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1.
Small ; 20(9): e2305798, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37849041

RESUMEN

As the most popular liquid metal (LM), gallium (Ga) and its alloys are emerging as functional materials due to their unique combination of fluidic and metallic properties near room temperature. As an important branch of utilizing LMs, micro- and submicron-particles of Ga-based LM are widely employed in wearable electronics, catalysis, energy, and biomedicine. Meanwhile, the phase transition is crucial not only for the applications based on this reversible transformation process, but also for the solidification temperature at which fluid properties are lost. While Ga has several solid phases and exhibits unusual size-dependent phase behavior. This complex process makes the phase transition and undercooling of Ga uncontrollable, which considerably affects the application performance. In this work, extensive (nano-)calorimetry experiments are performed to investigate the polymorph selection mechanism during liquid Ga crystallization. It is surprisingly found that the crystallization temperature and crystallization pathway to either α -Ga or ß -Ga can be effectively engineered by thermal treatment and droplet size. The polymorph selection process is suggested to be highly relevant to the capability of forming covalent bonds in the equilibrium supercooled liquid. The observation of two different crystallization pathways depending on the annealing temperature may indicate that there exist two different liquid phases in Ga.

2.
Chemistry ; 30(27): e202400474, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38456559

RESUMEN

The relationship among chemical structure, physicochemical property and aggregation behavior of organic functional material is an important research topic. Here, we designed and synthesized three bis(squaraine) dyes BSQ1, BSQ2 and BSQ3 through the combination of two kinds of unsymmetrical azulenyl squaraine monomers. Their physicochemical properties were investigated in both molecular and aggregate states. Generally, BSQ1 displayed different assembly behaviors from BSQ2 and BSQ3. Upon fabrication into nanoparticles, BSQ1 tend to form J-aggregates while BSQ2 and BSQ3 tend to form H-aggregates in aqueous medium. When in the form of thin films, three bis(squaraine) dyes all adopted J-aggregation packing modes while only BSQ1 presented the most significant rearrangement of aggregate structures as well as the improvement in the carrier mobilities upon thermal annealing. Our research highlights the discrepancy of aggregation behaviors originating from the molecular structure and surrounding circumstances, providing guidance for the molecular design and functional applications of squaraines.

3.
J Fluoresc ; 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38954082

RESUMEN

The current study looks into the characterization and differentiation of mango juices that are sold commercially using fluorescence spectroscopy. The emission spectra displayed well-defined and prominent peaks that suggested the existence of many fluorophores, such as water content, ß-carotene, tartrazine food color, and chlorophyll components. For this study, water and yellow food coloring solution, the two most popular adulterants were added to pure and authenticated mango pulp that had been diluted to an 8% concentration. The fluorophore profile of the samples was ascertained by using multivariate analysis (principal component analysis) in conjunction with fluorescence spectroscopy. The findings showed that the existence of water content is directly correlated with the spectral bands at 444 and 467 nm, and for food color at 580 nm thus the best indicators to detect adulteration of high water contents and food color. Chlorophyll and ß-carotene intensities varied among juices, acting as a discriminant marker to distinguish between those with unripened pulp (high chlorophyll intensity) and those with more water and other pigments (lower chlorophyll and ß-carotene intensities). With fluorescence emission spectroscopy, qualitative assessment of mango juice can be quickly determined by spectral features, providing details on composition and quality.

