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1.
Environ Geochem Health ; 46(2): 63, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38302793

RESUMO

This study investigates the effect of boundary conditions and treatment-time on the electro-desalination of artificially-contaminated soil. The effect of ion exchange membranes (IEM), calcium chloride (CaCl2), and ethylenediaminetetraacetic acid (EDTA) on the removal of salt (i.e., Na+, Cl-, and Ca2+) and metal (i.e., Co2+ and Fe2+) ions from the soil by electrokinetic (EK) was studied. The outcomes demonstrate that an increase in treatment-time decreases the electroosmosis and ion removal rate, which might be attributed to the formation of acid-base fronts in soil, except in the IEM case. Because a high pH jump and electroosmotic flow (EOF) of water were not observed within the soil specimen due to the IEM, the removal of ions was only by diffusion and electromigration. The collision of acid-base fronts produced a large voltage gradient in a narrow soil region with a reduced electric field (EF) in its remaining parts, causing a decrease in EOF and ion transport by electromigration. The results showed that higher electroosmosis was observed by using CaCl2 and EDTA; thus, the removal rate of Co2+, Na+, and Ca2+ was greater than Cl- due to higher EOF. However, for relatively low EOF, the removal of Cl- exceeded that of Co2+, Na+, and Ca2+, possibly due to a lack of EOF. In addition, the adsorption of Fe2+ in soil increased with treatment-time due to the corrosion of the anode during all EK experiments except in the case of IEM, where an anion exchange membrane (AEM) was introduced at the anode-soil interface.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Ácido Edético , Solo , Cloreto de Cálcio , Íons , Poluentes do Solo/análise
2.
Environ Monit Assess ; 194(9): 613, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35882690

RESUMO

The contamination of food commodities with mycotoxins could be a serious health threat to humans and animals. Therefore, identification, quantification and reduction of mycotoxins in food commodities, particularly of aflatoxins (AFs) and ochratoxin A (OTA) in grain foods, is essentially required to guarantee safe food. This study determined the levels of AFs and OTA in 135 maize grains samples belonging to eight salient maize varieties cultivated in Pakistan, and evaluated the usefulness of radiations and adsorbents to reduce their levels. High performance liquid chromatography (HPLC)-based method was validated for the determination of AFs and OTA in maize grains. The results showed that 69 and 61% samples were positive for AFs and OTA, respectively and 54 and 22% of the respective samples had AFs and OTA above the permissible limits set by Pakistan Standards and Quality Control Authority. The concentration of AFs, AFB1and OTA in grains ranged from 14.5 to 92.4, 1.02 to 2.46 and 1.41 to 53.9 µg kg-1, respectively. Among the varieties, Pearl had the highest level of total AFs and OTA, whereas YH-5427 had the highest AFB1 level. The lowest concentration of AFs and OTA was found in Malaka and 30Y87, respectively. The use of 15 kGy gamma irradiation for 24 h, sunlight-drying for 20 h and UV irradiation for 12 h almost completely degraded the mycotoxins. The microwave heating for 120 s resulted in 9-33% degradation of mycotoxins. Moreover, the treatment of grains' extract with activated charcoal (5% w/w) removed > 96% of total AFs and AFB1, and up to 43% of OTA. The use of bentonite at the same rate removed OTA, total AFs and AFB1 by 93, 73 and 92%, respectively. Thus, it is concluded that contamination of maize grains with mycotoxins was fairly high in the collected maize grain samples in Pakistan, and treatment with radiations and adsorbents can effectively reduce mycotoxins contamination level in maize grains.


