COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
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IF 4.9
Yu Huang,Xinyang Xu,Guangjian Fan,Xiaoxuan Zhu,Lin Zhu,Xi Chen
The effect of TiO 2 crystal phase on the photocatalytic properties of TiO 2 /g-C 3 N 4 heterojunction photocatalyst under sunlight irradiation was investigated through experiments and theoretical calculations. Results reveal that for TiO 2 /g-C 3 N 4 heterojunction photocatalyst, anatase phase TiO 2 can adjust the band edge positions to ensure the generation of strongly oxidizing radical species (·O 2- and ·OH), and rutile phase TiO 2 can effectively reduce the band gap to more efficiently utilize sunlight. Consequently, the combination of g-C 3 N 4 with P25 TiO 2 composed of both anatase and rutile phases is the most favorable combination for sunlight-driven photocatalyst among the obtained three TiO 2 /g-C 3 N 4 heterojunction photocatalyst. P25 TiO 2 and g-C 3 N 4 form a type-II/type-II heterostructure with stepped heterojunction and concave heterojunction. The P/CN photocatalyst exhibits excellent photocatalytic activity with degradation efficiencies for naphthalene reaching 100% within 120 min of sunlight irradiation, as well as considerable stability. The combination of P25 TiO 2 and g-C 3 N 4 has shown significant potentials in improving the separation and transfer efficiency of photogenerated electron-hole pairs, as well as enhancing the utilization of sunlight in photocatalytic process. This work provides a promising strategy for the preparation of highly active TiO 2 /g-C 3 N 4 heterojunction photocatalyst for the effective treatment of naphthalene from water.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 11
·2708
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IF 4.2
Yunteng Chen,Chunxian Hong,Qiang Xu,Haihong Zheng,Chao Wang,Hongshun Lu,Shuai Zhang,Mingming Du,Ganning Zeng
In this study, carbon-quantum-dot (CQD)-decorated TiO2was prepared using an ultrasonic doping method and applied in the photocatalytic degradation of naphthalene under sunlight irradiation. The CQDs were synthesized from a typical macroalgae via diluted sulfuric acid pretreatment and hydrothermal synthesis using an optimal design, i.e., 3 wt% and 200 °C, respectively. The CQD/TiO2composite remarkably enhanced the photocatalytic activity. The degradation of naphthalene under a visible light environment indicated that there is a synergistic mechanism between the CQDs and TiO2, in which the generation of reactive oxygen species is significantly triggered; in addition, the N that originated from the macroalgae accelerated the photocatalytic efficiency. Kinetic analysis showed that the photocatalytic behavior of the CQD/TiO2composite followed a pseudo-first-order equation. Consequently, our combined experimental approach not only provides a facile pretreatment process for bio-CQDs synthesis, but also delivers a suitable TiO2photocatalyst for the visible environment along with critical insights into the development of harmful macroalgae resources.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
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2025
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IF 7.7
Yi-Xin Xie,Wen-Chieh Cheng,Zhong-Fei Xue,Lin Wang,Md Mizanur Rahman
Although single bacteria have been applied to the Polycyclic Aromatic Hydrocarbons (PAHs) remediation, its efficacy is severely restricted by long degradation periods and low efficacy. A microbial symbiotic system founded by two or more bacterial strains may be an alternative to traditional remediation approaches. Its construction is, however, hampered by antagonistic interactions and remains challenging. The present work proposed a microbial symbiotic system consisting of the naphthalene degrading bacteria and the non-PAHs degrading bacteria and improved their interspecies interactions by using sequential inoculation. The non-PAHs degrading bacteria were inoculated after the inoculation of the naphthalene degrading bacteria. The sequential inoculation not only promoted the non-PAHs degrading bacteria to use the metabolites of the naphthalene degrading bacteria as an energy source but developed a resistance of the two bacterial strains to naphthalene. Vaterite and aragonite were identified following urea hydrolysis by the non-PAHs degrading bacteria. The faster precipitation rate in naphthalene degradation by the symbiotic system elevated the proportion of vaterite, allowing more naphthalene and its metabolites to be wrapped in or attached to minerals with the bacteria through the physisorption (van der Waals force) and chemisorption (Ca-π interaction with aromatic rings) and promoting the formation of aggregates. The formation of aggregates further reduced the mobility of naphthalene. Results indicate that 40% of naphthalene in the non-inoculated sterile control group was quickly released into the atmosphere, causing serious public concerns regarding health safety. According to the thermogravimetry-gas chromatography mass spectrometry (TG-GC/MS) analysis, no trace of naphthalene was found in the samples, indicating that the degrading bacteria fully degraded naphthalene after its adsorption. As a result, the degradation efficiency of 100% was attained using the symbiotic system even at 200 mg/L naphthalene. The findings underscore the relative merits of the symbiotic system applied to the remediation of naphthalene in an aqueous solution.
