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1.
J Hazard Mater ; 441: 129873, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36067555

RESUMO

Developing of fast and efficient adsorbents for removal of low concentration refractory organics in water is significant. Herein, a novel calix[4]arene-based porous organic polymer CaPy is constructed through Sonogashira-Hagihara cross-coupling polycondensation. The strong polar sulfonate is further anchored onto the polymer skeleton of CaPy and three sulfonate-modified anionic polymers CaPy-S1, CaPy-S2, and CaPy-S3 were obtained and fully characterized. The adsorption isotherms showed that the maximum adsorption capacities of CaPy, CaPy-S1, CaPy-S2, and CaPy-S3 toward methylene blue (MB) were 270, 1454, 558 and 1381 mg g-1, whereas those for Rhodamine B (RhB) were 183, 2653, 1132, and 1796 mg g-1, respectively. The maximum adsorption capacity toward RhB was the highest reported vale among the currently used synthetic adsorbents. In addition, the pseudo-second-order rate constants of CaPy, CaPy-S1, CaPy-S2, and CaPy-S3 toward MB were 0.00572, 0.488, 2.24, and 0.192 g mg-1 min-1, respectively, and those toward RhB were 0.000234, 0.138, 0.0819, and 0.203 g mg-1 min-1, respectively. The pseudo-second-order rate constant of CaPy-S2 toward MB was 2.24 g mg-1 min-1 indicating one of the highest adsorption speeds. The activation energy of CaPy-S1 for RhB and MB were 121 and 109 kJ mol-1, respectively, demonstrating that the adsorption of both dyes on CaPy-S1 was chemisorption process. Further, the obtained values of Gibbs free energy were negative, revealing that the adsorption process was spontaneous. This work provides an effective approach for improving adsorption performance via post-modification.


Assuntos
Calixarenos , Poluentes Químicos da Água , Purificação da Água , Adsorção , Alcanossulfonatos , Cátions , Corantes , Azul de Metileno , Polímeros , Porosidade , Eletricidade Estática , Água , Poluentes Químicos da Água/análise
2.
J Hazard Mater ; 441: 129834, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36067560

RESUMO

Metal oxides exist in porous media in the form of composite metal oxides, which can significantly affect the transport and transformation of pollutants in the soil environment. In this study, binary metal oxide porous media were prepared to explore the effects of solution chemistry, and the presence of binary metal oxides on the transport of functional group modified polystyrene nanoplastics (PSNPs) in saturated porous media. The results show that the existence of binary metal oxides significantly affects the migration ability of PSNPs in saturated porous media. The increase of ionic strength and the presence of multivalent cations affect the transport capacity of PSNPs in porous media. The types of binary metal oxides affect the migration of PSNPs in saturated porous media. The surface roughness and electrostatic interaction are important factors affecting the retention of PSNPs on the surface of binary metal oxide saturated porous media. The surface morphology has a more far-reaching impact. In addition, DLVO theory cannot fully explain the interaction between PSNPs and saturated porous media in the presence of Al3+. This study's results help provide some theoretical support for the migration of microplastics in the soil environment.


Assuntos
Poluentes Ambientais , Poliestirenos , Cátions , Microplásticos , Óxidos , Plásticos , Porosidade , Solo
3.
J Hazard Mater ; 441: 129871, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36067561

RESUMO

Highly efficient single atom catalysts are critical to substantially promote for peroxymonosulfate (PMS) activation to organic pollutant degradation, but it remains a challenge at present. Herein, single atom Mn anchored on N-doped porous carbon (SA-Mn-NSC) was synthesized by ball milling of Mn-doped carbon nitride and spirulina biochar to dominantly activate PMS. The precursor of carbon nitride and spirulina possessed a strong coordinating capability for Mn(II), facilitating the formation of highly dispersed nitrogen-coordinated Mn sites (Mn-N4). The SA-Mn-NSC catalyst exhibited high activity and stability in the heterogeneous activation of PMS to degrade a wide range of pollutants within 10 min, showing an outstanding degradation rate constant of 0.31 min-1 in enrofloxacin (ENR) degradation. The high surface density of Mn-N4 sites and abundant interconnected meso-macro pores were highly favorable for activating PMS to produce 1O2 and high-valent manganese (Mn(IV)) for pollutant degradation. This work offers a new pathway of using a low-cost and easily accessible single-atom catalysts (SACs) and could inspire more catalytic oxidation strategies.


