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1.
Front Chem ; 12: 1404107, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38873404

RESUMO

This study explores the innovative application of iron filings solid waste, a byproduct from mechanical workshops, as a heterogeneous catalyst in the production of biodiesel from waste cooking oil. Focusing on sustainability and waste valorization, the research presents a dual-benefit approach: addressing the environmental issue of solid waste disposal while contributing to the renewable energy sector. Particle size distribution analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence (XRF), Thermal analysis (TG-DTA), and FTIR analysis were used to characterize the iron filings. The response surface methodology (RSM) was used to guide a series of experiments that were conducted to identify the optimum transesterification settings. Important factors that greatly affect the production of biodiesel are identified by the study, including catalyst loading, reaction time, methanol-to-oil ratio, reaction temperature, and stirring rate. The catalyst proved to be successful as evidenced by the 96.4% biodiesel conversion efficiency attained under ideal conditions. The iron filings catalyst's reusability was evaluated, demonstrating its potential for numerous applications without noticeably decreasing activity. This work offers a road towards more environmentally friendly and sustainable chemical processes in energy production by making a strong argument for using industrial solid waste as a catalyst in the biodiesel manufacturing process.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38943002

RESUMO

Efficient catalysts play a pivotal role in advancing eco-friendly water treatment strategies, particularly in the removal of diverse organic contaminants found in water-petroleum sources. This study addresses the multifaceted challenges posed by contaminants, encompassing a spectrum of heavy metals such as As, Cd, Cr, Mn, Mo, Ni, Pb, Sb, Se, and Zn alongside pollutants like oily water (OIW), total suspended solids (TSS), chemical oxygen demand (COD), dyes, and pharmaceuticals, posing threats to both aquatic and terrestrial ecosystems. Herein, we present the synthesis of biogenically derived Mn@NiO nanocomposite (NC) photocatalysts, a sustainable methodology employing an aqueous Rosmarinus officinalis L. extract, yielding particles with a size of 36.7 nm. The catalyst demonstrates exceptional efficacy in removing heavy metals, achieving rates exceeding 99-100% within 30 min, alongside notable removal efficiencies for OIW (98%), TSS (87%), and COD (98%). Furthermore, our photodegradation experiments showed remarkable efficiencies, with 94% degradation for Rose Bengal (RB) and 96% for methylene blue (MB) within 120 min. The degradation kinetics adhere to pseudo-first-order behavior, with rate constants of 0.0227 min-1 for RB and 0.0370 min-1 for MB. Additionally, the NC exhibits significant antibiotic degradation rates of 97% for cephalexin (CEX) and 96% for amoxicillin (AMOX). The enhanced photocatalytic performance is attributed to the synergistic interplay between the Mn and NiO nanostructures, augmenting responsiveness to sunlight while mitigating electron-hole pair recombination. Notably, the catalyst demonstrates outstanding stability and reusability across multiple cycles, maintaining its stable nanostructure without compromise.

3.
Sci Total Environ ; 930: 172794, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38677421

RESUMO

The rapid urbanization witnessed in developing countries in Asia and Africa has led to a substantial increase in municipal solid waste (MSW) generation. However, the corresponding disposal strategies, along with constraints in land resources and finances, compounded by unorganized public behaviour, have resulted in ineffective policy implementation and monitoring. This lack of systematic and targeted orientation, combined with blind mapping, has led to inefficient development in many areas. This review examines the key challenges of MSW management in developing countries in Asia and Africa from 2013 to 2023, drawing insights from 170 academic papers. Rather than solely focusing on recycling, the study proposes waste sorting at the source, optimization of landfill practices, thermal treatment measures, and strategies to capitalize on the value of waste as more pertinent solutions aligned with local realities. Barriers to optimizing management systems arise from socio-economic factors, infrastructural limitations, and cultural considerations. The review emphasizes the importance of integrating the study area into the circular economy framework, with a focus on enhancing citizen participation in solid waste reduction and promoting recycling initiatives, along with seeking economic assistance from international organizations.

