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1.
BMC Microbiol ; 24(1): 304, 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39138453

RESUMEN

BACKGROUND: Ectomycorrhizal (ECM and ECM-like) structures associated with plant root systems are a challenge for scientists. The dispersion pattern of roots within the soil profile and the nutritional conditions are both favourable factors to motivate the plants to make ECM associations. RESULTS: This study discusses the colonization of mycorrhizal associations in Kobresia and Polygonum species including Polygonum viviparum, Kobresia filicina, K. myosuroides, Alnus nitida, Betula pendula, Pinus sylvestris, and Trifolium repens grown naturally in cold stressed soils of Gilgit-Baltistan (high-altitude alpine Deosai plains), Hazara, Swat, Dir, and Bajaur. Sieved soil batches were exposed to +5 °C (control), -10, -20, -30, -40, -50, -125 °C for 5 h, and selected plants were sown to these soils for 10 weeks under favourable conditions for ECM colonization. Ectomycorrhizal associations were examined in the above mentioned plants. Some ECM fungi have dark mycelia that look like the mantle and Hartig net. Examples of these are Kobresia filicina, K. myosuroides, and Polygonum viviparum. Findings of this study revealed that K. myosuroides excelled in ECM root tip length, dry mass, and NH4 concentration at -125 °C. Contrarily, A. nitida demonstrated the lower values, indicated its minimum tolerance. Notably, T. repens boasted the highest nitrogen concentration (18.7 ± 1.31 mg/g), while P. sylvestris led in phosphorus (3.2 ± 0.22 mg/g). The B. pendula showed the highest potassium concentration (9.4 ± 0.66 mg/g), emphasising species-specific nutrient uptake capabilities in extreme cold conditions. The PCA analysis revealed that the parameters, e.g., NH4 in soil mix (NH4), NO3 in soil mix (NO3), phosphorus in soil in species of Polygonum viviparum, Kobresia filicina, K. myosuroides, Alnus nitida, Betula pendula, Pinus sylvestris, and Trifolium repens are most accurately represented in cases of + 5 °C, -10 °C, and -20 °C temperatures. On the other hand, the parameters for ECM root tips (ECM) and Dry Mass (DM) are best described in -40 °C, -50 °C, and - 125 °C temperatures. All parameters have a strong influence on the variability of the system indicated the efficiency of ECM. The heatmap supported the nutrients positively correlated with ECM colonization with the host plants. CONCLUSION: At lower temperatures, hyphae and spores in roots were reduced, while soluble phosphorus concentrations of leaves were increased in cold stress soils. Maximum foliar nutrient concentrations were found in K. myosuroides at the lowest temperature treatments due to efficient functioning and colonization of ECM.


Asunto(s)
Frío , Micorrizas , Raíces de Plantas , Micorrizas/fisiología , Raíces de Plantas/microbiología , Microbiología del Suelo , Trifolium/microbiología , Trifolium/crecimiento & desarrollo , Suelo/química , Nutrientes/metabolismo , Cyperaceae/microbiología , Cyperaceae/crecimiento & desarrollo , Estrés Fisiológico , Simbiosis , Polygonum/microbiología , Polygonum/crecimiento & desarrollo , Fósforo/metabolismo , Fósforo/análisis
2.
Environ Res ; 262(Pt 2): 119879, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39243843

