scholarly journals Supramolecular Hybrid Material Based on Engineering Porphyrin Hosts for an Efficient Elimination of Lead(II) from Aquatic Medium

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 669 ◽  
Author(s):  
Chahrazad El Abiad ◽  
Smaail Radi ◽  
Maria Faustino ◽  
M. Neves ◽  
Nuno Moura

Porphyrins show great promise for future purification demands. This is largely due to their unique features as host binding molecules that can be modified at the synthetic level, and largely improved by their incorporation into inorganic based materials. In this study, we assessed the efficacy of a hybrid material obtained from the immobilization of 5,10,15,20-tetrakis(pentafluorophenyl)-porphyrin on silica surface to remove Pb(II), Cu(II), Cd(II), and Zn(II) ions from water. The new organic-inorganic hybrid adsorbent was fully characterized by adequate techniques and the results show that the hybrid exhibits good chemical and thermal stability. From batch assays, it was evaluated how the efficacy of the hybrid was affected by the pH, contact time, initial metal concentration, and temperature. The adsorption kinetic and isotherms showed to fit the recent developed fractal-like pseudo-second-order model and Langmuir–Freundlich model respectively. The highest adsorption capacities for Pb(II), Cu(II), Cd(II), and Zn(II) ions were 187.36, 125.17, 82.45, and 56.23 mg g−1, respectively, at pH 6.0 and 25 °C. This study also shows that metal cations from real river water samples can be efficient removed in the presence of the new adsorbent material.

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Hamid Ziyat ◽  
Mohammed Naciri Bennani ◽  
Hassan Hajjaj ◽  
Omar Qabaqous ◽  
Said Arhzaf ◽  
...  

The present work aims to study the affinity of a component of the thyme essential oil “thymol” to natural Moroccan clay “Rhassoul” using the adsorption technique. The physicochemical characterizations of the purified and modified clay were carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), DTA/TGA, and SEM-EDX. Thymol adsorption tests on the purified Rhassoul (Rh-P) and the modified one by CTAB (Rh-CTAB) were followed by UV-visible spectroscopy. They show that the adsorption isotherms can be described by the Freundlich model and that the kinetics of adsorption is in accordance with the pseudo-second-order model for the two clays. Adsorption capacities obtained were of the order of 6 mg/g for the purified Rhassoul and 16 mg/g for the modified Rhassoul by cetyltrimethylammonium bromide (CTAB). These values show that the modified Rhassoul has a better adsorption capacity compared to the purified Rhassoul.


2014 ◽  
Vol 970 ◽  
pp. 7-11 ◽  
Author(s):  
Siti Raihan Zakaria ◽  
Megat Ahmad Kamal Megat Hanafiah ◽  
Siti Norhafiza Mohd Khazaai ◽  
Zurhana Mat Hussin ◽  
Wan Khaima Azira Wan Mat Khalir ◽  
...  

Kenaf (Hibiscus cannabinus) is a hardy crop that has wide industrial applications such as insulator, paper, carpet padding, bedding and a good adsorbent for oil. This study investigated the ability of carbon disulfide (CS2) modified kenaf (CMK) to remove toxic Pb (II) from waste water. Adsorbent characterization was carried out by Field Emission Scanning Electron Microscope and Energy Dispersive X-ray Spectroscope (FESEM-EDX) analysis. The adsorption kinetic data was well described by pseudo-second-order model and the adsorption isotherm study indicated that Langmuir model fitted well with the experimental data than the Freundlich model. Based on the Langmuir model, the maximum adsorption capacities of Pb (II) (qmax) was 63.3 mg g-1 .This study suggested that CMK has a good potential to be used as an adsorbent material for Pb (II) removal from aqueous solutions.


2022 ◽  
Author(s):  
Changjin Jiang ◽  
Ting Zhang ◽  
Shuhui Li ◽  
Zhaoguang Yang

