scholarly journals Adsorption of Barium and Zinc Ions by Mesoporous TiO2 with Chemosorbed Carbonate Groups

2019 ◽  
Vol 20 (3) ◽  
pp. 282-290 ◽  
Author(s):  
H. Vasylyeva ◽  
I. Mironyuk ◽  
I. Mykytyn ◽  
N. Danyliyk

In the present paper the mesoporous TiO2 with chemosorbed carbonate groups was investigated as an adsorbent for the removal of Zn2+ and Ba2+ cations from aqueous solutions. The dependence of the adsorption values of Zn2+ and Ba2+ on the agitation time, solution’s acidity, and modification of surface of TiO2 was determined. The process of Zn2+ and Ba2+ adsorption fit well by Lagergren’s pseudo-second-order kinetic model. The equilibrium adsorption was investigated in the concentration of heavy metal’s ranges 27.46 mg/L - 7809 mg/L. The experimental data was approximated by Langmuir and DubininRadushcevich adsorption theories. The energy of adsorption Zn2+ and Ba2+ onto modified TiO2 and unmodified TiO2 was calculated using Dubinin-Radushkevich equations, and was found to be 15.82 - 9.399 kJ/mol, which corresponds to the mechanism of physical adsorption. The application of Langmuir theory to experimental adsorption data gives high R2, close to unit. Separation factor RL indicates, that adsorption Zn2+ and Ba2+ onto modified TiO2 is very favorable. Modified mesoporous ТіО2 is very efficient adsorbent toward Zn2+ and Ba2+ cations from their individual solutions as well as from their mixture, and able to compete with the best world analogues.

2012 ◽  
Vol 11 (02) ◽  
pp. 1250019 ◽  
Author(s):  
RAJESH KUMAR ◽  
S. K. JAIN

This study was carried out to evaluate the environmental application of functionalized carbon nanotubes through the experimental removal of strontium (II) from water. The aim was to find the optimal condition for the removal of strontium from water under different conditions such as initial concentration of strontium, contact time and neutral pH. The functionalized multi wall carbon nanotubes (f-MWCNT) were characterized by FT-IR and scanning electron microscopy (SEM). The adsorption isotherms were correlated to Freundlich and Langmuir models and it was found that the adsorption data could be fitted better by Langmuir model than Freundlich one. The kinetic data shows that the adsorption describes well with the pseudo-second order kinetic model. Functionalized MWCNT can be used as good adsorbent for the removal of the strontium ions from polluted water according to results.


SAINTIFIK ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 104-115
Author(s):  
Agusriyadin Agusriyadin

Penelitian ini bertujuan untuk menguji kemampuan AK dan AKPM dalam mengadsorpsi ion Cu (II), pengaruh parameter adsorpsi dan mekanisme adsorpsi. AK dan AKP Madsorben dibuat dari residu ampas kelapa. Adsorben dikarakterisasi dengan FTIR, SEM dan EDS. Pengaruh parameter adsorpsi seperti pH awal, dosis adsorben, waktu kontak dan konsentrasi ion Cu (II) awal diperiksa untuk menentukan kondisi optimum serapan tembaga (II). Ion Cu (II) yang teradsorpsi diukur berdasarkan pada konsentrasi Ion Cu (II) sebelum dan sesudah adsorpsi menggunakan metode AAS. Hasil karakterisasi menunjukkan bahwa struktur pori dan gugus fungsi tersedia pada permukaan adsorben. Menurut percobaan efek pH, kapasitas adsorpsi maksimum dicapai pada pH 7. Waktu kontak optimal dan konsentrasi tembaga awal (II) ditemukan masing-masing pada 120 menit dan 100 mg L-1. Data eksperimental sesuai dengan model kinetik orde dua orde dua, dan Langmuir isoterm adsorpsi yang diperoleh paling sesuai dengan data adsorpsi. Kapasitas adsorpsi maksimum adsorben ditemukan menjadi 4,73 dan 6,46 mg g-1 pada kondisi optimal. The results of characterization showed that the pore structure and the functional groups were available on adsorbent surface. According to the pH effect experiments, the maximum adsorption capacity was achieved at pH 7. Optimum contact time and initial copper(II) concentration were found at 120 min and 100 mg L-1, respectively. The experimental data were comply with the pseudo-second-order kinetic model, and Langmuir adsorption isotherm obtained best fitted the adsorption data. The maximum adsorption capacity of the adsorbents was found to be 4.73 and 6.46 mg g-1 at optimum conditions.


