Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 654
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Nano Lett ; 24(15): 4415-4422, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38577835

RESUMO

The increasing demand for personal protective equipment such as single-use masks has led to large amounts of nondegradable plastic waste, aggravating economic and environmental burdens. This study reports a simple and scalable approach for upcycling waste masks via a chemical vapor deposition technique, realizing a trichome-like biomimetic (TLB) N95 respirator with superhydrophobicity (water contact angle ≥150°), N95-level protection, and reusability. The TLB N95 respirator comprising templated silicone nanofilaments with an average diameter of ∼150 nm offers N95-level protection and breathability comparable to those of commercial N95 respirators. The TLB N95 respirator can still maintain its N95-level protection against particulate matter and viruses after 10 disinfection treatment cycles (i.e., ultraviolet irradiation, microwave irradiation, dry heating, and autoclaving), demonstrating durable reusability. The proposed strategy provides new insight into upcycle waste masks, breaking the existing design and preparation concept of reusable masks.


Assuntos
COVID-19 , Dispositivos de Proteção Respiratória , Humanos , Respiradores N95 , Máscaras , SARS-CoV-2
2.
BMC Bioinformatics ; 25(1): 8, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38172657

RESUMO

BACKGROUND: The increasing volume and complexity of genomic data pose significant challenges for effective data management and reuse. Public genomic data often undergo similar preprocessing across projects, leading to redundant or inconsistent datasets and inefficient use of computing resources. This is especially pertinent for bioinformaticians engaged in multiple projects. Tools have been created to address challenges in managing and accessing curated genomic datasets, however, the practical utility of such tools becomes especially beneficial for users who seek to work with specific types of data or are technically inclined toward a particular programming language. Currently, there exists a gap in the availability of an R-specific solution for efficient data management and versatile data reuse. RESULTS: Here we present ReUseData, an R software tool that overcomes some of the limitations of existing solutions and provides a versatile and reproducible approach to effective data management within R. ReUseData facilitates the transformation of ad hoc scripts for data preprocessing into Common Workflow Language (CWL)-based data recipes, allowing for the reproducible generation of curated data files in their generic formats. The data recipes are standardized and self-contained, enabling them to be easily portable and reproducible across various computing platforms. ReUseData also streamlines the reuse of curated data files and their integration into downstream analysis tools and workflows with different frameworks. CONCLUSIONS: ReUseData provides a reliable and reproducible approach for genomic data management within the R environment to enhance the accessibility and reusability of genomic data. The package is available at Bioconductor ( https://bioconductor.org/packages/ReUseData/ ) with additional information on the project website ( https://rcwl.org/dataRecipes/ ).


Assuntos
Gerenciamento de Dados , Genômica , Software , Linguagens de Programação , Fluxo de Trabalho
3.
Mod Pathol ; 37(1): 100350, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37827448

RESUMO

Recent progress in computational pathology has been driven by deep learning. While code and data availability are essential to reproduce findings from preceding publications, ensuring a deep learning model's reusability is more challenging. For that, the codebase should be well-documented and easy to integrate into existing workflows and models should be robust toward noise and generalizable toward data from different sources. Strikingly, only a few computational pathology algorithms have been reused by other researchers so far, let alone employed in a clinical setting. To assess the current state of reproducibility and reusability of computational pathology algorithms, we evaluated peer-reviewed articles available in PubMed, published between January 2019 and March 2021, in 5 use cases: stain normalization; tissue type segmentation; evaluation of cell-level features; genetic alteration prediction; and inference of grading, staging, and prognostic information. We compiled criteria for data and code availability and statistical result analysis and assessed them in 160 publications. We found that only one-quarter (41 of 160 publications) made code publicly available. Among these 41 studies, three-quarters (30 of 41) analyzed their results statistically, half of them (20 of 41) released their trained model weights, and approximately a third (16 of 41) used an independent cohort for evaluation. Our review is intended for both pathologists interested in deep learning and researchers applying algorithms to computational pathology challenges. We provide a detailed overview of publications with published code in the field, list reusable data handling tools, and provide criteria for reproducibility and reusability.