Abstract Fe(III)-chitosan and Fe(III)-chitosan-CTAB composites were prepared using an ionotropic gelation method. Various techniques were used to analyze the morphology, structure, and property of the adsorbents, including SEM, EDS, FT-IR, XPS, and zeta potential. Compared with Fe(III)-chitosan, Fe(III)-chitosan-CTAB was more effective for As(V) adsorption at a wide range of pH (3–8). The adsorption of As(V) onto Fe(III)-chitosan and Fe(III)-chitosan-CTAB could reach equilibrium in 20 min, and their maximum adsorption capacities were 33.85 and 31.69 mg g‒1, respectively. The adsorption kinetics was best described by the pseudo-second-order model (R2=0.998 and 0.992), whereas the adsorption isotherms was fitted well by the Freundlich model (R2=0.963 and 0.987). The presence of H2PO4− significantly inhibited the adsorption of As(V) onto Fe(III)-chitosan and Fe(III)-chitosan-CTAB, and humic acid also led to a slight decrease in As(V) adsorption by Fe(III)-chitosan-CTAB. Over 94% of As(V) at the initial concentration of no more than 5 mg L−1 was removed from real water by the two adsorbents. 1% (w/v) NaOH solution was determined to be the most suitable desorption agent. Fe(III)-chitosan and Fe(III)-chitosan-CTAB still maintained their initial adsorption capacities after five adsorption-desorption cycles. Based on different characterization results, both electrostatic attraction and surface complexation mechanisms played important roles in As(V) adsorption on Fe(III)-chitosan and Fe(III)-chitosan-CTAB.


Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 32 ◽  
Author(s):  
Changgil Son ◽  
Wonyeol An ◽  
Geonhee Lee ◽  
Inho Jeong ◽  
Yong-Gu Lee ◽  
...  

This study has evaluated the removal efficiencies of phosphate ions (PO43−) using pristine (TB) and chemical-activated tangerine peel biochars. The adsorption kinetics and isotherm presented that the enhanced physicochemical properties of TB surface through the chemical activation with CaCl2 (CTB) and FeCl3 (FTB) were helpful in the adsorption capacities of PO43− (equilibrium adsorption capacity: FTB (1.655 mg g−1) > CTB (0.354 mg g−1) > TB (0.104 mg g−1)). The adsorption kinetics results revealed that PO43− removal by TB, CTB, and FTB was well fitted with the pseudo-second-order model (R2 = 0.999) than the pseudo-first-order model (R2 ≥ 0.929). The adsorption isotherm models showed that the Freundlich equation was suitable for PO43− removal by TB (R2 = 0.975) and CTB (R2 = 0.955). In contrast, the Langmuir equation was proper for PO43− removal by FTB (R2 = 0.987). The PO43− removal efficiency of CTB and FTB decreased with the ionic strength increased due to the compression of the electrical double layer on the CTB and FTB surfaces. Besides, the PO43− adsorptions by TB, CTB, and FTB were spontaneous endothermic reactions. These findings demonstrated FTB was the most promising method for removing PO43− in waters.


2021 ◽  
Vol 19 (9) ◽  
pp. 46-54
Author(s):  
Makarim A. Mahdi ◽  
Aymen A.R. Jawad ◽  
Aseel M. Aljeboree ◽  
Layth S. Jasim ◽  
Ayad F. Alkaim

The AAc/GO nanocomposite hydrogel was successfully employed as a polymeric Nano sorbent of the removal efficiency of M G dye from the model. The complication of the mechanism of the adsorption system was completely exposed by examining how solution pH affects adsorption, Ionic strength isotherm models, kinetic models, and thermodynamics. The adsorption of the MG dye was greatly dependent on the solution pH. The Freundlich model has been demonstrated to be the most accurate in describing the MG dye sorption, whilst the Langmuir model was shown to be the least accurate. Additionally, these integrated mechanisms fit nicely within the framework of a pseudo-second-order model. Additionally, the contact time at equilibrium short (ten minutes) required to MG removes demonstrates the AAc/GO nanocomposite hydrogel can be considered an efficient and potentially useful adsorbent for MG removal from industrial effluents.


2012 ◽  
Vol 14 (2) ◽  
pp. 1-8 ◽  
Author(s):  
S. Ghadiri ◽  
R. Nabizadeh ◽  
A. Mahvi ◽  
S. Nasseri ◽  
A. Mesdaghinia ◽  
...  

Potential of granulated modified nanozeolites Y for MTBE removal from aqueous solutions: Kinetic and isotherm studies Adsorption of methyl tert-butyl ether (MTBE) from aqueous solutions by granulated modified nanozeolites Y was investigated. Nanozeolite Y powders were converted into granulated zeolites and subsequently modified with two cationic surfactants (20 mmol/dm3), to be used as adsorbent. Granulated nanozeolites were characterized by BET surface area analysis, elemental analysis and X-ray diffractometer. -Hexade-cyltrimethylammonium (HDTMA-Cl) modified granulated zeolite had more effective performance than N-cetylpyridinium bromide (CPB) modified granulated zeolite. The most conventional adsorption isotherms and kinetic models were applied to describe MTBE adsorption and reaction dynamic, respectively. The equilibrium sorption data fitted the Langmuir 2 isotherm model and the kinetic study was followed the pseudo-second-order model. The maximum adsorption capacities for HDTMA-Cl modified zeolite and CPB modified granulated zeolite were 333.33 and 142.8 mg/g, respectively as calculated by the Langmuir model. This study demonstrated that the removal of mtbe by granulated modified nanozeolites Y is a promising technique.


