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In the present work, the synthesis of cellulose nanowhiskers (CNW)/chitosan nanocomposite films via deep eutectic solvents (DES) changing the chemical structures were carried out. It was observed that a pure chitosan film has broadband at 3180-3400 cm-1, indicating amide and hydroxyl groups. Upon CNW incorporation, the peak gets sharper and stronger and shifts to a greater wavelength. Further, the addition of DES infuses more elements of amide into the nanocomposite films. Moreover, the mechanical properties incorporating CNW filler into a chitosan matrix show an enhancement in tensile strength (TS), Young's modulus (YM), and elongation at break. The TS and YM increase while the elongation decrease as the CNW concentration increases. The YM of biocomposite films is increased to 723 MPa at 25% CNW into chitosan films. Besides, the TS has enhanced to 11.48 MPa at 15% CNW concentration in the biocomposite films. The elongation at break has decreased to 11.7% at 25% CNW concentration. Hence, incorporating CNW into the chitosan matrix via DES can still improve the mechanical properties of the nanocomposite films. Therefore, the application of DES results in a lower YM and TS as the films are hygroscopic. In conclusion, DES can be considered the new green solvent media for synthesizing materials. It has the potential to replace ionic liquids due to its biodegradability and non-toxic properties while preserving the character of low-vapour pressure. Besides that, chitosan can be used as potential material for applications in process industries, such as the biomedical and pharmaceutical industries. Thus, DES can be used as a green solvent and aim to reduce the toxic effect of chemicals on the environment during chemical production.
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Quitosano , Nanocompuestos , Celulosa/química , Quitosano/química , Disolventes Eutécticos Profundos , Solventes , Nanocompuestos/químicaRESUMEN
In Asia, mulberry has long been used to treat various infectious and internal ailments as a traditional medication. The compounds found in it have the potential to improve human health. Because there is no approved and defined evaluation procedure, it has not been formally or scientifically recognized. As a result of these investigations, a new frontier in traditional Chinese medicine has opened up, with the possibility of modernization, for the interaction between active components of mulberry and their biological activities. These studies have used current biotechnological technologies. For ages, mulberry has been used as an herbal remedy in Asia to cure various diseases and internal disorders. It has a high concentration of bioactive chemicals that benefit human health. The most abundant phenolic components extracted from white mulberry leaves are flavonoids (Kuwanons, Moracinflavans, Moragrols, and Morkotins), phenolic acids, alkaloids, and so forth. Flavonoids, benzofurans, chalcones, and alkaloids have been discovered to have cytotoxic effects on human cancer cell lines. There is growing evidence that mulberry fruits can potentially prevent cancer and other aging-related disorders due to their high concentration of bioactive polyphenolic-rich compounds and macro and micronutrients. Anthocyanins are rapidly absorbed after eating, arriving in the plasmalemma within 15-50 min and entirely removed after 6-8 hr. Due to a lack of an approved and consistent technique for its examination, it has yet to be formally or scientifically recognized. The mulberry plant is commercially grown for silkworm rearing, and less attention is paid to its bioactive molecules, which have a lot of applications in human health. This review paper discusses the phenolic compounds of white mulberry and black mulberry in detail concerning their role in cancer prevention.
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Morus , Neoplasias , Humanos , Antocianinas/química , Frutas/química , Morus/química , Fenoles/química , Flavonoides/químicaRESUMEN
This investigation is centered on the effectiveness of methylene blue (MB), a cationic dye, adsorbed from an aqueous media by H3PO4 activated papaya skin/peels (PSPAC), with initial pH (2-10), contact time (30-180 min), MB dye concentration (varying from 10 to 50 mg/L), and MB dose (0.1-0.5 gm). The findings show that the best optimal conditions for MB dye removal occur at a 6 pH, 0.3 gm dose of PSPAC adsorbent for 10 mg/L MB dye concentration, with 90 min of contact time. To optimize and validate the extraction efficiency of MB dye, a response surface methodology (RSM) study was conducted using a central composite design (CCD) with a regression model showing R2 = 0.9940. FT-IR spectroscopy shows, CO, and O-H stretching functional groups while FE-SEM is assessed to supervise morphological features of the PSPAC adsorbent. The peak adsorption capacity with 46.95 mg/g for the Langmuir isotherm model conveniently satisfies the adsorption process with R2 = 0.9984 while with R2 = 0.999, a kinetic model, pseudo-second-order, confirms MB dye adsorption by PSPAC adsorbent. Moreover, thermodynamic parameters including ΔGáµ, ΔH°, and ΔS° were computed and found to be spontaneous and exothermic. Furthermore, regeneration studies employed with NaOH (0.1 M) and HCl (0.1 M) solution media show an acceptable MB removal efficiency consecutive up to three cycles. The study highlights that H3PO4 papaya skin/peel (PSPAC) is an effectual, sustainable, reasonably available biosorbent to remove industrial cationic dyes disposal.
