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1.
Polymers (Basel) ; 16(13)2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-39000647

RESUMO

High-density polyethylene (HDPE) waste poses a significant environmental challenge due to its non-biodegradable nature and the vast quantities generated annually. However, conventional recycling methods are energy-intensive and often yield low-quality products. Herein, HDPE waste is upcycled into anti-aging, superhydrophobic thin films suitable for outdoor applications. A two-layer spin-casting method combined with heating-induced crosslinking is utilized to produce an exceptionally rough superhydrophobic surface, featuring a root mean square (RMS) roughness of 50 nm, an average crest height of 222 nm, an average trough depth of -264 nm, and a contact angle (CA) of 148°. To assess durability, weathering tests were conducted, revealing the films' susceptibility to degradation under harsh conditions. The films' resistance to environmental factors is improved by incorporating a UV absorber, maintaining their hydrophobic properties and mechanical strength. Our research demonstrates a sustainable method for upcycling waste into high-performance, weather-resistant, superhydrophobic films.

2.
Polymers (Basel) ; 16(13)2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-39000655

RESUMO

Microfiltration membranes derived from semi-crystalline polymers face various challenges when synthesized through the extrusion-casting technique, including the use of large quantities of polymer, long casting times, and the generation of substantial waste. This study focuses on synthesizing these membranes using spin-casting, followed by stretch-induced pore formation. Recycled high-density polyethylene (HDPE) and virgin polyethylene powder, combined with a calcium carbonate filler, were used as the source materials for the membranes. The influence of the polymer-filler ratio with and without stretching on the morphology, tensile strength, and water flow rate was investigated. Optimal conditions were determined, emphasizing a balance between pore structure and mechanical integrity. The permeable membrane exhibited a water flow rate of 19 mL/min, a tensile strength of 32 MPa, and a water contact angle of 126°. These membranes effectively eliminated suspended particles from water, with their performance evaluated against that of commercially available membranes. This research, carried out utilizing the spin-casting technique, outlines a synthesis route for microfiltration membranes tailored to semi-crystalline polymers and their plastic forms.

3.
Polymers (Basel) ; 16(11)2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38891406

RESUMO

Traditional bulk adsorbents, employed for the removal of dyes and metal ions, often face the drawback of requiring an additional filtration system to separate the filtrate from the adsorbent. In this study, we address this limitation by embedding the adsorbent into the polymer matrix through a process involving dissolution-dispersion, spin-casting, and heat-stretching. Selective dissolution and dispersion facilitate the integration of the adsorbent into the polymer matrix. Meanwhile, spin-casting ensures the formation of a uniform and thin film structure, whereas heat-induced stretching produces a porous matrix with a reduced water contact angle. The adsorbent selectively captures dye molecules, while the porous structure contributes to water permeability. We utilized inexpensive and readily available materials, such as waste polyethylene and calcium carbonate, to fabricate membranes for the removal of methylene blue dye. The effects of various parameters, such as polymer-adsorbent ratio, initial dye concentration, and annealing temperature, were investigated. Equilibrium data were fitted to Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms. The equilibrium data were best represented by the Langmuir isotherm, with maximum adsorption capacity of 35 mg/g and 43 mg/g at 25 °C and 45 °C, respectively. The membranes can be regenerated and recycled with a 97% dye removal efficiency. The study aims to present a template for adsorbent-embedded polymeric membranes for dye removal, in which adsorbent can be tailored to enhance adsorption capacity and efficiency.

