查找使用阿拉丁产品的科研文献

Biodegradation Pathway and Detoxification of β-cyfluthrin by the Bacterial Consortium and Its Bacterial Community Structure

Haiyun Li,Yachun Ma,Tuo Yao,Li Ma,Jiangui Zhang,Changning Li

In the process of microbial degradation of pyrethroid pesticides, the synergistic effect of the microbial community is more conducive to the complete degradation of toxic compounds than a single strain. At present, the degradation pathway of pyrethroids in a single strain has been well revealed, but the synergistic metabolism at the community level has not been well explained. This study elucidated the bacterial community succession, metabolic pathway, and phytotoxicity assessment during β-cyfluthrin biodegradation by a novel bacterial consortium enriched from contaminated soil. The results showed that the half-life of β-cyfluthrin at different initial concentrations of 0.25, 0.5, 0.75, and 1.0 mg mL–1 were 4.16, 7.34, 12.81, and 22.73 days, respectively. Enterobacter was involved in β-cyfluthrin degradation metabolism in the initial stage, and other bacterial genera (Microbacterium, Ochrobactrum, Pseudomonas, Hyphomicrobiaceae, Achromobacter, etc.) significantly contribute to the degradation of intermediate metabolites in the later stages. Functional gene prediction and metabolite analysis showed that xenobiotic biodegradation and metabolism, especially benzoate degradation and metabolism by cytochrome P450 were the major means of β-cyfluthrin degradation. Further, two degradation pathways of β-cyfluthrin were proposed, which were mainly ester hydrolysis and oxidation to degrade β-cyfluthrin through the production of carboxylesterase and oxidoreductase. In addition, the inoculated bacterial consortium could degrade β-cyfluthrin residues in water and soil and reduce its phytotoxicity in Medicago sativa. Hence, this novel bacterial consortium has important application in the remediation environments polluted by β-cyfluthrin.

Measurement and control of containing-fluorine particulate matter emission during spent pot lining combustion detoxification process

Funian Han,Liang Yu,Xinyun Mo,Lu Zhang,Jiaqi Jia,Jingmeng Dong,Shaopeng Gu

The particle size distribution (PSD), composition, morphology, and formation mechanism of particulate matter (PM) released from the combustion of spent pot lining with and without CaSiO 3 were investigated. The results showed that NaF and Na 3 AlF 6 were found to be the main compositions of PM, and the particle size distribution of PM shows a bimodal distribution. CaSiO 3 substantially inhibited the emission of PM by transforming NaF, Na 3 AlF 6 , and CaF 2 into stable Ca 4 Si 2 O 7 F 2 . Moreover, CaSiO 3 also limited the formation of high hazardous PM 0.2 by providing SiO 2 , Al 2 O 3 , and NaAlSiO 4 with high melting points as the core of promoting the growth of PM in particle size.

Spontaneously super-hygroscopic MOF-gel microreactors for efficient detoxification of nerve agent simulant in atmospheric environments

Xuejiao Wang,Jing Yang,Ming Zhang,Qian Hu,Bai-Xue Li,Jin Qu,Zhong-Zhen Yu,Dongzhi Yang

We design a spontaneously super-hygroscopic alkaline microreactor by photoinduced integration of Zr-MOF catalyst and alkaline poly(dimethylaminoethyl acrylate) onto LiCl-salinized poly(N-isopropylacrylamide) gel, generating a microenvironment with non-volatile polymeric base and non-bulk water for detoxification of a typical nerve agent simulant, dimethyl 4-nitrophenyl phosphate (DMNP), in atmospheric environments. The super-hygroscopic gel with directional microchannels facilitates the absorption, transport and storage of water under different humidities, and exhibits fast hygroscopic efficiency with a high moisture absorption capacity of 6.4 g g −1 . The integrated microreactor achieves simultaneous water uptake and catalytic hydrolysis of DMNP in an atmospheric environment with an initial half-life of ∼1.9 h and a final conversion of 95.5%, which is attributed to the synergistic catalytic microenvironment of the exposed Zr-MOF catalyst, the polymeric base, and the water from moist air. This work provides a feasible strategy for designing spontaneously hygroscopic microreactors for detoxifying nerve agent simulants in atmospheric environments.

