scholarly journals Comparative study between adsorbents based on magnetic nanoferrite. Application to the removal of methyl orange from wastewater

2021 ◽  
Author(s):  
Sabrine Saad ◽  
Sarra Ben Amor ◽  
Amel Ben Slimane
Keyword(s):  
Methyl Orange ◽  
Capillary Condensation ◽  
Bismuth Ferrite ◽  
Isosteric Heat ◽  
Combustion Method ◽  
Intermolecular Forces ◽  
Point Of Zero Charge ◽  
Maximum Adsorption Capacity ◽  
Suitable Model ◽  
Mg Doped

Magnetic ferrite (Mg-doped bismuth ferrite) and its clay-based composite (Mg-doped bismuth ferrite-bentonite) were prepared by self-combustion method utilizing glycine as fuel and served for the removal of methyl orange (MO) from aqueous solutions. The ferrite-based adsorbents were characterized by the measurement of specific surface area (BET), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD). The different experimental parameters that affect the performance of this reaction such as: temperature, contact time, initial dye concentration and mass of adsorbent were investigated. The point of zero charge pH (pHPZC) was determined for the two adsorbents. Langmuir and Freundlich adsorption models were employed to provide a description of the equilibrium isotherms. Adsorption tests showed that the equilibrium time is a function of the initial concentration of dye. The adsorption kinetic study indicated that the equilibrium adsorption is established after 300 minutes for Mg-doped bismuth ferrite, while it is established after 180 minutes for Mg-doped bismuth ferrite-bentonite composite. Furthermore, this suggests that the adsorption of MO on both adsorbents can be perfectly described by pseudo-second order kinetics. The maximum adsorption capacity determined by the mathematical model of Langmuir is equal to 181.8 mg.g-1 for Mg-doped bismuth ferrite and to 188.7 mg.g-1 for its composite, at 298 K. Adsorption isotherms shows that the Freundlich model perfectly represents adsorption of methyl orange to the prepared Mg-doped bismuth ferrite. The ferrite/bentonite composite has 2-50 nm-sized pores and is indeed a mesoporous material. The small pores observed on the surface of the adsorbents are in line with type IV isotherm, with possible capillary condensation of the adsorbate. Moreover, Langmuir model seems to be the most suitable model for the absorption of methyl orange on the Mg-doped bismuth ferrite-bentonite composite. The thermodynamic parameters related to the sorbent/adsorbate system indicate that adsorption is spontaneous and exothermic. The determination of isosteric heat of adsorption suggested that it is indeed a physisorption characterized by weak intermolecular forces between MO and the surface.

One-step combustion synthesis of undoped c-ZrO2 for Cr(VI) removal from aqueous solutions

2021 ◽  
Author(s):  
Ekaterina Dzhevaga ◽  
Maria Chebanenko ◽  
Kirill Martinson ◽  
Artem Lobinsky ◽  
Vadim Popkov
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions ◽  
Zirconium Dioxide ◽  
Freundlich Isotherm ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
Point Of Zero Charge ◽  
Cubic Phase ◽  
Maximum Adsorption Capacity ◽  
Solution Combustion

Abstract The active practical application of materials based on cubic zirconium dioxide (c-ZrO2) for catalysis, luminescence, and sorption of heavy metals demands the development of methods for its preparation in a nanostructured form. In this work, nanoparticles of undoped cubic zirconia were obtained by solution combustion method, the features of their structure and morphology were investigated, and the efficiency of their use as a basis for sorbents for the removal of hexavalent chromium Cr(VI) from aqueous solutions was evaluated. Based on XPS, it was established that the stabilization of the high-temperature cubic phase of c-ZrO2 occurred due to multiple oxygen vacancies which were formed during the synthesis by glycine-nitrate combustion. The results of PXRD and Raman spectroscopy confirmed the cubic structure of the obtained zirconium dioxide nanoparticles, the average crystallite size was approximately 2 nm. Adsorption structural analysis and SEM indicated aggregation of c-ZrO2 nanocrystals into primary (45-95 nm) and secondary (submicron) agglomerates. The specific BET surface of the nanocrystals was 25.4 m2/g, the pore volume was 0.1670 cm3/g, the major part of which is associated with interparticle porosity. Using kinetic pH-metry, it was found that on the surface of synthesized c-ZrO2, rapidly hydrated aprotic Lewis acid centers predominated, and the point of zero charge (PZC) was 6.33. The results of Cr(VI) sorption from aqueous solutions with concentrations varying from 0.25 to 1.25 mmol/L were described by the Freundlich isotherm (R2 = 0.971), which corresponds to the multilayer adsorption. The maximum adsorption capacity according to Langmuir was 33 mg/g or 1.34 mg/m2 per unit area. These results allow us to consider the obtained undoped zirconium dioxide as a promising base for sorbents of heavy metals.