Assuntos
Aflatoxinas , Micotoxinas , Ocratoxinas , Aflatoxinas/análise , Aflatoxinas/química , Animais , Monitoramento Ambiental , Contaminação de Alimentos/análise , Humanos , Micotoxinas/análise , Ocratoxinas/análise , Ocratoxinas/química , Paquistão , Zea mays/química
3.
Nanotechnology ; 32(34)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34015775

RESUMO

Demand for freshwater increases day by day as impurity increases due to the industrial, domestic and municipal waste in the water. Inappropriate disposal of coal fly ash (CFA) is not eco-friendly, therefore the need is to convert it into some beneficial material like zeolite. Zeolite-based composites with metal oxides show high cation interchange capacity, fast adsorption, and high efficiency for the removal of wastewater pollutants. In this research work, metal oxide along with zeolite (derived for CFA) was prepared. Metal oxide (WO3) and magnetite (Fe3O4) based zeolite composite was used adsorption enhanced photocatalytic degradation of rhodamine B dye. Ternary composite (zeolite/WO3/Fe3O4) was characterized using a scanning electron microscope, x-ray diffraction, Fourier transform infrared spectroscopy. The bandgap energy of composite was estimated using Tauc plot method from the data obtained after UV-visible spectroscopy. The behavior of composite under acidic and basic conditions was analyzed using pHpzcof the composite. Influencing parameters like pH, dye concentration, contact time, and catalyst dosage was optimized under ultraviolet irradiations (254 nm). The results show that maximum degradation was achieved with zeolite/WO3/Fe3O4composite under optimized conditions of pH = 7, catalyst dosage = 10 mg/100 ml, RhB concentration 10 ppm, and time 60 min. The first-order kinetic model was best fitted to the experimental data. RSM was used as a statistical tool to analyze the data.

4.
Phys Chem Chem Phys ; 17(5): 3704-14, 2015 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-25557285

RESUMO

Spray coating technology has demonstrated great potential in the slow release fertilizers industry. The better understanding of the key spray parameters benefits both the environment and low cost coating processes. The use of starch based materials to coat the slow release fertilizers is a new development. However, the hydraulic spray jet breakup of the non-Newtonian starchy solutions is a complex phenomenon and very little known. The aim of this research was to study the axial and radial distributions of the Sauter Mean Diameter (SMD) and velocity vectors in pulsing spray patterns of native and modified tapioca starch solutions. To meet the objective, high speed imaging and Phase Doppler Anemometry (PDA) techniques were employed to characterize the four compositions of the starch-urea-borax complex namely S0, S1, S2 and S3. The unheated solutions exhibited very high viscosities ranging from 2035 to 3030 cP. No jet breakup was seen at any stage of the nozzle operation at an injection pressure of 1-5 bar. However, at 80 °C temperature and 5 bar pressure, the viscosity was reduced to 455 to 638 cP and dense spray patterns emerged from the nozzle obscuring the PDA signals. The axial size distribution revealed a significant decrease in SMD along the spray centreline. The smallest axial SMD (51 to 79 µm) was noticed in S0 spray followed by S1, S2 and S3. Unlikely, the radial SMD in S0 spray did not vary significantly at any stage of the spray injection. This trend was attributed to the continuous growth of the surface wave instabilities on the native starch sheet. However, SMD obtained with S1, S2 and S3 varied appreciably along the radial direction. The mean velocity vector profiles followed the non-Gaussian distribution. The constant vector distributions were seen in the near nozzle regions, where the spray was in the phase of development. In far regions, the velocity vectors were poly-dispersed and a series of ups and downs were seen in the respective radial distributions.

5.
Pak J Pharm Sci ; 27(5): 1265-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25176381

RESUMO

Carvedilol is an anti-hypertensive agent capable of blocking both alph (α) and beta (ß) receptors used to preclude cardiac arrhythmias and angina. The study was designed to evaluate the Pharmacokinetics of carvedilol in human male and female volunteers. Healthy male and female (twenty each) volunteers were finalized for the study after preliminarily clinical examination. Blood samples were collected at specific time intervals after giving an oral dose of 12.5mg carvedilol, separated the plasma and placed at -80°C until analysis. Estimation of carvedilol in human plasma was accomplished by High performance liquid chromatographic (HPLC) method using fluorescent detector. Plasma concentration-time curve was used for calculation of pharmacokinetic parameters using two-compartment open model. Mean (SD) values of AUC and Cmax 0.076±0.021ßg.h/ml and 0.024±0.005ßg/mL, respectively) in male differ significantly (P<0.05) from the female 0.197±0.042ßg.h/ml and 0.048±0.02ßg/mL, respectively). Overall, bioavailability of carvedilol was somewhat higher in females than in males, but these differences could be expounded by the lower body weight of female. Conversely, no significant differences were found for tmax, clearance and half-life in male and female. Moreover the ethnicity had significant impact on the Pharmacokinetics of carvedilol in human.