Assuntos
Aprendizado Profundo , Humanos , Reprodutibilidade dos Testes , Algoritmos , Patologistas
4.
Environ Res ; 252(Pt 2): 118931, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38615794

RESUMO

In the present work, the biomass of Aspergillus flavus (AF) was modified using magnetic nanoparticles MnFe2O4 and metal-organic framework of ZIF-67, and its ability to remove tetracycline antibiotic (TCH) was investigated. With the help of physicochemical tests, AF biomass modification with ZIF-67 and MnFe2O4 magnetic nanoparticles was confirmed. Based on the BET value, AF-MnFe2O4-ZIF-67 (139.83 m2/g) has a higher surface value than AF (0.786 m2/g) and AF/MnFe2O4 (17.504 m2/g). Also, the magnetic saturation value revealed that the modified biomass can be isolated from the treated solution using a simple magnetic field. Maximum TCH elimination (99.04%) using AF-MnFe2O4-ZIF-67 was obtained at pH 7, adsorber mass of 1 g/L, adsorption time of 40 min, and TCH content of 10 mg/L. The thermodynamic study indicated that the TCH abatement using the desired composite is spontaneous and exothermic. The experimental results showed that the adsorption process is compatible with the pseudo-second-order kinetic and Freundlich model. The maximum adsorption capacity for AF, AF-MnFe2O4, and AF-MnFe2O4-ZIF-67 was quantified to be 9.75 mg/g, 25.59 mg/g, and 43.87 mg/g, respectively. The reusability of the desired adsorbers was examined in up to 8 steps. The outcomes showed that the adsorbers can be used several times in TCH elimination. The provided composite can remove TCH from hospital wastewater, so it can be suggested for use in water and wastewater treatment works.


Assuntos
Aspergillus flavus , Biomassa , Tetraciclina , Poluentes Químicos da Água , Aspergillus flavus/metabolismo , Tetraciclina/química , Poluentes Químicos da Água/química , Adsorção , Antibacterianos/química , Estruturas Metalorgânicas/química , Compostos Férricos/química , Compostos de Manganês/química , Cinética , Nanopartículas de Magnetita/química , Purificação da Água/métodos , Imidazóis , Zeolitas
5.
Environ Res ; 245: 118019, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38142730

RESUMO

In this study, a new core-shell Fe3O4@SiO2/PAEDTC@MIL-101 (Fe) photocatalyst was prepared by sol-gel method and used to degrade diazinon (DZN) and chlorpyrifos (CPS) from aqueous solutions. The characteristics analyzed by various techniques indicate that the core-shell photocatalyst with a specific surface area of 992 m2/g, pore size of 1.35 nm and saturation magnetization of nanocomposite was 12 emu/g has been successfully synthesized and can be separated from the reaction solution by a magnetic field. The maximum efficiencies of DZN (98.8%) and CPS (99.9%) were provided at pH of 5, photocatalyst dosage of 0.6 g/L, pollutant concentration of 25 mg/L, radiation intensity of 15 W, and time of 60 min. The presence of anions such as sulfate, nitrate, bicarbonate, phosphate, and chloride had a negative effect on the performance of the photocatalysis system. Compared to the adsorption and photolysis systems alone, the photocatalytic process based on Fe3O4@SiO2/PAEDTC@MIL-101 (Fe) under two UV and visible light sources showed a high efficiency of 90% in the reaction time of 60 min. The BOD5/COD ratio improved after 50 min to above 0.4 with TOC and COD removal rates >80%. Scavenging tests showed that •OH radical, hole (h+), electron (e-), and O2•- anion were produced in the reaction reactor, and the •OH radical was the dominant species in the degradation of DZN and CPS. The stability tests confirmed the recyclability of the photocatalyst in 360 min of reactions, with a minimum reduction of 7%. Energy consumption for the present system during different reactions was between 15.61 and 25.06 kWh/m3 for DZN degradation and 10-22.87 kWh/m3 for CPS degradation.