4.
Front Microbiol ; 15: 1324099, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38550862

RESUMO

A recent focus has been on the recovery of single-cell protein and other nutritionally valuable bioproducts, such as Coenzyme Q10 (CoQ10) from purple non-sulfur bacteria (PNSB) biomass following wastewater treatment. However, due to PNSB's peculiar cell envelope (e.g., increased membrane cross-section for energy transduction) and relatively smaller cell size compared to well-studied microbial protein sources like yeast and microalgae, the effectiveness of common cell disruption methods for protein quantification from PNSB may differ. Thus, this study examines the efficiency of selected chemical (NaOH and EDTA), mechanical (homogenization and bead milling), physical (thermal and bath/probe sonication), and combined chemical-mechanical/physical treatment techniques on the PNSB cell lysis. PNSB biomass was recovered from the treatment of gas-to-liquid process water. Biomass protein and CoQ10 contents were quantified based on extraction efficiency. Considering single-treatment techniques, bead milling resulted in the best protein yields (p < 0.001), with the other techniques resulting in poor yields. However, the NaOH-assisted sonication (combined chemical/physical treatment technique) resulted in similar protein recovery (p = 1.00) with bead milling, with the former having a better amino acid profile. For example, close to 50% of the amino acids, such as sensitive ones like tryptophan, threonine, cystine, and methionine, were detected in higher concentrations in NaOH-assisted sonication (>10% relative difference) compared to bead-milling due to its less disruptive nature and improved solubility of amino acids in alkaline conditions. Overall, PNSB required more intensive protein extraction techniques than were reported to be effective on other single-cell organisms. NaOH was the preferred chemical for chemical-aided mechanical/physical extraction as EDTA was observed to interfere with the Lowry protein kit, resulting in significantly lower concentrations. However, EDTA was the preferred chemical agent for CoQ10 extraction and quantification. CoQ10 extraction efficiency was also suspected to be adversely influenced by pH and temperature.

5.
Heliyon ; 10(6): e27713, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38524540

RESUMO

Food waste has become a source of concern as it is generated abundantly worldwide and needs to be valorised into new products. In this study, cucumber, tomato, and carrot wastes were investigated as pyrolysis feedstocks as a single component (cucumber), a binary component mixture (cucumber and tomato), and a ternary component blend (cucumber, tomato, and carrot). Fourteen scenarios were simulated and evaluated based on varying the feedstock blend (single, binary, and tertiary), temperature (300 and 500 °C), and feedstock moisture content (5, 20, and 40%). Using an established empirical model, the effect of these parameters on product yields, techno-economic implications, energy requirements, and life cycle analysis (LCA) outcomes were investigated. The best performers of each scenario were determined, and their strengths and weaknesses were identified and compared with other scenarios. In terms of product yields, all three systems (single, binary, and tertiary) followed a similar pattern: bio-oil yields increased as temperature and feedstock moisture content increased, while biochar yields decreased as temperature and feedstock moisture content increased. The production of syngas, on the other hand, was only observed at elevated temperatures. The total energy requirement exhibited an increase with increasing temperature and feedstock moisture content. The economic evaluation revealed that the return on investment (ROI) value for the single component at 5% moisture content at 300 °C is 29%, with a payback period (PB) of only 3.4 years, which is potentially very appealing. The water footprint increased with increasing pyrolysis temperature but decreased with increasing moisture content in all scenarios. The land footprint is observed to remain constant despite changes in process conditions. The study's findings contribute to the pyrolysis process's scalability, technological advancement, and commercialisation.

6.
J Hazard Mater ; 466: 133597, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38310836

RESUMO

The global pollution crisis arising from the accumulation of plastic in landfills and the environment necessitates addressing plastic waste issues. Notably, polypropylene (PP) waste accounts for 20% of total plastic waste and holds promise for hydrophobic applications in the realm of recycling. Herein, the transparent and non-transparent superhydrophobic films made from waste PP are reported. A hierarchical structure with protrusions is induced through spin-casting and thermally induced phase separation. The films had a water contact angle of 159° and could vary in thickness, strength, roughness, and hydrophobicity depending on end-user requirements. The Bode plot indicated enhanced corrosion resistance in the superhydrophobic films. Antibacterial trials with Escherichia coli and Staphylococcus aureus microbial solutions showed that the superhydrophobic film had a significantly lower rate of colony-forming units compared to both the transparent surface and the control blank sample. Moreover, a life cycle assessment revealed that the film production resulted in a 62% lower embodied energy and 34% lower carbon footprint compared to virgin PP pellets sourced from petroleum. These films exhibit distinctiveness with their dual functionality as coatings and freestanding films. Unlike conventional coatings that require chemical application onto the substrate, these films can be mechanically applied using adhesive tapes on a variety of surfaces. Overall, the effective recycling of waste PP into versatile superhydrophobic films not only reduces environmental impact but also paves the way for a more sustainable and eco-friendly future.