Assuntos
Carbazóis/farmacocinética , Propanolaminas/farmacocinética , Adulto , Carvedilol , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Masculino , Caracteres Sexuais
6.
Scientifica (Cairo) ; 2024: 3318047, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38855033

RESUMO

Finding new catalysts and pyrolysis technologies for efficiently recycling wasted plastics into fuels and structured solid materials of high selectivity is the need of time. Catalytic pyrolysis is a thermochemical process that cracks the feedstock in an inert gas environment into gaseous and liquid fuels and a residue. This study is conducted on microwave-assisted catalytic recycling of wasted plastics into nanostructured carbon and hydrogen fuel using composite magnetic ferrite catalysts. The composite ferrite catalysts, namely, NiZnFe2O4, NiMgFe2O4, and MgZnFe2O4 were produced through the coprecipitation method and characterized for onward use in the microwave-assisted valorization of wasted plastics. The ferrite nanoparticles worked as a catalyst and heat susceptor for uniformly distributed energy transfer from microwaves to the feedstock at a moderate temperature of 450°C. The type of catalyst and the working parameters significantly impacted the process efficiency, gas yield, and structural properties of the carbonaceous residue. The tested process took 2-8 minutes to pulverize feedstock into gas and carbon nanotubes (CNTs), depending on the catalyst type. The NiZnFe2O4-catalyzed process produced CNTs with good structural properties and fewer impurities compared to other catalysts. The NiMgFe2O4 catalyst performed better in terms of hydrogen evolution by showing 87.5% hydrogen (H2) composition in the evolved gases. Almost 90% of extractable hydrogen from the feedstock evolved during the first 2 minutes of the reaction.

7.
PLOS Glob Public Health ; 4(2): e0002693, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38412169

RESUMO

Pakistan has among the highest rates of maternal, perinatal, and neonatal mortality globally. Many of these deaths are potentially preventable with low-cost, scalable interventions delivered through community-based health worker programs to the most remote communities. We conducted a cross-sectional survey of 10,264 households during the baseline phase of a cluster randomized controlled trial (cRCT) in Gilgit-Baltistan, Pakistan from June-August 2021. The survey was conducted through a stratified, two-stage sampling design with the objective of estimating the neonatal mortality rate (NMR) within the study catchment area, and informing implementation of the cRCT. Study outcomes were self-reported and included neonatal death, stillbirth, health facility delivery, maternal death, postpartum hemorrhage (PPH), and Lady Health Worker (LHW) coverage. Summary statistics (proportions and rates) were weighted according to the sampling design, and mixed-effects Poisson regression was conducted to explore the relationship between LHW coverage and maternal/newborn outcomes. We identified 7,600 women who gave birth in the past five years, among whom 13% reported experiencing PPH. The maternal mortality ratio was 225 maternal deaths per 100,000 live births (95% confidence interval [CI] 137-369). Among 12,376 total births, the stillbirth rate was 41.4 per 1,000 births (95% CI 36.8-46.7) and the perinatal mortality rate was 53.0 per 1,000 births (95% CI 47.6-59.0). Among 11,863 live births, NMR was 16.2 per 1,000 live births (95% CI 13.6-19.3) and 65% were delivered at a health facility. LHW home visits were associated with declines in PPH (risk ratio [RR] 0.89 per each additional visit, 95% CI 0.83-0.96) and late neonatal mortality (RR 0.80, 95% CI 0.67-0.97). Intracluster correlation coefficients were also estimated to inform the planning of future trials. The high rates of maternal, perinatal, and neonatal death in Gilgit-Baltistan continue to fall behind targets of the 2030 Sustainable Development Goals.