Assuntos
Poluentes Ambientais , Spirulina , Carbono , Catálise , Enrofloxacina , Manganês , Nitrilas , Nitrogênio , Peróxidos , Porosidade
4.
Ultrasonics ; 127: 106831, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36084514

RESUMO

Decreased thickness of the bone cortex due to bone loss in the course of ageing and osteoporosis is associated with reduced bone strength. Cortical thickness measurement from ultrasound images was recently demonstrated in young adults. This requires the identification of both the outer (periosteum) and inner (endosteum) surfaces of the bone cortex. However, with bone loss, the cortical porosity and the size of the vascular pores increase resulting in enhanced ultrasound scattering which may prevent the detection of the endosteum. The aim of this work was to study the influence of cortical bone microstructure variables, such as porosity and pore size, on the contrast of the endosteum in ultrasound images. We wanted to estimate the range of these variables for which ultrasound imaging of the endosteum is feasible. We generated synthetic data using a two-dimensional time-domain code to simulate the propagation of elastodynamic waves. A synthetic aperture imaging sequence with an array transducer operating at a center frequency of 2.5 MHz was used. The numerical simulations were conducted for 105 cortical microstructures obtained from high resolution X-ray computed tomography images of ex vivo bone samples with a porosity ranging from 2% to 24 %. Images were reconstructed using a delay-and-sum (DAS) algorithm with optimized f-number, correction of refraction at the periosteum, and sample-specific wave-speed. We observed a range variation of 18 dB of endosteum contrast in our data set depending on the bone microstructure. We found that as porosity increases, speckle intensity inside the bone cortex increases whereas the intensity of the signal from the endosteum decreases. Also, a microstructure with large pores (diameter >250 µm) was associated with poor endosteum visibility, compared with a microstructure with equal porosity but a more narrow distribution of pore sizes. These findings suggest that ultrasound imaging of the bone cortex with a probe operating at a central frequency of 2.5 MHz using refraction-corrected DAS is capable of detecting the endosteum of a cortex with moderate porosity (less than about 10%) if the largest pores remain smaller than about 200 µm.


Assuntos
Osso e Ossos , Osso Cortical , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-dissulfônico/análogos & derivados , Osso e Ossos/diagnóstico por imagem , Simulação por Computador , Osso Cortical/diagnóstico por imagem , Humanos , Porosidade , Ultrassonografia , Adulto Jovem
5.
J Biomed Mater Res A ; 111(1): 118-131, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36205385

RESUMO

Lyophilization of protein solutions, such as silk fibroin (silk), produces porous scaffolds useful for tissue engineering (TE). The impact of modifying lyophilization primary drying parameters on scaffold properties has not yet been explored previously. In this work, changes to primary drying duration and temperature were investigated using 3%, 6%, 9%, and 12% (w/v) silk solutions, via protocols labeled as Long Hold, Slow Ramp, and Standard. The 9% and 12% scaffolds were not successfully fabricated using the Standard protocol, while the Long Hold and Slow Ramp protocols resulted in scaffolds from all silk solution concentrations. Scaffolds fabricated using the Long Hold protocol had higher Young's moduli, smaller pore Feret diameters, and faster degradation. To investigate the utility of the different lyophilized scaffolds for in vitro cell culturing, the HepaRG liver cell line was cultured in the 3% to 12% scaffolds fabricated using the Long Hold protocol. The HepaRG cells grown in 3% scaffolds initially had greater lipid accumulation and metabolic activity than the other groups, although these differences were no longer apparent by Day 28. The deoxyribonucleic acid content of the HepaRG cells grown in 3% scaffold group was also initially significantly higher than the other groups. Significant differences in gene expression by 9% scaffolded HepaRG cells (CK19, HNFα) were seen on Day 14 while significant differences by 12% scaffolded HepaRG cells (ALB, APOA4) were seen on Day 28. Overall, modifying the primary drying parameters and silk concentration resulted in lyophilized scaffolds with tunable properties useful for TE applications.