Author(s):  
Xin Lu ◽  
Beibei Tang ◽  
Qi Zhang ◽  
Lizhu Liu ◽  
Ruqin Fan ◽  
...  

Batch experiments were conducted to investigate the adsorption characteristics of tetracycline (TC), and the interactive effects of copper (Cu) on the adsorption of TC onto water hyacinth roots. TC removal efficiency by water hyacinth roots was ranging from 58.9% to 84.6%, for virgin TC, 1:1 TC-Cu and 1:2 TC-Cu. The Freundlich isotherm model and the pseudo-second-order kinetic model fitted the adsorption data well. Thermodynamics parameters ΔG0 for TC were more negative in the TC plus Cu than the TC-only treatments, indicating the spontaneity of TC adsorption increased with increasing of Cu concentrations. An elevated temperature was associated with increasing adsorption of TC by water hyacinth roots. The additions of Cu(II) significantly increased TC adsorption onto water hyacinth roots within the pH range 4 to 6, because copper formed a strong metal bridge between root surface and TC molecule, facilitating the adsorption of TC by roots. However, Cu(II) hindered TC adsorption onto water hyacinth roots on the whole at pH range from 6–10, since the stronger electrostatic repulsion and formation of CuOH+ and Cu(OH)2. Therefore, the interaction between Cu(II) and TC under different environmental conditions should be taken into account to understand the environmental behavior, fate, and ecotoxicity of TC.


2019 ◽  
Author(s):  
Chem Int

An easy route for preparation emulsion of kaolinite (Al2Si2O5.4H2O) from Sweileh sand deposits, west Amman, Jordan by hydrochloric acid under continuous stirring for 4 h at room temperature was performed and nano kaolinite powder was used as an adsorbent for the removal of Cu(II), Zn(II) and Ni(II) ions. Nano kaolinite was characterized by XRD, FT-IR and SEM techniques. Effect of pH, adsorbent dose, initial metal ion concentration, contact time and temperature on adsorption process was examined. The negative values of ΔGo and the positive value of ΔHo revealed that the adsorption process was spontaneous and endothermic. The Langmuir isotherm model fitted well to metal ions adsorption data and the adsorption capacity. The kinetic data provided the best correlation of the adsorption with pseudo-second order kinetic model. In view of promising efficiency, the nano kaolinite can be employed for heavy metal ions adsorption.


2010 ◽  
Vol 7 (s1) ◽  
pp. S377-S385 ◽  
Author(s):  
A. K. Patil ◽  
V. S. Shrivastava

In this method,Leucaena leucocephalaseed pods (LLSP) have been used for removal of Cu(II) ions from aqueous solution. Batch adsorption experiments were conducted to study the effect of process parameters like pH, contact time initial Cu(II) ions concentration and adsorbent dose. The maximum adsorption of Cu(II) ions onLeucaena leucocephalaseed pods was 94.17% at pH 5. The amount of metal adsorbed per unit weight of adsorbent increases with time and reach equilibrium after 30 minutes of shaking time for the different initial metal concentrations. The Freundlich and Langmuir isotherm equations were applied for the equilibrium adsorption data and the various isotherm parameters were evaluated. The obtained plots were linear as evident fromR2values close to unity. The data agreed very well with the pseudo second-order kinetic model.


2014 ◽  
Vol 805 ◽  
pp. 581-584 ◽  
Author(s):  
Débora Martins Aragão ◽  
Maria de Lara P.M. Arguelho ◽  
Carolina Mangieri Oliveira Prado ◽  
José do Patrocinio Hora Alves

Natural kaolinite clay collected in the State of Sergipe (northeast Brazil) was used as an adsorbent for the ions Pb2+, Cd2+, and Cu2+present in aqueous solution. Adsorption equilibrium was reached rapidly, enabling use of a contact time of 30 minutes, and maximum adsorption was achieved at pH 7.0. For all three metal ions, the adsorption data could be fitted using the Langmuir isotherm and the adsorption process obeyed a pseudo-second order kinetic model.