8.
Plants (Basel) ; 13(8)2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38674489

RESUMO

Research on nanoparticles (NPs) is gaining great attention in modulating abiotic stress tolerance and improving crop productivity. Therefore, this investigation was carried out to evaluate the effects of copper oxide nanoparticles (CuO-NPs) on growth and biochemical characteristics in two maize hybrids (YH-5427 and FH-1046) grown under normal conditions or subjected to saline stress. A pot-culture experiment was carried out in the Botanical Research Area of "the University of Lahore", Lahore, Pakistan, in a completely randomized design. At two phenological stages, both maize hybrids were irrigated with the same amount of distilled water or NaCl solution (EC = 5 dS m-1) and subjected or not to foliar treatment with a suspension of CuO-NPs. The salt stress significantly reduced the photosynthetic parameters (photosynthetic rate, transpiration, stomatal conductance), while the sodium content in the shoot and root increased. The foliar spray with CuO-NPs improved the growth and photosynthetic attributes, along with the N, P, K, Ca, and Mg content in the roots and shoots. However, the maize hybrid YH-5427 responded better than the other hybrid to the saline stress when sprayed with CuO-NPs. Overall, the findings of the current investigation demonstrated that CuO-NPs can help to reduce the adverse effects of salinity stress on maize plants by improving growth and physio-biochemical attributes.

9.
Virol J ; 10: 90, 2013 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-23514695

RESUMO

BACKGROUND: Approximately 170 million people are infected with Hepatitis C virus (HCV) worldwide. The prevalence of chronic HCV infections in Pakistan is about 5%, with most individuals being infected with HCV genotype 3a. Data on HCV genotypes distribution across various districts of the country are scarce. One example is district Mardan from where such data is available only from 17 individuals. Accordingly, the present study aimed at determining HCV genotypes distribution among 177 HCV RNA positive individuals from district Mardan. FINDINGS: Serum samples (n = 215) from patients suspected of hepatitis C were collected and processed for Nested PCR based detection and subsequent genotyping. Gender-wise and age-wise differences in HCV prevalence and HCV genotypes distribution were determined by χ2 test. Out of the total 215 serum samples, 177 were found to be positive for HCV RNA. The genotype 3a was the most predominant genotype among HCV RNA positive samples with a prevalence of 90.3%, followed by genotype 1a (5.6%), mixed genotypes (2.8%), genotype 3b (0.6%) and genotype 4 (0.6%). The HCV prevalence was higher in young individuals than old people and was indicative of reduced survival rate beyond 40 years. CONCLUSION: HCV genotype 3a is the most predominant genotype in district Mardan. The state of the art preventive and therapeutic strategies should be implemented to control the spread of HCV infections. Further temporal studies involving different geographical areas of Pakistan, are required to improve the control measures for HCV infection.


Assuntos
Hepacivirus/classificação , Hepacivirus/genética , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Genótipo , Hepacivirus/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Paquistão/epidemiologia , Reação em Cadeia da Polimerase , Prevalência , RNA Viral/genética , RNA Viral/isolamento & purificação , Soro/virologia , Adulto Jovem
10.
Dalton Trans ; 52(19): 6343-6359, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37083039