4.
Environ Res ; 250: 118498, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38382665

RESUMEN

Soil heavy metal pollution is an important issue that affects human health and ecological well-being. In-situ thermal treatment techniques, such as self-sustaining smoldering combustion (SSS), have been widely studied for the treatment of organic pollutants. However, the lack of fuel in heavy metal-contaminated soil has hindered its application. In this study, we used corn straw as fuel to investigate the feasibility of SSS remediation for copper and lead in heavy metal-contaminated soil, as well as to explore the remediation mechanism. The results of the study showed that SSS increased soil pH, electrical conductivity (EC), total phosphorus (TP), total potassium (TK), rapidly available phosphorus (AP), and available potassium (AK), while decreasing total nitrogen (TN), alkali-hydrolyzed nitrogen (AN), and cation exchange capacity (CEC). The oxidation state of copper (Cu) increased from 10% to 21%-40%, and the residual state of lead (Pb) increased from 18% to 51%-73%. The Toxicity characteristic leaching procedure (TCLP) of Cu decreased by a maximum of 81.08%, and the extracted state of Diethylenetriaminepentaacetic acid (DTPA) decreased by 67.63%; the TCLP of Pb decreased by a maximum of 81.87%, and DTPA decreased by a maximum of 85.68%. The study indicates that SSS using corn straw as fuel successfully achieved remediation of heavy metal-contaminated soil. However, SSS does not reduce the content of copper and lead; it only changes their forms in the soil. The main reasons for the fixation of copper and lead during the SSS process are the adsorption of biochar, complexation with -OH functional groups, binding with π electrons, and the formation of crystalline compounds. This research provides a reference for the application of SSS in heavy metal-contaminated soil and has potential practical implications.


Asunto(s)
Cobre , Restauración y Remediación Ambiental , Estudios de Factibilidad , Plomo , Contaminantes del Suelo , Cobre/química , Cobre/análisis , Plomo/análisis , Plomo/química , Contaminantes del Suelo/análisis , Contaminantes del Suelo/química , Restauración y Remediación Ambiental/métodos , Zea mays/química , Suelo/química
5.
Food Microbiol ; 122: 104545, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38839231

RESUMEN

Despite their acidic pH, carbonated beverages can be contaminated by spoilage microorganisms. Thermal treatments, before and/or after carbonation, are usually applied to prevent the growth of these microorganisms. However, the impact of CO2 on the heat resistance of spoilage microorganisms has never been studied. A better understanding of the combined impact of CO2 and pH on the heat resistance of spoilage microorganisms commonly found in carbonated beverages might allow to optimize thermal treatment. Five microorganisms were selected for this study: Alicyclobacillus acidoterrestris (spores), Aspergillus niger (spores), Byssochlamys fulva (spores), Saccharomyces cerevisiae (vegetative cells), and Zygosaccharomyces parabailii (vegetative cells). A method was developed to assess the impact of heat treatments in carbonated media on microbial resistance. The heat resistances of the five studied species are coherent with the literature, when data were available. However, neither the dissolved CO2 concentration (from 0 to 7 g/L), nor the pH (from 2.8 to 4.1) have an impact on the heat resistance of the selected microorganisms, except for As. niger, for which the presence of dissolved CO2 reduced the heat resistance. This study improved our knowledge about the heat resistance of some spoilage microorganisms in presence of CO2.


Asunto(s)
Aspergillus niger , Calor , Aspergillus niger/crecimiento & desarrollo , Concentración de Iones de Hidrógeno , Dióxido de Carbono/metabolismo , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/fisiología , Alicyclobacillus/crecimiento & desarrollo , Alicyclobacillus/fisiología , Bebidas Gaseosas/microbiología , Byssochlamys/crecimiento & desarrollo , Microbiología de Alimentos , Zygosaccharomyces/crecimiento & desarrollo , Zygosaccharomyces/fisiología , Contaminación de Alimentos/análisis , Contaminación de Alimentos/prevención & control , Medios de Cultivo/química , Medios de Cultivo/metabolismo
6.
Int J Mol Sci ; 25(7)2024 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-38612437

RESUMEN

Alpinia officinarum is a representative of the Zingiberaceae family, which is known for its wide use in the food and pharmaceutical industries also due to its precious pharmacological potential. The major aim of the present study was to evaluate the influence of thermal treatment on the composition of the rhizome of Alpinia officinarum and its antioxidant activity. The fresh rhizome was subjected to various thermal treatment processes-boiling, frying and microwave heating during various time intervals-and their composition and antioxidant activity were determined using chromatographic (HPLC - High Performance Liquid Chromatography and HPLC-MS - High Performance Liquid Chromatography Mass Spectrometry) and spectrophotometric (DPPH and TPC - Total Phenolic Content) methods. Pinobanksin was the main compound found in the extract of the fresh rhizome (537.79 mg/kg), followed by galangin (197.7 mg/kg) and zingerone (185.5 mg/kg). The effect of thermal treatment on the rhizome composition was varied. In general, thermal processing significantly decreased the content of active compounds in the rhizome. However, there were some exceptions-boiling for 4 min significantly increased the content of pinobanksin (1162.4 mg/kg) and galangin (280.7 mg/kg), and microwave processing for 4 min increased the content of pinocembrin (213 mg/kg). It was found that boiling and microwave treatment significantly increased the antioxidant activity of the processed rhizomes.


