Removal of Strontium Ions from Aqueous Solution by Sunflower Straw

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.

2013 ◽  
Vol 22 (6) ◽  
pp. 096369351302200
Author(s):  
CunPing Liu

In the present investigation, bio-inorganic composite, which was synthesized with chitosan and hydroxyapatite by adding zinc(II) ions, have been prepared by precipitation method and was characterized by Fourier Transform infrared (FTIR) spectroscopy and energy dispersive X-ray analyzer (EDXA). Then, the composite was used for removal of Cobalt(II) from synthetic aqueous solution. The effects of initial pH, contact time, kinetic and isothermal adsorption were studied in detail using batch adsorption at different temperature. The results showed that Cobalt(II) ions can be efficiently removed and also demonstrated that the kinetic data were best described by the pseudo-second-order model (R2>0.99), While thermodynamic investigation of Cobalt(II) ions adsorption by zinc(II) doping Chitosan/hydroxyapatite (Zn-HAPCS) composite confirmed a spontaneous adsorption. Further investigations demonstrated that the adsorption pattern fitted well with Langmuir model (R2 > 0.99), but less-satisfied with Freundlich model (R2 < 0.95).


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.


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.


2020 ◽  
Vol 10 (10) ◽  
pp. 3437
Author(s):  
Jude Ofei Quansah ◽  
Thandar Hlaing ◽  
Fritz Ndumbe Lyonga ◽  
Phyo Phyo Kyi ◽  
Seung-Hee Hong ◽  
...  

We assessed the applicability of rice husk (RH) to remove cationic dyes, i.e., methylene blue (MB) and crystal violet (CV), from water. RH thermally treated at 75 °C showed a higher adsorption capacity than that at high temperatures (300–700 °C). For a suitable CV-adsorption model, a pseudo-first-order model for MB adsorption was followed by the kinetics adsorption process; however, a pseudo-second-order model was then suggested. In the qt versus t1/2 plot, the MB line passed through the origin, but that of CV did not. The Langmuir isotherm model was better than the Freundlich model for both dye adsorptions; furthermore, the adsorption capacity for MB and CV was 24.48 mg/g and 25.46 mg/g, respectively. Thermodynamically, the adsorption of both MB and CV onto the RH was found to be spontaneous and endothermic. This adsorption increased insignificantly on increasing the solution pH from 4 to 10. With an increasing dosage of the RH, there was an increase in the removal percentages of MB and CV; however, adsorption capacity per unit mass of the RH was observed to decrease. Therefore, we conclude that utilizing RH as an available and affordable adsorbent is feasible to remove MB and CV from wastewater.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Thi Hanh Nguyen ◽  
Thi Huong Pham ◽  
Hong Tham Nguyen Thi ◽  
Thi Nham Nguyen ◽  
Minh-Viet Nguyen ◽  
...  

A novel iron-modified biochar (FMBC) derived from rice straw was synthesized using FeCl3 modification for efficient As(V) removal from aqueous solution. FTIR and SEM-EDX analyses were carried out to determine the mechanism involved in the removal process and also demonstrated that Fe had loaded successfully on the surface of modified biochar. The iron-modified biochar showed higher arsenic removal ability than the raw biochar. The iron-modified biochar showed a maximum adsorption with an initial solution pH of 5.0. Moreover, for the tested biochar, the As(V) removal kinetics data were well fitted by the pseudo-second-order model. Furthermore, the As(V) removal data upon being well fitted by the Langmuir model showed the maximal removal capacity of 28.49 mg/g. The simple preparation process and high adsorption performance suggest that the iron-modified biochar derived from rice straw could be served as an effective, inexpensive, and environmentally sustainable adsorbent to replace typical granular activated carbon (AC) for As(III) removal from aqueous solution.