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Carica , Contaminantes Químicos del Agua , Azul de Metileno/química , Colorantes/química , Cinética , Espectroscopía Infrarroja por Transformada de Fourier , Concentración de Iones de Hidrógeno , Termodinámica , Agua , AdsorciónRESUMEN
In this study, fluoride removal from polluted potable water using magnetic carbon-based adsorbents derived from agricultural biomass was thoroughly investigated. An experimental matrix is designed considering the interactive effects of independent process variables (pH, adsorbent dose, contact time, and initial fluoride concentration) on the removal efficiency. Isotherms and kinetics studies, as well as anions interactions, were also investigated to understand the adsorption mechanisms further. The model parameters of isotherms and kinetics are estimated using nonlinear differential evolution optimization (DEO). Approaches like adaptive neuro-fuzzy inference system (ANFIS) and response surface methodology (RSM) are implemented to predict the fluoride removal and identify the optimal process values. The optimum removal efficiency of GAC-Fe3O4 (89.34%) was found to be higher than that of PAC-Fe3O4 (85.14%). Kinetics experiments indicated that they follow the intraparticle diffusion model, and adsorption isotherms indicated that they follow Langmuir and Freundlich models. Both PAC-Fe3O4 and GAC-Fe3O4 adsorbents have shown an adsorption capacity of 1.20 and 2.74 mg/g, respectively. The model predictions from ANFIS have a strong correlation with experimental results and superior to RSM predictions. The shape of the contours depicts the nonlinearity of the interactive effects and the mechanisms in the adsorption process.
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Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Fluoruros , Concentración de Iones de Hidrógeno , Cinética , Fenómenos Magnéticos , Contaminantes Químicos del Agua/análisisRESUMEN
Hospitals are considered an important factor in the spread of antibiotic-resistant bacteria (ARBs) and antibiotic-resistance genes (ARGs). The purpose of this research was to characterize the microbial populations in hospital wastewater and investigated the prevalence of ß-lactamase, SulÐ and QnrS resistance genes. In the first step, culture method was used to isolate Pseudomonas aeruginosa and Escherichia coli. In the next step, accurate identification of isolated bacteria was carried out using the polymerase chain reaction (PCR) method, then the resistance of the bacteria at different concentrations of antibiotics (8-128 µg/mL) was examined. Finally the ARGs were detected using the PCR method. The averages of heterotrophic plate count (HPC) and ARB concentration in wastewater samples were 1.8 × 108 and 4.3 × 106 CFU/100 mL, respectively. The highest resistance rates were found for sulfamethoxazole and the highest resistance rates in the ß-lactamase group were for ceftazidime, while highest sensitivity was for gentamicin and there was no isolate that was sensitive to the studied antibiotics. SulÐ and QnrS were the highest and lowest abundance of all ARGs in samples respectively and blaSHV was the highest ß-lactam resistance gene. Our results indicated an increase in the resistance of identified bacteria to several antibiotics. So it can be concluded that numerous antibiotic-resistant pathogens and vast numbers of ARGs exist in the human body so that their release from hospitals without effective treatment can cause many dangers to the environment and human health.
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Antibacterianos , Aguas Residuales , Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Escherichia coli/genética , Genes Bacterianos , Hospitales , Humanos , PseudomonasRESUMEN
End 2019, the zoonotic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), named COVID-19 for coronavirus disease 2019, is the third adaptation of a contagious virus following the severe acute respiratory syndrome coronavirus in 2002, SARS-CoV, and the Middle East respiratory syndrome virus in 2012, MERS-CoV. COVID-19 is highly infectious and virulent compared to previous outbreaks. We review sources, contagious routes, preventive measures, pandemic, outbreak, epidemiology of SARS-CoV, MERS-CoV and SARS-CoV-2 from 2002 to 2020 using a Medline search. We discuss the chronology of the three coronaviruses, the vulnerability of healthcare workers, coronaviruses on surface and in wastewater, diagnostics and cures, and measures to prevent spreading.
