scholarly journals Enhanced Adsorptive Removal of β-Estradiol from Aqueous and Wastewater Samples by Magnetic Nano-Akaganeite: Adsorption Isotherms, Kinetics, and Mechanism

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1197
Author(s):  
Anele Mpupa ◽  
Azile Nqombolo ◽  
Boris Mizaikoff ◽  
Philiswa Nosizo Nomngongo
Keyword(s):  
Electron Microscopy ◽  
Removal Efficiency ◽  
Desirability Function ◽  
Tap Water ◽  
Isotherm Models ◽  
Environmental Matrices ◽  
X Ray ◽  
Adsorptive Removal ◽  
Adsorption Capacities ◽  
Wastewater Samples

A surfactant-free method was used to synthesize iron oxyhydroxide (akaganeite, β-FeOOH) nanorods and characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDS), and transmission electron microscopy (TEM). The synthesized nanoadsorbent was applied for the adsorptive removal of β-estradiol from aqueous solutions. The parameters affecting the adsorption were optimized using a multivariate approach based on the Box–Behnken design with the desirability function. Under the optimum conditions, the equilibrium data were investigated using two and three parameter isotherms, such as the Langmuir, Freundlich, Dubinin–Radushkevich, Redlich–Peterson, and Sips models. The adsorption data were described as Langmuir and Sips isotherm models and the maximum adsorption capacities in Langmuir and Sips of the β-FeOOH nanorods were 97.0 and 103 mg g−1, respectively. The adjusted non-linear adsorption capacities were 102 and 104 mg g−1 for Langmuir and Sips, respectively. The kinetics data were analyzed by five different kinetic models, such as the pseudo-first order, pseudo-second order, intraparticle, as well as Boyd and Elovich models. The method was applied for the removal β-estradiol in spiked recoveries of wastewater, river, and tap water samples, and the removal efficiency ranged from 93–100%. The adsorbent could be reused up to six times after regeneration with acetonitrile without an obvious loss in the removal efficiency (%RE = 95.4 ± 1.9%). Based on the results obtained, it was concluded that the β-FeOOH nanorods proved to be suitable for the efficient removal of β-estradiol from environmental matrices.

scholarly journals Adsorptive Removal of Cd, Cu, Ni and Mn from Environmental Samples Using Fe3O4-Zro2@APS Nanocomposite: Kinetic and Equilibrium Isotherm Studies

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3209
Author(s):  
Aphiwe Siyasanga Gugushe ◽  
Anele Mpupa ◽  
Tshimangadzo Saddam Munonde ◽  
Luthando Nyaba ◽  
Philiswa Nosizo Nomngongo
Keyword(s):  
Electron Microscopy ◽  
Magnetic Nanomaterials ◽  
Batch Mode ◽  
X Ray ◽  
Freundlich Isotherms ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Wastewater Samples

In this study, Fe3O4-ZrO2 functionalized with 3-aminopropyltriethoxysilane (Fe3O4-ZrO2@APS) nanocomposite was investigated as a nanoadsorbent for the removal of Cd(II), Cu(II), Mn (II) and Ni(II) ions from aqueous solution and real samples in batch mode systems. The prepared magnetic nanomaterials were characterized using X-ray powder diffraction (XRD), scanning electron microscopy/energy dispersion x-ray (SEM/EDX) Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). Factors (such as adsorbent dose and sample pH) affecting the adsorption behavior of the removal process were studied using the response surface methodology. Under optimized condition, equilibrium data obtained were fitted into the Langmuir and Freundlich isotherms and the data fitted well with Langmuir isotherms. Langmuir adsorption capacities (mg/g) were found to be 113, 111, 128, and 123 mg/g for Cd, Cu, Ni and Mn, respectively. In addition, the adsorption kinetics was analyzed using five kinetic models, pseudo-first order, pseudo-second order, intraparticle diffusion and Boyd models. The adsorbent was successfully applied for removal of Cd(II), Cu(II), Mn (II) and Ni(II) ions in wastewater samples.

scholarly journals Application of Titanium Dioxide-Graphene Composite Material for Photocatalytic Degradation of Alkylphenols

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Chanbasha Basheer
Keyword(s):  
Electron Microscopy ◽  
Titanium Dioxide ◽  
Photocatalytic Efficiency ◽  
Ionization Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Flame Ionization ◽  
Transmission Electron ◽  
Wastewater Samples

Titanium dioxide-graphene (TiO2-G) composite was used for the photodegradation of alkylphenols in wastewater samples. The TiO2-G composites were prepared via sonochemical and calcination methods. The synthesized composite was characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and fluorescence spectroscopy. The photocatalytic efficiency was evaluated by studying the degradation profiles of alkylphenols using gas chromatography-flame ionization detector (GC-FID). It was found that the synthesized TiO2-G composites exhibit enhanced photocatalytic efficiencies as compared to pristine TiO2. The presence of graphene not only provides a large surface area support for the TiO2photocatalyst, but also stabilizes charge separation by trapping electrons transferred from TiO2, thereby hindering charge transfer and enhancing its photocatalytic efficiency.