Assuntos
Clorpirifos , Estruturas Metalorgânicas , Praguicidas , Praguicidas/química , Diazinon , Dióxido de Silício , Catálise
6.
Environ Res ; 247: 118204, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38224938

RESUMO

The synthesis of CuAu-based monometallic (MNPs) and bimetallic nanoparticles (BNPs) supported on chitosan-based hydrogels for their application as catalysts is presented. The hydrogels consisted of chitosan chains cross-linked with tripolyphosphate (TPP) in the form of beads with an approximate average diameter of 1.81 mm. The MNPs and BNPs were obtained by the adsorption of metallic ions and their subsequent reduction with hydrazine, achieving a metallic loading of 0.297 mmol per gram of dry sample, with average nanoparticle sizes that were found between 2.6 and 4.4 nm. Both processes, metal adsorption and the stabilization of the nanoparticles, are mainly attributed to the participation of chitosan hydroxyl, amine and amide functional groups. The materials revealed important absorption bands in the visible region of the light spectra, specifically between 520 and 590 nm, mainly attributed to LSPR given the nature of the MNPs and BNPs inside the hydrogels. Subsequently, the hydrogels were evaluated as catalysts against the reduction of 4-nitrophenol (4NP) into 4-aminophenol (4AP), followed by UV-visible spectroscopy. The kinetic advance of the reaction revealed important improvements in the catalytic activity of the materials by synergistic effect of BNPs and plasmonic enhancement under visible light irradiation, given the combination of metals and the light harvesting properties of the nanocomposites. Finally, the catalytic performance of hydrogels containing BNPs CuAu 3:1 showed an important selectivity, recyclability and reusability performance, due to the relevant interaction of the BNPs with the chitosan matrix, highlighting the potential of this nanocomposite as an effective catalyst, with a potential environmental application.


Assuntos
Quitosana , Nanopartículas Metálicas , Hidrogéis/química , Quitosana/química , Nanopartículas Metálicas/química , Prata/química , Catálise
7.
Environ Res ; 245: 118041, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38160973

RESUMO

In recent years, there has been a growing focus on treating textile wastewater due to its escalating threat to aquatic ecosystems and exposed communities. The present study investigates the adsorption efficacy of biopolymer functionalized nanoscale zero-valent iron (CS@nZVI) composite for the treatment of textile wastewater using the RSM-CCD model. The structure and morphology of CS@nZVI were characterized using XRD, FTIR, FESEM, and EDX. CS@nZVI was then evaluated for its adsorption potential in removing COD, color, and other physico-chemical parameters from textile wastewater. The results showed the high efficacy of CS@nZVI for COD and color removal from textile wastewater. Under optimal conditions (pH 6, contact time 60 min, and 1.84 g CS@nZVI), COD removal reached a maximum of 85.53%, and decolorization efficiency was found to be 89.73%. The coefficient of determination R2 (0.98) and AIC (269.75) values suggested quadratic model as the best-fitted model for optimizing the process parameters for COD removal. Additionally, the physico-chemical parameters were found to be within permissible limits after treatment with CS@nZVI. The influence of coexisting ions on COD removal followed the order PO43- > SO42- > Cl- >Na+ > Ca2+. The kinetics data fitted well with the pseudo-first-order reaction, indicating physisorption as the primary mechanism. The thermodynamic study revealed the endothermic nature of the removal process. Reusability tests demonstrated that great regeneration capacity of spent CS@nZVIafter five consecutive cycles. Furthermore, toxicological studies showed reduced toxicity in treated samples, leading to improved growth of Vigna radiata L. These findings suggest that CS@nZVI bionanocomposites could serve as an efficient, cost-effective, and eco-friendly remediation agent for the treatment of textile effluents, presenting significant prospects for commercial applications.


Assuntos
Quitosana , Poluentes Químicos da Água , Águas Residuárias/toxicidade , Quitosana/química , Ecossistema , Poluentes Químicos da Água/análise , Têxteis , Adsorção
8.
Appl Microbiol Biotechnol ; 108(1): 233, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38400957

