Carbon–titanium dioxide (C/TiO2) nanofiber composites for chemical oxidation of emerging organic contaminants in reactive filtration applications

2021 ◽  
Vol 8 (3) ◽  
pp. 711-722
Author(s):  
Katherine E. Greenstein ◽  
Matthew R. Nagorzanski ◽  
Bailey Kelsay ◽  
Edgard M. Verdugo ◽  
Nosang V. Myung ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Water Treatment ◽  
Organic Contaminants ◽  
Membrane Filtration ◽  
Titanium Dioxide Nanoparticles ◽  
Chemical Oxidation ◽  
Tio2 Nanofiber ◽  
System P ◽  
Filtration System ◽  
Emerging Organic Contaminants

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

scholarly journals Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Membrane System ◽  
Coagulation System ◽  
Fouling Control ◽  
Filtration System ◽  
Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

scholarly journals DEET Degradation by Titanium Dioxide–Zeolite Nanocomposites: Effects of Aggregation State, Water Chemistry, and Natural Organic Matter

2020 ◽  
Author(s):  
Tchemongo B. Berté ◽  
Anthony S. Chen ◽  
Riya A. Mathew ◽  
Sheyda Shakiba ◽  
Stacey M. Louie
Keyword(s):  
Titanium Dioxide ◽  
Organic Matter ◽  
Water Treatment ◽  
Water Chemistry ◽  
Natural Organic Matter ◽  
Titanium Dioxide Nanoparticles ◽  
Hard Water ◽  
Aggregation State ◽  
Byproduct Formation ◽  
Partial Dissociation

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.

scholarly journals Preparation of Titanium Dioxide Nanoparticles Immobilized on Polyacrylonitrile Nanofibres for the Photodegradation of Methyl Orange

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Pardon Nyamukamba ◽  
Omobola Okoh ◽  
Lilian Tichagwa ◽  
Corinne Greyling
Keyword(s):  
Electron Microscopy ◽  
Titanium Dioxide ◽  
Methyl Orange ◽  
Organic Contaminants ◽  
Uv Light ◽  
Titanium Dioxide Nanoparticles ◽  
Xrd Analysis ◽  
Rutile Phase ◽  
Electrospinning Technique ◽  
Carbon Nanofibres

Herein, we describe the synthesis of titanium dioxide (TiO2) nanoparticles by the hydrolysis and condensation of titanium tetrachloride. The resulting nanoparticles were immobilized on polyacrylonitrile (PAN) based nanofibres by an electrospinning technique in order to allow simple isolation and reuse of titania semiconductor photocatalyst. The composite nanofibres were heat treated to convert the polymer nanofibres to carbon nanofibres and to convert amorphous TiO2to crystalline TiO2. X-ray diffraction (XRD) analysis showed that the rutile phase was the major phase and the equatorial peaks of PAN disappeared after heat treatment at 600°C. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis confirmed that some TiO2nanoparticles were encapsulated whereas some were surface residing on the electrospun nanofibres. The TiO2nanoparticles were found to lower the cyclization temperature of PAN as indicated by differential scanning colorimetry (DSC) and differential thermal analysis (DTA). Photocatalytic studies on the degradation of methyl orange dye under UV light irradiation showed that composite nanofibres were capable of degrading organic contaminants in water. The carbon nanofibres with surface residing titanium dioxide nanoparticles (TiO2/CNF-SR) showed the highest photocatalytic activity (59.35% after 210 minutes) due to direct contact between the TiO2photocatalyst and methyl orange.

scholarly journals Non-Resorbable Nanocomposite Membranes for Guided Bone Regeneration Based On Polysulfone-Quartz Fiber Grafted with Nano-TiO2

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 985 ◽  
Author(s):  
Gheorghe Nechifor ◽  
Eugenia Eftimie Totu ◽  
Aurelia Cristina Nechifor ◽  
Ibrahim Isildak ◽  
Ovidiu Oprea ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Bone Regeneration ◽  
Titanium Dioxide Nanoparticles ◽  
Composite Membranes ◽  
Chemical Oxidation ◽  
Guided Bone Regeneration ◽  
Inorganic Nanoparticles ◽  
Phase Method ◽  
Nanocomposite Membranes ◽  
Nano Tio2

