Effect of the Thermal Treatment on the Capacity of Removal of Cr (VI) of Sol-Gel Hydrotalcite-like Materials

2012 ◽  
Vol 1372 ◽  
Author(s):  
E. Ramos ◽  
N. L. Gutiérrez ◽  
C. A. Contreras ◽  
G. A. del Angel
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Interlayer Space ◽  
Sol Gel ◽  
Textural Properties ◽  
Kinetic Studies ◽  
Before And After ◽  
Short Time ◽  
Thermally Treated

ABSTRACTIn this work the effect on the adsorption of Cr (VI) by thermally treated Hydrotalcite-like Material (HTM) synthesized by the sol-gel method with a Mg/Al = 2 was studied. The characterization of the HTM before and after Cr (VI) removal, as well as the kinetic studies were carried out. When the HTM are thermally treated at 350ºC the hydrotalcite crystalline structure remains and the textural properties improve. The Cr (VI) adsorption capacity of HTM was 125 mg of Cr (VI) / g of HTM. This capacity augments at 132 mg of Cr (VI) / g of HTM after heating HTM at 300°C. The crystallinity as well the porosity of the HTM diminished after adsorption of Cr (VI), due to the obstruction of both the pores and the interlayer space. The adsorption of Cr (VI) occurred before 4 minutes contact time. It can be concluded that HTM exhibits a high Cr (VI) adsorption capacity in a short time.

Structural, Textural and Thermal Characterization of Nano-Mg/Al Hydrotalcite before and after Cr (VI) Removal

2013 ◽  
Vol 755 ◽  
pp. 53-60
Author(s):  
Esthela Ramos Ramírez ◽  
Norma Leticia Gutiérrez Ortega ◽  
Cesar Augusto Contreras Soto ◽  
Gustavo Rangel Porras
Keyword(s):  
Crystalline Structure ◽  
Sol Gel ◽  
Textural Properties ◽  
Kinetic Studies ◽  
Thermal Characterization ◽  
Gel Method ◽  
Sol Gel Method ◽  
Before And After ◽  
Short Time

In this work there was studied the structural, textural and effect that has treat thermal on the removal of Cr (VI) of nanoMg/Al hydrotalcite (NHT) synthesized by the sol-gel method with a ratio of Mg/Al=3. These present the characterization of the nanoMg/Al hydrotalcite before and after Cr (VI) removal, as well as the kinetic studies and of balance. In agreement with the results, when the NHT are thermal treated to 350 °C the hydrotalcite crystalline structure remains but the textural properties are improved and structural. The NHT synthesized by the sol-gel method present a good capacity of removal with values of 91 mg of Cr (VI) removed / g of NHT. The above mentioned capacity of removal gets improved after thermal treating the material, reaching values of removal of 124 mg of Cr (VI) removed / g of NHT. The NHT with the Cr (VI) absorbed show decrease of the crystalline structure, as well as a saturation of the pores that annuls the porosity due to the fact that the Cr (VI) lodges both at the pores and at the intersheets. The time that him takes the HLM to remove the Cr (VI) of the watery solution is alone of 2 minutes, with which it is possible to conclude that the NHT have an excellent aptitude to remove Cr (VI) of watery solutions in an interval of very short time.

scholarly journals Sintesis dan Karakterisasi Silika Abu Ampas Tebu Termodifikasi Arginin sebagai Adsorben Ion Logam Cu(II)

2018 ◽  
Vol 14 (2) ◽  
pp. 333
Author(s):  
Candra Purnawan ◽  
Tri Martini ◽  
Ima Puspita Rini
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Sol Gel ◽  
Ftir Analysis ◽  
Batch Method ◽  
Modified Silica ◽  
Adsorption Ability ◽  
Copper Adsorption ◽  
Ability Test

