CHEMOSPHERE
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2021
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IF 7.086
Zhihui Chen,Jun Yao,Bo Ma,Bang Liu,Jonghyok Kim,Hao Li,Xiaozhe Zhu,Chenchen Zhao,Meseret Amde
The presence of chlorophenols in water and wastewater is considered a serious environmental issue . To eliminate these micropollutants, biodegradation of chlorophenols using enzyme-nanoparticle conjugated biocatalyst, is proposed as an economical and eco-friendly method. Herein, amino-functionalized superparamagnetic Fe 3 O 4 @SiO 2 –NH 2 nanoparticles with core-shell structure were constructed as a promising carrier for immobilization of laccase from Trametes versicolor . Compared with free laccase, Fe 3 O 4 @SiO 2 –NH 2 -Laccase displayed remarkable outcomes in all major areas such as temperature and storage stabilities, and tolerance to organic solvents and metal ions . The biocatalytic performance and reusability of Fe 3 O 4 @SiO 2 –NH 2 -Laccase were evaluated for the degradation of 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP) in repeated cycles. Even after 10 successive reuses, the degradation rate of 2,4-DCP and 2,4,6-TCP were found to be 54.9% and 68.7%, respectively. The influences of solution pH, initial chlorophenol concentration, and temperature on the degradation rate of these two chlorophenols were evaluated. The degradation intermediate products including dimers, trimers , and tetramers of 2,4-DCP and 2,4,6-TCP were identified. Release of chloride ions was observed during the enzymatic degradation of these two chlorophenols. Based on the determination of intermediate products and released chloride ions, the degradation pathway that was involved in dehydrogenation , reactive radical intermediates formation, dechlorination , self-coupling and oligomers/polymers formation was proposed. The toxicity of these two chlorophenols and their intermediates was substantially reduced during the enzymatic degradation. The results of this study might present an alternative clean biotechnology for the remediation of 2,4-DCP and 2,4,6-TCP contaminated water matrices.
研究领域:
环境科学
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生物技术
✓ 已验证
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
Juanjuan Wan,Lijuan Zhang,Bo Yang,Boyu Jia,Jiakuan Yang,Xintai Su
Enzymes have important advantages in sludge dewatering , but their catalytic performance is limited by their poor activity and stability. To address this issue, we develop a series of immobilized enzymes (immobilized acid protease, IE 1; immobilized pectinase, IE 2; immobilized laccase, IE 3) prepared by the electrostatic interaction between the Fe 3 O 4 @SiO 2 -NH 2 as immobilized carrier and the free enzyme, and used for sludge dewatering. As-obtained immobilized enzymes endowed high efficiency and stable sludge dewatering performance in a wide pH range, and had the best dewatering performance when the pH was 5. Specifically, the specific resistance filtration (SRF) performance of the immobilized enzyme at pH 5 was better than that of the control group, and the order was FE 3, 3.84 × 10 13 m kg −1 > FE 1, 2.52 × 10 13 m kg −1 > CL 1, 2.16 × 10 13 m kg −1 > CL 2, 1.34 × 10 13 m kg −1 > FE 2, 2.06 × 10 13 m kg −1 > IE 2, 0.89 × 10 13 m kg −1 > IE 1, 0.82 × 10 13 m kg −1 > IE 3, 0.73 × 10 13 m kg −1 . Such improvement is attributed to two respects: Firstly, the immobilized enzyme has good activity, stability, and abundant functional groups on the surface, which is conducive to the attachment and continuous decomposition of organic matter. Secondly, the solid immobilized carrier can construct the skeleton structure in situ and effectively promote the release of water in sludge. This study provides a feasible way for the practical application of biological enzyme in sludge dewatering.
研究领域:
环境工程
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生物技术
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2021
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IF 8.528
Kai Zhu,Zhuting Li,Fang Cheng,Chen Wu,Dong Cai,Qiuyu Zhang,Hepeng Zhang
Rapid self-healing of micro-configurations is an effective strategy to enhance the durability of superhydrophobic surfaces, however, this property is challenging to achieve. Here, a durable superhydrophobic coating with a precisely targeted self-healing ability to repair its’ dual structure was developed by spray-coating a polyimine film with a mixture of novel fluorinated epoxy resin and Fe 3 O 4 @SiO 2 –NH 2 nanoparticles . The superhydrophobic surface can heal both the broken morphology and wettability through a short irradiation process on account of its local photothermal conversion ability and dynamic imine bond, and can maintain the static water contact angle at a value higher than 159° even after six damage/healing cycles. Furthermore, superhydrophobic coatings can be controllably degraded in three ways. Additionally, because of the robust epoxy resin protection, the surface can withstand sixteen times the dynamic impact and still maintain a WCA greater than 150°. This preparation strategy may aid the fabrication of durable superhydrophobic surfaces for various practical applications.
研究领域:
材料科学
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表面化学
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纳米技术
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涂层技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY
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2020
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IF 1.992
Jin Xu,Xuejia Shi,Xiaomeng Zhang,Zhenzhong Wang,Wei Xiao,Linguo Zhao
To efficiently recycle GH78 thermostable rhamnosidase (TpeRha) and easily separate it from the reaction mixture and furtherly improve the enzyme properties, the magnetic particle Fe 3 O 4 -SiO 2 -NH 2 -Cellu-ZIF8 (FSNcZ8) was prepared by modifying Fe 3 O 4 -NH 2 with tetraethyl silicate (TEOS), microcrystalline cellulose and zinc nitrate hexahydrate. FSNcZ8 displayed better magnetic stability and higher-temperature stability than unmodified Fe 3 O 4 -NH 2 (FN), and it was used to adsorb and immobilize TpeRha from Thermotoga petrophilea 13995. As for properties, FSNcZ8-TpeRha showed optimal reaction temperature and pH of 90°C and 5.0, while its highest activity approached 714 U/g. In addition, FSNcZ8-TpeRha had better higher-temperature stability than FN. After incubation at 80°C for 3 h, the residual enzyme activities of FSNcZ8-TpeRha, FN-TpeRha and free enzyme were 93.5%, 63.32%, and 62.77%, respectively. The organic solvent tolerance and the monosaccharides tolerance of FSNcZ8-TpeRha, compared with free TpeRha, were greatly improved. Using naringin (1 mmol/l) as the substrate, the optimal conversion conditions were as follows: FSNcZ8-TpeRha concentration was 6 U/ml; induction temperature was 80°C; the pH was 5.5; induction time was 30 min, and the yield of products was the same as free enzyme. After repeating the reaction 10 times, the conversion of naringin remained above 80%, showing great improvement of the catalytic efficiency and repeated utilization of the immobilized α-L-rhamnosidase.
研究领域:
生物化学
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酶工程
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材料科学
✓ 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）