Asunto(s)
Alpinia , Forunculosis , Zingiberaceae , Animales , Antioxidantes , Rizoma , Cromatografía Líquida de Alta Presión
7.
J Environ Manage ; 351: 119730, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38086123

RESUMEN

In this study, the behavior of heavy metal transformation during the co-thermal treatment of hazardous waste incineration fly ash (HWIFA) and Fe-containing hazardous waste (including hazardous waste incineration bottom slag (HWIBS) and electroplating sludge (ES)) was investigated. The findings demonstrated that such a treatment effectively reduced the static leaching toxicity of Cr and Pb. Moreover, when the treatment temperature exceeded 1000 °C, the co-thermal treated sample exhibited low concentrations of dynamically leached Cr, Pb, and Zn, indicating that these heavy metals were successful detoxified. Thermodynamic analyses and phase transformation results suggested that the formation of spinel and the gradual disappearance of chromium dioxide in the presence of Fe-containing hazardous wastes contributed to the solidification of chromium. Additionally, the efficient detoxification of Pb and Zn was attributed to their volatilization and entry into the liquid phase during the co-thermal treatment process. Therefore, this study sets an excellent example of the co-thermal treatment of hazardous wastes and the control of heavy metal pollution during the treatment process.


Asunto(s)
Metales Pesados , Eliminación de Residuos , Ceniza del Carbón , Eliminación de Residuos/métodos , Aguas del Alcantarillado/análisis , Residuos Peligrosos/análisis , Galvanoplastia , Plomo , Incineración/métodos , Metales Pesados/análisis , Residuos Sólidos/análisis , Carbono , Material Particulado/análisis
8.
J Environ Manage ; 351: 119793, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38086117

RESUMEN

In this study, the effects of thermal treatment at moderately low temperatures (Tmax: 525 °C) on the composition and properties of two distinct green liquor dregs (GLD) samples from two different pulp mills were investigated. This in-depth characterization was conducted with the aim of enabling the use of GLD as raw materials in cementitious applications (e.g., alkali-activated binders). The elemental composition of the GLD samples primarily comprised Ca, Mg, S, Na, and Mn. Analysis using x-ray diffractometry, an electron probe microanalyzer, and scanning electron microscopy revealed that calcite was the main crystalline phase, whereas layered double hydroxides with varying compositions constituted the primary amorphous phase. Characterization through Fourier-transform infrared spectroscopy and thermogravimetric analysis coupled with mass spectrometer analysis, indicated the loss of water and carbon during thermal treatment. Total organic carbon analysis showed that most of the removed carbon was organic, despite some remaining after thermal treatment at 525 °C. A leaching test was conducted to quantify the soluble Ca, Mg, Na, and K content, as well as pH variations. Overall, the findings suggest that thermal treatment enhances the potential of GLD samples for use in binder materials in the construction sector.


Asunto(s)
Álcalis , Hidróxidos , Carbono
9.
Molecules ; 29(13)2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38999042

RESUMEN

Steamed ginseng water (SGW) is a by-product of the repeated thermal processing of red ginseng, which is characterized by a high bioactive content, better skin care activity, and a large output. However, its value has been ignored, resulting in environmental pollution and resource waste. In this study, UHPLC-Q-Exactive-MS/MS liquid chromatography-mass spectrometry and multivariate statistical analysis were conducted to characterize the compositional features of the repeated thermal-treated SGW. The antioxidant activity (DPPH, ABTS, FRAP, and OH) and chemical composition (total sugars, total saponins, and reducing and non-reducing sugars) were comprehensively evaluated based on the entropy weighting method. Four comparison groups (groups 1 and 3, groups 1 and 5, groups 1 and 7, and groups 1 and 9) were screened for 37 important common difference markers using OPLS-DA analysis. The entropy weight method was used to analyze the weights of the indicators; the seventh SGW sample was reported to have a significant weight. The results of this study suggest that heat treatment time and frequency can be an important indicator value for the quality control of SGW cycling operations, which have great potential in antioxidant products.


