scholarly journals Application of Titanium Dioxide Nanoparticles Synthesized by Sol-Gel Methods in Wastewater Treatment

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Saka Abel ◽  
Leta Tesfaye Jule ◽  
Fikadu Belay ◽  
R. Shanmugam ◽  
L. Priyanka Dwarampudi ◽  
...  

Nanotechnology from titanium dioxide has been deposited, and its application in desalination and water treatment has been investigated by using sol-gel methods. Homogeneously dispersed sphere shapes of titanium dioxide nanoparticles were observed from scanning electron microscope micrographs and decrease in size as aging time increases from 40 min to 60 min. SEM micrographs of highly transparent nanopowders show that they are detected in the visible region from UV/visible and that their red shift around maximum wavelength increases with increasing aging time due to an increase in water quality. The energy band gap of the generated nanosheet has narrowed as the aging time has increased, which is related to the red shift of the absorption spectrum edge in the sheet. The structural behaviors of deposited nanoparticles have also been investigated, which confirms the existence of anatase as well as rutile levels in the liquid phase. The findings of the PL allowed us to determine the total strength of the intensity. This shows that applying photodegradation by a solar absorber could play a vital role in desalination and water treatment.

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 625
Author(s):  
Fatma Y. Ahmed ◽  
Usama Farghaly Aly ◽  
Rehab Mahmoud Abd El-Baky ◽  
Nancy G. F. M. Waly

Most of the infections caused by multi-drug resistant (MDR) P. aeruginosa strains are extremely difficult to be treated with conventional antibiotics. Biofilm formation and efflux pumps are recognized as the major antibiotic resistance mechanisms in MDR P. aeruginosa. Biofilm formation by P. aeruginosa depends mainly on the cell-to-cell communication quorum-sensing (QS) systems. Titanium dioxide nanoparticles (TDN) have been used as antimicrobial agents against several microorganisms but have not been reported as an anti-QS agent. This study aims to evaluate the impact of titanium dioxide nanoparticles (TDN) on QS and efflux pump genes expression in MDR P. aeruginosa isolates. The antimicrobial susceptibility of 25 P. aeruginosa isolates were performed by Kirby–Bauer disc diffusion. Titanium dioxide nanoparticles (TDN) were prepared by the sol gel method and characterized by different techniques (DLS, HR-TEM, XRD, and FTIR). The expression of efflux pumps in the MDR isolates was detected by the determination of MICs of different antibiotics in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Biofilm formation and the antibiofilm activity of TDN were determined using the tissue culture plate method. The effects of TDN on the expression of QS genes and efflux pump genes were tested using real-time polymerase chain reaction (RT-PCR). The average size of the TDNs was 64.77 nm. It was found that TDN showed a significant reduction in biofilm formation (96%) and represented superior antibacterial activity against P. aeruginosa strains in comparison to titanium dioxide powder. In addition, the use of TDN alone or in combination with antibiotics resulted in significant downregulation of the efflux pump genes (MexY, MexB, MexA) and QS-regulated genes (lasR, lasI, rhll, rhlR, pqsA, pqsR) in comparison to the untreated isolate. TDN can increase the therapeutic efficacy of traditional antibiotics by affecting efflux pump expression and quorum-sensing genes controlling biofilm production.


2021 ◽  
Vol 8 (3) ◽  
pp. 711-722
Author(s):  
Katherine E. Greenstein ◽  
Matthew R. Nagorzanski ◽  
Bailey Kelsay ◽  
Edgard M. Verdugo ◽  
Nosang V. Myung ◽  
...  

Electrospun carbon nanofibers with integrated titanium dioxide nanoparticles are used for water treatment in a photoactive membrane filtration system.


2020 ◽  
Vol 854 ◽  
pp. 45-50
Author(s):  
Ekaterina N. Gubareva ◽  
Valeria V. Strokova ◽  
Yulia N. Ogurtsova ◽  
Pavel S. Baskakov ◽  
Lok Pratap Singh

The paper presents the process of sol-gel synthesis of titanium dioxide nanoparticles, the peculiarities of the influence of component composition (titanium precursor content, solvent and stabilizer − surfactant) on the properties of sol and powder obtained on its basis. As a result of the study, the nature of the influence of the type and content of the surfactant in the solution of tetrabutoxytitanium in ethanol on the size of the synthesized particles of titanium dioxide was revealed. The optimal composition of the reaction mixture of TiO–R sol was obtained and the optimal ratio of tetrabutoxytitanium and ethyl alcohol was revealed using which a material with a high content of nanosized titanium dioxide was obtained.


