Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.484
Filtrar
1.
Molecules ; 26(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34361556

RESUMO

Wastewater emissions from textile factories cause serious environmental problems. Manganese peroxidase (MnP) is an oxidoreductase with ligninolytic activity and is a promising biocatalyst for the biodegradation of hazardous environmental contaminants, and especially for dye wastewater decolorization. This article first summarizes the origin, crystal structure, and catalytic cycle of MnP, and then reviews the recent literature on its application to dye wastewater decolorization. In addition, the application of new technologies such as enzyme immobilization and genetic engineering that could improve the stability, durability, adaptability, and operating costs of the enzyme are highlighted. Finally, we discuss and propose future strategies to improve the performance of MnP-assisted dye decolorization in industrial applications.


Assuntos
Corantes/química , Enzimas Imobilizadas/química , Peroxidases/química , Têxteis , Águas Residuárias/química , Biodegradação Ambiental , Catálise
2.
Molecules ; 26(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34361616

RESUMO

The extraction of phenolic compounds from olive mill wastes is important, not only to avoid environmental damages, but also because of the intrinsic value of those biophenols, well-known for their high antioxidant potential and health benefits. This study focuses on tyrosol (Tyr) and hydroxytyrosol (HT), two of the main phenolic compounds found in olive mill wastes. A new, simple, and eco-friendly extraction process for the removal of phenolic compounds from aqueous solutions using native ß-cyclodextrin (ß-CD) in the solid state has been developed. Several ß-CD/biophenol molar ratios and biophenol concentrations were investigated, in order to maintain ß-CD mostly in the solid state while optimizing the extraction yield and the loading capacity of the sorbent. The extraction efficiencies of Tyr and HT were up to 61%, with a total solid recovery higher than 90% using an initial concentration of 100 mM biophenol and 10 molar equivalents of ß-CD. The photochemical stability of the complexes thus obtained was estimated from ∆E*ab curve vs. illumination time. The results obtained showed that the phenols encapsulated into solid ß-CD are protected against photodegradation. The powder obtained could be directly developed as a safe-grade food supplement. This simple eco-friendly process could be used for extracting valuable biophenols from olive mill wastewater.


Assuntos
Antioxidantes , Olea/química , Azeite de Oliva/química , Álcool Feniletílico/análogos & derivados , Extratos Vegetais/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Suplementos Nutricionais , Álcool Feniletílico/química , Álcool Feniletílico/isolamento & purificação , Águas Residuárias/química , beta-Ciclodextrinas/química
3.
Molecules ; 26(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34361706

RESUMO

Chemical and thermochemical transformations were performed on orange peel to obtain materials that were characterized and further tested to explore their potential as adsorbents for the removal of methylene blue (MB) from aqueous solutions. The results show the high potential of some of these materials for MB adsorption not only due to the surface area of the resulting substrate but also to the chemistry of the corresponding surface functional groups. Fitting of the kinetic as well as the equilibrium experimental data to different models suggests that a variety of interactions are involved in MB adsorption. The overall capacities for these substrates (larger than 192.31 mg g-1) were found to compare well with those reported for activated carbon and other adsorbents of agro-industrial origin. According to these results and complementary with theoretical study using Density Functional Theory (DFT) approximations, it was found that the most important adsorption mechanisms of MB correspond to: (i) electrostatic interactions, (ii) H-bonding, and (iii) π (MB)-π (biochar) interactions. In view of these findings, it can be concluded that adsorbent materials obtained from orange peel, constitute a good alternative for the removal of MB dye from aqueous solutions.