RESUMO

Enzyme immobilized on magnetic nanomaterials is a promising biocatalyst with efficient recovery under applied magnets. In this study, a recombinant extracellular lipase from Aspergillus niger GZUF36 (PEXANL1) expressed in Pichia pastoris GS115 was immobilized on ionic liquid-modified magnetic nano ferric oxide (Fe3O4@SiO2@ILs) via electrostatic and hydrophobic interaction. The morphology, structure, and properties of Fe3O4@SiO2@ILs and immobilized PEXANL1 were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, x-ray diffraction, vibration sample magnetometer, and zeta potential analysis. Under optimized conditions, the immobilization efficiency and activity recovery of immobilized PEXANL1 were 52 ± 2% and 122 ± 2%, respectively. The enzymatic properties of immobilized PEXANL1 were also investigated. The results showed that immobilized PEXANL1 achieved the maximum activity at pH 5.0 and 45 °C, and the lipolytic activity of immobilized PEXANL1 was more than twice that of PEXANL1. Compared to PEXANL1, immobilized PEXANL1 exhibited enhanced tolerance to temperature, metal ions, surfactants, and organic solvents. The operation stability experiments revealed that immobilized PEXANL1 maintained 86 ± 3% of its activity after 6 reaction cycles. The enhanced catalytic performance in enzyme immobilization on Fe3O4@SiO2@ILs made nanobiocatalysts a compelling choice for bio-industrial applications. Furthermore, Fe3O4@SiO2@ILs could also benefit various industrial enzymes and their practical uses. KEY POINTS: • Immobilized PEXANL1 was confirmed by SEM, FT-IR, and XRD. • The specific activity of immobilized PEXANL1 was more than twice that of PEXANL1. • Immobilized PEXANL1 had improved properties with good operational stability.


Assuntos
Líquidos Iônicos , Estabilidade Enzimática , Líquidos Iônicos/química , Aspergillus niger/genética , Aspergillus niger/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Dióxido de Silício/química , Lipase/metabolismo
9.
Mikrochim Acta ; 191(2): 107, 2024 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-38240908

RESUMO

A novel strategy based on gradient porous hollow fiber membrane (GPF) is proposed for the modular assembly of enzyme-nanozyme cascade systems. The porous structure of GPF provided sufficient specific surface area, while the gradient structure effectively minimized the leaching of enzymes and nanozymes. To enhance stability, we prepared and immobilized metal-organic framework (MOF) nanozymes, resulting in the fabrication of GPF-MOF with excellent stability and reusability for colorimetric H2O2 detection. To improve specificity and expand the detection range, micro-crosslinked natural enzymes were modularly assembled, using glucose oxidase as the model enzyme. The assembled system, GPF-mGOx@MOF, achieved a low detection limit of 0.009 mM and a linear range of 0.2 to 11 mM. The sensor retained 87.2% and 80.7% of initial activity after being stored for 49 days and 9 recycles, respectively. Additionally, the reliability of the biosensor was validated through glucose determination of human blood and urine samples, yielding comparable results to a commercial glucose meter.


Assuntos
Estruturas Metalorgânicas , Humanos , Estruturas Metalorgânicas/química , Glucose/química , Peróxido de Hidrogênio/química , Reprodutibilidade dos Testes , Glucose Oxidase/química
10.
Bioprocess Biosyst Eng ; 47(2): 249-261, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38197955

RESUMO

ß-galactosidase has been immobilized onto novel alginate/tea waste gel beads (Alg/TW) via covalent binding. Alg/TW beads were subjected to chemical modification through amination with polyethyleneimine (PEI) followed by activation with glutaraldehyde (GA). Chemical modification parameters including PEI concentration, PEI pH, and GA concentration were statistically optimized using Response Surface methodology (RSM) based on Box-Behnken Design (BBD). Analysis of variance (ANOVA) results confirmed the great significance of the model that had F value of 37.26 and P value < 0.05. Furthermore, the R2 value (0.9882), Adjusted R2 value (0.9617), and predicted R2 value (0.8130) referred to the high correlation between predicted and experimental values, demonstrating the fitness of the model. In addition, the coefficient of variation (CV) value was 2.90 that pointed to the accuracy of the experiments. The highest immobilization yield (IY) of ß-galactosidase (75.1%) was given under optimized conditions of PEI concentration (4%), PEI pH (9.5), and GA concentration (2.5%). Alg/TW beads were characterized by FT-IR, TGA, and SEM techniques at each step of immobilization process. Moreover, the immobilized ß-galactosidase revealed a very good reusability as it could be reused for 15 and 20 consecutive cycles keeping 99.7 and 72.1% of its initial activity, respectively. In conclusion, the environmental waste (tea waste) can be used in modern technological industries such as the food and pharmaceutical industry.