4.
ACS Omega ; 9(5): 5100-5126, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38343989

RESUMO

Mercury is a type of hazardous and toxic pollutant that can result in detrimental effects on the environment and human health. This review is aimed at discussing the state-of-the-art progress on the recent developments on the toxicity of mercury and its chemical compounds. More than 210 recent works of literature are covered in this review. It first delineates the types (covering elemental mercury, inorganic mercury compounds, organic mercury compounds), structures, and sources of mercury. It then discusses the pharmacokinetic profile of mercury, molecular mechanisms of mercury toxicity, and clinical manifestation of acute and chronic mercury toxicity to public health. It also elucidates the mercury toxicity to the environment and human health in detail, covering ecotoxicity, neurotoxicity diseases, neurological diseases, genotoxicity and gene regulation, immunogenicity, pregnancy and reproductive system damage, cancer promotion, cardiotoxicity, pulmonary diseases, and renal disease. In order to mitigate the adverse effects of mercury, strategies to overcome mercury toxicity are recommended. Finally, some future perspectives are provided in order to advance this field of research in the future.

5.
ACS Omega ; 9(1): 1962-1976, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38222655

RESUMO

This study focuses on upcycling cement kiln dust (CKD) as an industrial waste by utilizing the undissolved portion (UNP) as a multicomponent catalyst for bioethylene production from bioethanol, offering an environmentally sustainable solution. To maximize UNP utilization, CKD was dissolved in nitric acid, followed by calcination at 500 °C for 3 h in an oxygen atmosphere. Various characterization techniques confirmed that UNP comprises five different compounds with nanocrystalline particles exhibiting an average crystal size of 47.53 nm. The UNP catalyst exhibited a promising bioethylene yield (77.1%) and selectivity (92%) at 400 °C, showcasing its effectiveness in converting bioethanol to bioethylene with outstanding properties. This exceptional performance can be attributed to its distinctive structural characteristics, including a high surface area and multiple-strength acidic sites that facilitate the reaction mechanism. Moreover, the UNP catalyst displayed remarkable stability and durability, positioning it as a strong candidate for industrial applications in bioethylene production. This research underscores the importance of waste reduction in the cement industry and offers a sustainable path toward a greener future.

6.
Arch Gynecol Obstet ; 309(1): 183-193, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-36708424

RESUMO

PURPOSE: Dietary micronutrient intakes of iron, folate and vitamin B12 are known to influence hemoglobin. Low maternal hemoglobin (maternal anemia) has been linked to low birthweight and other adverse health outcomes in the fetus and infant. Our primary aim was to explore relationships between maternal dietary micronutrient intakes, maternal full blood count (FBC) parameters and fetal abdominal circumference (AC) and estimated fetal weight (EFW) growth trajectories. Secondarily, we aimed to assess relationships between maternal dietary micronutrient intakes, maternal hemoglobin values and placental weight and birthweight. METHODS: Mother-child pairs (n = 759) recruited for the ROLO study were included in this analysis. Maternal dietary micronutrient intakes were calculated from food diaries completed during each trimester of pregnancy. FBC samples were collected at 13- and 28-weeks' gestation. Fetal ultrasound measurements were recorded at 20- and 34-weeks' gestation. Growth trajectories for AC and EFW were estimated using latent class trajectory mixture models. RESULTS: Dietary intakes of iron and folate were deficient for all trimesters. Mean maternal hemoglobin levels were replete at 13- and 28-weeks' gestation. Dietary iron, folate and vitamin B12 intakes showed no associations with fetal growth trajectories, placental weight or birthweight. Lower maternal hemoglobin concentrations at 28 weeks' gestation were associated with faster rates of fetal growth and larger placental weights and birthweights. CONCLUSION: The negative association between maternal hemoglobin at 28 weeks' gestation and accelerated fetal and placental growth may be due to greater consumption of maternal iron and hemoglobin by fetuses' on faster growth trajectories in addition to placental biochemical responses to lower oxygen states.