Asunto(s)
Antioxidantes , Panax , Espectrometría de Masas en Tándem , Panax/química , Antioxidantes/química , Antioxidantes/análisis , Cromatografía Líquida de Alta Presión , Espectrometría de Masas en Tándem/métodos , Calor , Saponinas/química , Saponinas/análisis , Extractos Vegetales/química
10.
J Sci Food Agric ; 104(5): 2535-2550, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38318731

RESUMEN

Phenolic compounds have recently become one of the most interesting topics in different research areas, especially in food science and nutrition due to their health-promoting effects. Phenolic compounds are found together with macronutrients and micronutrients in foods and within several food systems. The coexistence of phenolics and other food components can lead to their interaction resulting in complex formation. This review article aims to cover the effects of thermal and non-thermal processing techniques on the protein-phenolic interaction especially focusing on the content and digestibility of phenolics by discussing recently published research articles. It is clear that the processing conditions and individual properties of phenolics and proteins are the most effective factors in the final content and intestinal fates of phenolic compounds. Besides, thermal and non-thermal treatments, such as high-pressure processing, pulsed electric field, cold plasma, ultrasonication, and fermentation may induce alterations  in those interactions. Still, new investigations are required for different food processing treatments by using a wide range of food products to enlighten new functional and healthier food product design, to provide the optimized processing conditions of foods for obtaining better quality, higher nutritional properties, and health benefits. © 2024 Society of Chemical Industry.


Asunto(s)
Manipulación de Alimentos , Fenoles , Manipulación de Alimentos/métodos , Fenoles/química , Antioxidantes/química
11.
J Sci Food Agric ; 104(3): 1784-1792, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37862233

RESUMEN

BACKGROUND: Pulsed electric field (PEF) has become a reality in the food industry as a non-thermal application. PEF is used due to its benefits such as increasing the extraction of anthocyanin or other bioactive substances, shortening the fermentation time, and reducing the microbiological load by electroporation. This study aimed to determine the effect of PEF pretreatment on the fermentation, chemical, microbiological, and sensory properties of shalgam juice. For this purpose, PEF with 1 kV cm-1 of field strength was used as a pretreatment for shalgam juice and changes in control and PEF-treated samples were monitored during fermentation and 70 days of cold storage (4 °C). RESULTS: The pH and lactic acid content during fermentation were similar for both samples. The effect of PEF on pH (3.15-3.39), titratable acidity (4.35-5.49 g L-1 ), total phenolic content (279-766 mg mL-1 GAE) and antioxidant activity (694-2091 µmol Trolox mL-1 ) during storage was insignificant. PEF-treated samples had lower total aerobic mesophilic bacteria (~9%) and lactic acid bacteria (~3%) counts than the control samples at the end of 70 days. Sensory analyses performed at 30th and 60th days of storage with 74 panelists revealed that the color, taste, sourness, saltiness, bitterness, and general acceptability were not inversely affected by PEF. CONCLUSION: Our results could be a basis to produce shalgam juice commercially by PEF treatment. Although more studies with new experimental designs should be carried out, preliminary results indicated that the use of PEF might have a potential for fermented products such as shalgam juices. © 2023 Society of Chemical Industry.


Asunto(s)
Bebidas , Manipulación de Alimentos , Manipulación de Alimentos/métodos , Bebidas/análisis , Fermentación , Alimentos , Antioxidantes/análisis
12.
J Sci Food Agric ; 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38821885

RESUMEN

BACKGROUND: The quality of surimi-based products can be improved by combining the flesh of different aquatic organisms. The present study investigated the effects of incorporating diverse ratios of unwashed silver carp (H) and scallop (A) and using various thermal treatments on the moisture, texture, microstructure, and conformation of the blended gels and myofibrillar protein of surimi. RESULTS: A mixture ratio of A:H = 1:3 yielded the highest gel strength, which was 60.4% higher than that of scallop gel. The cooking losses of high-pressure heating and water-bath microwaving were significantly higher than those of other methods (P < 0.05). Moreover, the two-step water bath and water-bath microwaving samples exhibited a more regular spatial network structure compared to other samples. The mixed samples exhibited a microstructure with a uniform and ordered spatial network, allowing more free water to be trapped by the internal structure, resulting in more favorable gel properties. The thermal treatments comprehensively modified the tertiary and quaternary structures of proteins in unwashed mixed gel promoted protein unfurling, provided more hydrophobic interactions, enhanced protein aggregation and improved the gel performance. CONCLUSION: The findings of the present study improve our understanding of the interactions between proteins from different sources. We propose a new method for modifying surimi's gel properties, facilitating the development of mixed surimi products, as well as enhancing the efficient utilization of aquatic resources. © 2024 Society of Chemical Industry.