RESUMO

Solar photocatalysis has emerged as a pollution-free and inexhaustible technique that has been extensively researched in the domains of environmental remediation and energy production. Herein, we have integrated ZnO and CdS nanoparticles through Cu as a solid-state electron mediator to design a ZnO-Cu-CdS Z-scheme heterosystem via a sol-gel route and further tested this as a photocatalyst for dye degradation, H2 evolution, and CO2 reduction. Within 60 min of visible light exposure, about 97% of methylene blue (MB) is degraded with a degradation rate constant of 0.042 min-1 for the ZnO0.45Cu0.1CdS0.45 catalyst. The MB degradation with this catalyst is 84, 21, 4.8, and 2 times as high as those of ZnO, CdS, ZnO0.5CdS0.5, and Cu0.1ZnO0.9 catalysts. The ZnO-Cu-CdS catalyst manifests an H2 evolution efficiency of 5579 µmol h-1 g-1, which is 169, 41, 3.9, and 3.5 times as high as those of ZnO, CdS, ZnO0.5CdS0.5, and Cu0.1ZnO0.9 catalysts. Using H2 as a reducing agent, the CO production rate over the ZnO0.45Cu0.1CdS0.45 catalyst reaches 770 µmol h-1 g-1, which is 3 and 1.8 times higher than those of ZnO0.5CdS0.5 and Cu0.1ZnO0.9 catalysts. Besides, the optimal CH4 production rate over ZnO0.45Cu0.1CdS0.45 reaches 890 µmol h-1 g-1. The improved photocatalytic response of the ZnO-Cu-CdS catalyst is assigned to the delayed recombination of photoexcited charge carriers through a Z-scheme charge transport mode, maintaining the photocarriers with strong redox potentials and the dual role of Cu to serve as a conductive bridge to accelerate the charge transfer rate and enhance the light absorption due to its SPR phenomenon. This research offers a promising strategy for developing binary/ternary Z-scheme heterojunction photocatalytic systems for different photocatalytic applications.

11.
Sci Rep ; 13(1): 29, 2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-36593267

RESUMO

Coxiella burnetii (Cb) is a hardy, stealth bacterial pathogen lethal for humans and animals. Its tremendous resistance to the environment, ease of propagation, and incredibly low infectious dosage make it an attractive organism for biowarfare. Current research on the classification of Coxiella and features influencing its presence in the soil is generally confined to statistical techniques. Machine learning other than traditional approaches can help us better predict epidemiological modeling for this soil-based pathogen of public significance. We developed a two-phase feature-ranking technique for the pathogen on a new soil feature dataset. The feature ranking applies methods such as ReliefF (RLF), OneR (ONR), and correlation (CR) for the first phase and a combination of techniques utilizing weighted scores to determine the final soil attribute ranks in the second phase. Different classification methods such as Support Vector Machine (SVM), Linear Discriminant Analysis (LDA), Logistic Regression (LR), and Multi-Layer Perceptron (MLP) have been utilized for the classification of soil attribute dataset for Coxiella positive and negative soils. The feature-ranking methods established that potassium, chromium, cadmium, nitrogen, organic matter, and soluble salts are the most significant attributes. At the same time, manganese, clay, phosphorous, copper, and lead are the least contributing soil features for the prevalence of the bacteria. However, potassium is the most influential feature, and manganese is the least significant soil feature. The attribute ranking using RLF generates the most promising results among the ranking methods by generating an accuracy of 80.85% for MLP, 79.79% for LR, and 79.8% for LDA. Overall, SVM and MLP are the best-performing classifiers, where SVM yields an accuracy of 82.98% and 81.91% for attribute ranking by CR and RLF; and MLP generates an accuracy of 76.60% for ONR. Thus, machine models can help us better understand the environment, assisting in the prevalence of bacteria and decreasing the chances of false classification. Subsequently, this can assist in controlling epidemics and alleviating the devastating effect on the socio-economics of society.


Assuntos
Coxiella burnetii , Humanos , Solo , Manganês , Aprendizado de Máquina , Redes Neurais de Computação , Máquina de Vetores de Suporte
12.
PLoS One ; 18(5): e0284468, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37196025