Assuntos
Fibroínas , Seda , Porosidade , Tecidos Suporte , Temperatura , Engenharia Tecidual , Liofilização
6.
Chemosphere ; 310: 136686, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36202373

RESUMO

Effective photoexcitation and carrier migration are the essential aspects to strengthen semiconductor-engaged redox reaction. Herein, a three-dimensional thin-wall hollow porous cystic-like g-C3N4 (HPCN) with curved layer edge was successfully fabricated via a non-template thermal-condensation strategy. The construction of unique distorted structure can evoke the hard-to-activate n→π* electronic transition to some extent, broadening the absorption spectrum to 800 nm. And benefiting from the multiple reflections of incident light, the effective photoactivation can be further achieved. Moreover, the thin-wall porous framework can shorten the diffusion distance and accelerate migration of photogenerated charge, favouring interfacial redox reactions. The optimized HPCN1.0 demonstrated an excellent photocatalytic degradation of SMX under blue-LED light irradiation, which was dramatically superior to that of pristine g-C3N4 (CN, 11.4 times). Ultimately, in consideration of reactions under several influencing factors with four different water samples, we demonstrated that the HPCN photocatalyst could be utilized far more productively for the elimination of SMX under real-world aqueous conditions. This work provides a straightforward approach for the removal of SMX and has immense potential to contribute to global scale environmental remediation.


Assuntos
Eletrônica , Sulfametoxazol , Porosidade , Catálise
7.
Chemosphere ; 310: 136839, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36244417

RESUMO

Excess sludge produced from biological wastewater treatment plant in petroleum industry is a kind of hazardous solid waste. Converting the sludge into biochar catalysts may help to reduce its environmental risk, recover resources and increase economic efficiency. However, the role of the sludge biochar in persulfate activation remains unclear, limiting its application in removing organic pollutants from water body. In this study, metal-rich petrochemical sludge was used to produce activated sludge biochar (ASC) via a two-step method of pyrolytic carbonization (400 °C-800 °C) and subsequent KOH activation (abbreviated as ASC 400-800). The physio-chemical properties of ASC 400-800 were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and Raman. The chloramphenicol (CAP) removal performances of ASC 400-800/peroxymonosulfate (PMS) systems were evaluated. Results showed that porous sludge biochar was successfully prepared by the two-step method. At 800 °C, the specific surface area of ASC reached the highest value of 202.92 m2 g-1. At 600-800 °C, Fe3O4, Fe0, and graphitized carbon were formed in ASC. Among ASC 400-800, ASC 800 exhibited the best CAP removal performance in ASC 800/PMS system by adsorption combined with catalytic degradation. The optimal conditions identified for 0.31 mM CAP removal were ASC 800 2.0 g L-1, PMS 6.2 mM, and pH 2.0. SO4•-, •OH, and 1O2 may contribute to CAP degradation. The degradation pathways of CAP were proposed based on the identified degradation intermediates. Overall, this study confirmed that porous biochar derived from petrochemical sludge was an effective adsorbent or PMS catalyst to remove organic pollutants from wastewater.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Águas Residuárias/química , Esgotos , Porosidade , Cloranfenicol , Carvão Vegetal/química , Poluentes Químicos da Água/análise
8.
Food Chem ; 403: 134394, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36179633

RESUMO

A rapid and efficient method based on a novel nitrogen-doped porous graphene nanostructure (NDPG) was used for the speciation of mercury in water and human blood samples by the CV-AAS. The mixture of the NDPG, ionic liquid, and acetone was rapidly injected into the human blood, water, and food samples for mercury separation by the cloud point assisted dispersive ionic liquid-micro solid-phase extraction (CPA-DIL-µ-SPE) at pH 7.5. The UV-microwave accessory converted the organic mercury (R-Hg) to inorganic mercury, and total mercury (TM) was determined. Finally, the organic mercury was calculated by subtracting the inorganic and entire mercury contents. By optimizing, the linear range, LOD, and enrichment factor were obtained (0.01-6.80 µg/L; 0.005-3.60 µg/L), (2.6 ng/L; 1.2 ng/L) and (9.8; 20.2) for the mercury species in human blood and water/food samples, respectively (Mean of RSD < 1.9 %). The CRM samples obtained the validation of the procedure.