13.
J Anim Physiol Anim Nutr (Berl) ; 108(2): 346-356, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37885333

RESUMEN

The major efforts to improve feed conversion, increase the body weight and breast muscle yield of broilers have been focused on feeding and management at the post hatch period. However, incubation temperature is the most significant factor for the egg hatching rate, chick quality, and post hatch performance. Therefore, incubation factors affecting the performance should be taken with necessary precautions. Incubation temperature not only affects the early development of the hatchlings but also has a lasting impact on the characteristics of the chicks, such as final body weight and meat quality traits. This article provides an overview about embryonic thermal manipulation (TM) of domestic fowls and review the lucrative and deleterious effects of embryonic TM on embryo development, muscle growth, thermotolerance acquisition, and immunity.


Asunto(s)
Pollos , Aves de Corral , Animales , Pollos/fisiología , Temperatura , Peso Corporal/fisiología , Carne
14.
J Environ Sci (China) ; 145: 205-215, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38844320

RESUMEN

Thermal treatment can effectively decontaminate soils but alter their properties. Previous research mainly focused on volatile organic compounds and metals, i.e. Hg, neglecting non-volatile metal(loid)s. This study aimed to investigate Cd and As transformation during aerobic and anaerobic calcination. The results showed that both aerobic and anaerobic calcination increased soil pH by reducing soil organic matter (SOM) content, which also influenced the cation exchange capacity (CEC) and the leaching behavior of Cd and As in the soil. The total concentrations of Cd and As in the calcined soils varied depending on the calcination temperature and atmosphere. When the aerobic calcination temperature exceeded 700 °C, Cd volatilized as CdCl2, while anaerobic calcination at relatively low temperatures (600 °C) involved reductive reactions, resulting in the formation of metallic Cd with a lower boiling point. Similarly, As volatilized at 800 °C aerobically and 600 °C anaerobically. The formation of As-based minerals, particularly Ca3(AsO4)2, hindered its gasification, whereas anaerobic calcination promoted volatilization efficiency through the generation of C-As(III) based gaseous components with lower boiling points. Contrasting trends were observed in the TCLP-extractable Cd and As contents of the calcined soils. Over 70% of TCLP-extractable Cd contents were suppressed after thermal treatment, attributed to the elevated pH and reduced CEC of the soil, as well as volatilization. However, TCLP-extractable As contents increased with elevated temperatures, likely due to the desorption of AsO43- and re-adsorption of gaseous As2O3 during cooling. These findings have implications for assessing the environmental impact of thermal treatment and provide insights for remediation strategies concerning Cd and As-contaminated soils.


Asunto(s)
Arsénico , Cadmio , Contaminantes del Suelo , Suelo , Cadmio/química , Cadmio/análisis , Contaminantes del Suelo/análisis , Contaminantes del Suelo/química , Arsénico/análisis , Arsénico/química , Suelo/química , Restauración y Remediación Ambiental/métodos , Calor
15.
Waste Manag Res ; : 734242X241251398, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38725233