RESUMO

The emergence of environmental nongovernmental organizations (ENGOs) has proved beneficial in improving environmental quality and related health issues. Therefore, this study attempts to investigate the impact of ENGO on human health in China from 1995 to 2020. To investigate the relationship between the variables, we have employed the ARDL model. The ARDL model results demonstrate that the long-run impact of ENGO is negative on infant mortality and death rate, meaning that an increase in the proportion of ENGOs in China considerably decreases infant mortality and death rate. On the other hand, ENGOs have a favorable influence on life expectancy in China, demonstrating ENGOs' supporting role in raising birth life expectancy. In the short run, estimates of ENGOs have no substantial influence on newborn mortality and death rates in China, whereas ENGOs have a positive and significant impact on life expectancy. These results imply that ENGOs help improves people's health status in China, which is also supported by the rise in GDP, technology, and health expenditures. The causal analysis confirms the bi-directional causal link between ENGO and IMR and ENGO and LE, while the unidirectional causal link runs from ENGO to DR. The results of the study provide insights into the impact of environmental NGOs on human health in China and may help guide policies aimed at improving public health outcomes through environmental protection efforts.


Assuntos
Conservação dos Recursos Naturais , Mortalidade Infantil , Lactente , Recém-Nascido , Humanos , China , Expectativa de Vida , Saúde Pública , Desenvolvimento Econômico
13.
Vet Ital ; 59(4)2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38828857

RESUMO

The present study evaluated the presence of Salmonella enterica in Pakistani backyard poultry. A total 48 chickens from 4 backyard poultry breeds with the clinical presentation of S. enterica infection were randomly selected from villages in the Punjab Province. Cloacal swabs from live poultry and liver samples from the dead birds were collected for bacterial culture and biochemical identification. Liver and spleen samples from dead birds were evaluated for gross and histopathological changes. Bacterial isolates were subjected to PCR and sequencing of ratA gene. Biochemical identification revealed 5/48 (10.42%) chickens positive for S. enterica. Gross pathology included enlarged, discoloured and congested liver and congested spleen. Histopathology demonstrated congestion of sinusoidal capillaries, cellular swelling and cellular/ballooning degeneration, congestion of central hepatic vein, granular hepatocytic cytoplasm and the presence of variable-sized vacuoles in hepatocytes. The PCR yielded a S. enterica specific amplicon (1047 bp). All liver samples that were positive for S. enterica by biochemical tests, were also positive by PCR. The ratA gene sequencing revealed a close resemblance with S. enteritidis isolates from humans. The present study highlights zoonotic risk from backyard poultry and suggests that PCR can be used as an alternate method for rapid detection of Salmonella serovars.


Assuntos
Galinhas , Doenças das Aves Domésticas , Salmonelose Animal , Salmonella enterica , Animais , Salmonella enterica/isolamento & purificação , Salmonella enterica/genética , Salmonella enterica/classificação , Paquistão , Salmonelose Animal/microbiologia , Salmonelose Animal/diagnóstico , Doenças das Aves Domésticas/microbiologia , Galinhas/microbiologia
14.
Adv Colloid Interface Sci ; 311: 102830, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36592501

RESUMO

The photocatalytic technology illustrates an eco-friendly and sustainable route to overcome environmental and energy issues. The successful construction of a photocatalyst depends on four key elements: light absorption ability, the density of active sites, redox capacity, and photoinduced electron-hole recombination rate. Sincemost of intrinsic semiconductor photocatalysts cannot meet all these requirements, they are often modified to boost their photocatalytic properties. Many strategies have been adopted to design novel and efficient photocatalysts for diverse applications. Herein, we review the most efficient of these strategies and methods focused on effectively overcoming the efficiency limitations of photocatalysts to promote their large-scale application. Subsequently, a particular aim is put on the most current studies for photocatalytic applications, including CO2 reduction, N2 fixation, H2 evolution, and pollutants degradation. Finally, key challenges and future perspectives in designing and implementing semiconductor photocatalysts for large-scale applications are discussed. Therefore, it is foreseen that this review will work as a guide for future research and provides a variety of strategies to develop novel and high-performance photocatalysts for various applications.