scholarly journals Insights into Starch Coated Nanozero Valent Iron-Graphene Composite for Cr(VI) Removal from Aqueous Medium

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Prasanna Kumarathilaka ◽  
Vimukthi Jayaweera ◽  
Hasintha Wijesekara ◽  
I. R. M. Kottegoda ◽  
S. R. D. Rosa ◽  
...  
Keyword(s):  
Point Of Zero Charge ◽  
Inert Material ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Graphene Composite ◽  
Removal Capacity ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
First Time

Embedding nanoparticles into an inert material like graphene is a viable option since hybrid materials are more capable than those based on pure nanoparticulates for the removal of toxic pollutants. This study reports for the first time on Cr(VI) removal capacity of novel starch stabilized nanozero valent iron-graphene composite (NZVI-Gn) under different pHs, contact time, and initial concentrations. Starch coated NZVI-Gn composite was developed through borohydrate reduction method. The structure and surface of the composite were characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), and point of zero charge (pHpzc). The surface area and pHpzc of NZVI-Gn composite were reported as 525 m2 g−1 and 8.5, respectively. Highest Cr(VI) removal was achieved at pH 3, whereas 67.3% was removed within first few minutes and reached its equilibrium within 20 min obeying pseudo-second-order kinetic model, suggesting chemisorption as the rate limiting process. The partitioning of Cr(VI) at equilibrium is perfectly matched with Langmuir isotherm and maximum adsorption capacity of the NZVI-Gn composite is 143.28 mg g−1. Overall, these findings indicated that NZVI-Gn composite could be utilized as an efficient and magnetically separable adsorbent for removal of Cr(VI).

scholarly journals Synthesis characterization and sorption properties of a sorbent synthesized using slag and red mud: Arsenic removal from spiked aqueous solutions

2016 ◽  
Vol 18 (2) ◽  
pp. 339-347 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Red Mud ◽  
Arsenic Removal ◽  
Point Of Zero Charge ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Equilibrium Studies ◽  
Metallurgical Wastes ◽  
Bet Method ◽  
Gf Aas

<p>The aim of the present study was to synthesize a sorbent, for arsenic removal from aqueous solutions, reusing two waste materials (slag and red mud). The sorbent was prepared after chemical and thermal treatment, during which amorphous silica sol and FeOOH sol were produced simultaneously and form Fe-Si complexes on the surface of the slag. To characterize the sorbent Powder X-ray diffraction (XRD); Fourier transform infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM-EDX) were applied. The surface area (BET method) and the Point of Zero Charge (PZC) of the sorbent were determined.). The sorption efficiency of the sorbent produced was investigated with kinetic and equilibrium studies, performed in batch conditions. The concentration of arsenic in solutions was determined by electro thermal atomic absorption spectroscopy (GF-AAS). The results of the study showed that with the described process, using metallurgical wastes, iron oxyhydroxides were &ldquo;loaded&rdquo; onto slag producing an effective sorbent for arsenic removal. Kinetic experiments proved that equilibrium was achieved within 15 hours, while the maximum adsorption capacity as evidenced by equilibrium experiments, was 16.14 mg g<sup>-1</sup>. Data proved to fit better to the Langmuir equation.</p>

scholarly journals Adsorción del naranja de metilo en solución acuosa sobre hidróxidos dobles laminares