2017 ◽  
Vol 8 (3) ◽  
pp. 350-359 ◽  
Author(s):  
Danyang Yin ◽  
Zhengwen Xu ◽  
Jing Shi ◽  
Lili Shen ◽  
Zexiang He

Abstract In this study, schorl was used as an effective adsorbent for ciprofloxacin removal from wastewater. The adsorption performance, mechanism and effect of metal ion on sorption were investigated. Adsorption capacity reached a maximum (8.49 mg/g) when the pH value was 5.5. The pseudo-second-order kinetic model and Freundlich model could better describe the experimental data. The negative ΔH (–22.96 KJ/mol) value showed that the adsorption process was exothermic. The results also indicated physical adsorption existed on the adsorption process, which was in agreement with the analysis of X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy. The desorption rate could reach 94%, which suggested that schorl had a good desorption and regeneration performance. Coexisting ions, such as Cu2+ and Al3+, could obviously inhibit adsorption, and the inhibition from Al3+ was significantly higher than that from Cu2+. However, the additional Zn2+ could slightly promote the adsorption.


2012 ◽  
Vol 9 (4) ◽  
pp. 2415-2423
Author(s):  
Hayet Ben Ali ◽  
Salma Besbes Hentati ◽  
Salem S. Al-Deyab ◽  
Mohamed Rzaigui ◽  
M'henni Mohamed Farouk

The objective of this paper is the study of the influence of the chemical structures of adsorbent and adsorbate on the adsorption process. By using of crab shell chitosan (CC) and deep-pink shrimp chitosan (CP) for removal of acid 183 and AR114 from aqueous solutions, it is shown that CP, which corresponds to the highest molecular weight, is the most efficient adsorbent material. In addition, the best extent of decolorization is obtained for AR 183 that is the smallest molecule. Langmuir model represents the best fit of the experimental data, indicating monolayer coverage of chitosan outer surface. Pseudo-second order kinetic model describes accurately the adsorption processes, suggesting chemical rate limiting steps. The positive values of the enthalpy changes indicated endothermic attachment of dyes to the biomaterials. CP/AR183 system corresponds to the most energetically favorable phenomenon. Besides, desorption of AR from chitosan was found to be very low in acidic aqueous medium for all couples.


2017 ◽  
Vol 4 (9) ◽  
pp. 170402 ◽  
Author(s):  
Shujuan Wang ◽  
Wei Guo ◽  
Fan Gao ◽  
Rui Yang

Corn straw- and municipal sludge-derived biochars (CS-BC and MS-BC, respectively) were used to remove Pb(II) from aqueous solutions. Despite being pyrolysed at the same temperature (723 K), MS-BC showed higher porosity and hydrophobicity than CS-BC. The optimum biochar loading and pH values allowing efficient Pb(II) removal (greater than 80%) were 0.2 g l −1 and 7.0, respectively. The presence of PO 4 3− (greater than 0.01 mol l −1 ) significantly affected the adsorptive performance of Pb(II) on the biochar samples. The adsorption data fitted well to a pseudo-second-order kinetic model and a Langmuir model, and the maximum Pb(II) adsorption capacities were 352 and 387 mg g −1 for CS-BC and MS-BC, respectively. The main mechanisms involved in the adsorption of Pb(II) on biochar were electrostatic attraction and surface complexation. When comparing both biochars, CS-BC showed better cost-effectiveness for the removal of Pb(II) from aqueous solutions.


2012 ◽  
Vol 209-211 ◽  
pp. 2081-2085 ◽  
Author(s):  
Shi You Li ◽  
Shui Bo Xie ◽  
Cong Zhao ◽  
Jin Xiang Liu ◽  
Hui Ling ◽  
...  

The effectives of pH value, contact time,sorbent dose and different initial concentration were analyzed to study the properties of the adsorption of uranium in wastewater by clay. The results show the highest adsorption capacity was obtained around neutral pH.The amount adsorbed of uranium on clay increase rapidly with increasing initial uranium concentration, but the removal rates of uranium are declined.Clay has a good adsorption capability to uranium with 18.25mg/g of adsorption capacity. The adsorption data on clay are followed by both Langmuir and Freundlich models and the results are well described by Langmuir isotherm. The pseudo-second-order kinetic model is more appropriate for the sorption process.


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