RESUMEN

The airborne microbiome significantly influences human health and atmospheric processes within Earth's troposphere and is a crucial focus for scientific research. This study aimed to analyze the composition, diversity, distribution, and spatiotemporal characteristics of airborne microbes in Qatar's ambient air. Air samples were collected using a sampler from ten geographically or functionally distinct locations during a period of one year. Spatial and seasonal variations significantly impacted microbial concentrations, with the highest average concentrations observed at 514 ± 77 CFU/m3 for bacteria over the dry-hot summer season and 134 ± 31 CFU/m3 for fungi over the mild winter season. Bacterial concentrations were notably high in 80% of the locations during the dry-hot summer sampling period, while fungal concentrations peaked in 70% of the locations during winter. The microbial diversity analysis revealed several health-significant bacteria including the genera Chryseobacterium, Pseudomonas, Pantoea, Proteus, Myroides, Yersinia, Pasteurella, Ochrobactrum, Vibrio, and fungal strains relating to the genera Aspergillus, Rhizopus Fusarium, and Penicillium. Detailed biochemical and microscopic analyses were employed to identify culturable species. The strongest antibiotic resistance (ABR) was observed during the humid-hot summer season, with widespread resistance to Metronidazole. Health risk assessments based on these findings indicated potential risks associated with exposure to high concentrations of specific bioaerosols. This study provides essential baseline data on the natural background concentrations of bioaerosols in Qatar, offering insights for air quality assessments and forming a basis for public health policy recommendations, particularly in arid regions.

3.
Environ Res ; 203: 111845, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34384753

RESUMEN

The best exceptional Physico-chemical attributes of MXenes including high conductivity, high surface area, high functionalization, hydroxide site, and other interesting properties have attracted recently the attention of scientists in the applications of MXene (Mn+1XnTx)-based nanomaterials for water treatment. To provide a full and comprehensive vision of the current state of the art, and improve the treatment performance, and motivate new researches in this area, this review focused on the uses of these novel 2D transition metal carbides for desalination of water and the general methods of fabrication of MXenes; thus, MXene-based nanomaterials are very efficient candidates in water desalination processes, in this review, the main properties of previous and current works about MXenes applications in this area were properly investigated. Moreover, a particular overview about the different properties of MXenes in desalination such as etching method, hydrophobicity, structural modification, and chemical modification has been performed; meanwhile, the investigation of MXenes and MXenes-based composites would be an excellent candidate in the future of water purification and environmental remediation fields, since they have several good properties compared to the other 2D materials.


Asunto(s)
Restauración y Remediación Ambiental , Nanoestructuras , Elementos de Transición , Purificación del Agua
4.
Environ Res ; 202: 111645, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34252426

RESUMEN

Nanofluids have shown their potential in the oil recovery process through surface modification. Due to their surface characteristics, they can apply to improve the oil production from reservoirs by enabling different enhanced recovery mechanisms. The preparation and development of the Fe3O4@SiO2 nanoparticles for the oil recovery process is an innovative and novel approach that influences the oil generation from reservoirs. The performance of the Fe3O4@SiO2 and the other nanofluids (seawater, Fe3O4, and SiO2) in the enhanced oil recovery process is assessed and compared with other flooding scenarios. The Fe3O4@SiO2 NPs achieved the highest oil production rate of 90.2% while Fe3O4 and SiO2 NPs achieved 70.8% and 55.3%, respectively. In contrast, the value achieved for the seawater injection was 76.5%. For the oil recovery process, the Fe3O4 was applied for the inhibition (i.e., decrease) of oil sedimentation, and the SiO2 NPs were applied for wettability alteration and IFT reduction. The experimental results showed that the produced Fe3O4@SiO2 NPs improved the oil recovery rates (90.2%) as well as the synergetic impact of the developed NPs by initiating several mechanisms corresponding to the use of the separate NPs in the micromodel. Moreover, the results exhibited that the reservoir conditions are a crucial function for increasing the oil recovery rates, improving the emulsion stability, and acts as a substantial step for the oil recovery method that applies this particular technique.


