scholarly journals Effective Magnetic MOFs Adsorbent for the Removal of Bisphenol A, Tetracycline, Congo Red and Methylene Blue Pollutions

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1917
Author(s):  
Guangpu Zhang ◽  
Rong Wo ◽  
Zhe Sun ◽  
Gazi Hao ◽  
Guigao Liu ◽  
...  

A magnetic metal−organic frameworks adsorbent (Fe3O4@MIL-53(Al)) was prepared by a typical solvothermal method for the removal of bisphenol A (BPA), tetracycline (TC), congo red (CR), and methylene blue (MB). The prepared Fe3O4@MIL-53(Al) composite adsorbent was well characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR). The influence of adsorbent quantity, adsorption time, pH and ionic strength on the adsorption of the mentioned pollutants were also studied by a UV/Vis spectrophotometer. The adsorption capacities were found to be 160.9 mg/g for BPA, 47.8 mg/g for TC, 234.4 mg/g for CR, 70.8 mg/g for MB, respectively, which is superior to the other reported adsorbents. The adsorption of BPA, TC, and CR were well-fitted by the Langmuir adsorption isotherm model, while MB followed the Freundlich model, while the adsorption kinetics data of all pollutants followed the pseudo-second-order kinetic models. The thermodynamic values, including the enthalpy change (ΔH°), the Gibbs free energy change (ΔG°), and entropy change (ΔS°), showed that the adsorption processes were spontaneous and exothermic entropy-reduction process for BPA, but spontaneous and endothermic entropy-increasing processes for the others. The Fe3O4@MIL-53(Al) was also found to be easily separated after external magnetic field, can be a potential candidate for future water treatment.

2018 ◽  
Vol 83 (1) ◽  
pp. 107-120 ◽  
Author(s):  
Zdravka Velkova ◽  
Gergana Kirova ◽  
Margarita Stoytcheva ◽  
Velizar Gochev

Pretreated waste Streptomyces fradiae biomass was utilized as an eco-friendly sorbent for Congo Red (CR) and Methylene Blue (MB) removal from aqueous solutions. The biosorbent was characterized by Fourier transform infrared spectroscopy. Batch experiments were conducted to study the effect of pH, biosorbent dosage, initial concentration of adsorbates, contact time and temperature on the biosorption of the two dyes. The equilibrium adsorption data were analysed using Freundlich and Langmuir models. Both models fitted well the experimental data. The maximum biosorption capacity of the pretreated Streptomyces fradiae biomass was 46.64 mg g-1 for CR and 59.63 mg g-1 for MB, at a pH 6.0, with the contact time of 120 min, the biosorbent dosage of 2 g dm-3 and the temperature of 298 K. Lagergren and Ho kinetic models were used to analyse the kinetic data obtained from different batch experiments. The biosorption of both dyes followed better the pseudo-second order kinetic model. The calculated values for ?G, ?S, and ?H indicated that the biosorption of CR and MB onto the waste pretreated biomass was feasible, spontaneous, and exothermic in the selected temperature range and conditions.


2020 ◽  
Vol 19 (2) ◽  
pp. 100
Author(s):  
Irwin Tan Kai Ge ◽  
Muhammad Wahyu Nugraha ◽  
Norashikin Ahmad Kamal ◽  
Nonni Soraya Sambudi

Dyeing industry is one of the fast-growing industries but at the same time has also brought us a big issue on environment pollution. Adsorption processes is the most effective method in dye removal compared to other methods of wastewater treatment. In recent years, there is an increasing interest in utilizing clay material such as kaolinite as an adsorbent to remove not only inorganic but also organic molecules. In this study, composite of kaolin-sodium alginate (SA) beads was synthesized by varying the weight of kaolin from 0.5 g to 2 g. XRD, FTIR, and surface area analyses were used to characterize the kaolin; while FTIR was used to characterize the composite where the functional groups of kaolin and SA are existing. The amount of 1 g kaolin in SA could improve the adsorption of methylene blue up to 78% of removal after 8 hours. The adsorption model fits pseudo second order kinetic and Langmuir isotherm


2021 ◽  
Vol 21 (2) ◽  
pp. 421
Author(s):  
Aldes Lesbani ◽  
Neza Rahayu Palapa ◽  
Rabelia Juladika Sayeri ◽  
Tarmizi Taher ◽  
Nurlisa Hidayati

Ni/Al layered double hydroxide was used as a starting material for composite formation with biochar as a matrix. The materials were characterized using X-ray, FTIR, nitrogen adsorption-desorption, thermal, and morphology analyses. The NiAl LDH/Biochar material is then used as an adsorbent of methylene blue from an aqueous solution. The factor that was influencing adsorption such as pH, time, methylene blue concentration, and temperature adsorption was studied systematically. The regeneration of adsorbent was performed to know the stability of NiAl LDH/Biochar under several cycle adsorption processes. The results showed that NiAl LDH/Biochar has a specific diffraction peak at 11.63° and 22.30°. NiAl LDH/Biochar has more than ten-fold surface area properties (438,942 m2/g) than biochar (50.936 m2/g), and Ni/Al layered double hydroxide (92.682 m2/g). The methylene blue adsorption on NiAl LDH/Biochar follows a pseudo-second-order kinetic adsorption model and classify as physical adsorption. The high reusability properties were found for NiAl LDH/Biochar, which was largely different from biochar and Ni/Al layered double hydroxide.