Assuntos
Grafite , Líquidos Iônicos , Mercúrio , Nanoestruturas , Humanos , Mercúrio/química , Água/química , Líquidos Iônicos/química , Nitrogênio , Porosidade , Pirróis
9.
J Colloid Interface Sci ; 631(Pt A): 181-190, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36371825

RESUMO

Microparticles can function as carriers of e.g. pharmaceuticals and food ingredients. Hollow microparticles can enhance the capacitance due to their large interior void. For preparing microparticles, polymers have been assembled into spherical structures through the use of porous CaCO3 templates, followed by polymer cross-linking and selective template removal. However, this often results in the formation of microparticles with a solid core. Here we use proteins with different aggregate size distributions (<10 nm or >100 nm) to either form solid or hollow microparticles. Proteins were mixed with CaCl2 and Na2CO3 solutions, which from CaCO3 microcrystals (with 20-60 nm pores) with encapsulated proteins. Here it will be shown that small protein aggregates uniformly distributed into the CaCO3 templates. However, larger protein aggregates accumulated at the template edges. Au3+ ions were then added, which oxidize and cross-link proteins and are reduced to form gold nanoparticles (AuNPs). After removal of the templates, the small proteins formed solid microparticles and the larger protein aggregates hollow microparticles. This method of fabrication of solid and hollow protein microparticles, with embedded AuNPs, could be used for generating biomaterials with a broader range of applications, such as hosting molecules and multimodal imaging due to the presence of the AuNPs.


Assuntos
Nanopartículas Metálicas , Agregados Proteicos , Ouro , Proteínas/química , Porosidade , Polímeros/química
10.
J Colloid Interface Sci ; 631(Pt A): 245-259, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36379083

RESUMO

HYPOTHESIS: In a porous medium saturated with oil (containing oleic surfactant) and saline water, salinity reduction alters the thermodynamic equilibrium and induces spatial redistribution of surfactants, changing the local fluid configuration. During fluid-fluid displacement, this local change reshapes global fluid flows, and thus results in improved oil displacement. EXPERIMENTS: We performed microfluidic experiments in a centimeter-long pore-network model with a fracture and a dead-end model to observe both the macroscale flows and microscopic fluid configuration evolution. Water with different salinities and model oils with different surfactant concentrations are used. FINDINGS: When oil contacts low salinity water, we observe (1) the solid surface becomes more water-wet, and (2) water-in-oil emulsion spontaneously emerges near the oil-water interface. At the macroscale, the fluid distribution remains unchanged in short term but dramatically changes after tens of hours, which appears as improved oil recovery. Two modes are identified during fluid redistribution: gradual imbibition and sudden collapse. The displacement efficiency is a non-monotonic function of surfactant concentration. This is attributed to the interplay between two opposing effects by adding surfactant: (1) enhancing initial hydrophobicity which negatively affects the displacement, and (2) allowing stronger oil swelling which is beneficial for displacement.


Assuntos
Águas Salinas , Salinidade , Tensoativos , Óleos , Porosidade
11.
Chemosphere ; 311(Pt 1): 136968, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36283429

RESUMO

The plastic concentration in terrestrial systems is orders of magnitude higher than that found in marine ecosystems, which has raised global concerns about their potential risk to agricultural sustainability. Previous research on the transport of nanoplastics in soil relied heavily on the qualitative prediction of the mean-field extended Derjaguin-Landau-Verwey-Overbeek theory (XDLVO), but direct and quantitative measurements of the interfacial forces between single nanoplastics and porous media are lacking. In this study, we conducted multiscale investigations ranging from column transport experiments to single particle measurements. The maximum effluent concentration (C/C0) of amino-modified nanoplastics (PS-NH2) was 0.94, whereas that of the carboxyl-modified nanoplastics (PS-COOH) was only 0.33, indicating PS-NH2 were more mobile than PS-COOH at different ionic strengths (1-50 mM) and pH values (5-9). This phenomenon was mainly attributed to the homogeneous aggregation of PS-COOH. In addition, the transport of PS-NH2 in the quartz sand column was inhibited with the increase of ionic strength and pH, and pH was the major factor governing their mobility. The transport of PS-COOH was inhibited with increasing ionic strength and decreasing pH. Hydrophilicity/hydrophobicity-mediated interactions and particle heterogeneity strongly interfered with interfacial forces, leading to the qualitative prediction of XDLVO, contrary to experimental observations. Through the combination of XDLVO and colloidal atomic force microscopy, accurate and quantitative interfacial forces can provide compelling insight into the fate of nanoparticles in the soil environment.


