scholarly journals Removal of Some Heavy Metals [Pb(II), Cd(II), Zn(II)] in Polluted Waters using Acid- Functionalized MCM-41 Mesoporous Materials: Adsorption Isotherm and Kinetic Studies

2021 ◽  
Vol 33 (12) ◽  
pp. 2934-2942
Author(s):  
Jayarangarao Prathipati ◽  
Paul Douglas Sanasi

Acid functionalized mesoporous silica materials like sulphonic acid (SO3HMCM-41) and phosphotungstic acid (PWMCM-41) were synthesized by a simple co-precipitation method. These materials were characterized using XRD, SEM-EDS, FT-IR, BET surface area techniques. The mesoporosity was retained even after acid functionalization into MCM-41. There was a significant fall in the surface area (SBET, m2 g-1), on incorporation of sulphonic acid (-SO3H) and phosphorous, tungsten atoms into the MCM-41 material. SO3HMCM-41 was found to be more acidic than PWMCM-41 and MCM-41. Their performance was evaluated by conducting experiments on the removal of heavy metals like Pb(II), Cd(II), Zn(II) present in industrial wastewaters, with atomic absorption spectrophotometer (AAS). The required experimental factors were analyzed and it was observed that the removal of metals was more efficient with the acid-functionalized materials than with MCM-41. Freundlich adsorption isotherm and pseudo-first order kinetics have confirmed the validity of the results.

2011 ◽  
Vol 399-401 ◽  
pp. 1425-1428
Author(s):  
Jun Zeng ◽  
Feng Chun Zeng ◽  
Jun Bo Zhong ◽  
Jian Zhang Li ◽  
Shao Hua Wang ◽  
...  

In this paper, Bi2O3 and Fe3+-doped Bi2O3 photocatalysts with different molar ratio of Bi /Fe (nBi:nFe =100:1,2,3,4) was prepared by paralled flaw co-precipitation method. The prepared photocatalysts were characterized by Brunauer-Emmet Teller (BET) method, X-ray diffraction( XRD) and UV-Vis diffuse reflectance spectroscopy. The results show that 3% Fe3+-Bi2O3 prepared has the highest BET surface area, pore volume, the smallest pore size and the particle average size. 3% Fe3+-Bi2O3 exhibits the best photocatalytic activity. The results of further experiments show that the specific surface area, UV-Vis diffuse reflectance all play an important role in promotion of photocatalytic activity of Bi2O3 nanostructure.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ali Q. Alorabi

In this work, magnetized activated Juniperus procera leaves (Fe3O4@AJPL) were successfully prepared via chemical activation of JPL and in situ coprecipitation with Fe3O4. A Fe3O4@AJPL nanocomposite was successfully applied for the elimination of malachite green (MG) dye from aqueous media. The prepared Fe3O4@AJPL adsorbent was characterized by SEM, EDX, TEM, XRD, FTIR, TGA, and BET surface area analyses. The BET surface area and pore size of the Fe3O4@AJPL nanocomposite were found to be 38.44 m2/g and 10.6 nm, respectively. The XRD and FTIR results indicated the formation of a Fe3O4@AJPL nanocomposite. Different parameters, such as pH of the solution (3–8), adsorbent dosage (10–100 mg), temperature (25–45°C), contact time (5-240 min), and initial MG concentrations (20–350 mg/L), for the elimination of the MG dye using Fe3O4@AJPL were optimized and found to be 7, 50 mg, 45°C, 120 min, and 150 mg/L, respectively. The nonlinear isotherm and kinetic studies exhibited a better fitting to second-order kinetic and Langmuir isotherm models, with a maximum monolayer adsorption capacity of 318.3 mg/g at 45°C, which was highly superior to the previously reported magnetic nanocomposite adsorbents. EDX analyses confirmed the presence of nitrogen on the Fe3O4@AJPL surface after MG adsorption. The calculated thermodynamic factors indicated endothermic and spontaneous processes. The desorption of MG dye from Fe3O4@AJPL was performed using a solution of 90% ethanol. Finally, it could be concluded that the designed Fe3O4@AJPL magnetic nanocomposite will be a cost-effective and promising adsorbent for the elimination of MG from aqueous media.


2015 ◽  
Vol 11 (9) ◽  
pp. 3950-3958 ◽  
Author(s):  
Chandrakant Vedu Nandre ◽  
C.P. Sawant

In the present study photocatalytic degradation of hazardous water soluble alizarin red dye by using Fe-Co nanoparticles  has been investigated. Fe-Co nanoparticles was synthesized by chemical co-precipitation method and characterized by TEM, SEM, EDAX and XRD. The photocatalytic degradation have been studied with the help of variety of parameters such as catalytic dose, dye concentration, pH, contact time and most important chemical oxygen demand. It was observed that The photocatalytic degradation of alizarin red dye by using Fe-Co nanoparticles was an effective ,economic, ecofriendly and faster mode of removing dye from an aqueous solution. The optimum condition for the degradation of the dye was 50 mg/L,pH 8.0, catalyst dose 60 mg/L and contact time 60 minutes. The kinetic studies also have been studied.


