scholarly journals Use of Different Natural Products to Control Growth of Titanium Oxide Nanoparticles in Green Solvent Emulsion, Characterization, and Their Photocatalytic Application

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Eneyew Tilahun Bekele ◽  
Bedasa Abdisa Gonfa ◽  
Fedlu Kedir Sabir

Water, one of the crucial and the pillar resources to every living thing, could be polluted day to day by different causes such as expansion in industrialization, rapid increment in population size, the threat of climate, and growth of urbanization. The existence of a number of organic dyes, detergents, and pesticides from industrial effluents could lead to severe diseases and even to the death of human beings. Currently, remediation of those hazardous organic contaminants using semiconductor metal oxide catalysts has received extensive attention in recent years. Among the numerous nanometal oxides, titanium oxide (TiO2) nanoparticles (NPs) have been well known as a significant photocatalytic material due to their suitable physiochemical behaviors such as stability, conductivity, high surface area to volume ratio, structure, and porosity nature at the nanoscale level. TiO2 semiconductor nanoparticles could be synthesized via several physiochemical approaches; among those, the biogenic technique is the most selective one which involves the synthesis of NPs using different templates. Biogenic synthesis of nanoparticles is an environmentally friendly protocol that involves the use of different parts and types of biogenic sources such as bacteria, fungi, yeast, virus, and green plants or the byproducts of their metabolism, which act as both reducing and stabilizing agents. TiO2 NPs obtained via the biogenic method provide a potential application for the degradation of organic dyes and other pollutants in wastewater. This method of synthesis of NPs has been given a great attention by researchers due to their nontoxicity, low cost, environmental friendliness, the usage of green solvents, and simplicity of the process. This review focuses on summarizing the synthesis of TiO2 NPs using various biogenic sources, characterization, and their photocatalytic applications for the degradation of different wastes and organic dyes from polluted water.

Author(s):  
Utkarsh Chadha ◽  
Senthil Kumaran Selvaraj ◽  
S. Vishak Thanu ◽  
Vishnu Cholapadath ◽  
Ashesh Mathew Abraham ◽  
...  

Abstract Water is a necessity for all living and non-living organisms on this planet. It is understood that clean water sources are decreasing by the day, and the rapid rise of Industries and technology has led to an increase in the release of toxic effluents that are discharged into the environment. Wastewater released from Industries, agricultural waste, and municipalities must be treated before releasing into the environment as they contain harmful pollutants such as organic dyes, pharmaceuticals wastes, inorganic materials, and heavy metal ions. If not controlled, they can cause serious risks to human beings' health and contaminate our environment. Membrane filtration is a proven method for the filtration of various harmful chemicals and microbes from water. Carbon nanomaterials are applied in wastewater treatment due to their high surface area, making them efficient adsorbents. Carbon nanomaterials are being developed and utilized in membrane filtration for the treated wastewater before getting discharged with the rise of nanotechnology. This review studies carbon nanomaterials like fullerenes, graphenes, and CNTs incorporated in the membrane filtration to treat wastewater contaminants. We focus on these CNM based membranes and membrane technology, their properties and applications, and how they can enhance the commonly used membrane filtration performance by considering adsorption rate, selectivity, permeability, antimicrobial disinfectant properties, and compatibility with the environment.


2021 ◽  
Vol 22 (12) ◽  
pp. 6357
Author(s):  
Kinga Halicka ◽  
Joanna Cabaj

Sensors and biosensors have found applications in many areas, e.g., in medicine and clinical diagnostics, or in environmental monitoring. To expand this field, nanotechnology has been employed in the construction of sensing platforms. Because of their properties, such as high surface area to volume ratio, nanofibers (NFs) have been studied and used to develop sensors with higher loading capacity, better sensitivity, and faster response time. They also allow to miniaturize designed platforms. One of the most commonly used techniques of the fabrication of NFs is electrospinning. Electrospun NFs can be used in different types of sensors and biosensors. This review presents recent studies concerning electrospun nanofiber-based electrochemical and optical sensing platforms for the detection of various medically and environmentally relevant compounds, including glucose, drugs, microorganisms, and toxic metal ions.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Garima Rathee ◽  
Amardeep Awasthi ◽  
Damini Sood ◽  
Ravi Tomar ◽  
Vartika Tomar ◽  
...  