Assuntos
Ecossistema , Microplásticos , Porosidade , Quartzo , Areia
12.
Chemosphere ; 311(Pt 1): 136987, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36306961

RESUMO

This study explains the modeling of synthesized membranes using the Donnan Steric Pore model (DSPM) based on the Extended Nernst Planck Equation (ENP). Conventionally, structural parameters required to predict the performance of the membranes were determined through tedious experimentation, which in this study are found using a new MATLAB technique. A MATLAB program is used to determine the unknown structural parameters such as effective charge density (Xd), effective pore radius (rp), and effective membrane thickness to porosity ratio (Δx/Ak) by using the single solute rejection and permeation data. It was found that the model predicted the rejection of studied membranes accurately, with the E5C1 membrane exceeding the others (E5, E5C5) for rejection of single and divalent salt's aqueous solutions. The rejection of 100 ppm aqueous solution of NaCl for E5C1 was around 60%, whereas, for an aqueous solution of 100 ppm, CaCl2 rejection reached up to 80% at 10 bar feed pressure. The trend of salt rejection for all three membranes was found to be in the following order: E5C1 > E5C5 > E5, confirming that their structural parameters-controlled ion transport in these membranes. The structural parameters, such as effective pore radius, effective membrane thickness to porosity ratio, and effective charge density for the best performing membrane, i.e., E5C1, were determined to be 0.5 nm, 16 µm, and -6.04 mol/m3,respectively. Finally, it can be asserted that this method can be used to predict the real performance of membranes by significantly reducing the number of experiments previously required for the predictive modeling of nanofiltration-type membranes.


Assuntos
Membranas Artificiais , Cloreto de Sódio , Estados Unidos , Centers for Medicare and Medicaid Services, U.S. , Membranas , Porosidade , Água
13.
J Colloid Interface Sci ; 630(Pt B): 134-143, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36327717

RESUMO

Porous particles composed of 2,2,6,6-tetramethylpiperidinyl-1-oxyl-oxidized cellulose nanofiber (TOCN) as building block, i.e., porous TOCN particles, are attracting attention due to their environmental friendliness, superior properties, such as easy handling, large surface area, and high adsorption capacity. However, the instability of TOCNs in aqueous environments limits their applications. An effective solution to improve water resistance of TOCN particles is to reduce the hydrophilicity of TOCNs by forming chemical bonds with a cross-linker. In this study, Carbodilite, a common, easy-to-use, commercially available cross-linker with carbodiimide groups, was used to investigate a chemical cross-linking strategy for porous TOCN particles prepared by spray drying. The water resistance of cross-linked TOCN particles was evaluated through morphological observation by SEM images. The presence of polycarbodiimide significantly increased water resistance of cross-linked TOCN particles up to 24 h. This study demonstrates the trade-off between water resistance and adsorption efficiency according to cross-linker concentrations. These data are useful for interface science of TOCNs in liquids, assisting in controlling specific properties of porous TOCN particles for particular applications in adsorption and separation.


Assuntos
Celulose Oxidada , Nanofibras , Nanofibras/química , Celulose/química , Adsorção , Porosidade , Água , Secagem por Atomização , Óxidos N-Cíclicos/química , Celulose Oxidada/química
14.
Chemosphere ; 311(Pt 1): 137023, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36330984

RESUMO

Microplastics (MPs) pollution is an emerging threat to soil ecosystems. The present study aims to investigate the impacts of MPs on soil water evaporation dynamics and patterns. Two series of laboratory experiments were conducted using sand particles and clay mixed with different MPs to investigate how evaporation dynamics and patterns are influenced by the presence of MPs. Quartz sand including 0, 0.75, 1.5, and 4.5% of Polyethylene (PE) and Polyvinylchloride (PVC) were used to evaluate MPs effects on evaporation rates while bentonite mixed with sand and 0, 0.75, 1.5, 4.5, 6, 8, and 10% of PE and PVC were used to investigate evaporation-induced cracking patterns. The experiments were conducted under controlled laboratory conditions in a climate chamber at constant ambient temperature. Our results suggest that the addition of MPs led to more water evaporation compared to the samples without MPs. Microscopic imaging and analysis enabled us to evaluate the possible MPs effects on the modification of soil characteristics and pore structure affecting the evaporation behavior. Moreover, although increasing MPs concentrations appeared to induce only minor effects on the crack morphology formed as a result of evaporation from the mixture of sand and bentonite, the type of MPs (PE vs PVC) had more notable effects on the drying-induced cracking patterns. The reported experimental data and analysis extend our physical understanding of the parameters influencing soil water evaporation in the presence of MPs.