<p>Telah dilakukan penelitian tentang sintesis dan karakterisasi silika dari abu ampas tebu termodifikasi arginin dengan senyawa penggandeng glisidoksipropiltrimetoksisilan (GPTMS) sebagai adsorben ion logam Cu(II). Penelitian ini bertujuan untuk mengetahui karakterisasi silika abu ampas tebu termodifikasi arginin dengan senyawa penggandeng GPTMS sebagai adsorben ion logam Cu(II). Sintesis silika termodifikasi arginin dengan senyawa penggandeng GPTMS dilakukan dengan metode sol-gel. Adsorben tersebut dikarakterisasi dengan XRD, FTIR dan SAA. Uji kemampuan adsorpsi dilakukan menggunakan metode batch dengan larutan ion logam Cu(II), variasi pH, waktu kontak dan konsentrasi. Hasil penelitian menunjukkan perubahan difraktogram XRD pada silika termodifikasi dan silika abu ampas tebu (silika AAT). Difraktogram menunjukkan puncak melebar pada 2θ sebesar 10-15° dan 20-25°. Analisis FTIR menunjukkan Serapan baru –CH, ̶ NH tekuk, ̶ CN berturut-turut pada daerah 2947, 1570, dan 1356 cm<sup>-1</sup>. Analisis SAA menunjukkan peningkatan luas permukaan pada silika termodifikasi arginin daripada silika dari 64,31 m<sup>2</sup>/g menjadi 382,67 m<sup>2</sup>/g. Kondisi terbaik adsorpsi ion logam Cu(II) dengan adsorben silika termodifikasi arginin terjadi pada pH 6 dengan waktu kontak 45 menit. Silika termodifikasi arginin mengalami peningkatan kapasitas adsorpsi dibandingkan silika dengan kapasitas adsorpsi yaitu dari 0,12 mg/g menjadi 0,52 mg/g. Isoterm adsorpsi ion logam Cu(II) lebih dominan mengikuti isoterm Langmuir dengan r = 0,997.</p><p><strong>Synthesis </strong><strong>a</strong><strong>nd Characterization </strong><strong>o</strong><strong>f Arginine-Modified Silica </strong><strong>f</strong><strong>rom Baggase Ash </strong><strong>a</strong><strong>s C</strong><strong>u</strong><strong>(I</strong><strong>I</strong><strong>) Ions Adsorbent</strong><strong>.</strong> The synthesis and characterization of arginine modified silica from bagasse ash with crosslinker glycydoxypropyltrimethoxyxylane (GPTMS) as an adsorbent for Cu (II) ions has been studied. This research aimed to determine the characterization of arginine modified silica with crosslinker GPTMS as an adsorbent for Cu(II) ions. Synthesis arginine modified silica with crosslinker GPTMS was conducted using sol-gel method. The adsorbent was characterized by XRD, FTIR and SAA. Adsorption ability test conducted using the batch method with a solution of Cu(II) ions, variation of pH, contact time and concentration. The results showed the change in the XRD diffractogram of arginine modified silica from bagasse (silica ATT). XRD diffractogram releaved broad peaks at 2θ 10-15° and 20-25°. FTIR analysis showed a new absorption -CH, -NH bending, -C-N on area of 2947, 1570, and 1356 cm<sup>-1</sup>, respectively SAA analysis showed that the arginine-modified silica with crosslinker GPTMS has higher surface area than silica from 64.31 m<sup>2</sup>/g to 382.67 m<sup>2</sup>/g. The best conditions for copper adsorption with adsorbent arginine modified silica occured at pH 6 with a contact time of 45 minutes. Arginine modified silica has higher adsorption capacity than silica with a adsorption capacity from 0.12 mg/g to 0.52 mg/g. Adsorption of Cu (II) metal ions more dominantly follows Langmuir isotherms with r = 0.997.<strong></strong></p><p> </p>

Study of the Bioactive Behavior of Thermally Treated Modified 58S Bioactive Glass

2008 ◽  
Vol 396-398 ◽  
pp. 131-134 ◽  
Author(s):  
Ourania Menti Goudouri ◽  
Xanthippi Chatzistavrou ◽  
Eleana Kontonasaki ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Bioactive Glass ◽  
Sol Gel ◽  
Bioactive Glasses ◽  
X Ray ◽  
Characteristic Temperatures ◽  
Calcium Silicates ◽  
Crystal Phases ◽  
Thermally Treated

Thermal treatment of bioactive glasses can affect their microstructure and thus their bioactivity. The aim of this study was the characterization of the thermally treated sol-gel-derived bioactive glass 58S at characteristic temperatures and the dependence of its bioactive behavior on the specific thermal treatment. The thermal behavior of the bioactive glass was studied by thermal analysis (TG/DTA). Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffractometry (XRD) were used for the characterization of the bioactive glass. The bioactive behavior in Simulated Body Fluid (SBF) was examined by Scanning Electron Microscopy (SEM-EDS) and FTIR. The major crystal phases after thermal treatment were Calcium Silicates, Wollastonite and Pseudowollastonite, while all thermally treated samples developed apatite after 48 hours in SBF. A slight enhancement of bioactivity was observed for the samples heated at the temperature range 910-970oC.