Assuntos
Citrus sinensis/química , Frutas/química , Azul de Metileno/isolamento & purificação , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Carvão Vegetal/química , Teoria da Densidade Funcional , Humanos , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Cinética , Pós , Eletricidade Estática , Resíduos/análise
4.
Molecules ; 26(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34361726

RESUMO

FINEAU (2021-2024) is a trans-disciplinary research project involving French, Serbian, Italian, Portuguese and Romanian colleagues, a French agricultural cooperative and two surface-treatment industries, intending to propose chènevotte, a co-product of the hemp industry, as an adsorbent for the removal of pollutants from polycontaminated wastewater. The first objective of FINEAU was to prepare and characterize chènevotte-based materials. In this study, the impact of water washing and treatments (KOH, Na2CO3 and H3PO4) on the composition and structure of chènevotte (also called hemp shives) was evaluated using chemical analysis, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray computed nanotomography (nano-CT), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, solid state NMR spectroscopy and thermogravimetric analysis. The results showed that all these techniques are complementary and useful to characterize the structure and morphology of the samples. Before any chemical treatment, the presence of impurities with a compact unfibrillated structure on the surfaces of chènevotte samples was found. Data indicated an increase in the crystallinity index and significant changes in the chemical composition of each sample after treatment as well as in surface morphology and roughness. The most significant changes were observed in alkaline-treated samples, especially those treated with KOH.


Assuntos
Cannabis/química , Produtos Agrícolas/química , Resíduos/análise , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Europa (Continente) , Humanos , Cinética , Teste de Materiais , Termogravimetria
5.
Molecules ; 26(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34443481

RESUMO

This study explores the capability of Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs) for the simultaneous disinfection and decontamination of urban wastewater. Sulfate and hydroxyl radicals in solution were generated activating peroxymonosulfate (PMS) under UV-C irradiation at pilot plant scale. The efficiency of the process was assessed toward the removal of three CECs (Trimethoprim (TMP), Sulfamethoxazole (SMX), and Diclofenac (DCF)) and three bacteria (Escherichia coli, Enterococcus spp., and Pseudomonas spp.) in actual urban wastewater (UWW), obtaining the optimal value of PMS at 0.5 mmol/L. Under such experimental conditions, bacterial concentration ≤ 10 CFU/100 mL was reached after 15 min of UV-C treatment (0.03 kJ/L of accumulative UV-C radiation) for natural occurring bacteria, no bacterial regrowth was observed after 24 and 48 h, and 80% removal of total CECs was achieved after 12 min (0.03 kJ/L), with a release of sulfate ions far from the limit established in wastewater discharge. Moreover, the inactivation of Ampicillin (AMP), Ciprofloxacin (CPX), and Trimethoprim (TMP) antibiotic-resistant bacteria (ARB) and reduction of target genes (ARGs) were successfully achieved. Finally, a harmful effect toward the receiving aquatic environment was not observed according to Aliivibrio fischeri toxicity tests, while a slightly toxic effect toward plant growth (phytotoxicity tests) was detected. As a conclusion, a cost analysis demonstrated that the process could be feasible and a promising alternative to successfully address wastewater reuse challenges.


Assuntos
Peróxidos/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Purificação da Água/métodos , Aliivibrio fischeri/efeitos dos fármacos , Antibacterianos/química , Bactérias/efeitos dos fármacos , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Oxirredução , Plantas/efeitos dos fármacos , Sulfatos/química , Raios Ultravioleta , Águas Residuárias/análise , Águas Residuárias/microbiologia , Águas Residuárias/toxicidade , Poluentes Químicos da Água/efeitos da radiação
6.
Molecules ; 26(16)2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34443681

RESUMO

Accurate and precise application of ion-selective electrodes (ISEs) in the quantification of environmental pollutants is a strenuous task. In this work, the electrochemical response of alendronate sodium trihydrate (ALN) was evaluated by the fabrication of two sensitive and delicate membrane electrodes, viz. polyvinyl chloride (PVC) and glassy carbon (GC) electrodes. A linear response was obtained at concentrations from 1 × 10-5 to 1 × 10-2 M for both electrodes. A Nernstian slope of 29 mV/decade over a pH range of 8-11 for the PVC and GC membrane electrodes was obtained. All assay settings were carefully adjusted to obtain the best electrochemical response. The proposed technique was effectively applied for the quantification of ALN in pure form and wastewater samples, acquired from manufacturing industries. The proposed electrodes were effectively used for the determination of ALN in real wastewater samples without any prior treatment. The current findings guarantee the applicability of the fabricated ISEs for the environmental monitoring of ALN.


