermore, the marked abundance of nifH, and pqqC genes in the NPK and SA treatments, respectively, suggested that different bio-stimulants might enrich certain bacterial assemblages. Besides, the significant distinctions (p < 0.05) between the bacterial consortia of HA (humic acid) and SA (sodium acetate) groups from NPK, OX (oxalic acid), UR (urea), NH4, and SC (salicylate) groups also suggested that different bio-stimulants might induce distinct ecological impacts influencing the succession of prokaryotic communities in distinct directions. This work provides new insight into the bacterial degradation of pyrene using the bio-stimulation technique. It suggests that it is equally important to investigate the community structure and functions along with studying their impacts on degradation when devising a bio-stimulation technology .
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
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Chong Zhang,Xiaoyi Jiang,Shuai Zhang,Xian Cao,Hui Wang,Takashi Sakamaki,Xianning Li
The polycyclic aromatic hydrocarbons (PAHs) frequently accumulate in sediments, particularly those near industrial sites. The efficacy of microbial electrochemical systems (MESs) in electricity generation and PAHs degradation is intricately linked to the microbiome’s response to high contaminant levels. Metabolomics and metagenomics were applied to elucidate the impact of a high pyrene concentration on the functional structure and metabolic dynamics of sediment microbiomes within MES. In sediment with a high pyrene concentration, both the electrical output of MES and efficiency of their microbiomes in degrading organic substrates and pyrene were markedly reduced. These conditions were associated with the enrichment of PAH-degrading microorganisms, such as Hydrogenophaga and Flavobacterium . Analyses of metabolites and genetic profiles revealed that metabolic pathways were primarily influenced in MES exposed to low pyrene concentrations whereas fewer metabolic pathways were activated in MES exposed to high concentrations; instead, pathways representing functions critical for microbial survival and communication were activated as well. According to enzymatic analyses, low pyrene levels promoted carbohydrate metabolism by sediment microorganisms, whereas high levels had an inhibitory effect. An examination of electron transport enzymes revealed that intracellular electron transfer was facilitated by both low and high concentrations. However, high levels impeded enzymes associated with outer membrane electron transfer, hindering electron movement from intracellular to extracellular electron acceptors and thus negatively affecting the electrical output of MES. Our study provides crucial theoretical insight and mechanistic understanding for addressing the challenges that may be encountered when MES are used to treat pyrene-contaminated sediment near industrial sites.
研究领域:
环境科学
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微生物学
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分子生物学
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DOI
高影响因子
ENVIRONMENTAL POLLUTION
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2024
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IF 7.6
Xuan Zhao,Xianghui Cheng,Xixi Cai,Shuang Wang,Jibing Li,Yeliang Dai,Longfei Jiang,Chunling Luo,Gan Zhang
Rhizoremediation and bioaugmentation have proven effective in promoting benzo[a]pyrene (BaP) degradation in contaminated soils. However, the mechanism underlying bioaugmented rhizospheric BaP degradation with native microbes is poorly understood. In this study, an indigenous BaP degrader ( Stenotrophomonas BaP-1) isolated from petroleum-contaminated soil was introduced into ryegrass rhizosphere to investigate the relationship between indigenous degraders and rhizospheric BaP degradation. Stable isotope probing and 16S rRNA gene amplicon sequencing subsequently revealed 15 BaP degraders, 8 of which were directly associated with BaP degradation including Bradyrhizobium and Streptomyces . Bioaugmentation with strain BaP-1 significantly enhanced rhizospheric BaP degradation and shaped the microbial community structure. A correlation of BaP degraders, BaP degradation efficiency, and functional genes identified active degraders and genes encoding polycyclic aromatic hydrocarbon-ring hydroxylating dioxygenase (PAH-RHD) genes as the primary drivers of rhizospheric BaP degradation. Furthermore, strain BaP-1 was shown to not only engage in BaP metabolism but also to increase the abundance of other BaP degraders and PAH-RHD genes, resulting in enhanced rhizospheric BaP degradation. Metagenomic and correlation analyses indicated a significant positive relationship between glyoxylate and dicarboxylate metabolism and BaP degradation, suggesting a role for these pathways in rhizospheric BaP biodegradation. By identifying BaP degraders and characterizing their metabolic characteristics within intricate microbial communities, our study offers valuable insights into the mechanisms of bioaugmented rhizoremediation with indigenous bacteria for high-molecular-weight PAHs in petroleum-contaminated soils.
研究领域:
环境科学
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微生物学
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DOI
高影响因子
危险品化学品经营许可证（带存储）