Chitosan-Bentonite Crosslinked Film As Indicator for Copper (II) Ions Adsorption

2021 ◽  
Author(s):  
Nurul Huda Osman ◽  
Nurul Najiha Mazu ◽  
Josephine Liew Ying Chyi ◽  
Muhammad Mahyiddin Ramli ◽  
Mohammad Abdull Halim Mohd Abdull Majid ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Dc Conductivity ◽  
Dielectric Constants ◽  
Peak Amplitude ◽  
Electrical Parameters ◽  
Before And After

This paper reports on chitosan/bentonite crosslinked (ChB-ECH) film for removal of Cu (II). The effects of chitosan/bentonite ratio on the removal percentage were studied along with the effect of different Cu (II) concentration and the contact time on the film adsorption capacity, qt. The electrical properties of the film are studied, before and after the adsorption occurred, by using impedance spectroscopy for different parameters such as DC conductivity, the complex dielectric constants (ε’ and ε”) and complex electrical modulas (M’ and M’’). The results showed that the chitosan/bentonite ratio of 3:1 produces highest removal percentage at 29 %, while the contact time of 120 minutes was found to be optimum. An increment in the DC conductivity of the ChB-ECH film’s was observed up to 10-7 S/cm as the removal percentage of film increased. The film with the highest Cu (II) adsorb also showed the highest value for ε’ and ε” while exhibiting non-Derby behavior. Shifting of peak amplitude of the M” towards the higher frequency was also observed as the Cu (II) adsorption in the film increased. The results showed that all the electrical parameters can be utilized to determine the amount of adsorbed copper (II) in chitosan/bentonite film.

scholarly journals Optimization, equilibrium and kinetic studies of Zn2+ and Ni2+ adsorption from aqueous solutions using composite adsorbent

2018 ◽  
Vol 67 (3) ◽  
pp. 279-290 ◽  
Author(s):  
Haider M. Zwain ◽  
Mohammadtaghi Vakili ◽  
Irvan Dahlan
Keyword(s):  
Contact Time ◽  
Coal Fly Ash ◽  
Sol Gel ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Isotherm Models ◽  
Experimental Conditions ◽  
Palm Oil Fuel Ash ◽  
Composite Adsorbent ◽  
Oil Fuel

Abstract A novel RHA/PFA/CFA composite adsorbent was synthesized from rice husk ash (RHA), palm oil fuel ash (PFA), and coal fly ash (CFA) by modified sol-gel method. Effect of different parameters such as adsorbent dosage, contact time, and pH were studied using batch experiment to optimize the maximum zinc (Zn2+) and nickel (Ni2) adsorption conditions. Results showed that the maximum adsorption condition occurred at adsorbent amount of 10 g/L, contact time of 60 min, and pH 7. At this condition, the removal efficiencies were 81% and 61% for Zn2+ and Ni2+, in which the adsorption capacities (qmax) were 21.74 mg/g and 17.85 mg/g, respectively. Adsorption behavior of RHA/PFA/CFA composite adsorbent was studied through the various isotherm models at different adsorbent amounts. The results indicated that the Freundlich isotherm model gave an excellent agreement with the experimental conditions. Based on the results obtained from the kinetic studies, pseudo-second-order was suitable for the adsorption of Ni2+ and Zn2+, compared to the pseudo-first-order model. The results presented in this study showed that RHA/PFA/CFA composite adsorbent successfully adsorbed Zn2+ and Ni2.

scholarly journals Synthesis and characterization of modified activated carbon (MgO/AC) for methylene blue adsorption: optimization, equilibrium isotherm and kinetic studies

2021 ◽  
Author(s):  
Vahab Ghalehkhondabi ◽  
Alireza Fazlali ◽  
Keyhan Ketabi
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Natural Waters ◽  
Sol Gel ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Human Beings ◽  
Operational Conditions ◽  
Coating Method