Assuntos
Indústria Farmacêutica , Resíduos de Drogas/análise , Técnicas Eletroquímicas , Resíduos Industriais/análise , Membranas Artificiais , Osteoporose/tratamento farmacológico , Águas Residuárias/química , Alendronato/análise , Alendronato/química , Carbono/química , Eletrodos , Vidro/química , Concentração de Íons de Hidrogênio , Cloreto de Polivinila/química , Potenciometria , Reprodutibilidade dos Testes
7.
J Chromatogr A ; 1652: 462352, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34233247

RESUMO

A method based on gas chromatography coupled with electron ionization mass spectrometry employing N,O-bis(trimethylsilyl)trifluoroacetamide with trimethylchlorosilane as derivatization agent was developed to quantify short-chain carboxylic acids (C1-C6) in hospital wastewater treated by wet air oxidation, an advanced oxidation process. Extraction from water and derivatization of volatile and semi-volatile short chain carboxylic acids were optimized and validated and limits of quantification (LOQ = 0.049 mg L-1-4.15 mg L-1), repeatability (RSD = 1.7-12.8%), recovery (31-119%) and trueness (relative bias = -19.0-3.4%) were acceptable. The validated method was successfully applied to monitor the concentration of organic acids formed after wet air oxidation of water samples. Results showed that the method described herein allowed to identify 38% and up to 46% of the final chemical oxygen demand's composition after wet air oxidation of acetaminophen spiked in deionised water and hospital wastewater samples, respectively. The developed method also allowed to perform qualitative non-targeted analysis in hospital wastewater samples after treatment. Results demonstrated that glycerol, methenamine, and benzoic acid were also present in the samples and their presence was confirmed with reference standards.


Assuntos
Ácidos Carboxílicos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Acetamidas/química , Ar , Hospitais , Compostos de Trimetilsilil/química
8.
Food Environ Virol ; 13(3): 303-315, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34296387

RESUMO

Wastewater surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging public health tool to understand the spread of Coronavirus Disease 2019 (COVID-19) in communities. The performance of different virus concentration methods and PCR methods needs to be evaluated to ascertain their suitability for use in the detection of SARS-CoV-2 in wastewater. We evaluated ultrafiltration and polyethylene glycol (PEG) precipitation methods to concentrate SARS-CoV-2 from sewage in wastewater treatment plants and upstream in the wastewater network (e.g., manholes, lift stations). Recovery of viruses by different concentration methods was determined using Phi6 bacteriophage as a surrogate for enveloped viruses. Additionally, the presence of SARS-CoV-2 in all wastewater samples was determined using reverse transcription quantitative PCR (RT-qPCR) and reverse transcription droplet digital PCR (RT-ddPCR), targeting three genetic markers (N1, N2 and E). Using spiked samples, the Phi6 recoveries were estimated at 2.6-11.6% using ultrafiltration-based methods and 22.2-51.5% using PEG precipitation. There was no significant difference in recovery efficiencies (p < 0.05) between the PEG procedure with and without a 16 h overnight incubation, demonstrating the feasibility of obtaining same day results. The SARS-CoV-2 genetic markers were more often detected by RT-ddPCR than RT-qPCR with higher sensitivity and precision. While all three SARS-CoV-2 genetic markers were detected using RT-ddPCR, the levels of E gene were almost below the limit of detection using RT-qPCR. Collectively, our study suggested PEG precipitation is an effective low-cost procedure which allows a large number of samples to be processed simultaneously in a routine wastewater monitoring for SARS-CoV-2. RT-ddPCR can be implemented for the absolute quantification of SARS-CoV-2 genetic markers in different wastewater matrices.