scholarly journals Preparation of Chitosan Coated Magnetic Hydroxyapatite Nanoparticles and Application for Adsorption of Reactive Blue 19 and Ni2+Ions

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Van Cuong Nguyen ◽  
Quoc Hue Pho
Keyword(s):  
Removal Efficiency ◽  
Weight Percent ◽  
Textile Dye ◽  
Gravimetric Analysis ◽  
Hydroxyapatite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reactive Blue 19 ◽  
Adsorption Capacities ◽  
Initial Ph

An adsorbent called chitosan coated magnetic hydroxyapatite nanoparticles (CS-MHAP) was prepared with the purpose of improvement for the removal of Ni2+ions and textile dye by coprecipitation. Structure and properties of CS-MHAP were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometer (VSM). Weight percent of chitosan was investigated by thermal gravimetric analysis (TGA). The prepared CS-MHAP presents a significant improvement on the removal efficiency of Ni2+ions and reactive blue 19 dye (RB19) in comparison with chitosan and magnetic hydroxyapatite nanoparticles. Moreover, the adsorption capacities were affected by several parameters such as contact time, initial concentration, adsorbent dosage, and initial pH. Interestingly, the prepared adsorbent could be easily recycled from an aqueous solution by an external magnet and reused for adsorption with high removal efficiency.

SYNTHESIS, CHARACTERIZATION AND THE APPLICABILITY OF β-CYCLODEXTRINS FUNCTIONALIZED MESOPOROUS SBA-15 MOLECULAR SIEVES

NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350050
Author(s):  
MIN GUAN ◽  
HAI-PENG BI ◽  
ZUYUAN WANG ◽  
SHAOHUA BU ◽  
LING HUANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Molecular Sieves ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Potential Applications ◽  
Adsorption Desorption

Mesoporous silicas SBA-15 are modified with β-Cyclodextrins (β-CD) by simple grafting method. β-CD functionalized SBA-15 was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), nitrogen adsorption–desorption measurements, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Furthermore, the applicability of it is investigated through studying the adsorption properties of clenbuterol. It showed better adsorption capacities of clenbuterol than pure SBA-15. β-CD functionalized SBA-15 material has the potential applications in the treatment of clenbuterol contamination in food and environment science.

scholarly journals Metal and polymer-mediated synthesis of porous crystalline hydroxyapatite nanocomposites for environmental remediation

2018 ◽  
Vol 5 (1) ◽  
pp. 171557 ◽  
Author(s):  
Danushika C. Manatunga ◽  
Rohini M. de Silva ◽  
K. M. Nalin de Silva ◽  
Nuwan de Silva ◽  
E. V. A. Premalal
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Environmental Remediation ◽  
Aqueous System ◽  
Isotherm Models ◽  
Nmr Studies ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Effective Removal ◽  
Diffraction Patterns

This study was focused on the preparation of metal and polymer-mediated porous crystalline hydroxyapatite (HAp) nanocomposites for environmental applications. Four different nano HAp systems were synthesized, namely, microwave irradiated HAp (M1), Zn doped HAp (M2), Mg-doped HAp (M3) and sodium alginate incorporated HAp (M4), and characterized using X-ray diffraction (XRD), Fourier transform infra-red spectroscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, nuclear magnetic resonance (NMR), X-ray fluorescence, thermogravimetric analysis and Brunauer–Emmett–Teller (BET) analyses. Systems M1–M4 showed morphologies similar to coral shapes, polymer-like interconnected structures, sponges and feathery mycelium assemblies. Using XRD, selected area electron diffraction patterns and 1 H and 31 P CP/MAS solid-state NMR studies, crystallinity variation was observed from highest to lowest in the order of M4 > M1 > M3 > M2. Surface area estimates using BET isotherm reflected the highest surface area for M3, and M1 > M2 > M4. Four systems of M1–M4 were used as potential adsorbent materials for the removal of metal containing azo dye from aqueous system. Adsorption data were correlated to Freundlich and Langmuir isotherm models. According to the results, the highest capacity of 212.8 mg g −1 was exhibited by M4 having mycelium like morphology with alginate groups. This study highlights the possibility of developing HAp nanocomposites for the effective removal of dye contaminants in the environment.