RESUMEN

Thermal soil treatment is a well-established remediation method to remove organic contaminants from soils in waste management. The co-contamination with heavy metals raises the question if thermal soil treatment affects heavy metal mobility in soils. In this study, four contaminated soils and a reference sample were subjected to thermal treatment at 105°C, 300°C and 500°C for 7 day. Thermogravimetry and differential scanning calorimetry were used to understand the reactions, and resulting gases were identified by Fourier-transformed infrared spectroscopy. Treated and untreated samples were characterised by X-ray diffraction (XRD) and electron microprobe analysis and subjected to pH-dependent leaching tests, untreated samples additionally by X-ray-fluorescence (XRF) and inductively coupled plasma mass spectroscopy (ICP-MS). Leachates were analysed using ICP-MS and ion chromatography. Maximum available concentrations were used for hydrogeochemical modelling using LeachXS/Orchestra to predict leaching control mechanisms. Leaching experiments show that thermal treatment tends to decrease the mobility at alkaline pH of Pb, Zn, Cd, As and Cu, but to increase the mobility of Cr. In the acidic to neutral pH range, no clear trend is visible. Hydrogeochemical modelling suggests that adsorption processes play a key role in controlling leaching. It is suggested that the formation of minerals with a more negatively charged surface during thermal treatment are one reason why cations such as Pb2+, Zn2+, Cd2+ and Cu2+ are less mobile after treatment. Future research should focus on a more comprehensive mineralogical investigation of a larger number of samples, using higher resolution techniques such as nanoscale secondary ion mass spectrometry to identify surface phases formed during thermal treatment and/or leaching.

16.
Angew Chem Int Ed Engl ; 63(1): e202311806, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-37773568

RESUMEN

In the evolving field of electrocatalysis, thermal treatment of nano-electrocatalysts has become an essential strategy for performance enhancement. This review systematically investigates the impact of various thermal treatments on the catalytic potential of nano-electrocatalysts. The focus encompasses an in-depth analysis of the changes induced in structural, morphological, and compositional properties, as well as alterations in electro-active surface area, surface chemistry, and crystal defects. By providing a comprehensive comparison of commonly used thermal techniques, such as annealing, calcination, sintering, pyrolysis, hydrothermal, and solvothermal methods, this review serves as a scientific guide for selecting the right thermal technique and favorable temperature to tailor the nano-electrocatalysts for optimal electrocatalysis. The resultant modifications in catalytic activity are explored across key electrochemical reactions such as electrochemical (bio)sensing, catalytic degradation, oxygen reduction reaction, hydrogen evolution reaction, overall water splitting, fuel cells, and carbon dioxide reduction reaction. Through a detailed examination of the underlying mechanisms and synergistic effects, this review contributes to a fundamental understanding of the role of thermal treatments in enhancing electrocatalytic properties. The insights provided offer a roadmap for future research aimed at optimizing the electrocatalytic performance of nanomaterials, fostering the development of next-generation sensors and energy conversion technologies.

17.
Crit Rev Biotechnol ; 43(5): 805-822, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35723574

RESUMEN

The tannery is one of the leading revenue-generating sectors in developing countries. The ever-increasing demand for leather products in the global market requires converting large amounts of rawhide/skins into resilient non-putrescible finished leather. Only 20% of the raw material is converted into a finished product; the rest 80% is discarded as solid and liquid wastes during leather processing. A heavy discharge of improperly treated solid tannery waste (STW) causes a severe impact on the surrounding environment by polluting soil, surface water, and groundwater resources, posing severe hazards to human and animal health. STW comprises proteinaceous untanned and tanned waste, which requires proper treatment for eco-friendly disposal. Several strategies have been developed over the years for the reduction and recycling of STW for producing renewable energy (biogas and biohydrogen), biofuels (biodiesel and briquettes), construction material, fertilizers, commercial products (adsorbents, animal feeds, proteins, fats, and enzymes), and biodegradable packaging and non-packaging materials. In this review, we discuss various strategies adopted for recycling, reutilization, and reduction of STW in an environment-friendly manner. Furthermore, an overview of the current perspectives toward achieving a zero-waste policy is also presented to reduce the environmental burden using green-clean technology to aid the survival of present-day tanneries.


Asunto(s)
Residuos Sólidos , Administración de Residuos , Humanos , Suelo , Residuos Industriales
18.
Nanotechnology ; 34(42)2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37437557