2021 ◽  
Author(s):  
BENSEDIRA Abderrahim ◽  
HADDAOUI Nacerddine ◽  
DOUFNOUNE Rachida ◽  
MEZIANE Ouahiba ◽  
N. S. Labidi

Abstract Conducting Polymeric composites have attracted great attention over the last years because of their potential uses in chemical, electronic and optical devices, and as catalysts as well as in adsorption processes. Chemical synthesis of polyaniline (PANI) and polyaniline-SiO2 composite and their adsorptive performance were reported in the present work. These materials were prepared and evaluated for their methylene blue (MB) dye adsorption characteristics from aqueous solution. Adsorption equilibrium kinetic and thermodynamic experiments of MB onto PANI and PANI/SiO2 were studied. The effects of initial dye concentration, contact time and temperature on the adsorption capacity of PANI/SiO2 for MB have been investigated. The pseudo-first order and pseudo-second order kinetic models were used to describe the kinetic data. It was found that adsorption kinetics followed the pseudo-second order at all of the studied temperatures. The Langmuir, Freundlich and Dubinin Raduschkevich adsorption models were used for the mathematical description and the fit obtained using the Dubinin Raduschkevich isotherm has a medium R2 value.


2020 ◽  
Vol 62 (4) ◽  
pp. 62-71
Author(s):  
Evgenia A. Tarasenko ◽  
◽  
Irina G. Ryltsova ◽  
Maksim N. Yapryntsev ◽  
Yevgenia Yu. Nakisko ◽  
...  

The work is devoted to the study of the sorption properties of hierarchical composite materials with a core-shell structure. The composites contained a core of SiO2 or Fe3O4@SiO2 obtained by sol-gel synthesis, on the surface of which a layered double hydroxide (MgAlFe-LDH) was deposited. The phase composition of the obtained materials was determined, and the textural characteristics and particle morphology were studied. It was found that hierarchical materials had larger surface and demonstrated high sorption capacity towards both cationic and anionic dyes in aqueous solution in comparison with individual systems (SiO2 and MgAlFe-LDH). It was shown that the sorption equilibrium in the system “dye solution – sorbent” for dye methylene blue was achieved faster in comparison with Congo red. The obtained kinetic data were analyzed using chemical kinetic models. The sorption of both Congo red and methylene blue on composite materials was found to be described by a pseudo-second order kinetic equation. Isotherms of sorption of Congo red and methylene blue on synthesized materials were plotted. The sorption capacity of Fe3O4@SiO2@LDH and SiO2@LDH towards Congo red were 0.19 mmol/g and 0.27 mmol/g, respectively. In the case of sorption of methylene blue, the sorption isotherms did not reach a plateau in the studied concentration range. However, it can be noted that at an initial methylene blue concentration of 0.051 mmol/L the sorption capacity of Fe3O4@SiO2@LDH and SiO2@LDH were 0.040 mmol/g and 0.033 mmol/g, respectively. The obtained data indicate that hierarchical composite materials containing LDH in their composition are effective bifunctional sorbents and can uptake both anionic and cationic forms of pollutants from a solution. An advantage of the Fe3O4 core system is its ability to be easily separate from a solution under the influence of an external magnetic field. It is important that the Fe3O4@SiO2@LDH sample exhibits a typical superparamagnetic behavior with zero coercitivity and residual magnetic induction.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ünal Geçgel ◽  
Gülce Özcan ◽  
Gizem Çağla Gürpınar

An activated carbon was prepared from pea shells and used for the removal of methylene blue (MB) from aqueous solutions. The influence of various factors such as adsorbent concentration, initial dye concentration, temperature, contact time, pH, and surfactant was studied. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. The adsorption isotherm was found to follow the Langmuir model. The monolayer sorption capacity of activated carbon prepared from pea shell for MB was found to be 246.91 mg g−1at 25∘C. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. Kinetic studies showed that the adsorption followed pseudo-second-order kinetic model. Various thermodynamic parameters such as , , and were evaluated. The results in this study indicated that activated carbon prepared from pea shell could be employed as an adsorbent for the removal of MB from aqueous solutions.


2012 ◽  
Vol 430-432 ◽  
pp. 197-201
Author(s):  
Feng Yu Li ◽  
Sheng Hua Zhang ◽  
Jin Yi Chen

Pyromellitic dianhydride(PMDA)- modified grain sorghum stalk was used as a novel low-cost adsorbent to remove cationic dye methylene blue(MB) from aqueous solution. Bath studies were carried out to investigate the effects of pH and retention time on the adsorption of MB. The adsorption process could obtain >98% removal percentage within 30 minutes as the MB concentration was at 200 and 300 mg/L. And for 400 mg/L MB, 99% was removed in 6 hrs. The kinetics study showed that the adsorption processes followed the pseudo-second-order kinetic model, which confirming that the sorption rate is controlled by chemical adsorption. Equilibrium isotherms were analyzed by the Langmuir and Freundlich models. Langmuir model can be fitted better than Freundlich with maximum monolayer adsorption capacity of 568.18 mg/g for MB.