Assuntos
Fracionamento Químico/métodos , SARS-CoV-2/isolamento & purificação , Ultrafiltração/métodos , Águas Residuárias/química , Águas Residuárias/virologia , Precipitação Química , Monitoramento Ambiental , Polietilenoglicóis/química , Saúde Pública , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , SARS-CoV-2/genética , Esgotos/química , Esgotos/virologia , Proteínas Virais/genética , Poluição da Água/análise
9.
Int J Biol Macromol ; 185: 629-643, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34216664

RESUMO

Historically, lignin has been produced as a waste by-product in industrial processes. In this study, lignosulfonate nanoparticles were fabricated and freeze-dried for use as a precursor material for carbonization. The use of the carbonized lignins for the adsorption of textile effluent as a value-added application is demonstrated. Characterization of the as received lignin (LN) and the developed nano-based freeze-dried lignin (NFLN) were performed prior to and after carbonization at 600, 750, 900 and 1050 °C. Using probe sonication, lignosulfonates were broken down into nanoparticles with lower weight-average molecular weight as verified by dynamic and static light scattering techniques. The difference between the LN and the NFLN was determined to be primarily morphological as the sonication and freeze-drying process imparted a platelet-like shape to the NFLN biocarbons and an increased surface area, while the remaining functionality was similar. The adsorption behaviour of methylene blue (MB), a synthetic cationic dye, was investigated using adsorption isotherm and kinetic models, with the NFLN exhibiting a maximum adsorption capacity of 109.77 mg/g. Overall, electrostatic attraction and hydrogen bonding contribute significantly to the MB adsorption. Further preliminary work was also performed demonstrating the coating of polyurethane foam for the adsorption of MB. These renewable biocarbons show promising properties for use as additive in adsorbent, coating, pigment or as a filler in polymer composite applications.


Assuntos
Carbono/química , Corantes/análise , Lignina/análogos & derivados , Poliuretanos/química , Águas Residuárias/química , Adsorção , Difusão Dinâmica da Luz , Liofilização , Ligação de Hidrogênio , Lignina/química , Azul de Metileno/análise , Nanopartículas , Sonicação
10.
Int J Biol Macromol ; 185: 761-772, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34216668

RESUMO

Cylinder-shaped NaY zeolite was used as an adsorbent for eradicating both heavy metal ions (Cu2+, Zn2+, Ni2+, and Co2+) and proteins from the waste streams. As a pseudo-metal ion affinity adsorbent, NaY zeolite was used in the capture of heavy metal ions in the first stage. The amount (molar basis) of metal ions adsorbed onto NaY zeolite decreased in the order of Cu2+ > Zn2+ > Co2+ > Ni2+. Bovine serum albumin (BSA) was utilized as a model of proteins used in the waste adsorption process by NaY zeolite. The adsorption capacities of NaY zeolite and Cu/NaY zeolite for BSA were 14.90 mg BSA/g zeolite and 84.61 mg BSA/g zeolite, respectively. Moreover, Cu/NaY zeolite was highly stable in the solutions made of 2 M NaCl, 500 mM imidazole or 125 mM EDTA solutions. These conditions indicated that the minimal probability of secondary contamination caused by metal ions and soluble proteins in the waste stream. This study demonstrates the potential of Cu/NaY zeolite complex as an efficient pseudo-metal chelate adsorbent that could remove metal ions and water-soluble proteins from wastewater concurrently.


Assuntos
Metais Pesados/análise , Soroalbumina Bovina/análise , Poluentes Químicos da Água/análise , Zeolitas/química , Adsorção , Quelantes , Concentração de Íons de Hidrogênio , Águas Residuárias/química
11.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207072