Identification, expression profiles and involvement in insecticides tolerance and detoxification of carboxylesterase genes in Bactrocera dorsalis

Zhenyu Li,Mengling Chen,Wenjie Bai,Shuxia Zhang,Liwei Meng,Wei Dou,Jinjun Wang,Guorui Yuan

Carboxylesterases (CarEs) are a multifunctional superfamily of enzymes and play an important role in detoxification of various insecticides in insects. The oriental fruit fly, Bactrocera dorsalis , is one of the most destructive agricultural pests and has developed different degrees of resistance to organophosphates in field. However, the involvement of BdCarEs in tolerance or resistance to other alternative insecticides are still unclear. In the present study, 33 BdCarEs genes were identified based on the genome database of B. dorsalis . Phylogenetic analysis demonstrated that they were classified into nine clades, with abundance of α -esterases. Meanwhile, the sequence characterization and the chromosome distribution were also analyzed. The spatiotemporal expression analysis of BdCarEs genes suggested that the diversity of potential function in different physiological processes . With the exception of BdCarE21 , all BdCarEs genes responded to at least one insecticide exposure, and BdCarE20 was found to be up-regulated after exposure to all five tested insecticides individually. Eight BdCarEs genes were overexpressed in MR strain when compared to that in SS strain. Subsequently, knockdown the expression of representative BdCarEs genes significantly increased the susceptibility of the oriental fruit fly to corresponding insecticides, which indicated that the tested BdCarEs genes contributed to one or multiple insecticide detoxification. These findings provide valuable insights into the potential role in respond to tolerance or resistance to insecticides with different mode of action, and will facilitate development of efficiency management strategy for B. dorsalis .

Surface-bound radicals enhancing detoxification of enrofloxacin during peroxymonosulfate oxidation: Activated carbon vs. alumina as catalyst carriers

Qiqi Zhang,Ren Zhang,Ying Chen,Anlin Xu,Albert T. Lebedev,Yongjun Zhang

Recent studies have found the presence of surface-bound radicals (Surf-R) during the heterogeneously catalyzed peroxymonosulfate (PMS), especially when the catalyst carriers possess a high adsorption capacity. However, the effects of Surf-R on the toxicity of transformation products (TPs) are still not well elucidated. In this study, Co and Mn were loaded onto commonly used carriers: activated carbon and alumina (CoMn@AC vs CoMn@Al 2 O 3 ) to create comparable catalytic centers but distinct adsorption capacity, which was proved by material characterization (SEM, EDS, BET, XPS), adsorption and catalytic tests. Both images and quantitative analysis with 3D excitation-emission matrix fluorescence spectroscopy demonstrated that the reaction solutions of enrofloxacin from two catalysts composed differently when a same degradation efficiency was achieved. It was further found that the respiratory inhibition of CoMn@AC catalyzed samples was only 7–36% of the counterpart. 50 TPs were identified with UPLC-MS/MS, among which 31 TPs were possibly more toxic than enrofloxacin according to the calculation with the Toxicity Estimation Software Tool. CoMn@Al 2 O 3 produced 14 unique toxic TPs while CoMn@AC only 4. The analysis with EPR revealed that both catalysts generated SO 4 •- , • OH, and 1 O 2 ; quenching tests proved a lot of Surf-R with CoMn@AC but not with CoMn@Al 2 O 3 . This study demonstrates the high potential of Surf-R to enhance the detoxification of organic contaminants during PMS oxidation and thus provides a reference for designing novel catalysts to achieve efficient contaminant degradation and detoxification.