Assuntos
Ácido Fólico , Ferro , Gravidez , Feminino , Humanos , Peso ao Nascer , Estudos de Coortes , Vitamina B 12 , Placenta , Desenvolvimento Fetal , Idade Gestacional , Hemoglobinas , Ingestão de Alimentos
7.
Ir J Med Sci ; 193(2): 921-925, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37733225

RESUMO

BACKGROUND: Seven per cent of general waste and 20% of healthcare risk waste produced in acute hospitals in Ireland comes from operating theatres. Surgical wrap comprises 11% of operating theatre waste. AIMS: The primary aim of this study was to pilot the implementation of a recycling initiative for surgical instrument set wrap in an operating theatre in Ireland. Secondary aims included quantification of the surgical wrap diverted from general waste to recycling streams over a 5-week period and estimation of the annual carbon emissions associated with gynaecology surgical wrap use in Cork. METHODS: The amount of polypropylene surgical wrap generated by a single gynaecology theatre at Cork University Maternity Hospital was prospectively quantified from 24/1/22 to 1/3/22. At the end of the study period, individual sheets of polypropylene wrap were counted and dimensions were measured to calculate the total surface area of surgical wrap saved for recycling. RESULTS: A total of 66 surgeries were performed over the 5-week study period. Two hundred twenty-one individual sheets of surgical wrap were collected, equating to 282.1 m2 of polypropylene wrap. An estimated 11,564 m2 of surgical wrap could be recycled annually from the gynaecology theatre service in Cork with an associated annual carbon emissions equivalent of at least 2.2 tonnes of CO2. CONCLUSION: Diversion of surgical wrap from general waste and clinical waste streams to the recycling stream is achievable in every operating theatre. Small changes to operating theatre waste disposal practices have the potential to yield significant reductions to theatre waste outputs and to hospital carbon emissions.


Assuntos
Polipropilenos , Reciclagem , Feminino , Gravidez , Humanos , Reciclagem/métodos , Salas Cirúrgicas , Hospitais Universitários , Carbono , Instrumentos Cirúrgicos
8.
Sci Rep ; 13(1): 11282, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37438448

RESUMO

Biomass waste streams are a possible feedstock for a range of eco-friendly products and a crucial alternative energy source for achieving carbon neutrality; therefore, the efficient management of biomass waste has taken on a greater significance in recent years. Due to its well-comparable physic-chemical properties with fossil diesel, biodiesel is a potential substitute for fossil fuel. This study aimed to synthesize biodiesel from the widely available non-edible seed oil of Sisymbrium irio L. (a member of the Brassicaceae family) via a transesterification procedure over a homemade TiO2 catalyst. At 1:16 oil to methanol ratio, 93% biodiesel yield was obtained over 20 mg catalyst at 60 °C and 60 min. The ASTM methods were used to analyze the fuel properties. The quantitative and qualitative analysis was performed by FT-IR, GC-MS, and NMR spectroscopy. GC-MS study confirms 16 different types of fatty acids of methyl esters. FT-IR analysis showed important peaks that confirm the successful occurrence of biodiesel. 1H-NMR and 13C-NMR showed important peaks for converting triglycerides into corresponding FAMEs. The acid value (0.42 mg KOH/mg/kg), flash point (106 °C), and water content (0.034) of biodiesel are below the specified limit of ASTM D6751 whereas kinetic viscosity (3.72 mm2/s), density (0.874 kg/L), cloud point (- 4.3 °C) and pour point (- 9.6 °C) and high heating value (41.62 MJ/kg) fall within the specified range of ASTM D6751 test limit. The Unsaturation degree and oxidative stability of biodiesel are above ASTM D6751 test limit. The physic-chemical properties of the SIB confirm that it is eco-friendly fuel and a competitive source for manufacturing biodiesel on a commercial scale. Furthermore, the SIB is engine friendly and has good fuel efficacy.


Assuntos
Biocombustíveis , Brassicaceae , Biomassa , Catálise , Ésteres/química , Ácidos Graxos/química , Triglicerídeos/química
9.
Int J Biol Macromol ; 247: 125839, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37454997