Assuntos
Microplásticos , Plásticos , Porosidade , Areia , Cloreto de Polivinila , Bentonita , Ecossistema , Solo , Polietileno , Água
15.
Chemosphere ; 311(Pt 1): 137022, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36330981

RESUMO

N-doped carbons have attracted extensive attention as catalysts for peroxymonosulfate (PMS) activation towards environmental remediation. However, synthesis of N-rich carbocatalysts is challenging and PMS activation mechanism is still unclear. Herein, novel N-rich porous carbocatalysts (C-PxCN-T) were synthesized by carbonization of polyaniline nanorods coated g-C3N4. C-P50CN-900 (polyaniline content 50%) calcined at 900 °C had high surface area (358 m2/g), product yield (27.1%) and N content (12.27 at%). It showed superior performance in activating PMS to degrade and mineralize various phenolic pollutants in a wide pH range (2-11) and with the co-existence of water constituents. A positive correlation was observed between phenol oxidation rates and contents of CO, C-C/CC and graphitic N, which served as active sites to facilitate adsorption of pollutants and PMS on C-P50CN-900 and subsequent electron-transfer from pollutants to PMS. Overall, this study provides new insights into rational design of N-doped carbocatalysts and elucidation of electron transfer pathway in PMS activation.


Assuntos
Carbono , Poluentes Ambientais , Carbono/química , Porosidade , Elétrons , Peróxidos/química , Fenóis
16.
J Colloid Interface Sci ; 630(Pt B): 714-726, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36347098

RESUMO

In this study, a novel carbon-wrapped-iron hierarchical porous catalyst (Fe/C-Mn800) was prepared from electrolytic manganese residue (EMR) and sewage sludge (SS), which showed outstanding degradation ability toward benzohydroxamic acid (BHA, nearly 90 % was removed within 60 min) with low metal leaching rate. Mechanism exploration found transition metal ions (Fe and Mn) can serve as electron acceptors and facilitate the generation of persistent free radicals (PFRs). These transition metal ions and PFRs mainly participated in the single-electron pathway via activating PMS to generate a large amount of reactive oxygen species (ROS). While the electron negative graphitic N and CO groups not only improve the electronegatively of catalyst, but also acted as the electron sacrificers to favor the electron transfer and directly oxidized the absorbed BHA through the ternary activated outer-sphere complexes. Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) analysis further demonstrated the crucial role of pre-adsorption during the degradation process. This work provided a deep insight into the degradation mechanism of metal/carbon composite and promising opportunity widened the horizon of the high-value utilization of EMR and SS.


Assuntos
Peróxidos , Resíduos Sólidos , Peróxidos/química , Porosidade , Hidroxianisol Butilado , Esgotos/química , Carbono/química , Metais , Radicais Livres
17.
Bioresour Technol ; 367: 128310, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36370946

RESUMO

Porous carbons are excellent sorbents for removing organic pollutants. Green conversion of biowaste into advanced porous carbons is crucial for industrialized production and practical applications, which, however, have rarely been investigated. This study develops a coassisted carbonization method for the preparation of porous carbons with the environmentally friendly agents HCOOK and (HCOO)2Ca for the first time. The bamboo waste-derived hydrochar was transformed into oxygen-doped porous carbons, which displayed a large surface area and pore volume, abundant oxygen content, graphene structure and many surface functional groups. These properties contributed to the extremely high sorption of large quantities of diethyl phthalate, which reached 761 mg g-1. Surface adsorption, including pore filling, hydrogen bonding, and π-π stacking, rather than partitioning, was the main sorption process. Therefore, this study provides a sustainable and promising route for the preparation of porous carbons that can be applied in the efficient removal of organic pollutants.