Detoxification and biodegradability enhancement of antibiotic production wastewater by hybrid process of resin adsorption and Fenton oxidation

Yan Liu,Yue Sun,Yi Tao

Antibiotic production wastewater exhibits high concentration of antibiotics and toxic intermediates, which would pose a serious threat to the ecological environment. The biodegradation methods are prevailing for this wastewater. However, it imposes a considerable toxic burden on biological treatment units in wastewater treatment plants (WWTPs), ultimately resulting in subpar treatment efficacy. For improving the biodegradability of antibiotic production wastewater, hybrid process of resin adsorption and Fenton oxidation was proposed. The adsorption experiments showed that NDA-150 exhibited removal rates of up to 99.1% and 94.8% for two key pollutants 8-hydroxyquinoline (8HQ) and o -aminophenol (OAP), respectively. The constant removal rates demonstrated stable performance and capacity of NDA-150 for practical industrial operation. The remaining high COD due to other organic contaminants in the effluent required the involvement of Fenton oxidation for the further processing. The results of single factor experiments and orthogonal tests showed that the COD removal rate of 56.5% could be realized under the optimal operating conditions. This work proposed a novel process which could alleviate obstacles between the antibiotic manufacture factories and biological treatment units, shed light on the mechanisms and feasibility of it, and provide a promising avenue for the toxicant organic industrial sewage.

Microbial detoxification of 3,5-xylenol via a novel process with sequential methyl oxidation by Rhodococcus sp. CHJ602

Ni-Hong Yao,Ya-Nan Du,Jia-Xi Xiong,Ying Xiao,Hang-Hang He,Ze-Feng Xie,Duo Huang,Qi Song,Jing Chen,Dazhong Yan,Hong-Jun Chao

The compound 3,5-xylenol is an essential precursor used in pesticides and industrial intermediate in the disinfectants and preservatives industry. Its widespread application makes it an important source of pollution. Microbial bioremediation is more environmentally friendly than the physicochemical treatment process for removing alkylphenols from a polluted environment. However, the 3,5-xylenol-degrading bacteria is unavailable, and its degradation mechanism remains unclear. Here, a 3,5-xylenol-metabolizing bacterial strain, designated Rhodococcus sp. CHJ602, was isolated using 3,5-xylenol as the sole source of carbon and energy from a wastewater treatment factory. Results showed that strain CHJ602 maintained a high 3,5-xylenol-degrading performance under the conditions of 30.15 °C and pH 7.37. The pathway involved in 3,5-xylenol degradation by strain CHJ602 must be induced by 3,5-xylenol. Based on the identification of intermediate metabolites and enzyme activities , this bacterium could oxidize 3,5-xylenol by a novel metabolic pathway. One methyl oxidation converted 3,5-xylenol to 3-hydroxymethyl-5-methylphenol, 3-hydroxy-5-methyl benzaldehyde, and 3-hydroxy-5-methylbenzoate. After that, another methyl oxidation is converted to 5-hydroxyisophthalicate, which is metabolized by the protocatechuate pathway. It is catalyzed by a series of enzymes in strain CHJ602. In addition, toxicity bioassay result indicates that 3,5-xylenol is toxic to zebrafish and Rhodococcus sp. CHJ602 could eliminate 3,5-xylenol in water to protect zebrafish from its toxicity. The results provide insights into the bioremediation of wastewater contaminated 3,5-xylenol.

Alginate Beads Embedded with Metal–Organic Framework Particles for Solid-Phase Detoxification of Organophosphate under Ambient Conditions

Hong-Bin Luo,Xin-Ru Wu,Xu-Wen Li,Zhen Zhang,Kai-Xin Zhao,Fang-Ru Lin,Guo-Qin Zhang,Xu-Sheng Gao,Yangyang Liu,Xiao-Ming Ren