RESUMO

Anthocyanins are potential bioactive compounds with less bioavailability due to instability in physicochemical and physiological harsh environments. This study synthesized a "nanolipo-fibersomes (NLFS)" using Lipoid® S75 and Nutriose® FB 06 (dextrinization of wheat starch) through a self-assembly technique with probe sonication. We aimed to encapsulate delphinidin-3-O-sambubioside (D3S) successfully and evaluate physicochemical and controlled release properties with improved antioxidant activity on palmitic acid (PA)-induced colonic cells (Caco-2 cells). D3S-loaded nanolipo-fibersomes (D3S-NLFS) were nanosized (<150 nm), spherical shaped, and homogenously dispersed in solution with promising encapsulation efficiency (~ 89.31 to 97.31 %). Particles formation was further verified by FTIR. NLFS were well-stable in thermal, storage, and gastrointestinal mimic environments. NLFS exhibited better-controlled release and mucoadhesive properties compared to nanoliposomes (NL). The NLFS showed better cellular uptake than NL, which was correlated to higher mucoadhesive properties. Furthermore, D3S-NLFS exhibited promising protective effects against PA-induced cytotoxicity, O2•- radicals generation, mitochondrial dysfunctions, and GSH depletion, while the free D3S was ineffective. Among D3S-loaded nanoparticles, D3S-NLFS 3 was the most efficient nanocarrier followed by D3S-NLFS 2, D3S-NLFS 1, and D3S-NL, respectively. The above data suggest that nanolipo-fibersomes can be considered as promising nanovesicles for improving colonic delivery of hydrophilic compounds with controlled release properties and greater antioxidant activity.


Assuntos
Antocianinas , Antioxidantes , Humanos , Antocianinas/farmacologia , Antocianinas/química , Antioxidantes/farmacologia , Preparações de Ação Retardada/farmacologia , Células CACO-2
10.
J Environ Manage ; 345: 118449, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37390731

RESUMO

Mechanical separation of anaerobic digestate has been identified as a method to reduce pollution risk to waterways by partitioning phosphorus in the solid fraction and reducing its application to land. Separators have adjustable parameters which affect separation efficiency, and hence the degree of phosphorous partitioning, but information on how these parameters affect separation performance is limited in the literature. Two well known technologies were investigated, decanter centrifuge and screw press, to determine the most efficient method of separation. Counterweight load and the use of an oscillator were adjusted for the screw press, while bowl speed, auger differential speed, feed rate and polymer addition were modified for the decanter centrifuge. Separation efficiency was determined for total solids, phosphorus, nitrogen, potassium, and carbon, and the total solids content of resulting fractions was measured. The decanter centrifuge had higher separation efficiency for phosphorus in all cases, ranging from 51% to 71.5%, while the screw press had a phosphorus separation efficiency ranging from 8.5% to 10.9% for digestate of ∼5% solids (slurry/grass silage mix). Separation by decanter centrifuge partitioned up to 56% of nitrogen in the solid fraction leaving a reduced nitrogen content in the liquid fraction available for land spreading; this nitrogen would most likely need to be replaced by chemical fertiliser which would add to the cost of the system. The decanter centrifuge is better suited to cases where phosphorus recovery is the most important factor, while the screw press could be advantageous in cases where cost is a limiting factor.


Assuntos
Poluição Ambiental , Nitrogênio , Anaerobiose , Nitrogênio/análise , Esterco , Fósforo/química
11.
Environ Sci Pollut Res Int ; 30(34): 82387-82405, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37326738

RESUMO

This research aims to remove two phenothiazines, promazine (PRO) and promethazine (PMT), from their individual and binary mixtures using olive tree pruning biochar (BC-OTPR). The impact of individual and combinatory effects of operational variables was evaluated for the first time using central composite design (CCD). Simultaneous removal of both drugs was maximized utilizing the composite desirability function. At low concentrations, the uptake of PRO and PMT from their individual solutions was achieved with high efficiency of 98.64%, 47.20 mg/g and 95.87%, 38.16 mg/g, respectively. No major differences in the removal capacity were observed for the binary mixtures. Characterization of BC-OTPR confirmed successful adsorption and showed that the OTPR surface was predominantly mesoporous. Equilibrium investigations revealed that the Langmuir isotherm model best describes the sorption of PRO/PMT from their individual solutions with maximum adsorption capacities of 640.7 and 346.95 mg/g, respectively. The sorption of PRO/PMT conforms to the pseudo-second-order kinetic model. Regeneration of the adsorbent surface was successfully done with desorption efficiencies of 94.06% and 98.54% for PRO and PMT, respectively, for six cycles.


