4-Sulfonylcalix[6]Arene Modified Fe3O4@Aspergillus Niger Biosorbents for Effective Removal of Uranium(VI) from Aqueous Solutions

2019 ◽  
Vol 19 (11) ◽  
pp. 6978-6986
Author(s):  
Le Li ◽  
Qi Liao ◽  
Chen Cao ◽  
Shuangyang Tang ◽  
Dexin Ding ◽  
...  

A biosorbent, 4-sulfonylcalix[6]arene modified Fe3O4@Aspergillus Niger (MFSC), was successfully prepared through a two-step route for the effective removal of uranium (U(VI)) from aqueous solutions with high selectivity. The structure of MFSC was characterized by FT-IR, SEM, XRD, TGA and VSM, respectively. The impacts of various experimental parameters were investigated in detail. The results indicated that the biosorption of U(VI) on MFSC was mainly attributed to the electrostatic attraction (91% within 8 hours for U(VI)). The adsorption kinetics and adsorption isotherm of U(VI) were found to follow the pseudo second-order model and to be fitted by the Langmuir model, respectively. The thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. The findings herein highlight the MFSC with high ability for removal of U(VI) from aqueous solutions.

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.


2021 ◽  
Vol 16 (2) ◽  
pp. 566-581
Author(s):  
B. Jagadeeswara Reddy ◽  
Sneha Latha Pala ◽  
Wondwosen Kebede Biftu ◽  
M. Suneetha ◽  
Kunta Ravindhranath

Abstract Sorbents derived from stem powders of Feronia limonia (FLSP), Amorphophallus paeoniifolius (APSP) and Pumpkin (Cucurbitapepo) (PSP) plants are investigated for the removal of Cu2+ ions from polluted water by adopting batch methods of extraction. Extraction conditions are optimized for the effective removal of Cu2+ ions. High sorption capacities are observed: 175.5 mg/g for FLSP; 140.4 mg/g for APSP; 130.0 mg/g for PSP. Effective pH ranges are: 5 to 10 for FLSP; 6 to 10 for APSP and 7 to 10 for PSP. The three spent adsorbents can be regenerated and used. Thermodynamic parameters indicate that the adsorption process is spontaneous, endothermic and have positive change in entropy values. As ΔH values are more than 25.0 kJ/mole, the adsorption may be due to surface complex formation between Cu2+ ions and functional groups of the adsorbents viz., -OH, -COOH etc. in the effective pH ranges. The good adsorption behaviour of FLSP even in acidic pHs may be due to the ion-exchange of Cu2+ ions for H+ ions of the functional groups of the adsorbent. The Langmuir adsorption isotherm and pseudo second-order model describe well the adsorption process. The sorbents are effectively applied to treat effluents from Cu-based industries and polluted lake water.


2012 ◽  
Vol 9 (3) ◽  
pp. 1266-1275 ◽  
Author(s):  
J.Raffiea Baseri ◽  
P.N. Palanisamy ◽  
P. Sivakumar

In this research, Polyaniline coated sawdust (Polyaniline nano composite) was synthesized via direct chemical polymerization and used as an adsorbent for the removal of acid dye (Acid Violet 49) from aqueous solutions. The effect of some important parameters such as pH, initial concentration of dye, contact time and temperature on the removal efficiency was investigated in batch adsorption system. The adsorption capacity of PAC was high (96.84 %) at a pH of 3-4. The experimental data fitted well for pseudo second order model. Langmuir model is more appropriate to explain the nature of adsorption with high correlation coefficient. The Energy of activation from arrehenius plot suggested that the adsorption of AV49 onto PAC involves physisorption mechanism.


2009 ◽  
Vol 60 (2) ◽  
pp. 467-474 ◽  
Author(s):  
K. L. Lv ◽  
Y. L. Du ◽  
C. M. Wang

Carboxylated chitosan (CKCTS) was prepared for the removal of Cd(II), Pb(II), and Cu(II) from aqueous solutions. The effects of experimental parameters such as pH value, initial concentration, contact time and temperature on the adsorption were studied. From the results we can see that the adsorption capacities of Cd(II), Pb(II), and Cu(II) increase with increasing pH of the solution. The kinetic rates were best fitted to the pseudo-second-order model. The adsorption equilibrium data were fitted well with the Langmuir isotherm, which revealed that the maximum adsorption capacities for monolayer saturation of Cd(II), Pb(II), and Cu(II) were 0.555, 0.733 and 0.827 mmol/g, respectively. The adsorption was an exothermic process.