2019 ◽  
Vol 944 ◽  
pp. 1192-1198
Author(s):  
Rong Wang ◽  
Zhi Xiang Lin ◽  
Yang Zhao ◽  
Xiao Dong Xu ◽  
Yan Xi Deng

An Al-supported cage-like mesoporous silica type MCM-41 has been prepared using a simple one-step synthetic procedure using oil shale residue and CTAB(Hexadecyl trimethyl Ammonium Bromide) as the template. The effects of temperature on the porosity, structure and surface area of Al-MCM-41 mesoporous materials were characterized by X-ray powder diffraction, N2adsorption desorption, scanning electron micrographs (SEM), transmission electron microscopy (TEM) techniques and Fourier transform infrared spectroscopy (FT-IR). The results indicated that temperature was a key to the characteristics of Al-MCM-41 materials, and when the temperature up to 333 K, Al-MCM-41 exhibited excellent characteristics with high degree of order, high surface area and pore volume. The one-step hydrothermal synthesized MCM-41 mesoporous material possessed high BET surface area, high pore size and high pore volume. They are respectively 835.1 m2/g, 32.6 Å and 1.22 cm3/g under the condition of the Si : Al =78:1, pH =10, crystallization temperature was 333K, crystallization time was 48h and calcination at 823 K for 5 h in air. All the results indicated the possibility of using oil shale residue as silicon and aluminum source to produce Al-MCM-41, and gave us a new way to recycle a solid waste. As well as this made it impossible to large-scale production of Al-MCM-41. Keywords: Al-MCM-41 mesoporous materials, oil shale residue, one-step synthesis


2016 ◽  
Vol 74 (1) ◽  
pp. 276-286 ◽  
Author(s):  
Bin Huang ◽  
Dan Xiong ◽  
Tingting Zhao ◽  
Huan He ◽  
Xuejun Pan

Biomorphic nano-hydroxyapatite (HAP) was fabricated by a co-precipitation method using cotton as bio-templates and employed in adsorptive removal of ofloxacin (OFL) and triclosan (TCS) that are two representative pharmaceuticals and personal care products (PPCPs). The surface area and porosity, crystal phase, functional group, morphology and micro-structure of the synthesized HAP were characterized by Brunauer–Emmett–Teller isotherm, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron macroscopic and transmission electron microscopy. The effects of initial pH, ionic strength, initial concentration, contact time and temperature on the removal of PPCPs were studied in a batch experiment. The adsorption of OFL and TCS was rapid and almost accomplished within 50 min. Kinetic studies indicated that the adsorption process of OFL and TCS followed the pseudo-first-order and pseudo-second-order models, respectively. The Freundlich isotherm described the OFL adsorption process well but the adsorption of TCS fitted the Langmuir isotherm better. Thermodynamics and isotherm parameters suggested that both OFL and TCS adsorption were feasible and spontaneous. Hydrogen bond and Lewis acid–base reaction may be the dominating adsorption mechanism of OFL and TCS, respectively. Compared to other adsorbents, biomorphic HAP is environmentally friendly and has the advantages of high adsorption capacity, exhibiting potential application for PPCPs removal.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Guotao Zhao ◽  
Zhenxiao Zhao ◽  
Junliang Wu ◽  
Daiqi Ye

Fluorine-containing hydrophobic mesoporous material (MFS) with high surface area is successfully synthesized with hydrothermal synthesis method by using a perfluorinated surfactant SURFLON S-386 template. The adsorption properties of water vapor on the synthesized MFS are also investigated by using gravimetric method. Results show that SEM image of the MFS depicted roundish morphology with the average crystal size of 1-2 μm. The BET surface area and total pore volume of the MFS are 865.4 m2 g−1and 0.74 cm3 g−1with a narrow pore size distribution at 4.9 nm. The amount of water vapor on the MFS is about 0.41 mmol g−1at 303 K, which is only 52.6% and 55.4% of MCM-41 and SBA-15 under the similar conditions, separately. The isosteric adsorption heat of water on the MFS is gradually about 27.0–19.8 kJ mol−1, which decreases as the absorbed water vapor amount increases. The value is much smaller than that on MCM-41 and SBA-15. Therefore, the MFS shows more hydrophobic surface properties than the MCM-41 and SBA-15. It may be a kind of good candidate for adsorption of large molecule and catalyst carrier with high moisture resistance.


2013 ◽  
Vol 545 ◽  
pp. 109-114 ◽  
Author(s):  
Kitirote Wantala ◽  
Pongsert Sriprom ◽  
Nusavadee Pojananukij ◽  
Arthit Neramittagapong ◽  
Sutasinee Neramittagapong ◽  
...  