2020 ◽  
Vol 81 (10) ◽  
pp. 2270-2280
Author(s):  
Yonggang Xu ◽  
Tianxia Bai ◽  
Yubo Yan ◽  
Yunfeng Zhao ◽  
Ling Yuan ◽  
...  

Abstract It is of great significance to remove Cr(VI) from water as a result of its high toxicity. Biochar from corn straw was modified by different acids (HNO3, H2SO4 and H3PO4) to remove Cr(VI) from aqueous solution. To estimate the removal mechanisms of Cr(VI) by the acid-modified biochars, batch experiments were performed in the light of contact time, Cr(VI) concentration, and pH, and the characteristics of acid-modified biochars before and after Cr(VI) adsorption were investigated by Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS). The adsorption kinetics of Cr(VI) by acid-modified biochars were consistent with the pseudo-second-order model, and the adsorption isotherm obeyed the Freundlich model. Furthermore, the acid- modified biochars could supply more oxygen-containing functional groups (-COOH and -OH) as electron donor (e−) and hydrogen ion (H+) to enhance the reduction of Cr(VI) to Cr(III), resulting in enhanced removal of Cr(VI). HNO3-modified biochar exhibited the highest removal efficiency of Cr(VI). In general, the acid modifition of biochar was an effective method to increase the removal of Cr(VI).


2011 ◽  
Vol 308-310 ◽  
pp. 178-181
Author(s):  
Xin Liang Liu ◽  
Li Jun Wang ◽  
Yong Li Chen ◽  
Nan Chen ◽  
Shuang Fei Wang

The bagasse fibers were activated by alkalize and etherified. 1,2-ethanediamine and carbon disulfide were used to modify the etherify fiber to get the chelate-fiber contained sulfur and nitrogen. The FTIR was used to characterize the xanthated aminating-fiber (XAF). The mechanism of sorption properties for heavy metal ions were studied. As the results shown, the optimal process to prepare the XAF was that the reaction time, concentration of NaOH and dosage of CS2 was 60min, 12% and 2mL, respectively. The chelate-fiber containing sulfur and nitrogen possessed high adsorption capacities for Cu(II) and the mechanism of sorption fitted the pseudo-second-order model well.


2013 ◽  
Vol 726-731 ◽  
pp. 1922-1925 ◽  
Author(s):  
Lian Ai ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Si Zhao Zhang

The sorptive potential of sunflower straw (≤125 μm) for Sr2+ from aqueous solution was evaluated. Batch adsorption experiments were carried out as a function of solution pH, adsorbent dosage, Sr2+ concentration and contact time. FT-IR spectra and SEM of sunflower straw were employed to explore the functional groups available for the binding of Sr2+ and morphology of the adsorbent. Maximum uptake capacity of sunflower straw was 17.48 mg/g occurred at around pH 3-7. The adsorption equilibrium can be achieved within 5 min and kinetic data were fitted well to pseudo-second-order model. The Langmuir and Freundlich models were applied to describe isotherm sorption data. The Langmuir model gave an acceptable fit than Freundlich model.


2016 ◽  
Vol 75 (2) ◽  
pp. 474-481 ◽  
Author(s):  
Sina Dobaradaran ◽  
Iraj Nabipour ◽  
Mozhgan Keshtkar ◽  
Fatemeh Faraji Ghasemi ◽  
Tayebeh Nazarialamdarloo ◽  
...  

The aim of this study was to determine adsorption properties of cuttlebone, cuttlefish bone as dead biomass, for lead(II) and copper(II) from aqueous solutions. Adsorption kinetic, isotherm and effect of pH (in the range of 2.0–7.0) were investigated in a single component batch system at room temperature (25 ± 1 °C). The heavy metal adsorption by cuttlebone was relatively rapid and reached equilibrium in 120 min in all the cases. The pseudo-second order rate equation described the adsorption kinetic of both the ions. The adsorption capacities of Pb2+ and Cu2+ were constantly increased by pH and the optimum condition of pH was determined to be 7.0. The Freundlich model was better fitted than other models with the isotherm data, indicating sorption of the metal ions in a heterogeneous surface. According to the Langmuir model, the maximum adsorption capacities of cuttlebone for Pb2+ and Cu2+ were determined to be 45.9 and 39.9 mg/g, respectively. The results indicated cuttlebone as a promising adsorbent for Pb2+ and Cu2+, which presents a high capacity of self-purification in marine environments and also can be used for removal of the metal ions from water and wastewater.


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