Assuntos
Semicondutores
15.
ACS Omega ; 8(15): 14122-14130, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37091425

RESUMO

The rise in the production of plastic waste has prompted the exploration of various recovery options instead of landfilling, burning, and other unethical ways of decomposing. The experimentally generated rate constants for the thermal processing of plastic waste do not yield enough liquid fuels and gases for commercial-scale usage. It is imperative to predict kinetic rate constants statistically using an appropriate combination of activation energies (E a) and frequency factors (A o) for the optimized thermal valorization of plastic waste. This approach also assists in controlling the selectivity and quantity of the pyrolysis products. A statistical kinetic model was tested to find the best combination of rate constants from different combinations of E a and A o to pyrolyze the high-density polyethylene. Two series of E a and A o were first assumed using R software. These series were then used to predict kinetic rate constants and analyze their sensitivity independently using MATLAB. The rate constants were varied from their originally predicted values during the sensitivity analysis. It was found that the rate constant k(7) dominated the other predicted rate constants where high oil and gas yields were concerned. The gas yield increased from lower to higher extreme positions in the range of 60%-74% with the first series and from 65% to 81% with the second series. The maximum oil content was found around 74% and 65% with the first series and second series, respectively.

16.
Sci Rep ; 13(1): 9057, 2023 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-37270598

RESUMO

This study performed in-situ microwave pyrolysis of plastic waste into hydrogen, liquid fuel and carbon nanotubes in the presence of Zeolite Socony Mobil ZSM-5 catalyst. In the presented microwave pyrolysis of plastics, activated carbon was used as a heat susceptor. The microwave power of 1 kW was employed to decompose high-density polyethylene (HDPE) and polypropylene (PP) wastes at moderate temperatures of 400-450 °C. The effect of plastic composition, catalyst loading and plastic type on liquid, gas and solid carbon products was quantified. This in-situ CMP reaction resulted in heavy hydrocarbons, hydrogen gas and carbon nanotubes as a solid residue. A relatively better hydrogen yield of 129.6 mmol/g as a green fuel was possible in this process. FTIR and gas chromatography analysis revealed that liquid product consisted of C13+ fraction hydrocarbons, such as alkanes, alkanes, and aromatics. TEM micrographs showed tubular-like structural morphology of the solid residue, which was identified as carbon nanotubes (CNTs) during X-ray diffraction analysis. The outer diameter of CNTs ranged from 30 to 93 nm from HDPE, 25-93 nm from PP and 30-54 nm for HDPE-PP mixure. The presented CMP process took just 2-4 min to completely pyrolyze the plastic feedstock into valuable products, leaving no polymeric residue.

17.
Front Chem ; 11: 1036478, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36936530

RESUMO

Introduction: Cadmium(Cd) an industrial poison present abundantly in the environment, causes human toxicity by an inflammatory process. Chronic exposure of cadmium can cause a number of molecular lesions that could be relevant to oncogenesis, through indirect or epigenetic mechanisms, potentially including abnormal activation of oncogenes and suppression of apoptosis by depletion of antioxidants. As induction of cyclooxygenase (COX)-2 is linked to inflammatory processes, use of luteolin, epiafzelechin, and albigenin alone or in different combinations may be used as anti-inflammatory therapeutic agents. Methods: We, herein, performed in silico experiments to check the binding affinity of phytochemicals and their therapeutic effect against COX-2 in cadmium administered rats. Wistar albino rats were given phytochemicals in different combinations to check their anti-inflammatory activities against cadmium intoxication. The level of alanine aminotransferases (ALT), 4-hydroxynonenal (4HNE), 8-hydroxy-2-deoxyguanosine (8-OHdG), tumor necrosis factor-alpha (TNF-α), isoprostanes (IsoP-2α), COX-2, and malondialdehyde (MDA) were estimated with their respective ELISA and spectrophotometric methods. Results: The generated results show that phytocompounds possessed good binding energy potential against COX-2, and common interactive behavior was observed in all docking studies. Moreover, the level of ALT, 4HNE, 8-OHdG, TNF-α, IsoP-2α, malondialdehyde, and COX-2 were significantly increased in rats with induced toxicity compared to the control group, whereas in combinational therapy of phytocompounds, the levels were significantly decreased in the group. Discussion: Taken together, luteolin, epiafzelechin, and albigenin can be used as anti-inflammatory therapeutic agents for future novel drug design, and thus it may have therapeutic importance against cadmium toxicity.