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
CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Ganning Zeng,Hanzhang You,Mingming Du,Yan Zhang,Yimei Ding,Chengda Xu,Bo Liu,Bing Chen,Xiangliang Pan
Remediating and controlling PAHs (Polyaromatic Hydrocarbons) contamination in the environment is essential all over the world. Nano-TiO 2 immobilized on large surface area adsorbent is a kind of emerging endeavor to enhance the photo-catalysis performance. In this paper, activated carbon samples (ACs) were synthesized by using a kind of subtropical macroalgae, i.e., Sargassum Horneri ( S.H. ) as raw material. ACs activated by FeCl 3 , ZnCl 2 , a composite activators mixture of FeCl 3 and ZnCl 2 (CA) were selected to immobilize nano-TiO 2 in aquatic environment, and naphthalene degradation performance of these materials was systematically assessed. The results showed that ACs could provide more activated space for naphthalene photocatalytic reaction, in which Zn 2+ helped to hold relative high specific surface area, Fe 3+ helped to extend the valid light responsive wavelength, and CA could take advantage of both metal ions, with the largest whole volume and surface functional groups. The highest naphthalene degradation efficiency of TiO 2 /AC-CA under simulated sunlight could arrive to 77.5%, while those of TiO 2 /AC-FeCl 3 and TiO 2 /AC-ZnCl 2 were 65.0%, 54.5%, respectively. Meanwhile, the pH-resistance and reusing capability of TiO 2 /AC-CA are better than those of other TiO 2 /ACs. The results helped to clarify the synergistic mechanism of AC and TiO 2 in photo-catalysis, especially the metal ions’ role in combining the two materials, and showed the industrial potential of S.H. in PAHs contamination.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Scientific Reports
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2017
·Vol. 7
·期 1
·1-11
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IF 4.259
Huang Haiying,Tao Xuanyu,Jiang Yiming,Khan Aman,Wu Qi,Yu Xuan,Wu Dan,Chen Yong,Ling Zhenmin,Liu Pu,Li Xiangkai
Soil contamination by PAH and heavy metals is a growing problem. Here, we showed that a new isolate, Pseudomonas brassicacearum strain LZ-4, can simultaneously degrade 98% of 6 mM naphthalene and reduce 92.4% of 500 μM hexavalent chromium [Cr (VI)] within 68 h. A draft genome sequence of strain LZ-4 (6,219,082 bp) revealed all the genes in the naphthalene catabolic pathway and some known Cr (VI) reductases. Interestingly, genes encoding naphthalene pathway components were upregulated in the presence of Cr (VI), and Cr (VI) reduction was elevated in the presence of naphthalene. We cloned and expressed these naphthalene catabolic genes and tested for Cr (VI) reduction, and found that NahG reduced 79% of 100 μM Cr (VI) in 5 minutes. Additionally, an nahG deletion mutant lost 52% of its Cr (VI) reduction ability compared to that of the wild-type strain. As nahG encodes a salicylate hydroxylase with flavin adenine dinucleotide (FAD) as a cofactor for electron transfer, Cr (VI) could obtain electrons from NADH through NahG-associated FAD. To the best of our knowledge, this is the first report of a protein involved in a PAH-degradation pathway that can reduce heavy metals, which provides new insights into heavy metal-PAH contamination remediation.