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This paper considers exposure to the concentration of fluoride in drinking water resources of Showt city in West Azerbaijan Province in, Iran, and its related potential health risk assessment issues to the resident populations. For this purpose, 88 drinking water samples were analyzed in 2016 by using the spectrophotometric method. Non-carcinogenic health risks due to F exposure through consumption of drinking water were assessed using the US EPA method. In addition, the associated zoning maps of the obtained results were presented using a geographic information system (GIS). The results indicated that fluoride concentration in drinking water ranged from 0.0 to 5.5â¯mgâ¯L-1 of the study area. Based on this research, 36.36% of the samples had a fluoride level higher than the permissible level, 13.63% had less than the permissible limit, and 50% of the samples had a level within the optimum limit of 0.5-1.5â¯mgâ¯L-1. The Hazard Quotient index (HQ) for children, teenager and adults had health hazards (HQâ¯>â¯1) in 54.55%, 31.82%, and 22.73% of samples, respectively. Groundwater resources having a risk of more than one were located in the villages of Khilajajam, Kolos, and Shorboulagh. So, in these study areas, there are potential risks of dental and skeletal fluorosis.
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Agua Potable/análisis , Fluoruros/análisis , Contaminantes Químicos del Agua/análisis , Adolescente , Adulto , Niño , Preescolar , Monitoreo del Ambiente/métodos , Sistemas de Información Geográfica , Agua Subterránea/análisis , Humanos , Lactante , Irán , Medición de RiesgoRESUMEN
There is discrepancy about intervals of fluoride monitoring in groundwater resources by Iranian authorities. Spatial and temporal variability of fluoride in groundwater resources of Larestan and Gerash regions in Iran were analyzed from 2003 to 2010 using a geospatial information system and the Mann-Kendall trend test. The mean concentrations of fluoride for the 8-year period in the eight cities and 31 villages were 1.6 and 2.0 mg/l, respectively; the maximum values were 2.4 and 3.8 mg/l, respectively. Spatial, temporal, and spatiotemporal variability of fluoride in overall groundwater resources were relatively constant over the years. However, results of the Mann-Kendall trend test revealed a monotonic trend in the time series of one city and 11 villages for the 8-year period. Specifically, one city and three villages showed positive significant Kendall's Tau values, suggesting an upward trend in fluoride concentrations over the 8-year period. In contrast, seven villages displayed negative significant Kendall's Tau values, arguing for a downward trend in fluoride concentrations over the years. From 2003 to 2010, approximately 52 % of the Larestan and Gerash areas have had fluoride concentrations above the maximum permissible Iranian drinking water standard fluoride level (1.4 mg/l), and about 116,000 people were exposed to such excess amounts. Therefore, our study supports for a close monitoring of fluoride concentrations from health authorities in monthly intervals, especially in villages and cities that showed positive trend in fluoride concentrations. Moreover, we recommend simultaneous implementation of cost-effective protective measures or interventions until a standard fluoride level is achieved.
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Agua Potable/química , Monitoreo del Ambiente , Fluoruros/análisis , Agua Subterránea/química , Contaminantes Químicos del Agua/análisis , Exposición a Riesgos Ambientales , IránRESUMEN
Wastewater-based epidemiology (WBE) is considered an innovative and promising tool for estimating community exposure to a wide range of chemical and biological compounds by analyzing wastewater. Despite scholars' interest in WBE studies, there are uncertainties and limitations associated with this approach. This current review focuses on the feasibility of the WBE approach in assessing environmental pollutants, including pesticides, heavy metals, phthalates, bisphenols, and personal care products (PCPs). Limitations and challenges of WBE studies are initially discussed, and then future perspectives, gaps, and recommendations are presented in this review. One of the key limitations of this approach is the selection and identification of appropriate biomarkers in studies. Selecting biomarkers considering the basic requirements of a human exposure biomarker is the most important criterion for validating this new approach. Assessing the stability of biomarkers in wastewater is crucial for reliable comparisons of substance consumption in the population. However, directly analyzing wastewater does not provide a clear picture of biomarker stability. This uncertainty affects the reliability of temporal and spatial comparisons. Various uncertainties also arise from different steps involved in WBE. These uncertainties include sewage sampling, exogenous sources, analytical measurements, back-calculation, and estimation of the population under investigation. Further research is necessary to ensure that measured pollutant levels accurately reflect human excretion. Utilizing data from WBE can support healthcare policy in assessing exposure to environmental pollutants in the general population. Moreover, WBE seems to be a valuable tool for biomarkers that indicate healthy conditions, lifestyle, disease identification, and exposure to pollutants. Although this approach has the potential to serve as a biomonitoring tool in large communities, it is necessary to monitor more metabolites from wastewater to enhance future studies.