2018 ◽  
Vol 7 (3.18) ◽  
pp. 87
Author(s):  
Soh Fong Lim ◽  
Agnes Yung Weng Lee ◽  
Yat Seng Kam ◽  
S N. David Chua

This paper provides insight on the removal of dyes from water using magnetic separation technique. A new alginate encapsulated zirconium-based encapsulated ferromagnetic sorbent has been synthesized by co-precipitation and electrostatic extrusion techniques. The ferromagnetic sorbent has the alginate as outer polymeric shell and zirconium-based iron oxides as inner ferromagnetic cores. The sorbent has the multi-functional properties as it is can be easily separated using external magnetic force, and effective in adsorptive removal of congo red, methyl violet, and methylene blue dyes. The sorbent was characterized by particle size analyser, Scanning Electron Microscope (SEM), Thermal Gravimetric-Differential Thermal Analyzer (TG-DTA), and Fourier Transform Infrared Spectroscopy (FT-IR).  Adsorption assays were performed in batch using methyl violet, methylene blue, and congo red dyes as contaminants. The alginate encapsulated zirconium-based ferromagnetic sorbent was a potential candidate for removal of dyes under a magnetic field as separating agent. The present investigation demonstrates the ferromagnetic sorbent exhibiting good performance to remove the methyl violet, congo red, and methylene blue dyes from aqueous solutions. The adsorption experiments reveal that the adsorption performance is higher for the cationic dye than the anionic dye. The SEM and FT-IR studies show that the interaction characteristics between the dyes and the ferromagnetic sorbent where the surface of the ferromagnetic sorbent became smoother and less porous when the metal-O group (Zr-O and Fe-O) of the ferromagnetic sorbent attaches to the dye.  


2020 ◽  
Vol 15 (2) ◽  
pp. 476-489
Author(s):  
Iis Intan Widiyowati ◽  
Mukhamad Nurhadi ◽  
Muhammad Hatami ◽  
Lai Sin Yuan

The study of TiO2-sulfonated carbon-derived from Eichhornia crassipes (TiO2/SCEC), as an effective adsorbent to remove Methylene blue (MB) and Congo red (CR) dyes from aqueous solution, has been conducted. The preparation steps of TiO2/SCEC adsorbent involved the carbonisation of E. crassipes powder at 600 °C for 1 h, followed by sulfonation of carbon for 3 h and impregnation through titanium(IV) isopropoxide (500 µmol). The physical properties of the adsorbents were characterized by using X-ray fluorescence (XRF), Fourier transform infrared, X-ray diffraction (XRD), Scanning electron microscopy with Energy dispersive X-ray (SEM-EDX), Thermogravimetric analysis (TGA) and nitrogen adsorption-desorption studies. The dye removal study using TiO2/SCEC adsorbent was carried out by varying of contact time, adsorbent dosage, initial dye concentration, pH, particles size of adsorbent and temperature. The kinetics models were determined by the effects of contact time and the thermodynamic parameters (ΔH, ΔS, and ΔG), which were calculated by the effects of temperature. The results showed that the maximum dye removal capacity of TiO2/SCEC were 18.8 mg.g-1 for MB and 36.5 mg.g-1 for CR. The removal of MB and CR dyes using TiO2/SCEC adsorbent performed a pseudo-second order kinetic models with spontaneity. Copyright © 2020 BCREC Group. All rights reserved 


Author(s):  
Saraa Muwafaq Ibrahim ◽  
Ziad T. Abd Ali

Batch experiments have been studied to remove methylene blue dye (MB) from aqueous solution using modified bentonite. The modified bentonite was synthesized by replacing exchangeable calcium cations in natural bentonite with cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The characteristics of modified bentonite were studied using different analysis such as Scanning electronic microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and surface area. Where SEM shows the natural bentonite has a porous structure, a rough and uneven appearance with scattered and different block structure sizes, while the modified bentonite surface morphology was smooth and supplemented by a limited number of holes. On other hand, (FTIR) analysis that proved NH group aliphatic and aromatic group of MB and silanol group are responsible for the sorption of contaminate. The organic matter peaks at 2848 and 2930 cm-1 in the spectra of modified bentonite which are sharper than those of the natural bentonite were assigned to the CH2 scissor vibration band and the symmetrical CH3 stretching absorption band, respectively, also the 2930 cm-1 peak is assigned to CH stretching band. The batch study was provided the maximum removal efficiency (99.99 % MB) with a sorption capacity of 129.87 mg/g at specified conditions (100 mg/L, 25℃, pH 11 and 250rpm). The sorption isotherm data fitted well with the Freundlich isotherm model. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules.


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