2012 ◽  
Vol 568 ◽  
pp. 380-383
Author(s):  
Song Tian Li ◽  
Guo Xu He ◽  
Wei Ma ◽  
Yan Hua Liu

In order to expand photoresponse range of TiO2, reduce energy consumption of semiconductor material optical catalytic, certain amount of rare earth element Erbiun was doped during preparation of anatase titanium dioxide to improve the light absorption and photocatalysis efficiency. A series of rare earth element doped TiO2 material were prepared by sol-gel process, and characterized by means of UV-vis diffuse reflectance spectra. UV-vis absorption verified that doping of Er3+ enhanced absorptive capacity of catalyst in visible region. The photocatalytic performance of anatase titanium dioxide and rare earth element Erbiun doped with TiO2 to basic fuchsin were studied.


2020 ◽  
Author(s):  
Tchemongo B. Berté ◽  
Anthony S. Chen ◽  
Riya A. Mathew ◽  
Sheyda Shakiba ◽  
Stacey M. Louie

Immobilization of titanium dioxide nanoparticles (TiO<sub>2</sub> NPs) facilitates their removal and reuse in water treatment applications. Composite materials of electrostatically-bound TiO<sub>2</sub> NPs and zeolite particles have been proposed, but limited mechanistic studies are available on their performance in complex media. This study delineates the relative importance of homo- and heteroaggregation, water chemistry, and surface fouling by natural organic matter (NOM) on the photocatalytic degradation of diethyltoluamide (DEET) by TiO<sub>2</sub>-zeolite composites. Zeolite adsorbs a portion of the DEET, rendering it unavailable for degradation; corrections for this adsorption depletion allowed appropriate comparison of the reactivity of the composites to the NPs alone. The TiO<sub>2</sub>-zeolite composites showed enhanced DEET degradation in moderately hard water (MHW) compared to deionized water (DIW), likely attributable to the influence of HCO<sub>3</sub><sup>−</sup>, whereas a net decline in reactivity was observed for the TiO<sub>2</sub> NPs alone upon homoaggregation in MHW. The composites also better maintained reactivity in the presence of NOM in MHW, as removal of Ca<sup>2+</sup> onto the zeolite mitigated fouling of the TiO<sub>2</sub> surface by NOM. However, NOM induced partial dissociation of the composites. DEET byproduct formation, identified by quadrupole–time of flight (QTOF) mass spectrometry, was generally unaffected by the zeolite, while NOM fouling favored de-ethylation over hydroxylation products. Overall, the most significant factor influencing TiO<sub>2</sub> reactivity toward DEET was NOM adsorption, followed by homoaggregation, electrolytes (here, MHW versus DIW), and heteroaggregation. These findings can inform a better understanding of NP reactivity in engineered water treatment applications.


2010 ◽  
Vol 8 (1) ◽  
pp. 142-148 ◽  
Author(s):  
L. Gomathi Devi ◽  
Nagaraju Kottam ◽  
S. Girish Kumar ◽  
K. Eraiah Rajashekhar

AbstractAnatase TiO2 was prepared by sol-gel method through the hydrolysis of TiCl4. Ni2+ was doped into the TiO2 matrix in the concentration range of 0.02 to 0.1 at.% and characterized by various analytical techniques. Powder X-ray diffraction revealed only anatase phase for all the samples, while diffuse reflectance spectral studies indicated a red shift in the band gap absorption to the visible region. The photocatalytic activities of these photocatalysts were probed for the degradation of methyl orange under natural solar light. The photocatalyst with optimum doping of 0.08 at.% Ni2+, showed enhanced activity, which is attributed to: (i) effective separation of charge carriers and (ii) large red shift in the band gap to visible region. The influence of crystallite size and dopant concentration on the charge carrier trapping — recombination dynamics is investigated.


2011 ◽  
Vol 76 (11) ◽  
pp. 1335-1346 ◽  
Author(s):  
Jing Wei ◽  
Xin Tan ◽  
Tao Yu ◽  
Lin Zhao

A series of copper-modified titanium dioxide (Cu/TiO2) nanoparticles were synthesized via one-step sol-gel method. The crystal structure and chemical properties were characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Cu/TiO2nanoparticles were applied to CO2photoconversion and the yield of formaldehyde was used to evaluate the photocatalytic performance. The optimum amount of copper modifying was 0.6 wt.% and the yield of formaldehyde was 946 μmol/gcatunder UV illumination for 6 h. 20 wt.% Cu/TiO2also performed a high photocatalytic activity, which yielded 433 μmol/gcatformaldehyde under UV illumination for 6 h.


2009 ◽  
Vol 4 (4) ◽  
pp. 187-191 ◽  
Author(s):  
H.A. Monreal ◽  
A. Martínez-Villafañe ◽  
P.G. Casillas ◽  
C.A. Martínez ◽  
U. Arce-Colunga ◽  
...  

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