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Recent advancements in polymer science and engineering underscore the importance of creating sophisticated soft materials characterized by well-defined structures and adaptable properties to meet the demands of emerging applications. The primary objective of polymeric composite technology is to enhance the functional utility of materials for high-end purposes. Both the inherent qualities of the materials and the intricacies of the synthesis process play pivotal roles in advancing their properties and expanding their potential applications. Polypyrrole (PPy)-based composites, owing to their distinctive properties, hold great appeal for a variety of applications. Despite the limitations of PPy in its pure form, these constraints can be effectively overcome through hybridization with other materials. This comprehensive review thoroughly explores the existing literature on PPy and PPy-based composites, providing in-depth insights into their synthesis, properties, and applications. Special attention is given to the advantages of intrinsically conducting polymers (ICPs) and PPy in comparison to other ICPs. The impact of doping anions, additives, and oxidants on the properties of PPy is also thoroughly examined. By delving into these aspects, this overview aims to inspire researchers to delve into the realm of PPy-based composites, encouraging them to explore new avenues for flexible technology applications.
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Our knowledge of fluorine's unique and complex properties has significantly increased over the past 20 years. Consequently, more sophisticated and innovative techniques have emerged to incorporate this feature into the design of potential drug candidates. In recent years, researchers have become interested in synthesizing fluoro-sulphonamide compounds to discover new chemical entities with distinct and unexpected physical, chemical, and biological characteristics. The fluorinated sulphonamide molecules have shown significant biomedical importance. Their potential is not limited to biomedical applications but also includes crop protection. The discovery of novel fluorine and Sulfur compounds has highlighted their importance in the chemical sector, particularly in the agrochemical and medicinal fields. Recently, several fluorinated sulphonamide derivatives have been developed and frequently used by agriculturalists to produce food for the growing global population. These molecules have also exhibited their potential in health by inhibiting various human diseases. In today's world, it is crucial to have a steady supply of innovative pharmaceutical and agrochemical molecules that are highly effective, less harmful to the environment, and affordable. This review summarizes the available information on the activity of Fluorine and Sulphonamide compounds, which have proven active in pharmaceuticals and agrochemicals with excellent environmental and human health approaches. Moreover, it focuses on the current literature on the chemical structures, the application of fluorinated sulphonamide compounds against various pathological conditions, and their effectiveness in crop protection.
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The consumption of unrefined vegetable oil poses acute and chronic health issues, yet improper disposal of waste plantain peels is not environmentally sustainable. This research investigates the feasibility, mechanism and thermodynamics of waste plantain peels, and commercial bentonite clay for soybean oil refining. Experiment was carried out using masses (1-4 g) of commercial bentonite clay, and unripe plantain peel ash (UPPA) to degummed and neutralized free fatty acid (FFA) contents in crude soybean oil at varying temperatures (50-120 °C), and time (15-35 min) for treatment of soybean oil. FTIR spectroscopy, SEM, and XRF techniques were applied to characterize the sample. The results established that at optimum 4.0 g dosage, the UPPA (97.73%) was more effective in the removal of FFA from oil at 50 °C and 20 min, while the clay (90%) was more effective in the removal of colour pigment from the vegetable oil 100 °C, and 25 min. The optimum efficiency of Clay-Ash-composite (70:30) in adsorbing pigment from soybean oil corresponds to 80%. The impact of changing viscosities, densities, and acid values on the performance of UPPA, clay, and clay-UPPA composite was investigated. Mechanistic studies confirmed the pseudo-second-order kinetics at 5 × 10-2 g/mg min-1 and 1.87 × 10-1 g/mg min-1, with corresponding adsorption capacity of 30.40 mg/g and 4.91 mg/g, at R2 ≤ 0.9982. The UPPA-driven sorption of FFA occurred as a physisorption and exothermic process (- 620.60 kJ/mol), while colour pigment removal occurred by chemisorption and endothermic process (22.40 kJ/mol). The finding recommends UPPA and composite as economically feasible for refining soybean oil.