2015 ◽  
Vol 25 (3) ◽  
pp. 25-34 ◽  
Author(s):  
Laura Alicia Ramírez Llamas ◽  
Araceli Jacobo Azuara ◽  
J. Merced Martínez Rosales
Keyword(s):  
Methyl Orange ◽  
Adsorption Capacity ◽  
Dye Adsorption ◽  
Temperature Programmed Desorption ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Suitable Temperature ◽  
Temperature Programmed ◽  
Double Hydroxides

In this paper, layered double hydroxides (LDH) were synthesized and characterized using techniques of Physisorption of Nitrogen, Infrared, Temperature Programmed Desorption, X-Ray Diffraction, TGA and Immersion Microcalorimetry, in order to determine the basic properties of the adsorbent. The methyl orange (MO) is used as a dye and as a result, it is frequently found in effluents from textile industries. The dye adsorption isotherms on LDH were studied as function of pH and temperature. The maximum adsorption capacity of methyl orange on LDH was carried out at pH 5, and the minimum adsorption capacity at pH 11, being 40.2 mg/g and 22.1 mg/g, respectively. Furthermore, the suitable temperature to promote the adsorption of methyl orange on LDH was at 25 °C, as at 35 °C shows a significant decrease. 

scholarly journals Influence of the La3+, Eu3+, and Er3+ Doping on Structural, Optical, and Electrical Properties of BiFeO3 Nanoparticles Synthesized by Microwave-Assisted Solution Combustion Method

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Angelika Wrzesinska ◽  
Alexander Khort ◽  
Izabela Bobowska ◽  
Adam Busiakiewicz ◽  
Aleksandra Wypych-Puszkarz
Keyword(s):  
Rare Earth ◽  
Electrical Properties ◽  
Bismuth Ferrite ◽  
Solution Combustion Synthesis ◽  
Combustion Method ◽  
Band Gap Energy ◽  
Rare Earth Doping ◽  
Optical And Electrical Properties ◽  
Solution Combustion ◽  
Microwave Assisted

In this study, nanocrystalline (18–28 nm) perovskite-like bismuth ferrite rare earth-doped powders (Bi0.9RE0.1FeO3, where RE = La (BLaFO), Eu (BEuFO), and Er (BErFO)) were obtained by microwave-assisted modification of solution combustion synthesis (SCS). The influence of high load La3+, Eu3+, and Er3+ doping on structural, optical, and electrical properties of BiFeO3 was investigated. It was found that rare earth doping along with fast phase formation and quenching significantly distorts the crystal cells of the obtained materials, which results in the formation of mixed rhombohedral- (R3c-) orthorhombic (Pbnm) crystal structures with decreased lengths of Bi-O and Fe-O bonds along with a decreasing radius size of doping ions. This promotes reduction of the optical band gap energy and suppression of ionic polarization at high frequencies and results in enhanced dielectric permittivity of the materials at 1 MHz.

scholarly journals Preparation, Characterization and Photocatalytic Activity of La-Doped Zinc Oxide Nanoparticles

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1195 ◽  
Author(s):  
Loan T. T. Nguyen ◽  
Lan T. H. Nguyen ◽  
Anh T. T. Duong ◽  
Bui Duc Nguyen ◽  
Nguyen Quang Hai ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Zinc Oxide Nanoparticles ◽  
Combustion Method ◽  
Poly Vinyl Alcohol ◽  
Oxide Nanoparticles ◽  
Visible Absorption ◽  
X Ray ◽  
La Doped

Lanthanum (La)-doped zinc oxide nanoparticles were synthesized with different La concentrations by employing a gel combustion method using poly(vinyl alcohol) (PVA). The as-synthesized photocatalysts were characterized using various techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), photoluminescence (PL) spectroscopy, and UV–visible absorption spectroscopy. The average size of ZnO nanoparticles decreased from 34.3 to 10.3 nm with increasing concentrations of La, and the band gap, as evaluated by linear fitting, decreased from 3.10 to 2.78 eV. Additionally, it was found that the photocatalytic activity of doped samples, as investigated by using methyl orange dye under visible lights, improved in response to the increase in La concentration. The decomposition of methyl orange reached 85.86% after 150 min in visible light using La0.1Zn0.9O as the photocatalyst.