RESUMO

The aim of the research was to prepare low-cost adsorbents, including raw date pits and chemically treated date pits, and to apply these materials to investigate the adsorption behavior of Cr(III) and Cd(II) ions from wastewater. The prepared materials were characterized using SEM, FT-IR and BET surface analysis techniques for investigating the surface morphology, particle size, pore size and surface functionalities of the materials. A series of adsorption processes was conducted in a batch system and optimized by investigating various parameters such as solution pH, contact time, initial metal concentrations and adsorbent dosage. The optimum pH for achieving maximum adsorption capacity was found to be approximately 7.8. The determination of metal ions was conducted using atomic adsorption spectrometry. The experimental results were fitted using isotherm Langmuir and Freundlich equations, and maximum monolayer adsorption capacities for Cr(III) and Cd(II) at 323 K were 1428.5 and 1302.0 mg/g (treated majdool date pits adsorbent) and 1228.5 and 1182.0 mg/g (treated sagai date pits adsorbent), respectively. It was found that the adsorption capacity of H2O2-treated date pits was higher than that of untreated DP. Recovery studies showed maximal metal elution with 0.1 M HCl for all the adsorbents. An 83.3-88.2% and 81.8-86.8% drop in Cr(III) and Cd(II) adsorption, respectively, were found after the five regeneration cycles. The results showed that the Langmuir model gave slightly better results than the Freundlich model for the untreated and treated date pits. Hence, the results demonstrated that the prepared materials could be a low-cost and eco-friendly choice for the remediation of Cr(III) and Cd(II) contaminants from an aqueous solution.


Assuntos
Cádmio/química , Cromo/química , Metais Pesados/química , Phoeniceae/química , Sementes/química , Água/química , Adsorção , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Purificação da Água/métodos
12.
Molecules ; 26(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206669

RESUMO

The history of colour is fascinating from a social and artistic viewpoint because it shows the way; use; and importance acquired. The use of colours date back to the Stone Age (the first news of cave paintings); colour has contributed to the social and symbolic development of civilizations. Colour has been associated with hierarchy; power and leadership in some of them. The advent of synthetic dyes has revolutionized the colour industry; and due to their low cost; their use has spread to different industrial sectors. Although the percentage of coloured wastewater discharged by the textile; food; pharmaceutical; cosmetic; and paper industries; among other productive areas; are unknown; the toxic effect and ecological implications of this discharged into water bodies are harmful. This review briefly shows the social and artistic history surrounding the discovery and use of natural and synthetic dyes. We summarise the environmental impact caused by the discharge of untreated or poorly treated coloured wastewater to water bodies; which has led to physical; chemical and biological treatments to reduce the colour units so as important physicochemical parameters. We also focus on laccase utility (EC 1.10.3.2), for discolouration enzymatic treatment of coloured wastewater, before its discharge into water bodies. Laccases (p-diphenol: oxidoreductase dioxide) are multicopper oxidoreductase enzymes widely distributed in plants, insects, bacteria, and fungi. Fungal laccases have employed for wastewater colour removal due to their high redox potential. This review includes an analysis of the stability of laccases, the factors that influence production at high scales to achieve discolouration of high volumes of contaminated wastewater, the biotechnological impact of laccases, and the degradation routes that some dyes may follow when using the laccase for colour removal.


Assuntos
Corantes/química , Proteínas Fúngicas/química , Lacase/química , Águas Residuárias/química , Purificação da Água , Biodegradação Ambiental , Cor
13.
Molecules ; 26(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209563

RESUMO

Propionic acid bacteria are the source of many metabolites, e.g., propionic acid and trehalose. Compared to microbiological synthesis, the production of these metabolites by petrochemical means or enzymatic conversion is more profitable. The components of microbiological media account for a large part of the costs associated with propionic fermentation, due to the high nutritional requirements of Propionibacterium. This problem can be overcome by formulating a medium based on the by-products of technological processes, which can act as nutritional sources and at the same time replace expensive laboratory preparations (e.g., peptone and yeast extract). The metabolic activity of P. freudenreichii was investigated in two different breeding environments: in a medium containing peptone, yeast extract, and biotin, and in a waste-based medium consisting of only apple pomace and potato wastewater. The highest production of propionic acid amounting to 14.54 g/L was obtained in the medium containing apple pomace and pure laboratory supplements with a yield of 0.44 g/g. Importantly, the acid production parameters in the waste medium reached almost the same level (12.71 g/L, 0.42 g/g) as the medium containing pure supplements. Acetic acid synthesis was more efficient in the waste medium; it was also characterized by a higher level of accumulated trehalose (59.8 mg/g d.s.). Thus, the obtained results show that P. freudenreichii bacteria exhibited relatively high metabolic activity in an environment with apple pomace used as a carbon source and potato wastewater used as a nitrogen source. This method of propioniate production could be cheaper and more sustainable than the chemical manner.