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Plantago , Contaminantes Químicos del Agua , Bentonita/química , Arcilla , Aceite de Soja , Termodinámica , Adsorción , Cinética , Concentración de Iones de Hidrógeno , Contaminantes Químicos del Agua/químicaRESUMEN
Valorization of waste materials and byproducts as adsorbents is a sustainable approach for water treatment systems. Pottery Granules (PG) without any chemical and thermal modification were used as a low-cost, abundant, and environmentally benign adsorbent against Pb(II), the toxic metal in drinking water. The porous structure and complex mineral composition of PG made it an efficient adsorbent material for Pb(II). The effect of key physicochemical factors was investigated to determine the significance of contact time, PG dose, pH, solution temperature, and coexisting ions, on the process. Pb(II) removal increased by PG dose in the range of 5-15 g/L, and agitation time from 5 to 60 min. Increasing Pb(II) concentration led to a drop in Pb(II) removal, however, adsorption capacity increased significantly as concentration elevated. Pb(II) removal also increased significantly from ~ 45% to ~ 97% by pH from 2 to 12. A ~ 20% improvement in Pb(II) adsorption after rising the solution temperature by 30ËC, indicated the endothermic nature of the process. The sorption was described to be a favorable process in which Pb(II) was adsorbed in a multilayer onto the heterogeneous PG surface. The qmax of 9.47 mg/g obtained by the Langmuir model was superior among many reported low-cost adsorbents. The Pb(II) adsorption was described well by the Pseudo- first-order kinetic model. Na+, Mg2+, Ca2+, Cd2+, and Zn2+ showed a negligible effect on Pb(II) adsorption. However, the presence of Mn2+ and Fe2+ significantly hindered the process efficacy. In conclusion, the use of waste material such as PG against Pb(II) is a viable option from the economic and effectiveness points of view.
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Organophosphate esters (OPEs) are widely used in various industrial items, including plastics, textiles, construction materials, electronics, and auto parts. Several studies have investigated the concentration of OPE compounds in the air, where different compounds have been measured. This systematic review aims to investigate and summarize the relationship between exposure concentrations of OPEs in outdoor air and health risk for different OPE compounds, and correlations between OPE compounds in emission sources. PubMed, Scopus, Embase, Web of Science, and Google Scholar were searched from January 2000 to September 2021 to identify relevant research. The quality of the studies was assessed using the OHAT risk of bias tool. Spearman's correlation and principal component analysis (PCA) were used to analyze the results and correlation between OPE compounds. A total of 7669 manuscripts were found from the search in 5 databases. Finally, 46 studies were included in the systematic review. According to the median concentrations in the studies that were included, Tris(1-chloro-2-propyl) phosphate (TCIPP) (25%), trimethylphenyl phosphate(TMPP) (19%), Tri-iso-butyl phosphate (TiBP) (12%), Triphenyl phosphate (TPHP) (9%) and Tris(2-chloroethyl) phosphate (TCEP) (8%) had the greatest concentrations of OPEs overall. The cumulative contribution of the two main factors, F1 and F2, from the principal component analysis (PCA) results is 49.81%. The EDI value for the compounds is TCEP > TCIPP > TiBP > TMPP > 2-Ethylhexyl diphenyl phosphate (EHDPP) > TPHP > Tri(2-Ethylhexyl) phosphate (TEHP) > Tri-m-cresyl phosphate (mTCP) > Tris(1, 3-dichloro-isopropyl) phosphate (TDCPP) > Tri-n-butyl phosphate (TnBP). The total amount of non-carcinogenic risk (HQ) was for children > infants > adults. The highest value of HQ was for TCEP, TCIPP, and TMPP, respectively. The highest carcinogenic risk value was for TCEP and TMPP.