Assuntos
Olea , Poluentes Químicos da Água , Águas Residuárias , Prometazina , Promazina , Cinética , Adsorção , Carvão Vegetal , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio
12.
Environ Chem Lett ; : 1-37, 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37362011

RESUMO

New technologies, systems, societal organization and policies for energy saving are urgently needed in the context of accelerated climate change, the Ukraine conflict and the past coronavirus disease 2019 pandemic. For instance, concerns about market and policy responses that could lead to new lock-ins, such as investing in liquefied natural gas infrastructure and using all available fossil fuels to compensate for Russian gas supply cuts, may hinder decarbonization efforts. Here we review energy-saving solutions with a focus on the actual energy crisis, green alternatives to fossil fuel heating, energy saving in buildings and transportation, artificial intelligence for sustainable energy, and implications for the environment and society. Green alternatives include biomass boilers and stoves, hybrid heat pumps, geothermal heating, solar thermal systems, solar photovoltaics systems into electric boilers, compressed natural gas and hydrogen. We also detail case studies in Germany which is planning a 100% renewable energy switch by 2050 and developing the storage of compressed air in China, with emphasis on technical and economic aspects. The global energy consumption in 2020 was 30.01% for the industry, 26.18% for transport, and 22.08% for residential sectors. 10-40% of energy consumption can be reduced using renewable energy sources, passive design strategies, smart grid analytics, energy-efficient building systems, and intelligent energy monitoring. Electric vehicles offer the highest cost-per-kilometer reduction of 75% and the lowest energy loss of 33%, yet battery-related issues, cost, and weight are challenging. 5-30% of energy can be saved using automated and networked vehicles. Artificial intelligence shows a huge potential in energy saving by improving weather forecasting and machine maintenance and enabling connectivity across homes, workplaces, and transportation. For instance, 18.97-42.60% of energy consumption can be reduced in buildings through deep neural networking. In the electricity sector, artificial intelligence can automate power generation, distribution, and transmission operations, balance the grid without human intervention, enable lightning-speed trading and arbitrage decisions at scale, and eliminate the need for manual adjustments by end-users.

13.
Environ Chem Lett ; : 1-31, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37362015

RESUMO

The rising amount of waste generated worldwide is inducing issues of pollution, waste management, and recycling, calling for new strategies to improve the waste ecosystem, such as the use of artificial intelligence. Here, we review the application of artificial intelligence in waste-to-energy, smart bins, waste-sorting robots, waste generation models, waste monitoring and tracking, plastic pyrolysis, distinguishing fossil and modern materials, logistics, disposal, illegal dumping, resource recovery, smart cities, process efficiency, cost savings, and improving public health. Using artificial intelligence in waste logistics can reduce transportation distance by up to 36.8%, cost savings by up to 13.35%, and time savings by up to 28.22%. Artificial intelligence allows for identifying and sorting waste with an accuracy ranging from 72.8 to 99.95%. Artificial intelligence combined with chemical analysis improves waste pyrolysis, carbon emission estimation, and energy conversion. We also explain how efficiency can be increased and costs can be reduced by artificial intelligence in waste management systems for smart cities.

14.
Ultrason Sonochem ; 95: 106405, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37084535

RESUMO

Hydrodynamic Cavitation (HC) offers an attractive platform for intensifying oxidative desulphurization of fuels. In the first part of this work, we present new results on oxidising single ring thiophene in a model fuel over the extended range of volume fraction of organic phase from 2.5 to 80 v/v %. We also present influence of type and scale of HC device on performance of oxidative desulphurization. Further experiments revealed that oxidising radicals generated in-situ by HC alone were not able to oxidise dual ring thiophenes. External catalyst (formic acid) and oxidising agents (hydrogen peroxide, H2O2) were therefore used with HC. Based on our prior work with acoustic cavitation (AC), the volumetric ratios for H2O2 and formic acid were identified as 0.95 v/v % and 6.25 v/v % respectively. The data of oxidation of dual ring thiophenes with n-dodecane and n-hexane as model fuels and typical transport fuels (diesel, kerosene, and petrol) using these oxidant and catalyst is presented. The observed performance with HC was compared with results obtained from a stirred tank and AC set-up. The presented data indicates that HC is able to intensify oxidation of sulphur species. The presented results provide a sound basis for further developments on HC based oxidative desulphurization processes.