Abstract Methylene blue (MB) is the cationic dye that is widely used for coloring cotton, wool, and silk. Since MB is harmful to human beings and toxic to microorganisms, there is the need to find cheap and efficient methods for removal of MB from wastewater prior to disposal into natural waters. In the present study, MB adsorption potential of MgO/AC prepared using a sol–gel-thermal deep-coating method was compared with the activated carbon (AC). The central composite design (CCD) as a method of the response surface methodology (RSM) was applied to minimize the number of runs and process optimization. The characterization of the microporous MgO/AC composite showed that the magnesium oxide nanoparticles were successfully coated on the AC and the BET specific surface area of AC and MgO/AC were 1,540 and 1,246 m2/g, respectively. The MB removal efficiency and the maximum adsorption capacity of AC and MgO/AC were 89.6, 97.5% and 571.7, 642.3 mg/g, respectively under optimum operational conditions of initial dye concentration of 100.9 mg/L, the adsorbent dosage of 69.4 mg/100 mL, pH of 10.2 and contact time of 149.1 min. According to an analysis of variance (ANOVA), the initial dye concentration and its interaction with the other effective factors have a large impact on adsorption efficiency. Furthermore, the mechanism of adsorption followed the Langmuir isotherm (R2 = 0.9935, Δqe = 2.9%) and adsorption kinetics fitted by the pseudo-second-order model (R2 = 0.9967, Δqe = 6.6%). Finally, our results suggest that the prepared MgO/AC is an efficient and promising material for dye wastewater treatment.

scholarly journals Adsorption Evaluation for the Removal of Nickel, Mercury, and Barium Ions From Single-Component and Mixtures of Aqueous Solutions by Using an Optimized Biobased Chitosan Derivative

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 232
Author(s):  
Efstathios V. Liakos ◽  
Mariza Mone ◽  
Dimitra A. Lambropoulou ◽  
Dimitrios N. Bikiaris ◽  
George Z. Kyzas
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Single Component ◽  
Chitosan Derivative ◽  
Barium Ions ◽  
Hydroxymethyl Furfural ◽  
Before And After ◽  
Equilibrium Data ◽  
Best Fitting

In this experimental study, the use of 5-hydroxymethyl-furfural (HMF) organic compound as a grafting agent to chitosan natural polymer (CS) was examined. One optimized chitosan derivative was synthesized, and then tested (CS-HMF), in order to uptake nickel, mercury, and barium metal ions from single- and triple-component (multi-component) aqueous solutions. The characterization of the material before and after the metal uptake was achieved by scanning electron microscopy (SEM). The ability of the adsorption of CS-HMF was tested at pH = 6. The adjusting of temperature from 25 to 65 °C caused the increase in the adsorption capacity. The equilibrium data were fitted to the models of Langmuir and Freundlich, while the data from kinetic experiments were fitted to pseudo-1st and pseudo-2nd order models. The best fitting was achieved for the Langmuir model (higher R2). The adsorption capacity for nickel, mercury, and barium removal at 25 °C (single component) was 147, 107, and 64 (mg/g), respectively. However, the total adsorption capacity for the multi-component was 204 mg/g. A thermodynamic study was also done, and the values of ΔG0, ΔH0, and ΔS0 were evaluated.

scholarly journals Kinetic Study, Modelling and Optimization of Adsorption Processes for Removal of Crude Oil from Contaminated Water using Chitosan-Rice Husk Ash Composite

2018 ◽  
pp. 1-10
Author(s):  
G. G. Oseke ◽  
M. T. Isa ◽  
M. S. Galadima ◽  
A. O. Ameh
Keyword(s):  
Crude Oil ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
Contact Time ◽  
Rice Husk Ash ◽  
Kinetic Studies ◽  
Contaminated Water ◽  
Adsorbent Dosage ◽  
Temkin Isotherm ◽  
Adsorbate Concentration

This study was aimed at developing chitosan-rice husk ash adsorbent for the removal of crude oil from contaminated water. Design Expert software 6.06 was used to design the adsorption experiment. The adsorption was tested for Langmuir, Freundlich and Temkin isotherms and the kinetic studies also carried out. The effect of influencing parameters such as contact time, adsorbate concentration, adsorbent dosage and formulation ratio were studied. It was generally shown that adsorption process increased with time and adsorbate concentration and decreased with adsorbent dosage. Models for the prediction of adsorption capacity for the composite was significant with R2 value of 0.8382 and P-value of 0.0017. Optimum conditions were found to be 0.90 wt/wt chitosan/silica ratio, contact time of 5 min, and oil/water ratio of 0.25 v/v, which gave 20.66 g/g sorption capacity respectively. Adsorption isotherm studies of Langmuir, Freundlich and Temkin were carried out for the chitosan-rice husk ash composite. Temkin isotherm best fitted with R2 value of 0.9999. The adsorption capacity of composite from isotherm studies was obtained to be 18.85 g/g adsorbent. The heat of adsorption bT (kJmol-1) obtained from Temkin isotherm study was -48.67 kJ/mol indicating physisorption of adsorbents to the crude oil.  Kinetic studies indicated that the pseudo-second order model suitably described the removal of crude oil by the composite with R2 value 0.9999.