Assuntos
Alginatos , Enzimas Imobilizadas , Enzimas Imobilizadas/química , Microesferas , Concentração de Íons de Hidrogênio , Alginatos/química , Chá , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , beta-Galactosidase/química
11.
Int J Phytoremediation ; 26(6): 975-992, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37968930

RESUMO

The current study aims to use a facile and novel method to remove Congo red (CR) and Methyl Orange (MO) dyes from contaminated water with Maize offal biomass (MOB) and its nanocomposite with magnetic nanoparticles (MOB/MNPs). The MOB and MOB/MNPs were characterized with Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), BET, XRD and point of zero charge (pHPZC). The influence of initial CR and MO levels (20-320 mg/L), adsorbent dosage (1-3 g/L), pH (3-9), co-exiting ions, temperature (25-45 °C) and time (15-180 min) was estimated. The findings demonstrated that MOB/MNPs exhibited excellent adsorption of 114.75 and 29.0 mg/g for CR and MO dyes, respectively while MOB exhibited 81.35 and 23.02 mg/g adsorption for CR and MO dyes, respectively at optimum pH-5, and dose 2 g/L. Initially, there was rapid dye removal which slowed down until equilibrium was reached. The interfering/competing ions in contaminated water and elevated temperature favored the dyes sequestration. The MOB/MNPs exhibited tremendous reusability and stability. The dyes adsorption was spontaneous, and exothermic with enhanced randomness. The adsorption effects were well explained with Freundlich model, pseudo second order and Elovich models. It is concluded that MOB/MNPs showed excellent, eco-friendly, and cost-effective potential to decontaminate the water.


Nanocomposite of Maize offal biomass demonstrated higher dyes removal.FTIR, SEM, BET, XRD and pHPZC provided vital evidence for dyes adsorption.MOB/MNPs displayed excellent stability and reusability for dyes adsorption.Groundwater samples exposed a higher dyes removal.Results were validated with equilibrium and kinetic adsorption models.


Assuntos
Compostos Azo , Nanocompostos , Poluentes Químicos da Água , Vermelho Congo , Corantes/química , Zea mays , Biomassa , Biodegradação Ambiental , Adsorção , Íons , Água , Nanocompostos/química , Fenômenos Magnéticos , Cinética , Poluentes Químicos da Água/química , Concentração de Íons de Hidrogênio
12.
Int J Phytoremediation ; 26(2): 178-192, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37409646

RESUMO

In the present study, we report the chemical modification of the dried and fallen pine needles (PNs) via a simple protocol using KMnO4 oxidation. The oxidized PNs (OPNs) were evaluated as adsorbents using some cationic and anionic dyes. The successful synthesis of OPNs adsorbent was characterized by various techniques to ascertain its structural attributes. The adsorbent showed selectivity for the cationic dyes with 96.11% removal (Pr) for malachite green (MG) and 89.68% Pr for methylene blue (MB) in 120 min. Kinetic models namely, pseudo-first order, pseudo-second order, and Elovich were applied to have insight into adsorption. Additionally, three adsorption isotherms, i.e., Langmuir, Freundlich, and Temkin were also applied. The dye adsorption followed a pseudo-second-order kinetic model with R2 > 0.99912 for MG and R2 > 0.9998 for MB. The adsorbent followed the Langmuir model with a maximum adsorption capacity (qm) of 223.2 mg/g and 156.9 mg/g for MG and MB, respectively. Furthermore, the OPNs showed remarkable regeneration and recyclability up to nine adsorption-desorption cycles with appreciable adsorption for both the dyes. The use of OPNs as an adsorbent for the removal of dyes from wastewater, therefore, provides an ecologically benign, low-cost, and sustainable solution.


We have carried out the chemical modification of the dried and fallen pine needles (PNs) via a simple protocol using KMnO4 oxidation. The oxidized PNs (OPNs) were evaluated as adsorbents using some cationic and anionic dyes and the adsorbent showed selectivity for the cationic dyes. As far as the authors are aware, no such report has been documented in the literature wherein an adsorbent based on oxidized PNs with a simple protocol has been used for dye removal.