Assuntos
Polipropilenos , Staphylococcus aureus , Corrosão , Interações Hidrofóbicas e Hidrofílicas , Tempo (Meteorologia)
7.
Materials (Basel) ; 16(23)2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38068107

RESUMO

The advancement of eco-friendly technology in the construction sector has been improving rapidly in the last few years. As a result, multiple building materials were developed, enhanced, and proposed as replacements for some traditional materials. One notable example presents geopolymer as a substitute for ordinary Portland concrete (OPC). The manufacturing process of (OPC) generates CO2 emissions and a high energy demand, both of which contribute to ozone depletion and global warming. The implementation of geopolymer concrete (GPC) technology in the construction sector provides a path to more sustainable growth and a cleaner environment. This is due to geopolymer concrete's ability to reduce environmental pollutants and reduce the construction industry's carbon footprint. This is achieved through its unique composition, which typically involves industrial byproducts like fly ash or slag. These materials, rich in silicon and aluminum, react with alkaline solutions to form a binding gel, bypassing the need for the high-energy clinker production required in OPC. The use of such byproducts not only reduces CO2 emissions but also contributes to waste minimization. Additionally, geopolymer offers extra advantages compared to OPC, including improved mechanical strength, enhanced durability, and good stability in acidic and alkaline settings. Such properties make GPC particularly suitable for a range of construction environments, from industrial applications to infrastructure projects exposed to harsh conditions. This paper comprehensively reviews the different characteristics of geopolymers, which include their composition, compressive strength, durability, and curing methods. Furthermore, the environmental impacts related to the manufacturing of geopolymer materials were evaluated through the life-cycle assessment method. The result demonstrated that geopolymer concrete maintains positive environmental impacts due to the fact that it produces fewer carbon dioxide CO2 emissions compared to OPC concrete during its manufacturing; however, geopolymer concrete had some minor negative environmental impacts, including abiotic depletion, human toxicity, freshwater ecotoxicity, terrestrial ecotoxicity, and acidification. These are important considerations for ongoing research aimed at further improving the sustainability of geopolymer concrete. Moreover, it was determined that silicate content, curing temperature, and the proportion of alkaline solution to binder are the major factors significantly influencing the compressive strength of geopolymer concrete. The advancement of geopolymer technology represents not just a stride toward more sustainable construction practices but also paves the way for innovative approaches in the field of building materials.

8.
Cells ; 12(23)2023 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-38067110

RESUMO

Targeting tumour metabolism through glucose transporters is an attractive approach. However, the role these transporters play through interaction with other signalling proteins is not yet defined. The glucose transporter SLC2A3 (GLUT3) is a member of the solute carrier transporter proteins. GLUT3 has a high affinity for D-glucose and regulates glucose uptake in the neurons, as well as other tissues. Herein, we show that GLUT3 is involved in the uptake of arsenite, and its level is regulated by peroxiredoxin 1 (PRDX1). In the absence of PRDX1, GLUT3 mRNA and protein expression levels are low, but they are increased upon arsenite treatment, correlating with an increased uptake of glucose. The downregulation of GLUT3 by siRNA or deletion of the gene by CRISPR cas-9 confers resistance to arsenite. Additionally, the overexpression of GLUT3 sensitises the cells to arsenite. We further show that GLUT3 interacts with PRDX1, and it forms nuclear foci, which are redistributed upon arsenite exposure, as revealed by immunofluorescence analysis. We propose that GLUT3 plays a role in mediating the uptake of arsenite into cells, and its homeostatic and redox states are tightly regulated by PRDX1. As such, GLUT3 and PRDX1 are likely to be novel targets for arsenite-based cancer therapy.


