Removal of Mercury From Aqueous Solutions by ETS-4 Microporous Titanosilicate: Effect of Contact Time, Titanosilicate Mass and Initial Metal Concentration

2007 ◽  
Author(s):  
C. B. Lopes ◽  
M. Otero ◽  
Z. Lin ◽  
E. Pereira ◽  
C. M. Silva ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Sorption Process ◽  
Exchange Equilibrium ◽  
Toxic Heavy Metals ◽  
Experimental Conditions ◽  
Freundlich Isotherms ◽  
Pseudo Second Order ◽  
Microporous Titanosilicate

Mercury is one of the most toxic heavy metals present in the environment and therefore is extremely important develop new, simple and reliable techniques for its removal from aqueous solutions. A recent line of research within this context is the application of microporous materials. The use of these materials for removing heavy metals from solutions may become a potential clean-up technology in the field of wastewater treatment. In this work it is reported the application of microporous titanosilicate ETS-4 as ion exchanger to remove Hg2+ from aqueous solution. Under batch conditions, we studied the effect of contact time, titanosilicate mass and initial Hg2+ concentration. Only 5 mg of ETS-4 are required to purify 2 litres of water with 50 μg L−1 of metal. Under the experimental conditions, the initial Hg2+ concentration and ETS-4 mass have strong influence on the sorption process, and it is proved that 24 h are almost always sufficient to attain ion exchange equilibrium. Langmuir and Freundlich isotherms were used to fit equilibrium experimental results. The kinetics of mercury removal was reliably described by a pseudo second-order model. On the whole, ETS-4 shows considerable potential to remove Hg2+ from wastewaters.

Adsorption of CuCl2 on Mg-Al HTlc: Effect of EDTA and Addition Sequences

2012 ◽  
Vol 573-574 ◽  
pp. 150-154
Author(s):  
Yun Bo Zang ◽  
Nai Ying Wu
Keyword(s):  
Aqueous Solutions ◽  
Sorption Capacity ◽  
Contact Time ◽  
Room Temperature ◽  
Copper Ions ◽  
Sorption Process ◽  
Langmuir Model ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order

In this study, removal of copper ions from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, EDTA and addition sequences at room temperature. It is found that HTlc could reduced copper ions concentration effectively. The kinetics closely fit pseudo-second order kinetics with necessary time 9 h to reach equilibrium. The sorption process followed langmuir model. The maximum sorption capacity calculated was found to be 39.4 mg/g. The presence of EDTA and addition sequences could affect sorption of Cu(II) onto HTlc.

scholarly journals Preparation of Nanochitosan as an Effective Adsorbent for Removal of Pb (II) From Aqueous Solution

2019 ◽  
Author(s):  
Camellia Zareie ◽  
Saeideh Kholghi Eshkalak ◽  
Ghasem Najafpour Darzi ◽  
Mazyar Sharifzadeh baei ◽  
Habibollah Younesi ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Ph Value ◽  
Sorption Process ◽  
Sorption Data ◽  
Kinetics Of Adsorption ◽  
Force Microscopy ◽  
Freundlich Isotherms ◽  
Atomic Force ◽  
Pseudo Second Order ◽  
Sorption Parameters

In this work, nanochitosan (NC) was prepared through ionic gelation using low-molecular-weight chitosan and maleic acid (MA). The synthesized NC was charac¬terized by means of Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). In the course of preparation, the particle size of the material was strongly depended on the parameters such as chitosan concentration and pH of the solution. By controlling the above parameters, NC with the size of smaller than 100 nm was prepared. The chitosan and prepared NC were used for the adsorption of Pb (II) from aqueous solutions in a batch system. Among the sorption parameters, pH showed the strongest effect on the sorption process and maximum Pb (II) removal was obtained at pH value of 6. The pseudo-first-order and pseudo-second-order were used to track the kinetics of adsorption process. Langmuir and Freundlich isotherms were subjected to sorption data to estimate the sorption capacity. NC proved to be an excellent adsorbent with remarkable capacity to remove Pb (II) ions from the aqueous solutions at various concentrations. The NC also showed incredible performance with a comparatively easier preparation process than other reported work.

scholarly journals Hen feather a bio-waste material for adsorptive removal of methyl red dye from aqueous solutions

2021 ◽  
Author(s):  
Samina Zaman ◽  
Md. Nayeem Mehrab ◽  
Md. Shahnul Islam ◽  
Gopal Chandra Ghosh ◽  
Tapos Kumar Chakraborty
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Methyl Red ◽  
Experimental Conditions ◽  
Potential Applicability ◽  
Pseudo Second Order ◽  
Red Dye ◽  
Adsorbent Dose