15.
Org Process Res Dev ; 27(2): 262-268, 2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36844035

RESUMO

Epoxidation of alkenes is a valuable transformation in the synthesis of fine chemicals. Described herein are the design and development of a continuous flow process for carrying out the epoxidation of alkenes with a homogeneous manganese catalyst at metal loadings as low as 0.05 mol%. In this process, peracetic acid is generated in situ and telescoped directly into the epoxidation reaction, thus reducing the risks associated with its handling and storage, which often limit its use at scale. This flow process lessens the safety hazards associated with both the exothermicity of this epoxidation reaction and the use of the highly reactive peracetic acid. Controlling the speciation of manganese/2-picolinic acid mixtures by varying the ligand:manganese ratio was key to the success of the reaction. This continuous flow process offers an inexpensive, sustainable, and scalable route to epoxides.

16.
Environ Chem Lett ; 21(1): 447-477, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36161092

RESUMO

Metal-organic frameworks are porous polymeric materials formed by linking metal ions with organic bridging ligands. Metal-organic frameworks are used as sensors, catalysts for organic transformations, biomass conversion, photovoltaics, electrochemical applications, gas storage and separation, and photocatalysis. Nonetheless, many actual metal-organic frameworks present limitations such as toxicity of preparation reagents and components, which make frameworks unusable for food and pharmaceutical applications. Here, we review the structure, synthesis and properties of cyclodextrin-based metal-organic frameworks that could be used in bioapplications. Synthetic methods include vapor diffusion, microwave-assisted, hydro/solvothermal, and ultrasound techniques. The vapor diffusion method can produce cyclodextrin-based metal-organic framework crystals with particle sizes ranging from 200 nm to 400 µm. Applications comprise food packaging, drug delivery, sensors, adsorbents, gas separation, and membranes. Cyclodextrin-based metal-organic frameworks showed loading efficacy of the bioactive compounds ranging from 3.29 to 97.80%.

17.
Environ Chem Lett ; 21(1): 97-152, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36245550

RESUMO

The development and recycling of biomass production can partly solve issues of energy, climate change, population growth, food and feed shortages, and environmental pollution. For instance, the use of seaweeds as feedstocks can reduce our reliance on fossil fuel resources, ensure the synthesis of cost-effective and eco-friendly products and biofuels, and develop sustainable biorefinery processes. Nonetheless, seaweeds use in several biorefineries is still in the infancy stage compared to terrestrial plants-based lignocellulosic biomass. Therefore, here we review seaweed biorefineries with focus on seaweed production, economical benefits, and seaweed use as feedstock for anaerobic digestion, biochar, bioplastics, crop health, food, livestock feed, pharmaceuticals and cosmetics. Globally, seaweeds could sequester between 61 and 268 megatonnes of carbon per year, with an average of 173 megatonnes. Nearly 90% of carbon is sequestered by exporting biomass to deep water, while the remaining 10% is buried in coastal sediments. 500 gigatonnes of seaweeds could replace nearly 40% of the current soy protein production. Seaweeds contain valuable bioactive molecules that could be applied as antimicrobial, antioxidant, antiviral, antifungal, anticancer, contraceptive, anti-inflammatory, anti-coagulants, and in other cosmetics and skincare products.