Assuntos
Arsenitos , Transportador de Glucose Tipo 3 , Arsenitos/toxicidade , Glucose/metabolismo , Transportador de Glucose Tipo 3/genética , Transportador de Glucose Tipo 3/metabolismo , Linfócitos Nulos/efeitos dos fármacos , Linfócitos Nulos/metabolismo , Peroxirredoxinas/metabolismo , Humanos , Células HEK293
9.
Molecules ; 28(18)2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37764337

RESUMO

Natural product waste treatment and the removal of harmful dyes from water by adsorption are two of the crucial environmental issues at present. Traditional adsorbents are often not capable in removing detrimental dyes from wastewater due to their hydrophilic nature and because they form strong bonds with water molecules, and therefore they remain in the dissolved state in water. Consequently, new and effective sorbents are required to reduce the cost of wastewater treatment as well as to mitigate the health problems caused by water pollution contaminants. In this study, the adsorption behaviour of methyl orange, MO, dye on chitosan bead-like materials was investigated as a function of shaking time, contact time, adsorbent dosage, initial MO concentration, temperature and solution pH. The structural and chemical properties of chitosan bead-like materials were studied using several techniques including SEM, BET, XRD and FTIR. The adsorption process of methyl orange by chitosan bead materials was well described by the Langmuir isotherm model for the uptake capacity and followed by the pseudo-second-order kinetic model to describe the rate processes. Under the optimal conditions, the maximum removal rate (98.9%) and adsorption capacity (12.46 mg/g) of chitosan bead-like materials were higher than those of other previous reports; their removal rate for methyl orange was still up to 87.2% after three regenerative cycles. Hence, this chitosan bead-like materials are very promising materials for wastewater treatment.

10.
Sci Rep ; 13(1): 14163, 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37644209

RESUMO

Sorbent pads and films have been commonly used for environmental remediation purposes, but designing their internal structure to optimize access to the entire volume while ensuring cost-effectiveness, ease of fabrication, sufficient strength, and reusability remains challenging. Herein, we report a trimodal sorbent film from recycled polypropylene (PP) with micropores, macro-voids, and sponge-like 3D cavities, developed through selective dissolution, thermally induced phase separation, and annealing. The sorbent has hundreds of cavities per cm2 that are capable of swelling up to twenty-five times its thickness, allowing for super-fast saturation kinetics (within 30 s) and maximum oil sorption (97 g/g). The sorption mechanism follows a pseudo-second-order kinetic model. Moreover, the sorbent is easily compressible, and its structure is retained during oil sorption, desorption, and resorption, resulting in 96.5% reuse efficiency. The oil recovery process involves manually squeezing the film, making the cleanup process efficient with no chemical treatment required. The sorbent film possesses high porosity for effective sorption with sufficient tensile strength for practical applications. Our integrated technique results in a strengthened porous polymeric structure that can be tailored according to end-use applications. This study provides a sustainable solution for waste management that offers versatility in its functionality.

11.
Environ Technol ; : 1-11, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37585599

RESUMO

Qatar's population has been rapidly increasing in recent years, and the country's long-term vision, QNV 2030, aims to sustain this growth by transforming the country into a sustainable state. One aspect of this vision is to convert waste into value-added products, which will reduce the environmental and spatial burden associated with waste in Qatar, while contributing to a circular economy. This study describes methods for producing biochar and activated carbon (AC) from gas-to-liquids derived biosolids, cardboard waste and mixed samples using pyrolysis and activation techniques. The characterisation of products revealed that the yield of biochar samples was higher than AC, and that the pH of the biochar samples was more alkaline than the feed samples due to metals after pyrolysis and reduced acid surface functional groups. Proximate analysis of samples showed lowered moisture and enhanced ash in feeds upon pyrolysis and activation due to increased temperature with reduced volatile content. AC application to water treatment is considered a potential benefit due to the increased surface area, pore volume and magnetic properties based on the Brunauer-Emmett-Teller (BET) and X-ray Powder Diffraction (XRD) analysis. The X-ray photoelectron spectroscopy (XPS) analysis also showed increased -CO3/O-C = O and potassium in the ACs as a result of potassium carbonate activation. The study proposes various applications that can support a circular economy, but future studies should investigate actual applications and potential health and environmental effects and evaluate the feasibility and environmental impact of production methods.