Assuntos
Malus/química , Extratos Vegetais/química , Propionatos/metabolismo , Propionibacterium freudenreichii/crescimento & desenvolvimento , Solanum tuberosum/química , Águas Residuárias , Meios de Cultura/química , Águas Residuárias/química , Águas Residuárias/microbiologia
14.
Molecules ; 26(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198752

RESUMO

In recent years, many studies have reported the frequent detection of antihypertensive agents such as sartans (olmesartan, valsartan, irbesartan and candesartan) in the influents and effluents of wastewater treatment plants (WWTPs) and in the superficial waters of rivers and lakes in both Europe and North America. In this paper, the degradation pathway for candesartan (CAN) was investigated by simulating the chlorination process that is normally used to reduce microbial contamination in a WWTP. Twelve isolated degradation byproducts (DPs), four of which were isolated for the first time, were separated on a C-18 column by employing a gradient HPLC method, and their structures were identified by combining nuclear magnetic resonance and mass spectrometry and comparing the results with commercial standards. On the basis of these results, a mechanism of formation starting from the parent drug is proposed. The ecotoxicity of CAN and its DPs was studied by conducting a battery of ecotoxicity tests; bioassays were performed using Aliivibrio fischeri (bacterium), Daphnia magna (planktonic crustacean) and Raphidocelis subcapitata (alga). The ecotoxicity results shed new light on the increased toxicity of DPs compared with the parent compound.


Assuntos
Benzimidazóis/análise , Compostos de Bifenilo/análise , Ácido Hipocloroso/química , Tetrazóis/análise , Poluentes Químicos da Água/análise , Aliivibrio fischeri/efeitos dos fármacos , Animais , Benzimidazóis/toxicidade , Compostos de Bifenilo/toxicidade , Clorofíceas/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Europa (Continente) , Lagos/química , América do Norte , Rios/química , Tetrazóis/toxicidade , Águas Residuárias/química , Poluentes Químicos da Água/toxicidade , Purificação da Água
15.
Molecules ; 26(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198808

RESUMO

Volatile methylsiloxanes (VMSs) constitute a group of compounds used in a great variety of products, particularly personal care products. Due to their massive use, they are continually discharged into wastewater treatment plants and are increasingly being detected in wastewater and in the environment at low concentrations. The aim of this work was to develop and validate a fast and reliable methodology to screen seven VMSs in water samples, by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography with flame ionization detection (GC-FID). The influence of several factors affecting the extraction efficiency was investigated using a design of experiments approach. The main factors were selected (fiber type, sample volume, ionic strength, extraction and desorption time, extraction and desorption temperature) and optimized, employing a central composite design. The optimal conditions were: 65 µm PDMS/Divinylbenzene fiber, 10 mL sample, 19.5% NaCl, 39 min extraction time, 10 min desorption time, and 33 °C and 240 °C as extraction and desorption temperature, respectively. The methodology was successfully validated, showing low detection limits (up to 24 ng/L), good precision (relative standard deviations below 15%), and accuracy ranging from 62% to 104% in wastewater, tap, and river water samples.


Assuntos
Siloxanas/análise , Microextração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Ionização de Chama , Água Doce/química , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Rios/química , Águas Residuárias/química
16.
Molecules ; 26(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070428