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
APPLIED SURFACE SCIENCE
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2024
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IF 6.3
Yu Huang,Xinyang Xu,Fengkun Han,Xi Chen,Guangjian Fan
Photocatalytic technology holds promising prospects for remediating naphthalene pollution in water bodies. In this work, the CN/Pt-P25 photocatalyst was successfully prepared via photodeposition combined with co-pyrolysis methods, and employed for naphthalene photodegradation under simulated sunlight. The chemical state of Pt was found to have a significant impact on the photocatalytic activity. H 2 secondary annealing effectively tuned Pt chemical states, increasing the proportion of Pt 0 species on the CN/Pt-P25 photocatalyst from 41.91 % to 62.24 %. The improved proportion of Pt 0 species proportion led to a reduction in the bandgap, which induced changes in the band positions and notably enhancing the separation efficiency of photogenerated electron-hole pairs. Under simulated sunlight irradiation, (H 2 ) CN/Pt-P25 photocatalyst achieved complete naphthalene photodegradation within 100 min. Thus, photocatalysts containing a high proportion of Pt 0 species exhibited an improved performance in naphthalene photodegradation. These findings provide new insights into the application of photocatalytic technology for the remediation of PAHs.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2023
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IF 9.8
Peng Ding,Ping Wu,Qihao Cao,Hongbo Liu,Chongjun Chen,Min-Hua Cui,He Liu
The use of co -metabolic substrates is effective for polycyclic aromatic hydrocarbons (PAHs) removal, but the potential of the high phenol concentrations in coal chemical wastewater (CCW) as a co-metabolic substrate in microbial electrolysis cell (MEC) has been neglected. In this study, the efficacy of varying phenol concentrations in comparison to simple substrates for degrading naphthalene in MEC under comparable COD has been explored. Results showed that phenol as a co-metabolic substrate outperformed sodium acetate and glucose in facilitating naphthalene degradation efficiency at 50 mg-COD/L. The naphthalene removal efficiency from R P , R A , and R G was found to be 84.11 ± 0.44 %, 73.80 ± 0.27 % and 72.43 ± 0.34 %, respectively. Similarly, phenol not only enhanced microbial biomass more effectively, but also exhibited optimal COD metabolism capacity. The addition of phenol resulted in a stepwise reduction in the molecular weight of naphthalene, whereas sodium acetate and glucose led to more diverse degradation pathways. Some bacteria with the potential ability to degrade PAHs were detected in phenol-added MEC, including Alicycliphilus , Azospira , Stenotrophomonas , Pseudomonas , and Sedimentibacter . Besides, phenol enhanced the expression of ncrA and nmsA genes, leading to more efficient degradation of naphthalene, with ncrA responsible for mediating the reduction of the benzene ring in naphthalene and nmsA closely associated with the decarboxylation of naphthalene. This study provides guidance for the effective co-degradation of PAHs in CCW with MEC, demonstrating the effectiveness of using phenol as a co-substrate relative to simple substrates in the removal of naphthalene.
研究领域:
环境工程
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微生物学
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废水处理
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生物修复
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL MICROBIOLOGY
·
2021
·Vol. 24
·期 1
·436-450
·
IF 5.491
Xiaoyu Qiu,Weiwei Wang,Lige Zhang,Lihua Guo,Ping Xu,Hongzhi Tang
Summary Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants threatening ecosystems and human health. Here, we isolated and characterized a new strain, Hydrogenibacillus sp. N12, which is a thermophilic PAH-degrader. Strain N12 utilizes naphthalene as a sole carbon and energy source above 60°C and co-metabolizes many other PAHs as well. The metabolites were identified in the catabolism of naphthalene by gas chromatography–mass spectrometry (GC–MS) and stable isotopic analysis. Based on the identified metabolites, we proposed two possible metabolic pathways, one via salicylic acid and the other via phthalic acid. Whole-genome sequencing reveals that strain N12 possesses a small chromosome of 2.6 Mb. Combining genetic and transcriptional information, we reveal a new gene cluster for the naphthalene degradation. The genes, designated as nar AaAb that are predicted to encode the alpha and beta subunits of naphthalene dioxygenase, were subsequently subcloned into Escherichia coli and the enzyme activity was detected by whole-cell transformation. Capacity to degrade several other tricyclic-PAHs was also characterized, suggesting co-existence of other constitutively expressed enzyme systems in strain N12 in addition to the naphthalene degradation gene cluster. Our study provides insights into the potential of the thermophilic PAH-degrader in biotechnology and environmental management applications.