Assuntos
Corantes , Poluentes Químicos da Água , Corantes/química , Biodegradação Ambiental , Águas Residuárias , Corantes de Rosanilina , Cátions/química , Adsorção , Cinética , Azul de Metileno/química , Poluentes Químicos da Água/química
13.
Sensors (Basel) ; 24(2)2024 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-38257439

RESUMO

The Internet of Things generates vast data volumes via diverse sensors, yet its potential remains unexploited for innovative data-driven products and services. Limitations arise from sensor-dependent data handling by manufacturers and user companies, hindering third-party access and comprehension. Initiatives like the European Data Act aim to enable high-quality access to sensor-generated data by regulating accuracy, completeness, and relevance while respecting intellectual property rights. Despite data availability, interoperability challenges impede sensor data reusability. For instance, sensor data shared in HTML formats requires an intricate, time-consuming processing to attain reusable formats like JSON or XML. This study introduces a methodology aimed at converting raw sensor data extracted from web portals into structured formats, thereby enhancing data reusability. The approach utilises large language models to derive structured formats from sensor data initially presented in non-interoperable formats. The effectiveness of these language models was assessed through quantitative and qualitative evaluations in a use case involving meteorological data. In the proposed experiments, GPT-4, the best performing LLM tested, demonstrated the feasibility of this methodology, achieving a precision of 93.51% and a recall of 85.33% in converting HTML to JSON/XML, thus confirming its potential in obtaining reusable sensor data.

14.
Sensors (Basel) ; 24(4)2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38400364

RESUMO

This article presents a new working electrode based on a bismuth-plated, gold-based microelectrode array, which is suitable for determining thallium(I) species using anodic stripping voltammetry (ASV). It allowed a significant increase in the sensitivity as compared to other voltammetric sensors. The main experimental conditions and the instrumental parameters were optimized. A very good proportionality between the Tl(I) peak current and its concentration was evidenced in the range from 5 × 10-10 up to 5 × 10-7 mol L-1 (R = 0.9989) for 120 s of deposition and from 2 × 10-10 up to 2 × 10-7 mol L-1 (R = 0.9988) for 180 s. A limit of detection (LOD) of 8 × 10-11 mol L-1 for a deposition time of 180 s was calculated. The effects of interfering ions on the Tl(I) analytical signal were studied. The proposed method was applied for quantitative Tl(I) detection in water certified reference material TM 25.5 as well as in spiked real water samples, for which satisfactory recovery values between 98.7 and 101.8% were determined.

15.
Int J Mol Sci ; 25(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38473992

RESUMO

Multi-enzymatic strategies have shown improvement in bioconversion during cofactor regeneration. In this study, purified l-arabinitol 4-dehydrogenase (LAD) and nicotinamide adenine dinucleotide oxidase (Nox) were immobilized via individual, mixed, and sequential co-immobilization approaches on magnetic nanoparticles, and were evaluated to enhance the conversion of l-arabinitol to l-xylulose. Initially, the immobilization of LAD or Nox on the nanoparticles resulted in a maximum immobilization yield and relative activity of 91.4% and 98.8%, respectively. The immobilized enzymes showed better pH and temperature profiles than the corresponding free enzymes. Furthermore, co-immobilization of these enzymes via mixed and sequential methods resulted in high loadings of 114 and 122 mg/g of support, respectively. Sequential co-immobilization of these enzymes proved more beneficial for higher conversion than mixed co-immobilization because of better retaining Nox residual activity. Sequentially co-immobilized enzymes showed a high relative conversion yield with broader pH, temperature, and storage stability profiles than the controls, along with high reusability. To the best of our knowledge, this is the first report on the mixed or sequential co-immobilization of LAD and Nox on magnetic nanoparticles for l-xylulose production. This finding suggests that selecting a sequential co-immobilization strategy is more beneficial than using individual or mixed co-immobilized enzymes on magnetic nanoparticles for enhancing conversion applications.


Assuntos
Enzimas Imobilizadas , Nanopartículas de Magnetita , Álcoois Açúcares , Enzimas Imobilizadas/metabolismo , Xilulose , Temperatura , Concentração de Íons de Hidrogênio , Estabilidade Enzimática
16.
J Environ Manage ; 351: 119503, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38043312