18.
ACS Omega ; 8(29): 26065-26078, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37521654

RESUMO

In this study, dual S-scheme ZnIn2S4-Al2O3-ZnO (ZIS-Al-Zn) heterojunctions were produced by a facile, low cost, and rapid combustion technique. These heterojunctions accelerated the photocatalytic hydrogen production due to the multi-channel-promoted separation of photocarriers. By optimizing the content of the components, the synthesized ZIS-Al-Zn composite with 20 wt% of ZnIn2S4 and 30 wt% of Al2O3 in the ZIS-Al-Zn composite demonstrated the highest hydrogen production rate of 54.2 mmol g-1 h-1, which was nearly 11 and 8.30 times better than ZnO-Al2O3 and ZnO-ZnIn2S4 composites, respectively. The results of DRS, PL, EIS, LSV, and CV techniques showed the highest shift in the light absorption, rapid interfacial transfer, and quenched recombination of photocarriers over the ternary ZIS-Al-Zn composite than single and binary catalysts. The obtained results revealed the formation of a dual S-scheme mechanism of transfer of photocarriers in ZIS-Al-Zn heterojunctions, contributing to better hydrogen production efficiency. The optimized ZIS-Al-Zn composite also exhibited good stability and reusability.

19.
ACS Omega ; 8(21): 18891-18900, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37273618

RESUMO

Nonthermal plasma is a well-recognized environmentally advantageous method for producing green fuels. This work used different photocatalysts, including PZO, SxZO, and SxZCx for hydrogen production using an atmospheric argon coaxial dielectric barrier discharge (DBD)-based light source. The photocatalysts were produced using a sol-gel route. The DBD discharge column was filled with water, methanol, and the catalyst to run the reaction under argon plasma. The DBD reactor was operated with a 10 kV AC source to sustain plasma for water splitting. The light absorption study of the tested catalysts revealed a decrease in the band gap with an increase in the concentration of Sr and carbon nanotubes (CNTs) in the Sr/ZnO/CNTs series. The photocatalyst S25ZC2 demonstrated the lowest photoluminescence (PL) intensity, implying the most quenched recombination of charge carriers. The highest H2 evolution rate of 2760 µmol h-1 g-1 was possible with the S25ZC2 catalyst, and the lowest evolution rate of 56 µmol h-1 g-1 was observed with the PZO catalyst. The photocatalytic activity of S25ZC2 was initially high, which decreased slightly over time due to the deactivation of the photocatalyst. The photocatalytic activity decreased from 2760 to 1670 µmol h-1 g-1 at the end of the process.

20.
Heliyon ; 9(5): e16049, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37215830

RESUMO

Sensitivity analyses of rate constants for chemical kinetics of the pyrolysis reaction are essential for the efficient valorization of plastic waste into combustible liquids and gases. Finding the role of individual rate constants can provide important information on the process conditions, quality, and quantity of the pyrolysis products. The reaction temperature and time can also be reduced through these analyses. For sensitivity analysis, one possible approach is to estimate the kinetic parameters using MLRM (multiple linear regression model) in SPSS. To date, no research reports on this research gap are documented in the published literature. In this study, MLRM is applied to kinetic rate constants, which slightly differ from experimental data. The experimental and statistically predicted rate constants varied up to 200% from their original values to perform sensitivity analysis using MATLAB software. The product yield was examined after 60 min of thermal pyrolysis at a fixed temperature of 420 °C. The predicted rate constant "k(8)" with a slight difference of 0.02 and 0.04 from the experiment revealed 85% oil yield and 40% light wax after 60 min of operation. The heavy wax was missing from the products under these conditions. This rate constant can be utilized to maximize the commercial-scale extraction of liquids and light waxes from thermal pyrolysis of plastics.

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