Zirconium-based metal-organic frameworks (Zr-MOFs), endowed with periodic Lewis-acidic nodes, have emerged as highly promising catalysts for the hydrolytic detoxification of organophosphorus nerve agents. However, their intrinsic powder form and dependence on liquid water during catalysis severely limit their applicability in practical protective platforms. Herein, we present the construction of composite beads by integrating Zr-MOF catalysts with an alginate matrix, enabling the rapid solid-phase degradation of the nerve agent simulant dimethyl-4-nitrophenyl phosphate (DMNP) under ambient conditions. In this design, MOF-808 particles were incorporated within the alginate network, supplying abundant active sites for catalytic hydrolysis, while the alginate matrix maintained moisture retention and generated a mildly alkaline microenvironment conducive to the hydrolytic reaction. Benefiting from this synergistic configuration, the resulting composite beads exhibit outstanding catalytic efficiency and remarkable reusability for solid-phase DMNP degradation under ambient conditions, surpassing the performance of most previously reported Zr-MOF-based catalytic materials.

Self-Healing Conjugated Microporous Polyanilines for Effective and Continuous Catalytic Detoxification of 4-Nitrophenol to 4-Aminophenol

Weiming Gao,Dingwu Jiang,Yiming Zhang,Yao Li,Zhilong Xu,Runxi Han,Hao Tian,Hufei Dai,Qijing Lu,Cuiping Li

Detoxification of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with high efficiency and dynamic performance is challenging for a polymeric catalyst. Herein, a series of conjugated microporous polyanilines (CMPAs), capable of efficiently catalytically reducing 4-NP, were synthesized based on the Buchwald–Hartwig cross-coupling reaction mechanism. By adjusting the types of linkers and the molar ratios of linker to core, CMPAs with different Brunauer–Emmett–Teller (BET) specific surface areas and reduction degrees were obtained and used as the catalysts in reducing 4-NP. The ultrahigh catalytic reduction efficiency (K = 141.32 s–1 g–1, kapp = 0.00353 s–1) was achieved when using CMPA-3-0.7 as the catalyst (prepared with 4,4′-diaminodiphenylamine as the linker and a 0.7:1 molar ratio of linker to core). The catalytic reduction performance exhibited a strong correlation with the reduction degree and BET specific surface area of CMPAs. Furthermore, they also exhibit excellent cycling stability and dynamic performance. The coexistence of a microporous structure and high BET specific surface area endowed CMPAs with an increased number of catalytic active centers. The reversible redox transformation of CMPAs in the presence of NaBH4 and air enabled self-healing (the oxidation units in CMPAs were reduced to reduction units by NaBH4, and the newly generated reduction unit in CMPAs was subsequently oxidized to its original state by the O2 in the air), leading to the reduction reaction of 4-NP proceeded continuously and stably. The aforementioned factors resulted in the high efficiency of CMPAs for reducing 4-NP to 4-AP, enhancing the practical application prospects of CMPAs in the detoxification of 4-NP wastewater.

Safe and targeted detoxification of aflatoxins from contaminated peanut oil by palygorskite infiltrated with Span series surfactant

Dan Wang,Yan Wang,Changjiang Li,Junmin Ji

In this work, using various Span series surfactant (Span 40, Span 60, and Span 80) liquor, three types of newly functional palygorskite adsorbents were developed for removing multiple aflatoxins from peanut oil. The palygorskite infiltrated with Span surfactants all showed excellent detoxification ability in the adsorption of aflatoxins. The removal of AFB 1 by palygorskite infiltrated with Span 40, Span 60, and Span 80 was 94.75 %, 93.85 %, and 91.99 %, respectively. Compared with unmodified palygorskite, the removal of aflatoxins by the three adsorbents was increased by 10.05 %, 9.58 %, and 8.40 %, respectively. What's more, the retention of nutrients in peanut oil was enhanced after treatment with modified adsorbents. Among them, the retention rate of sterols in the oil after Span 40-palygorskite detoxification was increased by 18.71 %, and the tocopherol was increased by 11.20 %. Lastly, the adsorption mechanism was further discussed using kinetic, isothermal, and thermodynamic models. The Freundlich isothermal, Dubinin-Radushkevich model, and the pseudo-second-order rate expression all exhibited a strong association with the test results. The adsorption process mainly involved ion exchange, hydrophobic interactions, and pore-filling effects. Thermodynamic analysis ( ΔG 0  < 0, ΔH 0  > 0, ΔS 0  > 0) denoted that the adsorption effect was spontaneous and endothermic. The composite adsorbents could be a suitable candidate for the elimination of multiple aflatoxins with the merits of high detoxification efficiency, low preparation cost, green, and safety, which may open up new ideas for the creation of novel adsorbents in the fats and oils industry.