Abstract This study investigates the potential applicability of hen feather (HF) to remove methyl red (MR) dye from aqueous solution with the variation of experimental conditions: contact time (1–180 min), pH (4–8), initial dye concentration (5–50 mg/L) and adsorbent dose (3–25 g/L). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) evaluate the surface morphology and chemistry of HF, respectively. The maximum removal of MR by HF was 92% when the optimum conditions were initial MR dye concentration 05 mg/L, pH 4.0, adsorbent dose 07.0 g/L and 90.0 min equilibrium contact time. Langmuir isotherm (R2 = 0.98) was more suited than Freundlich isotherm (R2 = 0.96) for experimental data, and the highest monolayer adsorption capacity was 6.02 mg/g. The kinetics adsorption data fitted well to pseudo-second-order model (R2 = 0.999) and more than one process were involved during the adsorption mechanism but film diffusion was the potential rate-controlling step. The findings of the study show that HF is a very effective and low-cost adsorbent for removing MR dye from aqueous solutions.

scholarly journals Comparison of novel Ziziphus lotus adsorbent and industrial carbon on methylene blue removal from aqueous solutions

2018 ◽  
Vol 78 (10) ◽  
pp. 2055-2063
Author(s):  
Asmaa Msaad ◽  
Mounir Belbahloul ◽  
Samir El Hajjaji ◽  
Abdeljalil Zouhri
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Aqueous Solutions ◽  
Low Cost ◽  
Sorption Process ◽  
Second Order ◽  
Order Kinetic ◽  
Industrial Carbon ◽  
Freundlich Isotherms ◽  
Pseudo Second Order

Abstract In this work, the use of a novel low-cost adsorbent derived from Ziziphus lotus (ZL) and industrial carbon (IC) has been successfully applied to the removal of methylene blue (MB) from aqueous solutions. The efficiency of this material was studied through Lagergren pseudo-first-order and pseudo-second-order kinetic models. The process for the novel activated carbon and the IC were best represented by the pseudo-second-order rate model. Langmuir and Freundlich isotherms were used to describe the sorption equilibrium data. The Langmuir model turned out to be the most adequate and maximum capacities were measured to be 833.33 and 142.85 mg.g−1 for ZL activated carbon and IC from Sigma Aldrich, respectively. The thermodynamic study revealed that the sorption process is spontaneous and endothermic for the two adsorbents. To explain the effectiveness of MB removal, ZL activated carbon was characterized by scanning electron microscopy, Brunauer–Emmett–Teller surface area, X-ray diffraction and Fourier transform infrared spectroscopy.

Adsorption of methyl violet from aqueous solution using brown algae Padina sanctae-crucis

2018 ◽  
Vol 43 (6) ◽  
pp. 623-631 ◽  
Author(s):  
Reza Mahini ◽  
Hossein Esmaeili ◽  
Rauf Foroutan
Keyword(s):  
Aqueous Solutions ◽  
Brown Algae ◽  
Contact Time ◽  
Methyl Violet ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Equilibrium Study ◽  
Freundlich Isotherms ◽  
Pseudo Second Order

Abstract Objective The presence of dyes in the water is toxic and harmful to human body so, it must be removed from the water. In the present study, the removal of methyl violet (MV) from aqueous solutions using brown algae “Padina sanctae-crucis” was investigated. Materials and methods The rate of adsorption was investigated under various parameters such as contact time (5–200), pH (2–11), dye concentration (10–60 mg/L), amount of adsorbent (0.25–5 g/L) and temperature (25–45°C). Results The maximum adsorption was achieved in 10 mg/L, pH=8 and adsorbent dose 2 g/L and 80 min contact time for removal of MV from aqueous solutions. Kinetic studies showed that the pseudo second-order model describes adsorbent kinetic behavior better. Besides, experimental data have been modeled using Langmuir and Freundlich isotherms and the results showed that both models are proper to describe adsorption isotherm behavior. In addition, the equilibrium study shows that the adsorption was physical and favorable. Moreover, a thermodynamic study revealed that the adsorption process is exothermic and spontaneously in nature. Furthermore, Maximum adsorption capacity using adsorbent was 10.02 mg/g. Conclusions It could be concluded that the P. sanctae-crucis biomass is a good adsorbent for removing MV dyes from aqueous solutions.

scholarly journals Study of the sorption properties of titanium phosphatestowards the metal ions.

2020 ◽  
Vol 11 (3-2020) ◽  
pp. 57-62
Author(s):  
P. E. Evstropova ◽  
◽  
M. V. Maslova ◽  
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Chemical Affinity ◽  
Cobalt Ions ◽  
Zinc Cadmium ◽  
Lead Zinc ◽  
Pseudo Second Order ◽  
Phosphate Groups

The process of sorption of lead, zinc, cadmium and cobalt ions from aqueous solutions on titanium-containing sorbents of various compositions is studied. Morris —Weber and Boyd diffusion models, Lagergren pseudo-first ordermodels, and Ho and Mackay pseudo-second order models were used to simulate sorption kinetics. It was shown that the speed of the sorption process is influenced by both the composition of the sorbent and the interaction in the sorbent —sorbate system. Thehigh chemical affinity of the studied cations to phosphate groups determines the prospects of using titanium phosphate for the concentration of heavy metals and their subsequent immobilization in phosphate matrices.

scholarly journals Removal of Malachite Green from Single and Multi-Dye Aqueous Solutions by Acid-Treated Sawdust

2019 ◽  
Vol 35 (4) ◽  
pp. 1384-1391
Author(s):  
Abdur-Rahim Adebisi ◽  
Giwa Khadijat Ayanpeju ◽  
Abdulsalam Francois Wewers ◽  
Mary Adelaide Oladipo
Keyword(s):  
Adsorption Isotherm ◽  
Aqueous Solutions ◽  
Malachite Green ◽  
Removal Efficiency ◽  
Contact Time ◽  
Adsorption Process ◽  
Parkia Biglobosa ◽  
Order Model ◽  
Experimental Conditions ◽  
Pseudo Second Order

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).

Biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus

2012 ◽  
Vol 66 (8) ◽  
pp. 1699-1707 ◽  
Author(s):  
A. K. Giri ◽  
R. K. Patel ◽  
P. C. Mishra
Keyword(s):  
Aqueous Solutions ◽  
Bacillus Cereus ◽  
Contact Time ◽  
Living Cells ◽  
Optimum Conditions ◽  
Order Model ◽  
Initial Concentration ◽  
Pseudo Second Order ◽  
Biomass Dosage ◽  
Batch Biosorption

In this work, the biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus has been reported. The batch biosorption experiments were conducted with respect to biosorbent dosage 0.5 to 15 g/L, pH 2 to 9, contact time 5 to 90 min, initial concentration 1 to 10 mg/L and temperature 10 to 40 °C. The maximum biosorption capacity of B. cereus for As(V) was found to be 30.04 at pH 7.0, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data were fitted to linearly transformed Langmuir isotherms with R2 (correlation coefficient) >0.99. Bacillus cereus cell surface was characterized using AFM and FTIR. The metal ions were desorbed from B. cereus using both 1 M HCl and 1 M HNO3. The pseudo-second-order model was successfully applied to predict the rate constant of biosorption.

Biosorption of Eosin by Chemically Modified Peanut Husk

2011 ◽  
Vol 233-235 ◽  
pp. 439-443
Author(s):  
Ying Hua Song ◽  
Sheng Ming Chen
Keyword(s):  
Freundlich Isotherm ◽  
Sorption Process ◽  
Intraparticle Diffusion ◽  
Transfer Model ◽  
Experimental Conditions ◽  
Isotherm Equation ◽  
Chemically Modified ◽  
Pseudo Second Order ◽  
Uptake Studies ◽  
Rate Controlling Step

The sorption of eosin by peanut husk, which was chemically modified by formaldehyde in acidic medium was studied with variation in the parameters of contact time, pH, initial eosin concentration and temperature. They were used for equilibrium sorption uptake studies with eosin. The results indicate that sorption equilibrium could be well described by the Freundlich isotherm equation. The sorption followed the pseudo-second order model. The mass transfer model as intraparticle diffusion was applied to the experimental data to examine the mechanisms of the rate controlling step. It was found that the intraparticle diffusion is becoming the significant controlling step under the experimental conditions. The thermodynamic constants of the sorption process were also evaluated, which suggest an endothermic physical sorption process which runs spontaneously.

scholarly journals DEVELOPMENT AND VALIDATION OF A SPECTROPHOTOMETRIC METHOD TO EVALUATE BIOSAFETY CAPACITY OF BARU (Dipteryx alata) PEELS

2018 ◽  
Vol 15 (30) ◽  
pp. 221-240
Author(s):  
E. C. CESARINO ◽  
D. S. MULHOLLAND ◽  
W. FRANCISCO
Keyword(s):  
Contact Time ◽  
Limit Of Detection ◽  
Copper Ions ◽  
Maximum Adsorption Capacity ◽  
Limit Of Quantification ◽  
Experimental Conditions ◽  
Inorganic Matter ◽  
Pseudo Second Order ◽  
Development And Validation ◽  
Dipteryx Alata

This study developed a new analytical method using Molecular Absorption Spectroscopy (MAS) to track the ion cover in adsorption solution per peel (mesocarp) of Baru (Dipteryx alata). The adsorption study was conducted at different pH and contact time (kinetic), encountering 4.0 as the best pH for adsorption experimental conditions. The variation of contact time showed a pseudo-second-order adsorption kinetic behavior. The interpretation of the isotherms allowed to approach the Langmuir model with R² of 0.918 and to determine the maximum adsorption capacity (qmáx) as 11.481 mg.g⁻¹. The characterization of biomass by MAS in the Infrared (FT-IR) identified the possible functional groups belonging to protein, fatty acids and lipids, while thermal analysis (TG-DSC) showed a greater removal of inorganic matter by the biomass washed with water. The method underwent analytical validation, being classified as specific, sensitive, linear, robust, precise and accurate, with LD (limit of detection) and LQ (limit of quantification) equal to 3.873 and 12.912 mg.L⁻¹, respectively. The results obtained demonstrated the potential use of mesocarp Baru as a natural adsorbent for copper ions in solution, opening power for future expansion and improvement of the method.

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