Abstract It would be of great significance to introduce a new biocompatible Layered Double Hydroxide (LDH) for the efficient remediation of wastewater. Herein, we designed a facile, biocompatible and environmental friendly layered double hydroxide (LDH) of NiFeTi for the very first time by the hydrothermal route. The materialization of NiFeTi LDH was confirmed by FTIR, XRD and Raman studies. BET results revealed the high surface area (106 m2/g) and the morphological studies (FESEM and TEM) portrayed the sheets-like structure of NiFeTi nanoparticles. The material so obtained was employed as an efficient adsorbent for the removal of organic dyes from synthetic waste water. The dye removal study showed >96% efficiency for the removal of methyl orange, congo red, methyl blue and orange G, which revealed the superiority of material for decontamination of waste water. The maximum removal (90%) of dyes was attained within 2 min of initiation of the adsorption process which supported the ultrafast removal efficiency. This ultrafast removal efficiency was attributed to high surface area and large concentration of -OH and CO32− groups present in NiFeTi LDH. In addition, the reusability was also performed up to three cycles with 96, 90 and 88% efficiency for methyl orange. Furthermore, the biocompatibility test on MHS cell lines were also carried which revealed the non-toxic nature of NiFeTi LDH at lower concentration (100% cell viability at 15.6 μg/ml). Overall, we offer a facile surfactant free method for the synthesis of NiFeTi LDH which is efficient for decontamination of anionic dyes from water and also non-toxic.


Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-26 ◽  
Author(s):  
Helge Skarphagen ◽  
David Banks ◽  
Bjørn S. Frengstad ◽  
Harald Gether

Borehole thermal energy storage (BTES) exploits the high volumetric heat capacity of rock-forming minerals and pore water to store large quantities of heat (or cold) on a seasonal basis in the geological environment. The BTES is a volume of rock or sediment accessed via an array of borehole heat exchangers (BHE). Even well-designed BTES arrays will lose a significant quantity of heat to the adjacent and subjacent rocks/sediments and to the surface; both theoretical calculations and empirical observations suggest that seasonal thermal recovery factors in excess of 50% are difficult to obtain. Storage efficiency may be dramatically reduced in cases where (i) natural groundwater advection through the BTES removes stored heat, (ii) extensive free convection cells (thermosiphons) are allowed to form, and (iii) poor BTES design results in a high surface area/volume ratio of the array shape, allowing high conductive heat losses. The most efficient array shape will typically be a cylinder with similar dimensions of diameter and depth, preferably with an insulated top surface. Despite the potential for moderate thermal recovery, the sheer volume of thermal storage that the natural geological environment offers can still make BTES a very attractive strategy for seasonal thermal energy storage within a “smart” district heat network, especially when coupled with more efficient surficial engineered dynamic thermal energy stores (DTES).


2008 ◽  
Vol 72 (1) ◽  
pp. 85-89 ◽  
Author(s):  
J. R. Leake ◽  
A. L. Duran ◽  
K. E. Hardy ◽  
I. Johnson ◽  
D. J. Beerling ◽  
...  

AbstractBiological weathering is a function of biotic energy expenditure. Growth and metabolism of organisms generates acids and chelators, selectively absorbs nutrient ions, and applies turgor pressure and other physical forces which, in concert, chemically and physically alter minerals. In unsaturated soil environments, plant roots normally form symbiotic mycorrhizal associations with fungi. The plants provide photosynthate-carbohydrate-energy to the fungi in return for nutrients absorbed from the soil and released from minerals. In ectomycorrhiza, one of the two major types of mycorrhiza of trees, roots are sheathed in fungus, and 15—30% of the net photosynthate of the plants passes through these fungi into the soil and virtually all of the water and nutrients taken up by the plants are supplied through the fungi. Here we show that ectomycorrhizal fungi actively forage for minerals and act as biosensors that discriminate between different grain sizes (53—90 μm, 500—1000 μm) and different minerals (apatite, biotite, quartz) to favour grains with a high surface-area to volume ratio and minerals with the highest P content. Growth and carbon allocation of the fungi is preferentially directed to intensively interact with these selected minerals to maximize resource foraging.