The reactive red 3 was degraded by catalytic wet oxidation process over Fe-RH-MCM-41 prepared by Direct Hydrothermal Technique (DHT) at Si/Fe molar ratio of 10 using silica from rice husk. The extended reaction conditions were studied as a function of reaction temperatures, initial H2O2 concentrations and initial pH of solutions designed by Box-Behnken design (BBD) based on Response Surface Methodology (RSM) to achieve the optimal condition and interaction of independent variables. The characterizations of catalyst were studied by XRD, BET surface area and TEM to explain the morphology of surface and to confirm the hexagonal structure. The results showed the 2theta peak can be indexed to hexagonal lattice that also confirmed by TEM result and surface area about 650 m2/g. All of independent variables showed significant on the degradation of reactive red 3 except for initial H2O2 concentration.


2020 ◽  
Vol 4 (1) ◽  
pp. 9-16
Author(s):  
FS Nworie ◽  
EC Oroke ◽  
II Ikelle ◽  
JS Nworu

AbstractStudies on the adsorption of Pb(II) on plantain peels biochar (PPB) was conducted. The carbonized and activated, biochar was characterized using Braunauer-Emmett-Teller (BET) surface area and x-ray diffraction crystallography (XRD). BET analysis of the PPB indicated that the pore size (cc/g) and pore surface area (m2/g) was 8.79 and 16.69 respectively. Result of the XRD evaluated through Debye-Scherrer equation, showed a nanostructure with crystallite size of 14.56 nm. Effects of initial metal ion concentration, pH, and contact time were studied in a batch reaction process. Results showed that the adsorption of lead from aqueous solution increased with an increase in pH and initial concentration. Equilibrium modeling studies suggested that the data fitted mainly to the Langmuir isotherm. Adsorption kinetic data tested using various kinetic models fitted the Weber and Morris intraparticle diffusion model implicating pore diffusion as the main rate limiting step. The sorption studies indicated the potential of plantain peel biochar as an effective, efficient and low cost adsorbent for remediating lead (II) ions contaminated environment.


2020 ◽  
Vol 57 (3) ◽  
pp. 40-47
Author(s):  
M. Sirait ◽  
K.Sari Dewi Saragih ◽  
S. Gea ◽  

AbstractHeavy metal waste is very dangerous, which can change the condition of water into a solid substance that can be suspended in water and can reduce the cleanliness level of water consumed by living things. To date, heavy metals can be managed through several processes, namely physics, biology or chemistry. One of the ways to overcome heavy metal pollution is to use natural zeolite applying a co-precipitation method, as it is known that zeolite is a powerful natural material to be used for certain purposes. In order to justify the research results, several analyses have been performed, such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Surface Area Analyser (SAA), and Atomic Adsorption Spectrophotometric (AAS). From the XRD results, it has been found out that the size of each zeolite with variations in size of 150 mesh, 200 mesh, and 250 mesh is 29.274 nm, 38.665 nm and 43.863 nm, respectively. Moreover, the SEM-EDX has shown that the zeolite under consideration is a type of Na-Zeolite and that the co-precipitation method successfully removes impurity elements, namely, Fe, Ti, and Cl. The results of SAA testing have indicated that the total surface area for each variation of zeolite sizes is 63.23 m2/g, 45.14 m2/g and 59.76 m2/g. The results of the AAS test analysis have demonstrated that the optimal absorption of metal content is observed in a size of 150 mesh zeolite with adsorption power of 99.6 % for Pb metal, 98 % for Cu metal, and 96 % Zn metal.


2021 ◽  
Vol 71 (12) ◽  
pp. 34-46
Author(s):  
Nagy A. E. Emara ◽  
Rehab M. Amin ◽  
Ahmed F Youssef ◽  
Souad A. Elfeky

This study was steered to convert waste acid ensued from the pickling process in steel industries to an esteemed nanocomposite for the elimination of heavy metals (HMs) from wastewater. Magnetic nanoparticles (Fe3O4) preparation from waste was performed by the co-precipitation method. These magnetic nanoparticles are modified by carboxymethyl-a-cyclodextrin polymer (CM-a-CD) through copolymerization reactions. The data obtained from FTIR, XRD, and TEM point up that CM-a-CD is entrenched onto Fe3O4 nanoparticles. The generated CM-a-CD / Fe3O4 was employed for HMs deportation from contaminated water and the adsorption results revealed that CM-a-CD/ Fe3O4 sorption efficiency was in the order of Pb(II) ] Cd(II) ] Cr(VI). The highest adsorption capacity was 64.2 (mg/g) for Pb(II). The kinetic study revealed that the HMs sorption by CM-a-CD/ Fe3O4 follows the pseudo-second-order model. The equilibrium modeling study proved that the Langmuir isotherm model was more fitting. The coexisting ions do not significantly alter the percentage removal of the measured metal ions. The efficiency of the synthesized polymer is particularly high in the tested field samples. Thus, CM-a-CD/ Fe3O4 has an extremely high adsorption capability in the field application as well as excellent reusability results, which will reduce the cost for the CM-a-CD / Fe3O4 as an adsorbent for wastewater treatment.


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