RESUMO

Human health and the environment are negatively affected by endocrine-disrupting chemicals (EDCs), such as bisphenol A. Therefore, developing appropriate remediation methods is essential for efficiently removing phenolic compounds from aqueous solutions. Enzymatic biodegradation is a potential biotechnological approach for responsibly addressing water pollution. With its high catalytic efficiency and few by-products, laccase is an eco-friendly biocatalyst with significant promise for biodegradation. Herein, two novel supporting materials (NH2-PMMA and NH2-PMMA-Gr) were fabricated via the functionalization of poly(methylmethacrylate) (PMMA) polymer using ethylenediamine and reinforced with graphene followed by glutaraldehyde activation. NH2-PMMA and NH2-PMMA-Gr were utilized for laccase immobilization with an immobilization yield (IY%) of 78.3% and 82.5% and an activity yield (AY%) of 81.2% and 85.9%, respectively. Scanning electron microscope (SEM) and Fourier-transform infrared (FTIR) were used to study the characteristics of fabricated material supports. NH2-PMMA-Gr@laccase exhibited an optimal pH profile from 4.5 to 5.0, while NH2-PMMA@laccase exhibited optimum pH at 5.0 compared to a value of 4.0 for free form. A wider temperature ranges of 40-50 °C was noted for both immobilized laccases compared to a value of 40 °C for the free form. Additionally, it was reported that immobilized laccase outperformed free laccase in terms of substrate affinity and storage stability. NH2-PMMA@laccase and NH2-PMMA-Gr@laccase improved stability by up to 3.9 and 4.6-fold when stored for 30 days at 4 °C and preserved up to 80.5% and 86.7% of relative activity after ten cycles of reuse. Finally, the degradation of BPA was achieved using NH2-PMMA@laccase and NH2-PMMA-Gr@laccase. After five cycles, NH2-PMMA@laccase and NH2-PMMA-Gr@laccase showed that the residual degradation of BPA was 77% and 84.5% using 50 µm of BPA. This study introduces a novel, high-performance material for organic pollution remediation in wastewater that would inspire further progress.


Assuntos
Grafite , Nanoestruturas , Humanos , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Lacase/química , Lacase/metabolismo , Polimetil Metacrilato , Concentração de Íons de Hidrogênio
17.
J Environ Manage ; 351: 119767, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38109826

RESUMO

Ten novel hydrophobic dicationic ionic liquids (DILs) were synthesized and applied for the extraction of heavy metals in aqueous solutions. Their physicochemical properties were measured at ambient temperature, and the leaching behaviors of the as-prepared DILs in water were assessed by TOC analysis. Metal extraction experiments were carried out to evaluate the extraction performances of the DILs. It was found that the extraction rates of up to 0.45 and 0.53 mg·(g·min)-1 were achieved with 100 mg DILs for 5 mL of 5 mg/L Cd2+ and Pb2+ solutions. Besides, the extraction efficiencies of Cd2+ and Pb2+ were respectively up to 95.48% and 98.46%, when the volumes of the simulated wastewater were expanded by a factor of 20 at a constant extraction phase ratio (1000 mg DILs for 50 mL of 5 mg/L Cd2+ or Pb2+ solutions). The reusability of the novel DILs was successfully proved by the back-extraction experiments with 0.5 M HNO3. Finally, taking Cd2+ extraction as an example, the extraction mechanism based on FTIR analysis and quantum chemical calculations showed that both S and O atoms in the anions of DILs had physical and quasi-chemical interactions with Cd2+, which were stronger than the electrostatic attraction.


Assuntos
Líquidos Iônicos , Metais Pesados , Líquidos Iônicos/química , Cádmio , Água , Chumbo , Metais Pesados/química
18.
Molecules ; 29(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38257330