Asunto(s)
Nanopartículas , Dióxido de Silicio , Emulsiones , Humectabilidad
5.
Environ Res ; 201: 111494, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34171373

RESUMEN

This study underlines the biotechnical valorization of the accumulated and unusable remains of agro-industrial orange fruit peel waste to produce α-amylase under submerged conditions by Streptomyces sp. KP314280 (20r). The response surface methodology based on central composite design (RSM-CCD) and artificial neural network coupled with a genetic algorithm (ANN-GA) were used to model and optimize the conditions for the α-amylase production. Four independent variables were evaluated for α-amylase activity including substrate concentration, inoculum size, sodium chloride powder (NaCl), and pH. A ten-fold cross-validation indicated that the ANN has a greater ability than the RSM to predict the α-amylase activity (R2ANN = 0.884 and R2RSM = 0.725). The analysis of variance indicated that the aforementioned four factors significantly affected the α-amylase activity. Additionally, the α-amylase production experiments were conducted according to the optimal conditions generated by the GA. The results indicated that the amylase yield increased by 4-fold. Moreover, the α-amylase production (12.19 U/mL) in the optimized medium was compatible with the predicted conditions outlined by the ANN-GA model (12.62 U/mL). As such, the ANN and GA combination is optimizable for α-amylase production and exhibits an accurate prediction which provides an alternative to other biological applications.


Asunto(s)
Citrus sinensis , Streptomyces , Medios de Cultivo , Residuos Industriales , Redes Neurales de la Computación
6.
Molecules ; 25(18)2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-32961921

RESUMEN

Heightened levels of carbon dioxide (CO2) and other greenhouse gases (GHGs) have prompted research into techniques for their capture and separation, including membrane separation, chemical looping, and cryogenic distillation. Ionic liquids, due to their negligible vapour pressure, thermal stability, and broad electrochemical stability have expanded their application in gas separations. This work provides an overview of the recent developments and applications of ionic liquid membranes (ILMs) for gas separation by focusing on the separation of carbon dioxide (CO2), methane (CH4), nitrogen (N2), hydrogen (H2), or mixtures of these gases from various gas streams. The three general types of ILMs, such as supported ionic liquid membranes (SILMs), ionic liquid polymeric membranes (ILPMs), and ionic liquid mixed-matrix membranes (ILMMMs) for the separation of various mixed gas systems, are discussed in detail. Furthermore, issues, challenges, computational studies and future perspectives for ILMs are also considered. The results of the analysis show that SILMs, ILPMs, and the ILMMs are very promising membranes that have great potential in gas separation processes. They offer a wide range of permeabilities and selectivities for CO2, CH4, N2, H2 or mixtures of these gases. In addition, a comparison was made based on the selectivity and permeability of SILMs, ILPMs, and ILMMMs for CO2/CH4 separation based on a Robeson's upper bound curves.


Asunto(s)
Gases/aislamiento & purificación , Líquidos Iónicos/química , Dióxido de Carbono/química , Dióxido de Carbono/aislamiento & purificación , Gases/química , Calentamiento Global , Hidrógeno/química , Hidrógeno/aislamiento & purificación , Membranas Artificiales , Metano/química , Metano/aislamiento & purificación , Nitrógeno/química , Nitrógeno/aislamiento & purificación , Permeabilidad
7.
J Environ Manage ; 247: 738-748, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31279805

RESUMEN

The present study assesses and models the growth of microalgae during the combined processes of concurrent eliminations of CO2 from off-gas and nutrients from wastewater. The growth of single (Spirulina platensis, SP.PL) and mixed (mixed indigenous microalgae, MIMA) algae strains was tested in a pilot plant under natural conditions. The specific growth rate (µ), biomass production (Pbio), CO2 biofixation rate (RCO2), and contaminate (organic matter and nutrient) reductions were investigated in response to the changes in concentration of CO2, nutrient and organic matters as well as solar irradiation. A mathematical model that incorporates the effect of growth variables: organic matter (COD), total inorganic nitrogen (TIN), total phosphate (TP), solar irradiation and dissolved CO2 was developed to predict the strains growth rate. The maximum value of µ for single strain was determined to occur at 40 mg COD/L, 20 mg-N/L, 8.9 mg-P/L, 12% CO2 (v/v) and 7.45 µE/m2.s. MIMA showed a maximum value of µ at 55 mg COD/L, 17 mg-N/L, 10 mg-P/L, 17% CO2 and 8.45 µE/m2.s. The predicted growth rates confirmed the ability of the model to match experimental data. Microalgae can be successfully used in sustainable CO2 capturing and wastewater treatment technology.


Asunto(s)
Microalgas , Biomasa , Carbono , Dióxido de Carbono , Nutrientes , Aguas Residuales
8.
Environ Monit Assess ; 190(2): 90, 2018 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-29353320

RESUMEN

Monitoring of microalgae in water supplies and industrial applications are becoming increasingly important, yet there are few options available that are simple and accurate, and can provide real-time information. The present work illustrates a new method to determine the concentration of microalgae in water and wastewater using spectrophotometry and the first derivative of absorbance. Chlorella vulgaris was used as an indicator microalga, spiked in water samples representing a range of water qualities (distilled water, surface water, and wastewater), and correlations among C. vulgaris concentrations, absorbance, and the first derivative of absorbance measurements were investigated. In addition, detection limits were established and sensitivity analyses were carried out to determine the lowest C. vulgaris concentrations that can be confidently measured in different water matrices. Finally, the study compared the performance and detection limits of the spectrophotometry-based methods with the well-accepted chlorophyll extraction method. A strong linear relationship (R2 > 0.97) was found between C. vulgaris concentration and absorbance at 695 nm. Using the first derivative of absorbance improved C. vulgaris detection limits by reducing the effects of the background noise and interferences from other substances. The detection limits established using the first derivative method were 0.47, 0.56, and 1.96 mg TVS/L in distilled water, surface water, and wastewater, respectively. In comparison, the detection limits of the chlorophyll extraction method were found to be 19.6, 38.6, and 48.3 mg TVS/L in the same water matrices. These results indicate that first derivative of absorbance can be successfully used for monitoring of microalgae in surface waters and environmental samples as well as in bioreactors used for microalgae cultivation in industrial applications.


Asunto(s)
Clorofila/análisis , Monitoreo del Ambiente/métodos , Microalgas/crecimiento & desarrollo , Reactores Biológicos , Chlorella vulgaris/crecimiento & desarrollo , Aguas Residuales/química
9.
Environ Technol ; 35(13-16): 1596-604, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24956749

RESUMEN

The goal of this study was to investigate the potential use ofmoving bed biofilm reactor (MBBR) systems as ammonia removal post-treatment units for wastewater (WW) treatment lagoons that demonstrate large temperature changes throughout their operational year (1 - 20 degrees C). The study was carried out over a six-month period using laboratory-scale MBBR reactors fed with incoming effluent from a full-scale lagoon. The study shows that significant average ammonia removal rates of 0.26 and 0.11 kgN/m . d were achieved at 20 degrees C and 1C. The increase in the ammonia removal rates with increasing temperature from 1 degrees C to 20 degrees C showed a strong correlation to an applied temperature correction coefficient model. No significant accumulation of effluent nitrite was observed at 1 degrees C or after being fed with synthetic wastewater (SWW); indicating that cold temperatures and transitions from real WW to SWW did not stress the nitrifiers. Furthermore, the study demonstrates that changes in temperature or changes from real WW to SWW do not affect the mass of biofilm attached per MBBR carrier. Hence, based on the results of this study, it is concluded that MBBR is a promising technology for post-treatment ammonia removal of WW lagoon effluent.


Asunto(s)
Amoníaco/aislamiento & purificación , Reactores Biológicos , Frío , Nitrificación , Purificación del Agua/instrumentación , Aclimatación , Biopelículas , Cinética , Modelos Biológicos
10.
Heliyon ; 10(18): e37888, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39381202

RESUMEN

To meet the required load of a farm in the rural area in Mafraq, Jordan, the complete floating photovoltaic (FPV) water pumping sizing, modelling, and optimization of an on-grid PV system with comprehensive capacity, energy output cost, and emission estimations are outlined in this work. The novelty of this study lies in its comprehensive approach that integrates technical, environmental, and economic factors into a unified framework for designing a PV water pumping system, particularly in scenarios where grid supply is feasible or economically viable. A proposal has been made to install PV panels over the water lake to improve the overall system efficiency and to give an aesthetic appearance. The proposed system is composed of a 165 kW PV array and three 55 kW inverters, which cost 54696.92 JD as the initial cost, CO2 emission reduction of more than 5000 tons and produce electricity at 0.028 JD/kWh. The results indicated that the FPV option demonstrates an about 5 % increase in efficiency compared to the other two scenarios. Also, the FPV option has higher costs due to a 25 % increase in system cost but results in lower CO2 emissions compared to the other two options. Top of Form As shown from the results, the two sizing methods for solar water pumping systems, the equations-based method, and the PVsyst simulation tool give the same results. By following this methodology, one can assess the load, size the system, simulate its operation, and analyse the expected performance. Furthermore, the findings of this study could be valuable in designing a grid-connected FPV water pumping system.

11.
Chemosphere ; 365: 143373, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39306101

RESUMEN

Humic acid (HA) is a prominent contaminant in wastewater, and its elimination is crucial to ensure purified drinking water. A variety of sources of HA in wastewater exist, ranging from agricultural runoff, industrial discharges, and natural decomposition. Adsorption is a technique that has been heavily investigated in this direction. The process complexities, technological advancements, and sustainable approaches are discussed in this review. A range of adsorbents can be employed for HA removal, including modified membranes, carbon nanotubes (CNTs), clay nanoparticles, and acid-modified natural materials. This work compares the effectiveness of the preceding adsorbents along with their advantages and limitations. This review also discusses the optimization of various process parameters, such as pH, ionic strength, and temperature, with an emphasis on response surface methodology for process optimization. Furthermore, the challenges and limitations associated with each removal technique are discussed, along with the potential areas for improvement and future directions in the field of wastewater treatment.


Asunto(s)
Sustancias Húmicas , Nanotubos de Carbono , Aguas Residuales , Contaminantes Químicos del Agua , Purificación del Agua , Sustancias Húmicas/análisis , Adsorción , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/análisis , Aguas Residuales/química , Purificación del Agua/métodos , Nanotubos de Carbono/química , Concentración de Iones de Hidrógeno , Concentración Osmolar , Eliminación de Residuos Líquidos/métodos
12.
Environ Pollut ; 343: 123190, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38142809

RESUMEN

Microplastic pollution has emerged as a new environmental concern due to our reliance on plastic. Recent years have seen an upward trend in scholarly interest in the topic of microplastics carrying contaminants; however, the available review studies have largely focused on specific aspects of this issue, such as sorption, transport, and toxicological effects. Consequently, this review synthesizes the state-of-the-art knowledge on these topics by presenting key findings to guide better policy action toward microplastic management. Microplastics have been reported to absorb pollutants such as persistent organic pollutants, heavy metals, and antibiotics, leading to their bioaccumulation in marine and terrestrial ecosystems. Hydrophobic interactions are found to be the predominant sorption mechanism, especially for organic pollutants, although electrostatic forces, van der Waals forces, hydrogen bonding, and pi-pi interactions are also noteworthy. This review reveals that physicochemical properties of microplastics, such as size, structure, and functional groups, and environmental compartment properties, such as pH, temperature, and salinity, influence the sorption of pollutants by microplastic. It has been found that microplastics influence the growth and metabolism of organisms. Inadequate methods for collection and analysis of environmental samples, lack of replication of real-world settings in laboratories, and a lack of understanding of the sorption mechanism and toxicity of microplastics impede current microplastic research. Therefore, future research should focus on filling in these knowledge gaps.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Microplásticos/toxicidad , Microplásticos/química , Plásticos/análisis , Contaminantes Ambientales/toxicidad , Contaminantes Ambientales/análisis , Ecosistema , Contaminantes Químicos del Agua/análisis , Adsorción
13.
Environ Technol ; 34(9-12): 1473-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24191481

RESUMEN

The present work compares electrochemical degradation of red and blue azo textile dyes in single- and two-compartment electrochemical cells in the presence of Fenton reagent (Fe2+) and using a boron-doped diamond anode. Degradation of both dyes was related to the concentration of dye, applied current density and the concentration of FeSO4 catalyst. Complete colour removal and approximately 91% of organic matter oxidation was achieved in a two-compartment electrochemical cell at an applied current density of 20 mA x cm(-2), pH of 3 and Fe(2+) ion concentration of 0.02 mM. Higher current density and reaction time were required to achieve the same removals in a one-compartment electrochemical cell. Dye degradation kinetics as well as chemical oxygen demand removal rate were successfully modelled to pseudo first-order kinetics. The apparent first-order rate constants (k(o)) for degradation of red dye with an initial concentration of 20, 40 and 60 ppm were found to be 2.67 +/- 0.16, 2.19 +/- 0.09 and 1.5 +/- 0.03 min(-1), and for blue dye at the same initial concentrations were 1.99 +/- 0.2, 0.95 +/- 0.02 and 0.71 +/- 0.030 min(-1), respectively.


Asunto(s)
Compuestos Azo/química , Boro/química , Colorantes/química , Diamante/química , Eliminación de Residuos Líquidos/métodos , Compuestos Azo/análisis , Análisis de la Demanda Biológica de Oxígeno , Electrodos , Compuestos Ferrosos/química , Cinética , Oxidación-Reducción , Aguas Residuales/química , Contaminantes Químicos del Agua
14.
Heliyon ; 9(11): e21227, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37954330

RESUMEN

The past decade has witnessed a breakthrough in novel strategies to treat cancer. One of the most common cancer treatment modalities is chemotherapy which involves administering anti-cancer drugs to the body. However, these drugs can lead to undesirable side effects on healthy cells. To overcome this challenge and improve cancer cell targeting, many novel nanocarriers have been developed to deliver drugs directly to the cancerous cells and minimize effects on the healthy tissues. The majority of the research studies conclude that using drugs encapsulated in nanocarriers is a much safer and more effective alternative than delivering the drug alone in its free form. This review provides a summary of the types of nanocarriers mainly studied for cancer drug delivery, namely: liposomes, polymeric micelles, dendrimers, magnetic nanoparticles, mesoporous nanoparticles, gold nanoparticles, carbon nanotubes and quantum dots. In this review, the synthesis, applications, advantages, disadvantages, and previous studies of these nanomaterials are discussed in detail. Furthermore, the future opportunities and possible challenges of translating these materials into clinical applications are also reported.

15.
Environ Sci Pollut Res Int ; 30(44): 98895-98906, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36036347

RESUMEN

This work presents a novel triple-renewable energy system (TRES) that is based on integrating the photovoltaic panels (PVPs), conventional solar chimney (CSC), and cooling tower (CT) in one structure. The ultimate objective of the proposed TRES system is to produce electrical power (Pelc), desalinated water (Dw), and if required cooling utilities. The components of the system include a chimney tower, collector, base, PVPs, water pool, bi-directional turbine, and water sprinklers. The TRES system can be operated as CSC during the daytime and CT at night providing 24-h operation. The PVPs were integrated within the structure to increase the Pelc production and enhance the process performance by heating the air inside the system. The TRES structure increased the efficiency to 0.860% in comparison with the CSC (0.313%). The annual Pelc production from the TRES system was found to be 792 MWh compared with only 380 MWh generated by the CSC achieving 2.1 folds overall improvement. The CSC-PV and CT contributed to 47% (494 MWh) and 24% (253 MWh) of the Pelc production, respectively. The annual Dw production was found to be 1.2-fold higher (163,142 tons) higher than the CSC (139,443 tons). The newly developed TRES system offers a great potential to produce Pelc and Dw and save fossil fuel consumption while reducing the emissions of greenhouse gasses (GHGs) to the atmosphere.


Asunto(s)
Energía Solar , Agua , Energía Renovable , Luz Solar , Combustibles Fósiles , Electricidad
16.
Environ Pollut ; 336: 122473, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37659632

RESUMEN

While the study of bioaerosols has a long history, it has garnered heightened interest in the past few years, focusing on both culture-dependent and independent sampling and analysis approaches. Observations have been made regarding the seasonal fluctuations in microbial communities and their connection to particular ambient atmospheric factors. The study of airborne microbial communities is important in public health and atmospheric processes. Nevertheless, the establishment of standardized protocols for evaluating airborne microbial communities and utilizing microbial taxonomy as a means to identify distinct bioaerosols sources and seasonal patterns remains relatively unexplored. This article discusses the challenges and limitations of ambient bioaerosols sampling and analysis, including the lack of standardized methods and the heterogeneity of sources. Future prospects in the field of bioaerosols, including the use of high-throughput sequencing technologies, omics studies, spectroscopy and fluorescence-based monitoring to provide comprehensive incite on metabolic capacity, and activity are also presented. Furthermore, the review highlights the factors that affect bioaerosols composition, including seasonality, atmospheric conditions, and pollution levels. Overall, this review provides a valuable resource for researchers, policymakers, and stakeholders interested in understanding and managing bioaerosols in various environments.


Asunto(s)
Microbiología del Aire , Clima , Aerosoles/análisis , Contaminación Ambiental/análisis , Salud Pública , Monitoreo del Ambiente/métodos
17.
Environ Pollut ; 336: 122401, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37598930

RESUMEN

This study investigates the size distribution, microbial composition, and antibiotic resistance (ABR) of airborne bioaerosols at a suburban location in Doha, Qatar between October 2021 and January 2022. Samples were collected using an Andersen six-stage viable cascade impactor and a liquid impinger. Findings showed that the mean bacteria concentration (464 CFU/m3) was significantly higher than that of fungi (242 CFU/m3) during the study period. Both bacteria and fungi were most abundant in the aerodynamic size fractions of 1.10-2.21 µm, with peak concentrations observed in the mornings and lowest concentrations in the afternoons across all size fractions. A total of 24 different culturable species were identified, with the most abundant ones being Pasteurella pneumotropica (9.71%), Pantoea spp. 1 (8.73%), and Proteus penneri (7.77%) spp. At the phylum level, the bacterial community configurations during the autumn and winter seasons were nearly identical as revealed by molecular genomics, with Proteobacteria being the most predominant, followed by Firmicutes, Bacteroidetes, Acidobacteriota, and Planctomycetota. However, there was a significant variation in dominant genera between autumn and winter. The most abundant genera included Sphingomonas, Paraburkholderia, Comamonas, Bacillus, and Lysinibacillus. Several bacterial genera identified in this study have important public health and ecological implications, including the risk of respiratory tract infections. Furthermore, the study found that ABR was highest in December, with bioaerosols exhibiting resistance to at least 5 out of 10 antibiotics, and 100% resistance to Metronidazole in all samples. Metagenomics analysis revealed the presence of various airborne bacteria that were not detected through culture-dependent methods. This study provides valuable insights into the airborne microbial composition, temporal variability and ABR in the Arabian Gulf region.

18.
Water Sci Technol ; 66(3): 465-71, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22744674

RESUMEN

Electrochemical oxidation (decolorization/degradation) of blue and red commercial reactive azo dyes was carried out on boron-doped diamond (BDD) electrode. The effect of various quantities of FeSO(4) was investigated in the electro-Fenton reaction on BDD. Progress of dyes degradation during the electrolysis and electro-Fenton reaction was monitored by UV-visible absorption and by estimation of the chemical oxygen demand (COD). Direct electrolysis showed a limiting capacity for red and blue dye removal even at high current densities, e.g. maximum red color and COD removal were 70 and 20%, respectively at 30 mA cm(-2) after 300 min. Higher red and blue color removal efficiencies were achieved by electro-Fenton oxidation. Current density of 30 mA cm(-2) in the presence of 0.05 mmol/L of FeSO(4) resulted in the red color and COD removal of 98 and 96%, respectively. The optimum FeSO(4) concentration for the electro-Fenton reaction was determined to be 0.05 mmol/L. Instantaneous current efficiency (ICE) in the presence of FeSO(4) was almost three times higher than for experiments carried out without FeSO(4).


Asunto(s)
Compuestos Azo/química , Boro/química , Colorantes/química , Diamante/química , Electroquímica/métodos , Análisis de la Demanda Biológica de Oxígeno , Color , Electricidad , Electrodos , Peróxido de Hidrógeno/química , Hierro/química , Oxidación-Reducción , Espectrofotometría Ultravioleta , Factores de Tiempo
19.
Chemosphere ; 291(Pt 3): 133099, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34848221

RESUMEN

The formation of stable emulsions is a fundamental problem in oil industry that can result in a sequence of environmental and operational problems. Chemical demulsification is extensively applied for the recovery of oil from water as well as water from oil. This review introduces different chemical demulsifiers applied for the demulsification and recovery of oil from oil in water (O/W) emulsions. Main types of surfactants (anionic, cationic, nonionics and amphoteric) involved in the formation of emulsions and enhances their stability were discussed. Promising demulsifiers such as nanoparticle (NP), hyperbranched polymers, and ionic liquids (IL), which achieved high oil recovery rate, parameters influencing demulsification efficiency and demulsification mechanisms were explored. Lastly, improvements, challenges, and new changes being made to chemical demulsifiers were underlined. Functionalized magnetic nanoparticles and hyperbranched polymers were very effective in recovering oil from O/W emulsions with an efficiency >95%. Polymers with highly hydrophilic content and high molecular weight can achieve excellent oil recovery rates due to higher interfacial activity, higher dispersion, and presence of specific functional groups. Although ionic liquids could achieve oil recovery up to 90%, high cost limits their applications. NPs showed excellent oil recovery behavior at low concentrations and ambient temperature. Demulsification efficiency of NPs can be enhanced by functionalize with other components (e.g., polymers and surfactants), while service life can be extend by silica coating. Future challenges include scaling up the use of NPs in oil recovery process and highlighting contrasts between lab-scale and field-scale applications.


Asunto(s)
Líquidos Iónicos , Dióxido de Silicio , Emulsiones , Tensoactivos , Agua
20.
Membranes (Basel) ; 12(1)2022 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-35054621

RESUMEN

Diffusion dialysis (DD) is an anion exchange membrane-based functional separation process used for acid recovery. TMA (trimethylamine) and BPPO (brominated poly(2,6-dimethyl-1,4-phenylene oxide) were utilized in this manuscript to formulate AEMs (anion exchange membranes) for DD (diffusion dialysis) using the phase-inversion technique. FTIR (Fourier transfer infrared) analysis, proton NMR spectroscopy, morphology, IEC (ion exchange capacity), LER (linear expansion ratio), CR (fixed group concentration), WR (water uptake/adsorption), water contact angle, chemical, and thermal stability, were all used to evaluate the prepared membranes. The effect of TMA content within the membrane matrix on acid recovery was also briefly discussed. It was reported that porous AEMs have a WR of 149.6% to 233.8%, IEC (ion exchange capacity) of 0.71 to 1.43 mmol/g, CR (fixed group concentration) that ranged from 0.0046 mol/L to 0.0056 mol/L, LER of 3.88% to 9.23%, and a water contact angle of 33.10° to 78.58°. The UH (acid dialysis coefficients) for designed porous membranes were found to be 0.0043 to 0.012 m/h, with separation factors (S) ranging from 13.14 to 32.87 at the temperature of 25 °C. These observations are comparable to those found in the DF-120B commercial membrane with UH of 0.004 m/h and S of 24.3 m/h at the same temperature (25 °C). This porous membranes proposed in this paper are excellent choices for acid recovery through the diffusion dialysis process.

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