The polymer-inorganic nanoparticles composite membranes are the latest solutions for multiple physicochemical resistance and selectivity requirements of membrane processes. This paper presents the production of polysulfone-silica microfiber grafted with titanium dioxide nanoparticles (PSf-SiO2-TiO2) composite membranes. Silica microfiber of length 150–200 μm and diameter 12–15 μm were grafted with titanium dioxide nanoparticles, which aggregated as microspheres of 1–3 μm, applying the sol-gel method. The SiO2 microfibers grafted with nano-TiO2 were used to prepare 12% polysulfone-based nanocomposite membranes in N-methyl pyrrolidone through the inversion phase method by evaporation. The obtained nanocomposite membranes, PSf-SiO2-TiO2, have flux characteristics, retention, mechanical characteristics, and chemical oxidation resistance superior to both the polysulfone integral polymer membranes and the PSf-SiO2 composite membranes. The antimicrobial tests highlighted the inhibitory effect of the PSf-SiO2-TiO2 composite membranes on five Gram (-) microorganisms and did not allow the proliferation of Candida albicans strain, proving that they are suitable for usage in the oral environment. The designed membrane met the required characteristics for application as a functional barrier in guided bone regeneration.

Natural Organic Matter Adsorption Conditions Influence Photocatalytic Reaction Pathways of Phosphate-Treated Titanium Dioxide Nanoparticles

2021 ◽  
Author(s):  
Riya A Mathew ◽  
Gang Wu ◽  
Ye Zhang ◽  
Sheyda Shakiba ◽  
Yan Yao ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Organic Matter ◽  
Water Treatment ◽  
Natural Organic Matter ◽  
Titanium Dioxide Nanoparticles ◽  
Reaction Pathways ◽  
Photocatalytic Reaction

Titanium dioxide (TiO2) nanoparticles have been widely studied for water treatment applications; however, natural organic matter (NOM) is often reported to hamper the efficiency of the nanoparticles toward the degradation...

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 ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Water Treatment ◽  
Aging Time ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Visible Region ◽  
Vital Role ◽  
Red Shift ◽  
Total Strength ◽  
Solar Absorber

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.

scholarly journals Comparison of Manganese Dioxide and Permanganate as Amendments with Persulfate for Aqueous 1,4-Dioxane Oxidation

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3061
Author(s):  
Logan Bridges ◽  
Ruba A. M. Mohamed ◽  
Naima A. Khan ◽  
Mark L. Brusseau ◽  
Kenneth C. Carroll
Keyword(s):  
Manganese Dioxide ◽  
Organic Contaminants ◽  
Degradation Kinetics ◽  
Product Formation ◽  
Chemical Oxidation ◽  
In Situ Chemical Oxidation ◽  
Radical Trap ◽  
Soil Systems ◽  
Emerging Organic Contaminants ◽  
Chemical Inputs

Persulfate (PS) is widely used to degrade emerging organic contaminants in groundwater and soil systems, and various PS activation methods (e.g., energy or chemical inputs) have been considered to increase oxidation strength. This study investigates PS activation through manganese amendment in the form of potassium permanganate (KMnO4) and manganese dioxide (MnO2) to subsequently degrade the emerging and recalcitrant groundwater contaminant 1,4-dioxane (1,4-D). The activation of PS by MnO2 was confirmed by radical trap and by product formation. The degradation kinetics of 1,4-D by PS was also compared with varying amendments of KMnO4 and MnO2. The results showed that MnO2 activated PS, which increased the degradation rate constant of 1,4-D. KMnO4 activation of PS was not observed even though the binary oxidant mixture did enhance the degradation of 1,4-D. These results have implications for applying in situ chemical oxidation in subsurface systems, especially for conditions wherein manganese exists naturally in groundwater or aquifer minerals to support possible PS activation.

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