Author(s):  
Edit Hirsch ◽  
Márió Nacsa ◽  
Ferenc Ender ◽  
Miklós Mohai ◽  
Zsombor K. Nagy ◽  
...  

Nanoscale fibers were prepared for the fabrication of scaffolds by using a strong electrostatic field on the polymer solution. Electrospinning is widely applied for production of drug delivery, tissue engineering, and regenerative medicine systems as well as biosensors and enzyme immobilization. Nanofibers, thanks to their high surface area to volume ratio, can also mimic the extracellular matrix, thus it has been recognized as a suitable technique for the fast fabrication of scaffolds. This article demonstrates the fabrication of several nanofibrous scaffolds from biopolymers such as polycaprolactone, poly(lactic acid), poly(lactide-co-glycolide), poly(lactide-co-caprolactone) and poly(hydroxybutyrate-co-hydroxy valerate). The characterization and comparison of the scaffolds were achieved based on the morphology and surface characteristic of the nanofibers. The samples showed hydrophobic characteristic, thus a plasma surface treatment was applied successfully to increase hydrophilicity and the effect of the treatment was evaluated based on the wettability and the change in elemental composition of the surface based on X-ray photoelectron spectroscopy.


2020 ◽  
Vol 9 (4) ◽  
pp. 93-99
Author(s):  
Hung Mac Van ◽  
Tuan Vu Anh

Corals-like molybdenum disulfide (MoS2) have been successfully synthesized via the hydrothermal method. The as-prepared MoS2 material with a high surface area of 83.9 m2.g-1 was used for the removal of tartrazine from an aqueous solution. The effects of parameters including contact time, MoS2 dosage, and solution pH on adsorption capacity were studied. The optimal dosage of MoS2 for removing tartrazine was 0.08 g and the removal efficiency of tartrazine reached 81.5 % for 100 min of adsorption. The adsorption kinetics studies were carried out using pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. The results showed that the pseudo-second-kinetic model better described the adsorption kinetics of tartrazine on MoS2 and film diffusion was the rate-limiting step. In addition, the adsorption capacity of MoS2 was also performed with various organic dyes such as nile blue, janus green B, and congo red.


Author(s):  
Andrew D. Dias ◽  
David M. Kingsley ◽  
Douglas B. Chrisey ◽  
David T. Corr

Microbeads are becoming popular tools in tissue engineering as 3D microstructure hydrogels. The gel nature of microbeads enables them to sequester soluble factors and mammalian cells, and their high surface area-to-volume ratio allows diffusion between the bead and the environment [1,2]. Microbeads are thus good systems for drug delivery and can serve as 3D microenvironments for cells. To fully maximize their potential as delivery systems and microenvironments, it is highly desirable to create spatially-precise hybrid cultures of microbeads and mammalian cells. Precise placement of microbeads in proximity to patterned cells will allow the study of spatial cellular interactions, paracrine signaling, and drug delivery.


Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1760 ◽  
Author(s):  
Fernanda Guerra ◽  
Mohamed Attia ◽  
Daniel Whitehead ◽  
Frank Alexis

Environmental remediation relies mainly on using various technologies (e.g., adsorption, absorption, chemical reactions, photocatalysis, and filtration) for the removal of contaminants from different environmental media (e.g., soil, water, and air). The enhanced properties and effectiveness of nanotechnology-based materials makes them particularly suitable for such processes given that they have a high surface area-to-volume ratio, which often results in higher reactivity. This review provides an overview of three main categories of nanomaterials (inorganic, carbon-based, and polymeric-based materials) used for environmental remediation. The use of these nanomaterials for the remediation of different environmental contaminants—such as heavy metals, dyes, chlorinated organic compounds, organophosphorus compounds, volatile organic compounds, and halogenated herbicides—is reviewed. Various recent examples are extensively highlighted focusing on the materials and their applications.


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