RESUMO

Magnetic MXene composite Fe3O4@Ti3C2 was successfully prepared and employed as 17α-ethinylestradiol (EE2) adsorbent from water solution. The response surface methodology was employed to investigate the interactive effects of adsorption parameters (adsorption time, pH of the solution, initial concentration, and the adsorbent dose) and optimize these parameters for obtaining maximum adsorption efficiency of EE2. The significance of independent variables and their interactions were tested by the analysis of variance (ANOVA) and t-test statistics. Optimization of the process variables for maximum adsorption of EE2 by Fe3O4@Ti3C2 was performed using the quadratic model. The model predicted maximum adsorption of 97.08% under the optimum conditions of the independent variables (adsorption time 6.7 h, pH of the solution 6.4, initial EE2 concentration 0.98 mg L-1, and the adsorbent dose 88.9 mg L-1) was very close to the experimental value (95.34%). pH showed the highest level of significance with the percent contribution (63.86%) as compared to other factors. The interactive influences of pH and initial concentration on EE2 adsorption efficiency were significant (p < 0.05). The goodness of fit of the model was checked by the coefficient of determination (R2) between the experimental and predicted values of the response variable. The response surface methodology successfully reflects the impact of various factors and optimized the process variables for EE2 adsorption. The kinetic adsorption data for EE2 fitted well with a pseudo-second-order model, while the equilibrium data followed Langmuir isotherms. Thermodynamic analysis indicated that the adsorption was a spontaneous and endothermic process. Therefore, Fe3O4@Ti3C2 composite present the outstanding capacity to be employed in the remediation of EE2 contaminated wastewaters.


Assuntos
Etinilestradiol/química , Magnetismo , Termodinâmica , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Etinilestradiol/isolamento & purificação , Cinética , Nanopartículas Metálicas/química , Águas Residuárias/química , Difração de Raios X
17.
Forensic Sci Int ; 325: 110873, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34153554

RESUMO

The consumption of licit and illicit psychoactive drugs (PAD) is ubiquitous in all communities and a serious public health problem. Measuring drug consumption is difficult but essential for health-care professionals, risk assessment and policymakers. Different sources of information have been used for a comprehensive analysis of drug consumption. Among them, Wastewater based epidemiology (WBE) emerged as an essential and complementary methodology for estimating licit and illicit drugs consumption. This methodology can be used for quantification of unchanged drugs or their human-specific metabolites in wastewater for estimation of consumption or screening of new PAD. Although some limitations are still being pointed out (e.g., estimation of the population size, use of suitable biomarkers or pharmacokinetics studies), the non-invasive and potential for monitoring real-time data on geographical and temporal trends in drug use have been showing its capacity as a routine and complementary tool. Chromatographic methods, both non-enantioselective and enantioselective are the analytical tools used for quantification of PAD in wastewaters and further estimation of consumption. Therefore, this manuscript aims to summarize and critically discuss the works used for wastewater analysis of PAD based on WBE using non-enantioselective and enantioselective methods for estimation of consumption. Non-enantioselective methods are among the most reported including for chiral PAD. Nevertheless, a trend has been seen towards the development of enantioselective methods as most PAD are chiral and determination of the enantiomeric fraction can provide additional information (e.g., distinction between consumption or direct disposal, or manufacture processes) and fulfill some WBE gaps.


Assuntos
Psicotrópicos/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Humanos , Estereoisomerismo , Detecção do Abuso de Substâncias/métodos
18.
Molecules ; 26(11)2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34067394

RESUMO

Pharmaceuticals are found in waterbodies worldwide. Conventional sewage treatment plants are often not able to eliminate these micropollutants. Hence, Advanced Oxidation Processes (AOPs) have been heavily investigated. Here, metoprolol is exposed to UV irradiation, hydrogen peroxide, and ozonation. Degradation was analyzed using chemical kinetics both for initial and secondary products. Photo-induced irradiation enhanced by hydrogen peroxide addition accelerated degradation more than ozonation, leading to complete elimination. Degradation and transformation products were identified by high-performance liquid-chromatography coupled to high-resolution higher-order mass spectrometry. The proposed structures allowed to apply Quantitative Structure-Activity Relationship (QSAR) analysis to predict ecotoxicity. Degradation products were generally associated with a lower ecotoxicological hazard to the aquatic environment according to OECD QSAR toolbox and VEGA. Comparison of potential structural isomers suggested forecasts may become more reliable with larger databases in the future.