2015 ◽  
Vol 73 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
Hejun Gao ◽  
Luanluan Zhang ◽  
Yunwen Liao

A novel adsorbent consisting of polyethyleneimine-modified multi-wall carbon nanotubes (PEI-MWCNTs) was synthesized by grafting PEI on the carboxyl MWCNTs. The surface properties of the PEI-MWCNTs were measured by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared, and zeta potential. The adsorption behavior of the PEI-MWCNTs was investigated using sunset yellow FCF as adsorbate. The effects of dosage of adsorbent, the initial pH of solution, contact time and temperature on the adsorption capacity were studied. Then, the kinetics and thermodynamics of the adsorption process were further investigated. Experimental results showed that the adsorption kinetics fitted a pseudo-second-order model and the adsorption isotherms agreed well with the Langmuir model. The adsorption process occurred very fast and the adsorption capacity of PEI-MWCNTs was much higher than that of many of the previously reported adsorbents. Additionally, the plausible adsorption mechanism was discussed.


2015 ◽  
Vol 52 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Zhenyu Wu ◽  
Dasheng Gao ◽  
Ningning Liu

An anion-functionalized nanoporous polymer was successfully prepared by quaternary ammonization and anion-exchange treatment method. The polymer was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, N2 adsorption/desorption isotherms and thermogravimetric analysis. Batch experiments were conducted to investigate the adsorption behavior of phosphate on the polymer. The results indicated that the experimental equilibrium data can be well described by the Langmuir model. The maximum adsorption capacity determined from the Langmuir model was 4.92 mg g−1. For kinetic study, the adsorption behavior followed the pseudo-second-order model. Thermodynamic studies indicated that the adsorption process was spontaneous and exothermic.


2019 ◽  

<p>Synthetic dyes have a hurtful effect on human health and the environment. In this work, activated carbon was produced from date stones for use in elimination of methylene blue charged in aqueous solutions. Before that, the adsorbent was characterized by BET method, SEM, X-ray and TGA. The results of the adsorption kinetics are describe better with the pseudo-second order model (R2= 0.998). Frendlich adsorption isotherm model describe better the experimental data than the Langmuir model. The capacity for methylene blue removal was found to be 163.67 mg/g. Batch experiments studies show that the activated carbon produced as of date stones can be used effectively in the treatment of cationic dyes in aqueous solutions.</p>


2019 ◽  
Vol 35 (4) ◽  
pp. 1384-1391
Author(s):  
Abdur-Rahim Adebisi ◽  
Giwa Khadijat Ayanpeju ◽  
Abdulsalam Francois Wewers ◽  
Mary Adelaide Oladipo

The study investigates the effectiveness and mechanism of the adsorption of malachite green from single and mixed dyes aqueous solutions by an adsorbent prepared from acid-treated Parkia biglobosa sawdust. The adsorbent was characterized using different techniques, and the adsorption was conducted in single, binary, ternary and quaternary dye systems under different experimental conditions. Experimental results were subjected to different isotherm and kinetics models. The adsorption process was endothermic and thermodynamically feasible with the removal efficiency increasing with increase in adsorbent dosage, solution working pH, initial dye concentration and contact time. The rate of sorption of the dye was fast; it attained equilibrium within 180 minutes in both the single and mixed solute systems. Pseudo-second order model gives the best kinetics fit (R2 = 0.998). The adsorption isotherm in all solute systems have best fits for the Temkin model (R2 > 0.96).


2017 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Łukasz Klapiszewski ◽  
Przemysław Bartczak ◽  
Tomasz Szatkowski ◽  
Teofil Jesionowski

Abstract We demonstrate here that lignin can be successfully combined with silica to create a multifunctional material with considerable sorption capabilities. Experiments were carried out in which a silica/lignin hybrid was used for the removal of lead(II) ions from water solutions. Adsorption kinetics were also determined and preliminary regeneration tests were performed. The effectiveness of the adsorption process depends on the following parameters: contact time of adsorbent and adsorbate (equilibrium times: 5 min for concentration 25 mg/L, 10 min for 50 and 75 mg/L, 60 min for 100 mg/L), pH (optimal pH = 5) and adsorbent mass. The kinetics of the adsorption of lead(II) ions on the SiO2/lignin biosorbent are best described by a pseudo-second-order model. Adsorption isotherms of lead(II) ions were also determined. The experimental data were found to be in agreement with the Langmuir model, and the maximal sorption capacity of the adsorbent with respect to lead(II) was 89.02 mg/g.


2021 ◽  
Vol 10 (2) ◽  
pp. 43-48
Author(s):  
Dang Le Hai ◽  
Trang Luu Thu ◽  
Hoang Tran Vinh ◽  
Doanh Vu Viet ◽  
Thu Le Dieu ◽  
...  

Core shell magnetite nanoparticles (Fe3O4@C) as adsorbent for lead ions from aqueous solution were synthesized. The characteristics of the modified materials were analysed. It could also be shown that the adsorption isotherms were well described by the Langmuir model. The kinetic of the adsorption process was found to follow the pseudo-second-order model expression. Thermodynamic studies indicated that the adsorption process was feasible, spontaneous and endothermic.


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