12.
Int J Mol Sci ; 24(15)2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37569746

RESUMO

The use of Polypropylene PP in disposable items such as face masks, gloves, and personal protective equipment has increased exponentially during and after the COVID-19 pandemic, contributing significantly to microplastics and nanoplastics in the environment. Upcycling of waste PP provides a useful alternative to traditional thermal and mechanical recycling techniques. It transforms waste PP into useful products, minimizing its impact on the environment. Herein, we synthesized an oil-sorbent pouch using waste PP, which comprises superposed microporous and fibrous thin films of PP using spin coating. The pouch exhibited super-fast uptake kinetics and reached its saturation in fewer than five minutes with a high oil uptake value of 85 g/g. Moreover, it displayed high reusability and was found to be effective in absorbing oil up to seven times when mechanically squeezed between each cycle, demonstrating robust oil-sorption capabilities. This approach offers a potential solution for managing plastic waste while promoting a circular economy.


Assuntos
COVID-19 , Plásticos , Humanos , Polipropilenos , Máscaras , Pandemias , COVID-19/prevenção & controle
13.
Polymers (Basel) ; 15(14)2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37514461

RESUMO

Mixed polyolefin-based waste needs urgent attention to mitigate its negative impact on the environment. The separation of these plastics requires energy-intensive processes due to their similar densities. Additionally, these materials cannot be blended without compatibilizers, as they are inherently incompatible and immiscible. Herein, non-wettable microporous sheets from recycled polyethylene (PE) and polypropylene (PP) are presented. The methodology involves the application of phase separation and spin-casting techniques to obtain a bimodal porous structure, facilitating efficient oil-water separation. The resulting sheets have an immediate and equilibrium sorption uptake of 100 and 55 g/g, respectively, due to the presence of micro- and macro-pores, as revealed by SEM. Moreover, sheets possess enhanced crystallinity, as evidenced by XRD; hence, they retain their structure during sorption and desorption and are reusable with 98% efficiency. The anti-wetting properties of the sheets are enhanced by applying a silane coating, ensuring waterless sorption and a contact angle of 140°. These results highlight the importance of implementing sustainable solutions to recycle plastics and mitigate the oil spill problem.

14.
J Hazard Mater ; 453: 131356, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37084516

RESUMO

Environmental pollution caused by plastic waste and oil spills has emerged as a major concern in recent years. Consequently, there has been a growing interest in exploring innovative solutions to address these challenges. Herein, we report a method to upcycle polyolefins-based plastic waste by converting it into a bimodal super-oleophilic sorbent using dissolution, spin-coating, and annealing techniques. The resulting sorbent possesses an extensive network of pores and cavities with a size range from 0.5 to 5 µm and 150-200 µm, respectively, with an average of 600 cavities per cm2. Each cavity can swell up to twenty times the thickness of the sorbent, exhibiting sponge-like behavior. The sorbent had an oil uptake capacity of 70-140 g/g, depending on the type of sorbate and dripping time. Moreover, the sorbent can be mechanically or manually squeezed to recover the sorbed oil. Our integrated methodology provides a promising approach to upcycling plastic waste as an abundant source of value-added materials.