研究领域:
环境微生物学
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生物修复
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基因组学
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DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2015
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IF 7.435
Shengjie Xia,Lianyang Zhang,Xiaobo Zhou,Mengmeng Shao,Guoxiang Pan,Zheming Ni
In this paper, Ti-contained Schiff base complex was intercalated into the interlayer of the ZnCr layered double hydroxides (LDHs) to form a novel layered organic–inorganic nanoscale material. And then, the hybrid material was further calcined to make metal oxides composite contained Zn, Cr and Ti (Ti/ZnO–Cr 2 O 3 ). This composite was used to study the performance and mechanism for naphthalene ( l -acid) photodegradation under visible light. The characterization results showed that Ti/ZnO–Cr 2 O 3 composite has higher specific area, more uniform pores size distribution and narrower band gap than that of original ZnCr–LDHs. Both physico-chemical property and photocatalytic performance for l -acid degradation by Ti/ZnO–Cr 2 O 3 were greatly improved with the increasing of calcination temperature, due to the highly crystalline structures with appearance of spinel ingredients of Zn, Cr and Ti. In addition, the molar ratio of Ti/Cr would also influence the photocatalytic property of the materials. Ti/ZnO–Cr 2 O 3 composite with Ti/Cr = 1 and calcined at 800 °C not only has narrow bang gap (2.11 eV) and high surface area (227 m 2 ), but also shows highest photocatalytic performance for l -acid degradation (90.2% within 240 min). Furthermore, the types and amounts of active radicals of photo oxidation reaction were also tested. The photocatalytic mechanism of the Ti/ZnO–Cr 2 O 3 composite was also discussed. Moreover, based on the results from HPLC–MS, GC–MS, FT–IT and DFT analysis, the decomposition intermediates and reaction pathway for l -acid were investigated in detail.
研究领域:
材料科学
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环境化学
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光催化
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纳米材料
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物理化学
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环境工程
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能源与可持续发展
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2016
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IF 4.917
Haiying Huang,Kejia Wu,Aman Khan,Yiming Jiang,Zhenmin Ling,Pu Liu,Yong Chen,Xuanyu Tao,Xiangkai Li
Combined pollutants with polycyclic aromatic hydrocarbons (PAHs) and heavy metals have been identified as toxic and unmanageable contaminates. In this work, Pseudomonas gessardii strain LZ-E isolated from wastewater discharge site of a petrochemical company degrades naphthalene and reduces Cr(VI) simultaneously. 95% of 10 mg L −1 Cr(VI) was reduced to Cr(III) while 77% of 800 mg L −1 naphthalene was degraded when strain LZ-E was incubated in BH medium for 48 h. Furthermore, naphthalene promotes Cr(VI) reduction in strain LZ-E as catechol and phthalic acid produced in naphthalene degradation are able to reduce Cr(VI) abiotically. An aerated bioreactor system was setup to test strain LZ-E’s remediation ability. Strain LZ-E continuously remediated naphthalene and Cr(VI) at rates of 15 mg L −1 h −1 and 0.20 mg L −1 h −1 of 800 mg L −1 naphthalene and 10 mg L −1 Cr(VI) addition with eight batches in 16 days. In summary, strain LZ-E is a potential applicant for combined pollution remediation.
研究领域:
环境微生物学
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生物修复
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环境工程
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DOI
PubMed
高影响因子
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