RESUMEN

The dual sintering of copper (Cu) nanoparticles (NPs) was introduced to produce conductive patterns suitable for flexible electronics applications. In this method, laser irradiation using a Nd:YAG laser with a wavelength of 1064 nm was performed at laser powers of 400, 600 and 800 mJ. The laser irradiation time was 15 and 30 s for each laser power. After laser irradiation, all of the Cu NP patterns were thermally sintered under formic acid vapors. The temperature and time for thermal treatment were selected as 260 °C and 15 min, respectively. The resultant physical, chemical, electrical and mechanical properties were evaluated and compared considering the six different dual sintering conditions. The Cu NP patterns sintered using 800 mJ for 30 s showed increased necking and coalescence compared to the other patterns and featured a microstructure with increased density. Despite being oxidized, the Cu NP patterns sintered with 800 mJ for 30 s showed the lowest electrical resistivity of 11.25µΩ cm. The surface of every sintered Cu pattern was oxidized, and mechanical hardness increased with increasing laser power. The Cu NP pattern sintered with 800 mJ for 30 s demonstrated the highest hardness of 48.64 N mm-2. After sintering using the six different conditions, the Cu NP patterns exhibited a weight loss of 0.02-3.87 wt%, and their roughness varied in the range of 26.15-74.08 nm. This can be attributed to the effective removal of organic residues and the degree of particle agglomeration. After performing folding tests up to 50 cycles, Cu NP patterns showed an upward trend in resistance with increasing laser power and time. The highest and lowest resistance ratios were observed as 3.97 and 17.24 for the patterns sintered at 400 mJ for 15 s and 800 mJ for 30 s, respectively.

19.
Environ Sci Technol ; 57(15): 6179-6187, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-37018767

RESUMEN

The thermal decomposition products and mechanisms of per- and polyfluoroalkyl substances (PFASs) are poorly understood despite the use of thermal treatment to remediate PFAS-contaminated media. To identify the thermal decomposition products and mechanisms of perfluorocarboxylic acids (PFCAs), gaseous perfluoropropionic acid (PFPrA) and perfluorobutyric acid (PFBA) were decomposed in nitrogen and oxygen at temperatures from 200 to 780 °C. In nitrogen (i.e., pyrolysis), the primary products of PFPrA were CF2═CF2, CF3CF2H, and CF3COF. CF3CF═CF2 was the dominant product of PFBA. These products are produced by HF elimination (detected as low as 200 °C). CF4 and C2F6 were observed from both PFCAs, suggesting formation of perfluorocarbon radical intermediates. Pyrolysis products were highly thermally stable, resulting in poor defluorination. In oxygen (i.e., combustion), the primary product of both PFPrA and PFBA below 400 °C was COF2, but the primary product was SiF4 above 600 °C due to reactions with the quartz reactor. Oxygen facilitated thermal defluorination by reacting with PFCAs and with pyrolysis products (i.e., fluoroolefins and fluorocarbon radicals). Platinum improved combustion of PFCAs to COF2 at temperatures as low as 200 °C, while quartz promoted the combustion of PFCAs into SiF4 at higher temperatures (>600 °C), highlighting the importance of surface reactions that are not typically incorporated into computational approaches.


Asunto(s)
Fluorocarburos , Contaminantes Químicos del Agua , Gases , Cuarzo , Fluorocarburos/análisis , Oxígeno , Nitrógeno
20.
Environ Sci Technol ; 57(8): 3095-3103, 2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36799869

RESUMEN

Chlorinated paraffins (CPs) as plasticizers are massively added to polyvinyl chloride (PVC) products, during whose life cycle CPs can be continuously released especially under thermal stress. In this study, a PVC cable sheath was adopted as a representative kind of PVC material to investigate the release behaviors of short- and medium-chain CPs (SCCPs and MCCPs) under thermal treatment. Release percentages of CPs with increasing temperature followed a Gaussian-like curve. At the unmolten stage of 80 °C, heating for 10 min caused 0.051% of added SCCPs and 0.029% of added MCCPs to be released. At the molten stage of 270 °C, accumulative release rates of SCCPs and MCCPs within 10 min were up to 30 and 14%, respectively. The developed emission model indicated that material-gas partitioning and internal diffusion simultaneously governed the release of CPs. During thermal treatment, the release of CPs could be remarkably affected by the thermal expansion of the PVC material and the formation of breakage and micropores. Congener group profiles of released CPs indicated a slight fractionation effect for SCCPs during the release process. Furthermore, the release risk of CPs from the whole life cycle of PVC products was preliminarily evaluated.


Asunto(s)
Hidrocarburos Clorados , Parafina , Parafina/análisis , Hidrocarburos Clorados/análisis , Monitoreo del Ambiente , Plastificantes , Fraccionamiento Químico , China
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