15.
Molecules ; 28(5)2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36903559

RESUMO

Py-GC/MS combines pyrolysis with analytical tools of gas chromatography (GC) and mass spectrometry (MS) and is a quick and highly effective method to analyse the volatiles generated from small amounts of feeds. The review focuses on using zeolites and other catalysts in the fast co-pyrolysis of various feedstocks, including biomass wastes (plants and animals) and municipal waste materials, to improve the yield of specific volatile products. The utilisation of zeolite catalysts, including HZSM-5 and nMFI, results in a synergistic reduction of oxygen and an increase in the hydrocarbon content of pyrolysis products. The literature works also indicate HZSM-5 produced the most bio-oil and had the least coke deposition among the zeolites tested. Other catalysts, such as metals and metal oxides, and feedstocks that act as catalysts (self-catalysis), such as red mud and oil shale, are also discussed in the review. Combining catalysts, such as metal oxides and HZSM-5, further improves the yields of aromatics during co-pyrolysis. The review highlights the need for further research on the kinetics of the processes, optimisation of feed-to-catalyst ratios, and stability of catalysts and products.

16.
Molecules ; 28(3)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36771176

RESUMO

Global waste production is significantly rising with the increase in population. Efforts are being made to utilize waste in meaningful ways and increase its economic value. This research makes one such effort by utilizing gas-to-liquid (GTL)-derived biosolids, a significant waste produced from the wastewater treatment process. To understand the surface properties, the biosolid waste (BS) that is activated directly using potassium carbonate, labelled as KBS, has been characterized using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), and Brunauer-Emmett-Teller (BET). The characterization shows that the surface area of BS increased from 0.010 to 156 m2/g upon activation. The EDS and XPS results show an increase in the metal content after activation (especially iron); additionally, XRD revealed the presence of magnetite and potassium iron oxide upon activation. Furthermore, the magnetic field was recorded to be 0.1 mT using a tesla meter. The magnetic properties present in the activated carbon show potential for pollutant removal. Adsorption studies of methylene blue using KBS show a maximum adsorption capacity of 59.27 mg/g; the adsorption process is rapid and reaches equilibrium after 9 h. Modelling using seven different isotherm and kinetic models reveals the best fit for the Langmuir-Freundlich and Diffusion-chemisorptionmodels, respectively. Additional thermodynamic calculations conclude the adsorption system to be exothermic, spontaneous, and favoring physisorption.

17.
Environ Res ; 225: 115534, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-36841521

RESUMO

Ongoing global population boom has led to the rise in waste and related research on increasing its economic value. In such an attempt, this study aims to activate gas-to-liquids (GTL) derived biosolids (BS) and cardboard (CB) and mixed samples (50:50) using potassium carbonate to produce three activated carbons (ACs): KBS, KCB and KM respectively. The characterization of the samples revealed surface areas of 156, 515, and 527 m2/g for KBS, KCB, and KM, respectively based on Brunauer-Emmett-Teller (BET) analysis, with increased porosity and metal content after activation evident from the Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) results, as well as the presence of magnetite in the KBS and KM samples apparent from the X-ray powder diffraction (XRD) results. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) results indicate increased C-O-C stretches and O-H bonds after activation of the samples. The ACs were used for methylene blue (MB) removal process which is a rapid for all three samples, reaching equilibrium after 9 h, and optimal at neutral pH and maximum at the highest temperature, 40 °C. The MB adsorption capacity was highest for KM (191.07 mg/g), followed by the KCB and KBS samples. Isotherm modelling of the samples showed best fits for KBS, KCB and KM as Langmuir-Freundlich (LF), Langmuir and Toth models respectively. On the contrary, kinetic modelling using contact time study data for all samples exhibited best fits by the Diffusion-chemisorption (DC) model. Finally, the thermodynamic calculations of the mixed sample disclosed the adsorption process to be exothermic and spontaneous, with potential mechanisms being electrostatic attraction, ion exchange, π-π interactions, and hydrogen bonding. Multiple cycles of KM regeneration was also achieved with good adsorption capacities. Future work will explore other activation methods and examine the magnetic properties of KBS and KM for real water treatment.