Detoxification of organic pollutants over novel niobium and cobalt codoped molybdenum oxy-sulfide photocatalyst under visible light

Bekena Fekadu Tadesse,Kuo Dong-Hau,Duresa Lalisa Wakjera

Photocatalysis is one of the latest and the most promising technologies to remove organic pollutants from the environment. In this work, novel Nb/Co-codoped MoOS photocatalyst was prepared by a simple chemical precipitation method and thereafter the as-prepared photocatalysts were systematically characterized by different techniques. The photocatalytic performance of the as-prepared samples was surveyed by the degradation of methyl orange (MO), rhodamine B (RhB), and methylene blue (MB) dyes under visible light irradiation. All the codoped photocatalysts exhibited enhanced photocatalytic activity than pure and mono doped samples for degradation of these dyes with the highest degradation efficiency observed for the sample with 10 % Nb amount, which degrade 94.4 % of MO, 97.1 % of RhB, and 99.7 % of MB within 150, 20, and 40 min irradiation time, respectively. The HPLC test further confirmed the degradation of these dyes. The rate constants of MO, RhB, and MB removal in the photodegradation process over 10Nb-10Co-MoOS were determined. The enhanced photocatalytic activity of the sample was due to high charge separation and inhibition of recombination of photogenerated electron-hole pairs. The scavenger studies indicate that the primary active species in the photocatalytic process for MO and MB were superoxide radicals and for RhB were hydroxyl radicals, indicating 10Nb-10Co-MoOS had be widely used for different dye degradation. The catalyst revealed excellent recyclability and stability even after three runs. Finally, a reasonable reaction mechanism was proposed.

Organosilicon-Mediated Cadmium Uptake, Transport, and Detoxification in Rice: Comparison Between Low-Cd and Conventional Rice Varieties

Cadmium (Cd) contamination in rice threatens rice food safety. Organosilicon shows substantial potential to reduce the uptake and accumulation of Cd in crops. However, the current understanding of the mechanisms by which organosilicon reduces Cd toxicity in rice remains fragmented. In a one-season pot experiment using soil with a total Cd concentration of 1.04 mg·kg−1, we examined organosilicon-modulated physiological responses and Cd-transport gene expression in two rice varieties. The three organosilicon compounds tested were KH590 (3-mercaptopropyltrimethoxysilane), DMDCS (dimethyldichlorosilane), and D6 (dodecamethylcyclohexasiloxane). Two-way ANOVA confirmed significant cultivar × treatment interactions for Cd in all organs (p< 0.05). DMDCS treatment reduced grain Cd in Shaoxiang 100 by about 43.4%. Subcellular fractionation revealed that DMDCS enhanced Cd sequestration in root and culm cell walls (60.8% increase in culm), while D6 and KH590 showed greater efficacy in leaves. Gene expression analysis indicated that KH590 most potently suppressed the root uptake gene OsNramp5 (76% reduction), whereas DMDCS and D6 exerted stronger inhibition on the long-distance transport gene OsLCT1 (up to 91.8%). Principal component analysis further confirmed that KH590 primarily inhibited root uptake, DMDCS mainly enhanced root Fe oxide deposition and culm Cd retention, while D6 best maintained biomass and reduced late-stage Cd transport to grains, increasing yield by 28%. These findings provide evidence for differential pathways through which organosilicon compounds mitigate Cd stress in rice under pot conditions, offering a theoretical reference for reducing Cd pollution in farmland.