Preparation of titanate nanoflower for sorption of 75Se(IV) radioisotope from aqueous solution: Equilibrium, kinetic and thermodynamic studies

2015 ◽  
Vol 103 (12) ◽  
Author(s):  
Sahar El-Sayed Abd El-Kader Sharaf El-Deen ◽  
Karam Fatwhi Allan ◽  
Mohamed Holeil ◽  
Gehan El-Sayed Abd El-Kader Sharaf El-Deen
Keyword(s):  
Aqueous Solution ◽  
Electrostatic Interactions ◽  
Outer Sphere ◽  
Solution Temperature ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
X Ray ◽  
Adsorptive Removal ◽  
Order Kinetic Model

AbstractIn this study, the adsorptive removal of selenium (IV) from aqueous solution by titanate nanoflower (TNF) was prepared via alkaline hydrothermal method. The morphology and crystal phase of the TNF were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscope (EDX), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR) and specific surface area. This study was conducted to determine the influence of various operating parameters such as pH, adsorbate weight, initial anion concentration, contact time and solution temperature on the adsorptive removal of selenium (IV). Equilibrium adsorption data were analyzed using Freundlich, Langmuir and Dubinin–Radushkevich (D–R) isotherm models. The results demonstrated that the adsorption was well described by the Langmuir adsorption isotherm with the maximum adsorption capacity up to 46.52 mg/g at pH 3.5. The adsorption of Se(IV) anions onto the surface of TNF may proceed through outer sphere electrostatic interactions and/or inner-sphere complexation interaction. The kinetic data indicated that the adsorption fit well with the pseudo-second-order kinetic model. The thermodynamic parameters implied that the adsorption process was spontaneous and endothermic in nature.

Chiral poly(amide-imide)/ZnS nanocomposite as a new adsorbent for simultaneous removal of cationic dyes from aqueous solution

2020 ◽  
pp. 095400832093914
Author(s):  
Maryam Sadeghi ◽  
Zahra Rafiee
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
High Efficiency ◽  
Second Order ◽  
Isotherm Models ◽  
Simultaneous Removal ◽  
Base Interaction ◽  
X Ray ◽  
Operational Variables ◽  
Pseudo Second Order

A new adsorbent, poly(amide-imide)/zinc sulfide nanocomposite (PAI/ZnS NC), was fabricated and identified by Fourier-transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, field emission-scanning electron microscopy, and transmission electron microscopy. Then, the obtained NC was applied for the simultaneous removal of auramine O (AO) and rhodamine B (RB) dyes from aqueous solution via the interactions of hydrogen bonding, π– π stacking, and Lewis acid–base interaction. The effects of operational variables including pH, PAI/ZnS NC mass, AO and RB concentration, and sonication time on removal efficiency were examined and optimized values were found to be 8.0, 16 mg, 11 mg L−1, and 6 min, respectively. The adsorption capacities of PAI/ZnS NC for the removal of AO and RB dyes were found to be 70.92 and 91.74 mg g−1, respectively. Ultraviolet–visible spectrophotometer was used to determine the amount of residual dye in solution. Fitting the experimental equilibrium data to isotherm models such as Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich reveals the suitability of the Langmuir model with high correlation coefficients ( R 2 = 0.998 for AO and R 2 = 0.999 for RB). Pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich kinetic models applicability was tested and the pseudo-second-order equation controls the kinetics of the adsorption process. Furthermore, this study establishes that PAI/ZnS NC can be successfully applied as a low-cost adsorbent and conserve its high efficiency after nine cycles for the removal of AO and RB dyes.

scholarly journals LDH Nanocubes Synthesized with Zeolite Templates and Their High Performance as Adsorbents

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3315
Author(s):  
Moftah Essa Elkartehi ◽  
Rehab Mahmoud ◽  
Nabila Shehata ◽  
Ahmed Farghali ◽  
Shimaa Gamil ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Average Pore Size ◽  
Second Order ◽  
Polluted Water ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Average Pore ◽  
X Ray ◽  
Pseudo Second Order

In this work, the efficiency of the adsorptive removal of the organic cationic dye methylene blue (MB) from polluted water was examined using three materials: natural clay (zeolite), Zn-Fe layered double hydroxide (LDH), and zeolite/LDH composite. These materials were characterized via X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) diffraction (XRF), low-temperature N2 adsorption, pore volume and average pore size distribution and field emission scanning electron microscopy (FE-SEM). The properties of the applied nanomaterials regarding the adsorption of MB were investigated by determining various experimental parameters, such as the contact time, initial dye concentration, and solution pH. In addition, the adsorption isotherm model was estimated using the Langmuir, Freundlich, and Langmuir–Freundlich isotherm models. The Langmuir model was the best-fitting for all applied nanomaterials. In addition, the kinetics were analyzed by using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, and the pseudo-second-order model was an apparent fit for all three applied nanomaterials. The maximum Adsorption capacity toward MB obtained from the materials was in the order zeolite/LDH composite > zeolites > Zn-Fe LDH. Thus, the zeolite/LDH composite is an excellent adsorbent for the removal of MB from polluted water.