Assuntos
Azul de Metileno , Poluentes Químicos da Água , Azul de Metileno/química , Biossólidos , Adsorção , Poluentes Químicos da Água/análise , Termodinâmica , Carvão Vegetal , Cinética , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Polymers (Basel) ; 16(1)2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38201800

RESUMO

Recycling low-end, one-time-use plastics-such as low-density polyethylene (LDPE)-is of paramount importance to combat plastic pollution and promote sustainability in the modern green economy. This study valorizes LDPE waste by transforming it into 3D oleophilic swellable thin films through a process involving dissolution, phase separation, and extraction. These films are subsequently layered using a customized polypropylene (PP) based nonwoven fabric separator and securely sealed in a zigzag pattern. The zigzag-shaped seal enhances the adhesion of pollutants to the sorbent by providing wire curvatures that increase retention time and uptake capacity. As a result, the sorbent exhibits impressive oil uptake capacities, with immediate and equilibrium values of 120 g/g and 85 g/g, respectively. Notably, the as-prepared sorbent demonstrates low water retention and high selectivity for oil, outperforming commercially available oil sorbents. The unique design involving a 3D-film structure, superposed films, and a zigzag-shaped seal offers a sustainable and value-added solution to the issues of LDPE waste and oil spills on water surfaces.

19.
Polymers (Basel) ; 14(22)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36432992

RESUMO

Plastic waste comprises 15% of the total municipal solid waste and can be a rich source for producing value-added materials. Among them, polyethylene (PE) and polypropylene (PP) account for 60% of the total plastic waste, mainly due to their low-end and one-time-use applications. Herein, we report reusable oil sorbent films made by upcycling waste PE and PP. The as-prepared oil sorbent had an uptake capacity of 55 g/g. SEM analysis revealed a macroporous structure with a pore size range of 1-10 µm, which facilitates oil sorption. Similarly, the contact angle values reflected the oleophilic nature of the sorbent. Moreover, thermal properties and crystallinity were examined using DSC, while mechanical properties were calculated using tensile testing. Lastly, 95% of the sorbed oil could be easily recovered by squeezing mechanically or manually.

20.
J Environ Manage ; 323: 116223, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36261981

RESUMO

Jatropha curcas L. (JCL) is one of the most prominent energy crops due to its superior agronomical traits, where it can grow in non-arable lands and harsh climates with minimal water requirements. A significant number of studies were published on the utilisation of JCL for biofuel production, whereas there are no studies on its use in greenbelt (GB) or windbreak technologies reported thus far. Meanwhile, a few approaches on the delineation of greenbelts to fight desertification in the arid regions exist in literature. This study presents a novel approach to delineate a multipurpose energy-greenbelt using JCL crop for biofuel production, as well as to preserve the soil and enhance air quality, thereby helping to combat desertification and sand-dust storms (SDS). The methodology is demonstrated using a case study in the state of Qatar for the diversification of its renewable energy resources. Moreover, Qatar is also suffering from land degradation due to erosion factors and desert creep. A multi-dimensional approach is proposed for this purpose using satellite and meteorological data to initially select the optimal plantation sites that potentially contribute to the highest possible biofuel yield. The spatial analysis was carried out using the analytical hierarchy process (AHP) technique for multi-criteria decision making in the geographic information system (ArcGIS). In addition, the Landsat and MODIS satellite imagery were utilised in combination with historical records from the weather stations to evaluate the patterns of SDS, land degradation and urban expansion, to best define optimal GB pathway. COMSOL Multiphysics software was subsequently employed to evaluate the performance of Jatropha-GB and determine its optimal density. The different solutions for GB delineation spans 166.6-227.8 km length and (6 × 6 m) of field density. It is expected that the economic and environmental benefits from the derived GB configuration include: (a) protection of up to 87% of Qatar farms against further deterioration; (b) yield of up to 36 M gallon of green liquid fuels; (c) capture of 0.33 M tonnes of CO2 per 1 km GB-depth annually; and (d) provide a better air quality for around 95% of the Qatar population.


Assuntos
Biocombustíveis , Jatropha , Conservação dos Recursos Naturais , Areia , Dióxido de Carbono , Clima Desértico , Solo , Poeira , Água
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