scholarly journals EFFECT OF ACID CONCENTRATION ON CHARACTERS OF SILICA GEL SYNTHESIZED FROM SODIUM SILICATE

2010 ◽  
Vol 5 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Nuryono Nuryono ◽  
Narsito Narsito
Keyword(s):  
Citric Acid ◽  
Water Content ◽  
Adsorption Capacity ◽  
Sodium Silicate ◽  
Silica Gel ◽  
Acid Concentration ◽  
Water Adsorption ◽  
Sol Gel ◽  
Silica Gels

In this research, synthesis and characterization of silica gel from sodium silicate through sol-gel process using H2SO4, HCl, and citric acid have been investigated. Synthesis was carried out by mixing and stirring  20 mL of H2SO4, HCl or citric acid  at certain concentration with 50 mL of sodium silicate solution (Na2O 0.17 M and SiO2 0.61 M) for one hour and let to form gel.  The gel was washed with distillated water, and dried in an oven at 100 oC. Characterization of silica gel was carried out by determination of acidity, water adsorption capacity, and water content. Identification of functional group and structure were identified using x-ray diffractometer (XRD) and infrared (IR) spectrophotometer, respectively.  Results showed that at a range of investigated concentration (0.6 - 3.0 M) the increase of concentration, formation of gel with H2SO4 tended to be faster, but with HCl and citric acid to be slower. The increase of acid concentration caused water content, water adsorption capacity, and acidity of the silica gel resulted with HCl and citric acid tended to be increased, increased, and increased, but with H2SO4 to be decreased, increased, and decreased, respectively. Based on the IR spectra and XRD data, it could concluded that the synthetic silica gels contained silanol (Si-OH) and siloxane (Si-O-Si) and were amorphous, showing similar pattern to kieselgel G 60 produced by Merck.   Keywords: silica gel, adsorption capacity, sodium silicate, acidity

scholarly journals Synthesis, Characterization of Iron Oxide (Α-Fe2o3) Nanoparticles and its Application in Photocatalytic Reduction of Cadmium (Ii)

2018 ◽  
Vol 7 (3.34) ◽  
pp. 388
Author(s):  
Shrikrishna H Gurlhosur ◽  
Dr Sreekanth B ◽  
. .
Keyword(s):  
Iron Oxide ◽  
Metal Concentration ◽  
Contact Time ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
Crystalline Size ◽  
Fe2o3 Nanoparticles ◽  
Constant Ph ◽  
Sem Morphology

The α-Fe2O3 Nanoparticles were successfully synthesized by Sol-Gel method and the powder was calcinated at 4000. SEM, XRD, FTIR, EDX studies were carried out for characterization. The XRD confirmed that nanoparticles were Hematite (α-Fe2O3 ) having  crystalline size of 11.55nm which confirms the Hematite(α-Fe2O3) on comparison with obtained spectra against Joint Committee on Powder Diffraction Standards Database(JCPDS) and SEM morphology indicated that  IronOxide Nanoparticles were of flower shape at higher magnifications . The FTIR showed the bonds between functional groups and Fe-O group, O-H bending and vibration bonds. The presence  of  FeO, Fe, C, in nanomaterial was confirmed by EDX . Synthesized iron oxide α-Fe2O3 (Hematite) crystalline size of 11.55nm was used in the study of photo catalytic reduction of Cadmium (II) .Different parameters like Metal concentration, Dosage of Nanoparticles, Contact time and pH were studied. pH maintained for the solutions of different concentrations were 4,5,6,7 and 10. Concentration of cadmium solution taken for the study were 2,4,6,8 and 10ppm. Keeping concentration and dosage constant, pH was varied. Then concentration was varied by keeping dosage and pH constant. Then dosage was varied by keeping concentration and pH constant. Dosage of iron oxide taken was 50 mg, 75mg, 100mg, 125 mg and 150mg. It was observed that photo catalytic reduction by Iron oxide nanoparticles (IONP)  was  more effective at metal concentration 4ppm, IONP dosage 100mg, pH 5, and contact time of 150 min with 97.02%  reduction of Cadmium (II). 

Sign in / Sign up

Export Citation Format

Share Document