18.
ACS Omega ; 7(43): 38856-38868, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36340116

RESUMO

The utilization of Mg-O-F prepared from Mg(OH)2 mixed with different wt % of F in the form of (NH4F·HF), calcined at 400 and 500 °C, for efficient capture of CO2 is studied herein in a dynamic mode. Two different temperatures were applied using a slow rate of 20 mL·min-1 (100%) of CO2 passing through each sample for only 1 h. Using the thermogravimetry (TG)-temperature-programed desorption (TPD) technique, the captured amounts of CO2 at 5 °C were determined to be in the range of (39.6-103.9) and (28.9-82.1) mgCO2 ·g-1 for samples of Mg(OH)2 mixed with 20-50% F and calcined at 400 and 500 °C, respectively, whereas, at 30 °C, the capacity of CO2 captured is slightly decreased to be in the range of (32.2-89.4) and (20.9-55.5) mgCO2 ·g-1, respectively. The thermal decomposition of all prepared mixtures herein was examined by TG analysis. The obtained samples calcined at 400 and 500 °C were characterized by X-ray diffraction and surface area and porosity measurements. The total number of surface basic sites and their distribution over all samples was demonstrated using TG- and differential scanning calorimetry-TPD techniques using pyrrole as a probe molecule. Values of (ΔH) enthalpy changes corresponding to the desorption steps of CO2 were calculated for the most active adsorbent in this study, that is, Mg(OH)2 + 20% F, at 400 and 500 °C. This study's findings will inspire the simple preparation and economical design of nanocomposite CO2 sorbents for climate change mitigation under ambient conditions.

19.
BMC Ophthalmol ; 22(1): 397, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36199054

RESUMO

INTRODUCTION: Glaucoma is the leading cause of irreversible blindness worldwide and is often undetected in resource-limited settings. Early screening and treatment of elevated intraocular pressure (IOP) reduces both the development and progression of visual field defects. IOP screening in developing countries is limited by access to ophthalmic equipment, trained ophthalmic staff, and follow up. High-volume cataract surgery outreaches in resource-limited countries provide ample opportunity for glaucoma screening, intervention and follow up. METHODS: This prospective cross-sectional study took place during a cataract outreach campaign sponsored by the Himalayan Cataract Project (HCP) in partnership with Felege Hiwot Hospital in Bahir Dar, Ethiopia, during April 5th - April 10th 2021. IOP was measured on the surgical eye of patients before undergoing small incision cataract surgery (SICS) using rebound tonometry with an iCare tonometer model IC100. RESULTS: Intraocular pressure (IOP) was measured in 604 eyes of 595 patients who received SICS. Mean IOP was 12.1 mmHg (SD = 5.0 mmHg). A total of 29 patients had an IOP greater than 21 mmHg representing 4.8% of total IOP measurements. A total of 17 patients received oral acetazolamide prior to surgery to acutely lower IOP. Six of these patients had their surgery delayed due to elevated IOP and 9 patients received excisional goniotomy at the time of SICS. A temporal approach during SCIS was taken for all patients with elevated IOP to allow for possible trabeculectomy at a future date. DISCUSSION: IOP screening during high-volume cataract outreach campaigns can be performed safely, accurately and on a large scale with minimal resources and supplemental training. Pre-operative IOP measurement can improve surgical care at the time of cataract surgery as well as help establish long-term follow up for patients with glaucoma.


Assuntos
Catarata , Glaucoma , Trabeculectomia , Acetazolamida , Estudos Transversais , Etiópia , Glaucoma/diagnóstico , Glaucoma/cirurgia , Humanos , Pressão Intraocular , Estudos Prospectivos
20.
ACS Sustain Chem Eng ; 10(37): 12433-12447, 2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36161095

RESUMO

Plastic and biomass waste pose a serious environmental risk; thus, herein, we mixed biomass waste with plastic bottle waste (PET) to produce char composite materials for producing a magnetic char composite for better separation when used in water treatment applications. This study also calculated the life cycle environmental impacts of the preparation of adsorbent material for 11 different indicator categories. For 1 functional unit (1 kg of pomace leaves as feedstock), abiotic depletion of fossil fuels and global warming potential were quantified as 7.17 MJ and 0.63 kg CO2 equiv for production of magnetic char composite materials. The magnetic char composite material (MPBC) was then used to remove crystal violet dye from its aqueous solution under various operational parameters. The kinetics and isotherm statistical theories showed that the sorption of CV dye onto MPBC was governed by pseudo-second-order, and Langmuir models, respectively. The quantitative assessment of sorption capacity clarifies that the produced MPBC exhibited an admirable ability of 256.41 mg g-1. Meanwhile, the recyclability of 92.4% of MPBC was demonstrated after 5 adsorption/desorption cycles. Findings from this study will inspire more sustainable and cost-effective production of magnetic sorbents, including those derived from combined plastic and biomass waste streams.

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