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Retardadores de Llama , Material Particulado , Niño , Adulto , Humanos , Material Particulado/análisis , Monitoreo del Ambiente/métodos , Ésteres/análisis , Retardadores de Llama/análisis , Organofosfatos/análisis , Fosfatos/análisis , Carcinógenos/análisis , ChinaRESUMEN
Water is one of the major sources that spread human diseases through contamination with bacteria and other pathogenic microorganisms. This review focuses on microbial hazards as they are often present in water and wastewater and cause various human diseases. Among the currently used disinfection methods, sonochemical reactors (SCRs) that produce free radicals combined with advanced oxidation processes (AOPs) have received significant attention from the scientific community. Also, this review discussed various types of cavitation reactors, such as acoustic cavitation reactors (ACRs) utilizing ultrasonic energy (UE), which had been widely employed, involving AOPs for treating contaminated waters. Besides ACRs, hydrodynamic cavitation reactors (HCRs) also effectively destroy and deactivate microorganisms to varying degrees. Cavitation is the fundamental phenomenon responsible for initiating many sonochemical reactions in liquids. Bacterial degradation occurs mainly due to the thinning of microbial membranes, local warming, and the generation of free radicals due to cavitation. Over the years, although extensive investigations have focused on the antimicrobial effects of UE (ultrasonic energy), the primary mechanism underlying the cavitation effects in the disinfection process, inactivation of microbes, and chemical reactions involved are still poorly understood. Therefore, studies under different conditions often lead to inconsistent results. This review investigates and compares other mechanisms and performances from greener and environmentally friendly sonochemical techniques to the remediation of microbial hazards associated with water and wastewater. Finally, the energy aspects, challenges, and recommendations for future perspectives have been provided.
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Contaminantes Químicos del Agua , Purificación del Agua , Humanos , Aguas Residuales , Purificación del Agua/métodos , Agua , Oxidación-Reducción , Desinfección , Contaminantes Químicos del Agua/análisisRESUMEN
Meat, poultry, and seafood such as fish are a valuable source of protein, vitamins and minerals. Considering their high consumption in the human diet, it is necessary to study pollutants (such as PAHs) in them. This present study has focused on the PAHs level and probabilistic risk of health in meat, poultry, fish and related product samples by MSPE-GC/MS technique (magnetic solid-phase extraction with gas chromatography-mass spectrometry). The maximum mean of 16 PAH was detected in smoked fish samples (222.7 ± 13.2 µg/kg) and the minimum mean of 16 PAH was detected in chicken (juje) kebab (112.9 ± 7.2 µg/kg µg/kg). The maximum mean of 4PAHs was detected in tuna fish (23.7 ± 2.4 µg/kg) and the minimum mean of 4PAHs was seen in grilled chicken and sausage samples (non-detected). Our results showed the 4PAHs and B[a]P were lower than the EU (European Union) standard levels (these standard levels were 30 and 5 µg/kg, respectively). Furthermore, the correlation among the type and concentrations of PAHs congeners was investigated through cluster analysis by heat map and principal component analysis. The 90th percentile ILCR (incremental lifetime cancer risk) of PAH compounds in fish, poultry, meat and related products samples was 3.39E-06, which was lower than the maximum acceptable level of risk (10-4). Finally, the highest ILCR was related to hamburger (4.45E-06). Therefore, there is no risk in consuming these foods in Iran, but it is necessary to monitor PAHs concentration in different types of foods.
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Discharging untreated dye-containing wastewater gives rise to environmental pollution. The present study investigated the removal efficiency and adsorption mechanism of Acid Red 18 (AR18) utilizing hexadecyl-trimethyl ammonium chloride (HDTMA.Cl) modified Nano-pumice (HMNP), which is a novel adsorbent for AR18 removal. The HDTMA.Cl is characterized by XRD, XRF, FESEM, TEM, BET and FTIR analysis. pH, contact time, initial concentration of dye and adsorbent dose were the four different parameters for investigating their effects on the adsorption process. Response surface methodology-central composite design was used to model and improve the study to reduce expenses and the number of experiments. According to the findings, at the ideal conditions (pH = 4.5, sorbent dosage = 2.375 g/l, AR18 concentration = 25 mg/l, and contact time = 70 min), the maximum removal effectiveness was 99%. The Langmuir (R2 = 0.996) and pseudo-second-order (R2 = 0.999) models were obeyed by the adsorption isotherm and kinetic, respectively. The nature of HMNP was discovered to be spontaneous, and thermodynamic investigations revealed that the AR18 adsorption process is endothermic. By tracking the adsorption capacity of the adsorbent for five cycles under ideal conditions, the reusability of HMNP was examined, which showed a reduction in HMNP's adsorption effectiveness from 99 to 85% after five consecutive recycles.