2015 ◽  
Vol 61 (6) ◽  
pp. 399-408 ◽  
Author(s):  
Huining Zhang ◽  
Li Liu ◽  
Qing Chang ◽  
Hongyu Wang ◽  
Kai Yang

The adsorption behavior of Cr(VI) ions from aqueous solution by a chromium-tolerant strain was studied through batch experiments. An isolate designated Zer-1 was identified as a species of Bosea on the basis of 16S rRNA results. It showed a maximum resistance to 550 mg·L−1 Cr(VI). The effects of 3 important operating parameters, initial solution pH, initial Cr(VI) concentration, and biomass dose, were investigated by central composite design. On the basis of response surface methodology results, maximal removal efficiency of Cr(VI) was achieved under the following conditions: pH, 2.0; initial concentration of metal ions, 55 mg·L−1; and biomass dose, 2.0 g·L−1. Under the optimal conditions, the maximum removal efficiency of Cr(VI) ions was found to be nearly 98%. The experimental data exhibited a better fit with the Langmuir model than the Freundlich model. The biosorption mechanisms were investigated with pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetics models. These results revealed that biosorption of Cr(VI) onto bacterial biomass could be an alternative method for the removal of metal ions from aqueous solution.


2018 ◽  
Vol 14 (2) ◽  
pp. 193-197 ◽  
Author(s):  
Mohd Sukri Hassan ◽  
Khairul Adli Nikman ◽  
Fisal Ahmad

Chemical activation process was applied to prepare a cocoa nib-based activated carbon using potassium carbonate (K2CO3). The performance of the activated carbon in removing Methylene Blue from aqueous solution was investigated by batch adsorption studies. The adsorptive properties were studied in terms of initial concentration (C0: 100-300 mg/L) and contact time effects. The experimental isotherm data fitted well the Langmuir and Temkin models. The adsorption kinetic followed the pseudo-second-order model and Boyd model explained the mechanism of adsorption. The results indicate that the chemically produced activated cocoa nib carbon has significant potential to be used as an adsorbent material for adsorption of Methylene Blue from aqueous solution.


2012 ◽  
Vol 30 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Fadela Nemchi ◽  
Benaouda Bestani ◽  
Nouredine Benderdouche ◽  
Mostefa Belhakem ◽  
Louis Charles de Minorval

Adsorbents prepared from seawater algae, viz. green Ulva lactuca (PGA) and brown Systoceira stricta (PBA), by chemical activation were successfully tested for the removal of Supranol Yellow 4GL dye from aqueous solutions. Impregnation in 20% phosphoric acid for 2 h at 170 °C and subsequent air activation at 600 °C for 3 h significantly enhanced the adsorption capacities of both algae relative to their inactivated states. Parameters influencing the adsorption capacity such as contact time, adsorbent dosage, pH and temperature were studied. Similar experiments were carried out with commercially available Merck activated carbon (MAC) for comparative purposes. Adsorption efficiencies were measured at a pH 2 and dosages of 8 g/ℓ and 12 g/ℓ for PGA and PBA, respectively. Batch adsorption experiments resulted in maximum adsorption capacities determined from Langmuir models of up to 263, 93 and 84 mg/g for PGA, PBA and MAC, respectively. BET, FT-IR analyses, iodine number and Methylene Blue index determination were also performed to characterize the prepared adsorbents. The adsorption kinetics were found to comply with the pseudo-second-order model with intra-particle diffusion being the rate-determining step. Thermodynamic analysis confirmed that the adsorption reaction was spontaneous and endothermic. These studies indicate that these seawater algae could be used as low-cost alternatives for the removal of dyes.


2014 ◽  
Vol 522-524 ◽  
pp. 469-472
Author(s):  
Yi Wang ◽  
Zhuan Nian Liu ◽  
Yang Guan ◽  
Long Chen ◽  
Zhao Qing Lu

The flesh ash (F) was grafted with diethylenetriamine (DETAF), triethylenetetramine (TETAF) and polyethylene polyamine (HPAXF), respectively. A comparative study of Cu2+ and Pb2+ removal from aqueous solution using F, DETAF, TETAF and HPAXF was performed. Effects of liquid-solid ratio, temperature and time on adsorption capacity were studied. Batch tests were carried out to investigate the adsorption performance. The process of Cu2+ and Pb2+ onto DETAF, TETAF and HPAXF both fitted well with Lagergren pseudo-second-order model, The isothermal of Cu2+ and Pb2+ adsorption onto DETAF, TETAF and HPAXF can be described by Freundlich model.


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.


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