RESUMO

In the present investigation of copper ferrite, a CuFe2O4 nanocomposite adsorbent was synthesized using the sol-gel method, and its relevance in the adsorptive elimination of the toxic Congo red (CR) aqueous phase was examined. A variety of structural methods were used to analyze the CuFe2O4 nanocomposite; the as-synthesized nanocomposite had agglomerated clusters with a porous, irregular, rough surface that could be seen using FE-SEM, and it also contained carbon (23.47%), oxygen (44.31%), copper (10.21%), and iron (22.01%) in its elemental composition by weight. Experiments were designed to achieve the most optimized system through the utilization of a central composite design (CCD). The highest uptake of CR dye at equilibrium occurred when the initial pH value was 5.5, the adsorbate concentration was 125 mg/L, and the adsorbent dosage was 3.5 g/L. Kinetic studies were conducted, and they showed that the adsorption process followed a pseudo-second-order (PSO) model (regression coefficient, R2 = 0.9998), suggesting a chemisorption mechanism, and the overall reaction rate was governed by both the film and pore diffusion of adsorbate molecules. The process through which dye molecules were taken up onto the particle surface revealed interactions involving electrostatic forces, hydrogen bonding, and pore filling. According to isotherm studies, the equilibrium data exhibited strong agreement with the Langmuir model (R2 = 0.9989), demonstrating a maximum monolayer adsorption capacity (qmax) of 64.72 mg/g at pH 6 and 302 K. Considering the obtained negative ΔG and positive ΔHads and ΔSads values across all tested temperatures in the thermodynamic investigations, it was confirmed that the adsorption process was characterized as endothermic, spontaneous, and feasible, with an increased level of randomness. The CuFe2O4 adsorbent developed in this study is anticipated to find extensive application in effluent treatment, owing to its excellent reusability and remarkable capability to effectively remove CR in comparison to other adsorbents.

19.
Environ Monit Assess ; 196(8): 754, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39031225

RESUMO

In the contemporary landscape, the reuse of wastewater holds paramount significance. Concurrently, wastewater carries an array of pollutants encompassing chemical dyes and heavy metals. This study delves into the potential of Tamarix aphylla (TA) and Eucalyptus camaldulensis (EC) species for mitigating heavy metals in soil and eliminating methylene blue dye (MB) from wastewater. The research begins with assessing the dye adsorption process, considering pivotal factors such as initial pH, adsorbent dosage, initial dye concentration, and contact time. Outcomes reveal EC's superiority in dye removal compared to TA. As a bioremediation agent, EC exhibits a 90.46% removal efficacy for MB within 15 min, with pH 7.0 as the operative condition. Equilibrium analysis employs Temkin (T), Freundlich (F), and Langmuir (L) isotherms, revealing an excellent fit with the L isotherm model. The study delves further by probing surface adsorption kinetics through pseudo-first-order (PFO) and pseudo-second-order (PSO) models. Furthermore, to discern the divergent impacts of EC and TA on soil heavy metal reduction, soil samples were collected from three distinct zones: an untouched control area, alongside areas where EC and TA were cultivated at the Yazd wastewater site in Iran. Heavy metal levels in the soil were meticulously assessed through rigorous measurement and statistical scrutiny. The findings spotlight TA-cultivated soil as having the highest levels across all examined factors. Ultimately, EC emerges as the superior contender, proficiently excelling in both MB eliminations from wastewater and heavy metal amelioration in the soil, positioning it as the preferred phytoremediation agent.


Assuntos
Biodegradação Ambiental , Eucalyptus , Metais Pesados , Azul de Metileno , Poluentes do Solo , Solo , Tamaricaceae , Águas Residuárias , Poluentes Químicos da Água , Eucalyptus/química , Metais Pesados/análise , Águas Residuárias/química , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Azul de Metileno/química , Solo/química , Adsorção , Eliminação de Resíduos Líquidos/métodos , Recuperação e Remediação Ambiental/métodos
20.
Waste Manag Res ; 42(8): 595-607, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38366790

RESUMO

This study introduces an innovative approach for enhancing oil-water emulsion separation using a polyethersulfone (PES) membrane embedded with a nanocomposite of graphene oxide (GO) and silver oxide (AgO). The composite membrane, incorporating PES and polyvinyl chloride (PVC), demonstrates improved hydrophilicity, structural integrity and resistance to fouling. Physicochemical characterization confirms successful integration of GO and AgO, leading to increased tensile strength, porosity and hydrophilicity. Filtration tests reveal substantial improvements in separating various oils from contaminated wastewater, with the composite membrane exhibiting superior efficiency and reusability compared to pristine PES membranes. This research contributes to the development of environmentally friendly oil-water separation methods with broad industrial applications.


Assuntos
Emulsões , Filtração , Grafite , Membranas Artificiais , Nanocompostos , Polímeros , Sulfonas , Grafite/química , Nanocompostos/química , Sulfonas/química , Polímeros/química , Filtração/métodos , Compostos de Prata/química , Óleos/química , Águas Residuárias/química , Água/química , Interações Hidrofóbicas e Hidrofílicas , Óxidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA