scholarly journals Effect of Trifluralin, Zero-Valent Iron and Magnetite Nanoparticles on Growth of Micromycetes

Author(s):  
Valentina Josan ◽  
Inna Rastimesina ◽  
Olga Postolachi ◽  
Tatiana Gutul

Abstract Nowadays many reports confirmed the effect of different nanoparticles (NPs) on the growth and secondary metabolite production in various microorganisms. Some of them, NPs like Ag, Au and oxides of Al, Ti, Si and Zn have harmful effect on the cells of microorganisms. Iron NPs are expected to be nontoxic, due to using Fe atom in several pathways of cell metabolism and, therefore, low iron toxicity. The use of iron NPs in technologies for remedying polluted environment was caused by their efficiency in reduction reactions, mobility, and high reactivity, due to the high surface area. The present study aims to determine the effect of magnetite (Fe3O4), zero-valent iron Fe(0) NPs, and fluorinated dinitroaniline herbicide trifluralin on growth of mycelial fungi. Fungal strains were isolated from soil long-term polluted with obsolete pesticides, DDT and trifluralin. The inhibition activity of iron NPs and trifluralin was evaluated using express-method. Each fungal strain had an individual reaction to the solutions of iron nanoparticles. At the same time, Fe(0) NPs, as well as magnetite NPs, had a stimulating effect on the formation and maturation of spores of micromycetes. Addition of trifluralin to the culture medium had a growth inhibition effect on micromycetes, but this effect was reduced, when trifluralin was mixed and incubated with iron NPs for 1 hour before.

2020 ◽  
Vol 50 (2) ◽  
pp. 59-64
Author(s):  
Carlos Negro ◽  
Ana Balea Martín ◽  
Jose Luis Sanchez-Salvador ◽  
Cristina Campano ◽  
Elena Fuente ◽  
...  

Nanocellulose (NC) and its wide applications have attracted high attention due to its desirable properties such as high surface area, extraordinary mechanical properties, high reactivity and easy modification of NC surface due to the presence of primary hydroxyl groups. NC also presents several environmental benefits, including high potential availability because its production is coming from natural sources, renewability and nontoxicity. This paper briefly summarizes some of the activities of the research group “Cellulose, Paper and Water Advanced Treatments” from Complutense University of Madrid that were presented in CAIQ 2019, including the main types of NC, the production processes and their characterization. Additionally, the most promising NC applications are described such as for paper and board, for wastewater treatment, food and cement-based materials. Moreover, a market perspective of NC is also presented.


1998 ◽  
Vol 26 ◽  
pp. 69-72 ◽  
Author(s):  
Martin Schneebeli ◽  
Cécile Coléou ◽  
François Touvier ◽  
Bernard Lesaffre

Time-domain reflectometry (TDR) is widely used in soil physics to determine water content. Existing equipment and methods ran be adapted to measurements of snow wetness. The main advantages compared to other methods are flexibility in constructing sensors, minimal influence on snow cover during measurements and sensors can be multiplexed. We developed sensors suitable for continuous and non-continuous measurements of snow wetness and density, measured the apparent permittivity in different snow densities and snow types, and compared the measurements to existing mixing formulas for mixtures of snow and air. In dry snow, density was measured from 110 to 470 kg m−3. The residual error is 14 kg m −3 and the 95% confidence interval of our model is 3 kg m−3. To measure snow density and wetness continuously suitable sensors have been constructed. Their small size and high surface area to weight ratio minimizes their movement in the snowpack, except when they are exposed to intense solar radiation. Results show that changes in dry-snow density of less than 5 kgm−3 can be detected. Infiltration of even small amounts of water clearly shows up in the permittivity. At the surface of the snowpack, problems occur due to the formation of air pockets around the sensors during long-term measurements.


1998 ◽  
Vol 26 ◽  
pp. 69-72 ◽  
Author(s):  
Martin Schneebeli ◽  
Cécile Coléou ◽  
François Touvier ◽  
Bernard Lesaffre

Time-domain reflectometry (TDR) is widely used in soil physics to determine water content. Existing equipment and methods ran be adapted to measurements of snow wetness. The main advantages compared to other methods are flexibility in constructing sensors, minimal influence on snow cover during measurements and sensors can be multiplexed. We developed sensors suitable for continuous and non-continuous measurements of snow wetness and density, measured the apparent permittivity in different snow densities and snow types, and compared the measurements to existing mixing formulas for mixtures of snow and air. In dry snow, density was measured from 110 to 470 kg m−3. The residual error is 14 kg m −3 and the 95% confidence interval of our model is 3 kg m−3. To measure snow density and wetness continuously suitable sensors have been constructed. Their small size and high surface area to weight ratio minimizes their movement in the snowpack, except when they are exposed to intense solar radiation. Results show that changes in dry-snow density of less than 5 kgm−3 can be detected. Infiltration of even small amounts of water clearly shows up in the permittivity. At the surface of the snowpack, problems occur due to the formation of air pockets around the sensors during long-term measurements.


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1225 ◽  
Author(s):  
Dengchao Xia ◽  
Junpeng Quan ◽  
Guodong Wu ◽  
Xinling Liu ◽  
Zongtao Zhang ◽  
...  

Novel N-doped carbon nanonet flakes (NCNFs), consisting of three-dimensional interconnected carbon nanotube and penetrable mesopore channels were synthesized in the assistance of a hybrid catalytic template of silica-coated-linear polyethyleneimine (PEI). Resorcinol-formaldehyde resin and melamine were used as precursors for carbon and nitrogen, respectively, which were spontaneously formed on the silica-coated-PEI template and then annealed at 700 °C in a N2 atmosphere to be transformed into the hierarchical 3D N-doped carbon nanonetworks. The obtained NCNFs possess high surface area (946 m2 g−1), uniform pore size (2–5 nm), and excellent electron and ion conductivity, which were quite beneficial for electrochemical double-layered supercapacitors (EDLSs). The supercapacitor synthesized from NCNFs electrodes exhibited both extremely high capacitance (up to 613 F g−1 at 1 A g−1) and excellent long-term capacitance retention performance (96% capacitive retention after 20,000 cycles), which established the current processing among the most competitive strategies for the synthesis of high performance supercapacitors.


2013 ◽  
Vol 1498 ◽  
pp. 91-96 ◽  
Author(s):  
Sajid Bashir ◽  
James Dinn ◽  
Jingbo Liu

ABSTRACTMetallic silver nanoparticles (NPs) have extensively been used in the treatment of disease and purification and heralded the ‘first wave’ of disinfection science, the ‘second wave’ being the nanocomposite of metal-doped TiO2. Recent advances in engineered surfaces have enabled ultrahigh surface area and rapid sterilization via using metal-organic frameworks (MOFs) as the ‘third wave’ disinfectant. MOFs offer the same advantages as colloids but also have ultra high surface area, long term persistence and ultra low doses, applied for water purification.


Author(s):  
E.A. Mun ◽  
B.A. Zhaisanbayeva

Over the past few decades, nanoparticles have been attracting significant attention of researches in chemical, biomedical, pharmaceutical sciences, due to their unique physicochemical properties. This includes ultra small size, large surface area, good biocompatibility and high reactivity. In particular, nanoparticles are promising for pharmaceutical and biomedical fields, as they can be applied as drug carriers and diagnostic tools. Among nanomaterials for biomedical application, silica nanoparticles exhibit great potential due to their straightforward synthesis and separation, low cost, safety, biocompatibility and possibility to further functionalization. Silica nanoparticles have been attractive for pharmaceutical science due to their unique properties, such as tunable size, high surface area and large pore volume, and potential in biomedical application as drug and gene delivery vectors and bioimaging agents. However, some of their properties remain poorly investigated. This short communication discusses the main routes for synthesis of silica nanoparticles, their properties and opportunities for their application in pharmaceutical and biomedical industries, as well as a few challenges in the development of silica-based systems that need to be overcome.


2007 ◽  
Vol 4 (4) ◽  
pp. 2793-2808
Author(s):  
B. A. S. Van Mooy ◽  
T. Moutin ◽  
S. Duhamel ◽  
P. Rimmelin ◽  
F. Van Wambeke

Abstract. Membrane lipid molecules are a major component of planktonic organisms and this is particularly true of the microbial picoplankton that dominate the open ocean; with their high surface-area to volume ratios, the synthesis of membrane lipids places a major demand on their overall cell metabolism. The synthesis of one class of membrane lipids, the phospholipids, also creates a demand for the nutrient phosphorus, and we sought to refine our understanding of the role of phospholipids in the upper ocean phosphorus cycle. We measured the rates of phospholipid synthesis in a transect of the eastern subtropical South Pacific from Easter Island to Concepcion, Chile as part of the BIOSOPE program. Our approach combined standard phosphorus radiotracer incubations and lipid extraction methods. We found that phospholipid synthesis rates varied from less than 1 to greater than 200 pmol P L−1 h−1, and that phospholipid synthesis contributed between less than 5% to greater than 22% of the total PO43− incorporation rate. Changes in the percentage that phospholipid synthesis contributed to total PO43− incorporation were strongly correlated with the ratio of primary production to bacterial production, which supported our hypothesis that heterotrophic bacteria were the primary agents of phospholipid synthesis. The spatial variation in phospholipid synthesis rates underscored the importance of heterotrophic bacteria in the phosphorus cycle of the eastern subtropical South Pacific, particularly the hyperoligotrophic South Pacific subtropical gyre.


2017 ◽  
Vol 17 (4) ◽  
pp. 1097-1105 ◽  
Author(s):  
Xiaodong Xin ◽  
Shaohua Sun ◽  
Mingquan Wang ◽  
Qinghua Zhao ◽  
Yan Chen ◽  
...  

N-Dimethylnitrosamine (NDMA) has aroused increasing concern among public health agencies. It is necessary to develop some effective methods to remove NDMA from drinking water. A reductive process has been investigated as an alternative treatment method for NDMA removal from water. In this manuscript, zero-valent iron nanoparticles (ZVINPs) were synthesized, and then supported on mesoporous silica materials with high surface area (MCM-41) to prepare a stable ZVINP/MCM-41 nanocomposite. X-ray diffraction measurements showed the stabilization of the ZVINPs upon their support on MCM-41, which enhanced their activity. The ZVINP/MCM-41 nanocomposite was used for the catalytic reduction of NDMA in the model solution, and the results showed the dependency of the removal process on the ZVINP/MCM-41 mass, time of removal, and solution pH. The mechanism of NDMA reduction by ZVINP/MCM-41 was studied, and the results showed the conversion of NDMA to unsymmetrical dimethylhydrazine, dimethylamine (DMA) and NH4+. The product analysis found that in the process of removal, adsorption and reduction existed at the same time.


Author(s):  
Brij Bhushan Tewari

Environmental contamination is one of the important issues that the world is facing today, it is always expanding and leading to the grave and harmful effect on the Earth. Nanoparticles have a diameter less than 100 nm exhibit new size-dependent properties compared with the bulk material. Engineered nanoparticles (ENPs) have unique characteristics in addition to the high surface area-to-volume ratio, which may increase their toxicity relative to bulk materials. Due to the high volume production of ENPs products such as carbon nanotubes, titanium dioxide, silver, zinc oxide environmental exposure to these compounds is very common. ENPs have their unique properties and applications in the areas of medicine, food& drink, construction, automotive, textiles, energy, electronics, environment etc. The present critical review is focused on the recent development of the applications of ENPs in the environmental remediation and their toxic effects.


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