Substituted Co–Cu–Zn nanoferrites: synthesis, fundamental and redox catalytic properties for the degradation of methyl orange

RSC Advances ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 1360-1375 ◽  
Author(s):  
Santosh Bhukal ◽  
Manisha Dhiman ◽  
S. Bansal ◽  
Mukesh K. Tripathi ◽  
Sonal Singhal
Keyword(s):  
Methyl Orange ◽  
Catalytic Properties ◽  
Sol Gel ◽  
Combustion Method ◽  
Auto Combustion ◽  
Recyclable Catalysts ◽  
Degradation Of Methyl Orange

Co0.6Zn0.4Cu0.2MxFe1.8−xO4 (M = Zn2+, Co2+, Ni2+ and Mn3+. x = 0.2, 0.4, 0.6 and 0.8) magnetically recyclable catalysts have been synthesized via a sol–gel auto combustion method.

Fe3O4-CS-L: a magnetic core-shell nano adsorbent for highly efficient methyl orange adsorption

2017 ◽  
Vol 77 (3) ◽  
pp. 628-637 ◽  
Author(s):  
Shuangzhen Guo ◽  
Jian Zhang ◽  
Xianlong Li ◽  
Fan Zhang ◽  
Xixi Zhu
Keyword(s):  
Methyl Orange ◽  
Adsorption Capacity ◽  
Thermo Gravimetric Analysis ◽  
Kinetic Studies ◽  
Magnetic Core ◽  
Infrared Spectrometry ◽  
Core Shell ◽  
Maximum Adsorption Capacity ◽  
Gravimetric Analysis ◽  
Equilibrium Studies

Abstract A novel core-shell bio-adsorbent was fabricated by using biological materials for removing methyl orange (MO) from aqueous solution. The structure characteristics results of scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), thermo-gravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) shows that Fe3O4-CS-L has been successfully prepared. The effects of contact time, pH, temperature and initial concentration were explored. The results suggested pH was a negligible factor in adsorption progress. Kinetic studies showed that the experiment data followed pseudo-second-order model. Boyd mode suggested that external mass transfer showed a rather weak rate control for MO adsorption onto Fe3O4-CS-L. Equilibrium studies showed that isotherm data were the best described by Langmuir model. The maximum adsorption capacity of MO estimated to be 338.98 mg/g at 298 K. Moreover, the adsorption capacity of Fe3O4-CS-L can keep about 74% in the fifth adsorption–regeneration cycle. Thus, the Fe3O4-CS-L could be a kind of promising material for removing MO from wastewater.

Utilization of cross-linked chitosan/bentonite composite in the removal of methyl orange from aqueous solution

2014 ◽  
Vol 71 (2) ◽  
pp. 174-182 ◽  
Author(s):  
Ruihua Huang ◽  
Qian Liu ◽  
Lujie Zhang ◽  
Bingchao Yang
Keyword(s):  
Methyl Orange ◽  
Aqueous Solutions ◽  
Ph Value ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Wide Ph Range ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Ph Range ◽  
A Minor

A kind of biocomposite was prepared by the intercalation of chitosan in bentonite and the cross-linking reaction of chitosan with glutaraldehyde, which was referred to as cross-linked chitosan/bentonite (CCS/BT) composite. Adsorptive removal of methyl orange (MO) from aqueous solutions was investigated by batch method. The adsorption of MO onto CCS/BT composite was affected by the ratio of chitosan to BT and contact time. pH value had only a minor impact on MO adsorption in a wide pH range. Adsorption kinetics was mainly controlled by the pseudo-second-order kinetic model. The adsorption of MO onto CCS/BT composite followed the Langmuir isotherm model, and the maximum adsorption capacity of CCS/BT composite calculated by the Langmuir model was 224.8 mg/g. Experimental results indicated that this adsorbent had a potential for the removal of MO from aqueous solutions.

Sign in / Sign up

Export Citation Format

Share Document