scholarly journals Capacity and Modeling of Acid Blue 113 Dye Adsorption onto Chitosan Magnetized by Fe2O3 Nanoparticles

2021 ◽  
Author(s):  
Tariq Al-Musawi ◽  
Nezamaddin Mengelizadeh ◽  
Orabi Shareef AL-Rawi ◽  
Davoud Balarak
Keyword(s):  
Electron Microscopy ◽  
Removal Efficiency ◽  
Active Sites ◽  
Dye Removal ◽  
Dye Adsorption ◽  
Point Of Zero Charge ◽  
Coefficient Of Determination ◽  
X Ray ◽  
Acid Blue 113 ◽  
Acid Blue

Abstract A chitosan polymer was magnetized by coating with magnetite Fe2O3 nanoparticles, and the resultant material (C–Fe2O3) was first characterized through scanning electron microscopy equipped with energy–dispersive X-ray spectroscopy, transmission electron microscopy, atomic force microscopy, thermogravimetric, X-ray diffractometry, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, and point of zero charge analyses. C–Fe2O3 was then employed as a separable and efficient adsorptive agent to remove acid blue 113 (AB113) dye from aqueous solution. The removal efficiency was optimized at different environmental parameter values (pH: 3–11, C–Fe2O3 dose: 0.1–1 g/L, initial AB113 dye concentration: 10–100 mg/L, adsorption time: 0–300 min, and temperature: 388–318 K). Under optimum conditions, an AB113 dye removal efficiency of 99.68% was achieved. In addition, the effect of the presence of NaCl, NaNO3, Na2CO3, and MgSO4 ions on the AB113 dye removal efficiency could be ranked as NaCl > NaNO3 > MgSO4 > Na2CO3. The statistical analysis using the coefficient of determination, root mean square error, chi-square test, sum of squared errors, and average relative error showed that the Freundlich and pseudo-second-order equations were the best mathematical models for fitting the isothermal and kinetics data. Further kinetics analyses showed that the adsorption of AB113 molecules on C–Fe2O3 active sites was dominated by the intraparticle diffusion process. Thermodynamic parameters indicated that the AB113 dye adsorption process was favorable, endothermic, and spontaneous. Furthermore, an increase in temperature had a positive impact on AB113 dye removal. The regeneration study confirmed the excellent shelf life of C–Fe2O3, with only a slight loss in the removal efficiency (< 7%) being detected after six operational cycles of AB113 dye adsorption. Compared with other adsorbents, C–Fe2O3 was more effective for the adsorption of AB113 dye, with an adsorption uptake up to 128 mg/g.

scholarly journals Synthesis of Highly Active Heterostructured Al2TiO5/TiO2 Photocatalyst in a Neutral Medium

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Nguyen D. Trung ◽  
Nguyen Tri ◽  
Phan H. Phuong ◽  
Ha C. Anh
Keyword(s):  
Electron Microscopy ◽  
Removal Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Bandgap Energy ◽  
Neutral Medium ◽  
Airflow Rate ◽  
Step Method ◽  
X Ray ◽  
Photodegradation Efficiency

In this work, heterostructured catalyst Al2TiO5/TiO2 (ATO/Ti) was synthesized by a two-step method: low-temperature sol-gel process along with hydrothermal treatment in a neutral medium. Characteristics of the fabricated catalyst were analyzed by various techniques including X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller adsorption, UV-Vis diffuse reflectance spectroscopy, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and the point of zero charges. The content of ATO strongly affected the activity of ATO/Ti catalysts for photocatalytic degradation of cinnamic acid (CA). The catalyst, in which 33% TiO2 was replaced by ATO (33ATO/Ti), exhibited the highest activity for the removal of CA. Compared with the bare titanium oxide synthesized in water (TiO2(w)) as well as Al2TiO5 (ATO), the hybrid 33ATO/Ti catalyst exhibited the enhanced photocatalytic activity in the CA degradation under ultraviolet light. The enhancement in the catalytic activity of ATO/Ti could be related to the increase of the specific surface area and the reduction of bandgap energy obtained from the hybridization of TiO2(w) and ATO. The factors as the catalyst dosage ( C cat ), the airflow rate ( Q air ), and the solution initial pH (pH) affected the CA removal efficiency were studied on 33ATO/Ti catalyst. The optimum condition for photodegradation efficiency of CA was found to be at C cat = 0.75   g L − 1 , Q air = 0.3   Lmi n − 1 , and pH = 3.8 . The highest 60-minute removal efficiency of CA reached 77.1% on 33ATO/Ti compared with 67.1% and 30.4% on TiO2(w) and on ATO, respectively. The recyclability of the 33ATO/Ti was also measured at the optimal parameters. The results showed that, compared with TiO2, the hybrid catalyst was easier to recover and reuse, and its activity decreased by 35% after 6 continuous cycles.

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