Assuntos
Poluentes Ambientais , Oxigênio , Porosidade , Carbono/química , Adsorção , Água/química
18.
Sci Total Environ ; 856(Pt 2): 159084, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36179834

RESUMO

The mobility of biochar in saturated quartz sand under a direct current (DC) electric field was investigated by column transport test. The effects of biochar preparation temperature (350 and 550 °C), solution chemistry (pH of 4, 7, and 10, and ion strength of 1, 10, 100 mM) and voltage gradient (0, 0.5 and 1.0 V cm-1) on the mobility of biochar were explored. It was found that DC electric field could significantly promote the migration of biochar, and the recovery rate of particles could be improved by 0.5-6.1 folds under 0.5 V cm-1. Higher voltage potential, solution pH and ionic strength were more favorable for biochar migration. The transport of biochar could be well interpreted by deterministic nonequilibrium convection-dispersion equation model. The enhanced mobility caused by DC electric field was attributed to the following reasons: enhanced electromigration following electrostatic attraction from the anode; increasing surface negative charges and functional groups on biochar surface as a result of electrochemical oxidization; reducing size blocking of biochar particles by decreasing particle size. Moreover, the interaction between biochar particles and electrode could alter solution chemistry, in particular, increasing solution pH, which in turn facilitated the transport of biochar. This study provided a perspective to modulate the transport behavior of biochar particle in the soil for the remediation of polluted sites.


Assuntos
Carvão Vegetal , Solo , Porosidade , Tamanho da Partícula , Soluções
19.
Food Chem ; 403: 134442, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36358078

RESUMO

More and more attention has been paid to undesirable chemical contaminants from food raw materials and ingredients. The study aimed to fabricate novel hydroxyl-functionalized magnetic porous organic polymer Fe3O4@SiO2-NH2@Ph-POP and explore its use as magnetic adsorbents for magnetic solid-phase extraction (MSPE) for extracting 31 amide herbicides from fruit wine samples prior to high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Several operational parameters were optimized and the as-prepared magnetic polymer displayed favorable extraction efficiency. The method also showed low limits of detection (0.015-1.412 µg·L-1) and limits of quantitation (0.049-4.707 µg·L-1). Recoveries for all of the herbicides in four different spiked level samples were between 65.06 % and 101.95 % with intra-day and inter-day relative standard deviations less than 9.89 % and 10.54 %, respectively. The proposed MSPE-HPLC-MS/MS method was successfully applied to simultaneously determine 31 amide herbicides in fruit wine.


Assuntos
Herbicidas , Vinho , Cromatografia Líquida de Alta Pressão/métodos , Herbicidas/análise , Espectrometria de Massas em Tandem , Vinho/análise , Polímeros/análise , Dióxido de Silício/química , Amidas/análise , Porosidade , Frutas/química , Extração em Fase Sólida/métodos , Fenômenos Magnéticos , Limite de Detecção
20.
J Colloid Interface Sci ; 630(Pt A): 573-585, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36270177

RESUMO

Producing a desirable adsorbent with strong affinity adsorption sites, excellent selectivity properties, and the ability to easily separate solid from liquid for the removal of phenol to a permissible level remains a great challenge in wastewater treatment. Herein, an N-doped magnetic carbon skeleton is presented as a porous adsorbent matrix. Importantly, the pore volume and specific surface area of the adsorbent matrix can be meticulously tuned by adjusting the thermal treatment condition, while dispersing and immobilizing the N fraction. This would ultimately result in an N-rich matrix structure with flexible mass transfer channel. The imprinted modification generates a large number of phenol-shaped geometrical cavities on the matrix. This helps to activate the phenol recognition "awareness" of N-active sites and greatly endows the adsorbent with selective adsorption property. Due to the advantageous balance between the hierarchical porous adsorbent matrix with uniformly distributed N-active sites and the imprinted polymer, the adsorbent has a superior adsorption capacity of 995.2 mg g-1 and selective recognition (Kd = 3.92, 3.78; HQ, PTBP) towards phenol. It outperforms previously reported adsorbents. In addition, its easy magnetic separation property makes the adsorbent to have excellent reusability. The adsorbent presents a promising potential for separating pollutants from wastewater and it sheds light on the design of an efficient comprehensive adsorbent.


Assuntos
Fenol , Águas Residuárias , Carbono , Polímeros/química , Porosidade , Adsorção , Fenóis , Fenômenos Magnéticos
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