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4-Chlorophenol pollution is a significant environmental concern. In this study, powdered activated carbon modified with amine groups is synthesized and investigated its efficiency in removing 4-chlorophenols from aqueous environments. Response surface methodology (RSM) and central composite design (CCD) were used to investigate the effect of different parameters, including pH, contact time, adsorbent dosage, and initial 4-chlorophenol concentration, on 4-chlorophenol removal efficiency. The RSM-CCD approach was implemented in R software to design and analyze the experiments. The statistical analysis of variance (ANOVA) was used to describe the roles of effecting parameters on response. Isotherm and kinetic studies were done with three Langmuir, Freundlich, and Temkin isotherm models and four pseudo-first-order, pseudo-second-order, Elovich, and intraparticle kinetic models in both linear and non-linear forms. The synthesized adsorbent was characterized using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses. The results showed that the synthesized modified activated carbon had a maximum adsorption capacity of 316.1 mg/g and exhibited high efficiency in removing 4-chlorophenols. The optimal conditions for the highest removal efficiency were an adsorbent dosage of 0.55 g/L, contact time of 35 min, initial concentration of 4-chlorophenol of 110 mg/L, and pH of 3. The thermodynamic study indicated that the adsorption process was exothermic and spontaneous. The synthesized adsorbent also showed excellent reusability even after five successive cycles. These findings demonstrate the potential of modified activated carbon as an effective method for removing 4-chlorophenols from aqueous environments and contributing to developing sustainable and efficient water treatment technologies.
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The presence of heavy metal, chromium (VI), in water environments leads to various diseases in humans, such as cancer, lung tumors, and allergies. This review comparatively examines the use of several adsorbents, such as biosorbents, activated carbon, nanocomposites, and polyaniline (PANI), in terms of the operational parameters (initial chromium (VI) concentration (Co), temperature (T), pH, contact time (t), and adsorbent dosage) to achieve the Langmuir's maximum adsorption capacity (qm) for chromium (VI) adsorption. The study finds that the use of biosorbents (fruit bio-composite, fungus, leave, and oak bark char), activated carbons (HCl-treated dry fruit waste, polyethyleneimine (PEI) and potassium hydroxide (KOH) PEI-KOH alkali-treated rice waste-derived biochar, and KOH/hydrochloric acid (HCl) acid/base-treated commercial), iron-based nanocomposites, magnetic manganese-multiwalled carbon nanotubes nanocomposites, copper-based nanocomposites, graphene oxide functionalized amino acid, and PANI functionalized transition metal are effective in achieving high Langmuir's maximum adsorption capacity (qm) for chromium (VI) adsorption, and that operational parameters such as initial concentration, temperature, pH, contact time, and adsorbent dosage significantly affect the Langmuir's maximum adsorption capacity (qm). Magnetic graphene oxide functionalized amino acid showed the highest experimental and pseudo-second-order kinetic model equilibrium adsorption capacities. The iron oxide functionalized calcium carbonate (IO@CaCO3) nanocomposites showed the highest heterogeneous adsorption capacity. Additionally, Syzygium cumini bark biosorbent is highly effective in treating tannery industrial wastewater with high levels of chromium (VI).
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In this research, a simple, label-free, and ultra-sensitive fluorescent platform based on a metal-organic framework (MOF) has been developed to detect melamine in milk powder. This fluorescence sensor was fabricated from sensitized terbium (Tb)@NH2-MIL-253 (Al) MOF using a hydrothermal method that involved combining the green emission of Tb (λem = 545 nm) with the blue emission of NH2-MIL-253(Al) MOF (λem = 430 nm) under a single excitation wavelength (λex = 335 nm). The fluorescence sensor was then used under optimized conditions (pH = 9.0; sensor concentration = 30 mg/L; response time = 30 s) to quantify melamine in milk powder. The accuracy, sensitivity, and reproducibility of this sensor were established compared to the high-performance liquid chromatography (HPLC) method. The linear range and lower limit of detection (LLOD, computed with 3σ/S) of the sensor were between 40-396.45 nM (equal to 25 µg/kg-0.25 mg/kg) and 40 nM (equal to 25 µg/kg), respectively, which is much less than the maximum residual level (MRL) for the detection of melamine in infant formula (1 mg/kg) and other foods/feeds (2.5 mg/kg). Additionally, the results had good agreement with the HPLC outcomes, suggesting that the NH2-MIL-253(Al) MOF sensing probe has great precision and repeatability. To conclude, the new fluorescence sensor developed in this study can accurately and sensitively detect melamine in food samples, which may be useful for screening for adulteration of milk powders and other foods.