Assuntos
Ecotoxicologia , Metoprolol/análise , Ozônio/química , Relação Quantitativa Estrutura-Atividade , Esgotos/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Algoritmos , Reatores Biológicos , Cromatografia Líquida de Alta Pressão , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Cinética , Metoprolol/química , Oxigênio/química , Fotoquímica , Fotólise , Software , Raios Ultravioleta , Poluentes Químicos da Água/química
19.
J Chromatogr A ; 1651: 462279, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34090053

RESUMO

In this paper, a helical copper wire, coated with copper-benzene-1,4-dicarboxylic acid metal-organic framework (Cu-BDC) was used as a sorbent for stir-bar sorptive extraction of fenthion from water and fruit samples. The homogenous coating was fabricated through two simple and fast steps. The chemical conversion of copper substrate to copper hydroxide nanotubes (Cu(OH)2 NTs) was performed in an alkaline solution and then Cu-BDC was formed through a neutralization reaction. Corona discharge ion mobility spectrometry in positive mode was applied for the detection of fenthion. To improve the sensitivity of the method, some synthesis and extraction parameters affecting the extraction efficiency such as benzene-1,4-dicarboxylic acid concentration, ionic strength, sample pH, stirring rate, extraction temperature, and extraction time were investigated. The linear dynamic range between 0.5 and 80 µg L-1 and detection limit of 0.1 µg L-1 were obtained under optimal conditions. The intra- and inter-day relative standard deviations were less than 6.4 and 8.6%, respectively. The applicability of the method was examined for the analysis of different samples (i.e., well water, agricultural wastewater, and orange). The recovery for the determination of fenthion in spiked samples varied from 88 to 111%.


Assuntos
Fracionamento Químico/métodos , Fention/isolamento & purificação , Espectrometria de Mobilidade Iônica/métodos , Estruturas Metalorgânicas/química , Citrus sinensis/química , Cobre , Fention/análise , Hidróxidos , Limite de Detecção , Nanotubos/química , Reprodutibilidade dos Testes , Águas Residuárias/química
20.
J Chromatogr A ; 1651: 462347, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34166861

RESUMO

Herein, we report the fabrication of a novel, well-defined core-double-shell-structured magnetic Fe3O4@polydopamine@naphthyl microporous organic network (MON), Fe3O4@PDA@NMON, for the efficient magnetic extraction of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and p-nitrophenol (p-Npn) from wastewater samples. The hierarchical nanospheres were designed and constructed with the Fe3O4 nanoparticle core, the inner shell of a polydopamine (PDA) layer, and the outer shell of a porous naphthyl MON (NMON) coating, allowing efficient and synergistic extraction of OH-PAHs and p-Npn via hydrophobic, hydrogen bonding, and π-π interactions. The Fe3O4@PDA@NMON nanospheres were well characterized and employed as an efficient sorbent for magnetic solid-phase extraction (MSPE) coupled with high performance liquid chromatography (HPLC) for analyzing of OH-PAHs and p-Npn. Under optimal conditions, the Fe3O4@PDA@NMON-based-MSPE-HPLC-UV method afforded wide linear range (0.18-500 µg L-1), low limits of detection (0.070 µg L-1 for p-Npn, 0.090 µg L-1 for 2-OH-Nap, 0.090 µg L-1 for 9-OH-Fluo and 0.055 µg L-1 for 9-OH-Phe, respectively), large enrichment factors (92.6-98.4), good precisions (intra-day and inter-day relative standard deviations (RSDs); <6.4%, n=6) and less consumption of the adsorbent. Furthermore, trace OH-PAHs and p-Npn with concentrations of 0.29-0.80 µg L-1 were successfully detected in various wastewater samples. Fe3O4@PDA@NMON also functioned as a good adsorbent to enrich a wide scope of trace contaminants containing hydrogen bonding sites and aromatic structures, highlighting the potential of functional MONs in sample pretreatment.


Assuntos
Indóis/química , Nanosferas/química , Nitrofenóis/isolamento & purificação , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Polímeros/química , Extração em Fase Sólida/métodos , Águas Residuárias/química , Cromatografia Líquida de Alta Pressão , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Fenômenos Magnéticos , Nitrofenóis/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Porosidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...