scholarly journals The Adsorption of Pb, Zn, Cu, Ni, and Cd by Modified Ligand in a Single Component Aqueous Solution: Equilibrium, Kinetic, Thermodynamic, and Desorption Studies

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
E. Igberase ◽  
P. Osifo ◽  
A. Ofomaja

In this investigation, an amino functionalized adsorbent was developed by grafting 4-aminobenzoic acid onto the backbone of cross-linked chitosan beads. The 3 sets of beads including chitosan (CX), glutaraldehyde cross-linked chitosan (CCX), and 4-aminobenzoic acid grafted cross-linked chitosan (FGCX) were characterized by FTIR, XRD, SEM, and TGA. The water content and amine concentration of FGCX were determined. The effect of adsorption parameters was studied and the optimum was used for further studies. Equilibrium data was obtained from the adsorption experiment carried out at different initial concentration; the data were applied in isotherm, thermodynamics, and kinetic studies. The Langmuir and Dubinin-Kaganer-Radushkevich (DKR) models were successful in describing the isotherm data for the considered metal ions while the Freundlich and Temkin model fit some of the considered metal ions. Pseudo-second-order and intraparticle model described the kinetic data quite well. Thermodynamic parameters such as Gibb’s free energy change (ΔGo), enthalpy change (ΔHo), and entropy change (ΔSo) were calculated and the results showed that the adsorption of Pb, Cu, Ni, Zn, and Cd ions onto FGCX is spontaneous and endothermic in nature. Regeneration of the spent adsorbent was efficient for the considered metal ions.

e-Polymers ◽  
2018 ◽  
Vol 18 (3) ◽  
pp. 217-228 ◽  
Author(s):  
Amir Vahedi ◽  
Mohammadreza Rahmani ◽  
Zahra Rahmani ◽  
Mohammadali Moghaddasi ◽  
Farid Talebnia Rowshan ◽  
...  

AbstractIn this study, humic acid-immobilized-amine-modified polyacrylamide/sepiolite (Ha-Am-Paa-Sep) and phytic acid-modified polyacrylamide/sepiolite composites (Phy-Paa-Sep) were prepared and characterized for removal of Cu(II) and Ni(II) from aqueous solutions. The effects of contact time, initial concentration of adsorbent and metal ions, pH and temperature on the adsorption process were investigated. The optimum adsorption of metal ions occurred at pH 5 and 25°C. Ion exchange and complexation reactions were the main mechanisms for adsorption of metal ions. Removal of metal ions followed a pseudo-second-order kinetics and equilibrium occurred after 60 min. The conformity of various adsorption models to the equilibrium data was evaluated among which Freundlich isotherm model gave the best fitting result. The highest monolayer adsorption capacity of Cu(II) and Ni(II) ions were 244 and 250 mg·g−1 for Ha-Am-Paa-Sep and 256.4 and 277 mg·g−1 for Phy-Paa-Sep, respectively, at room temperature. Ultimately, desorption experiments were performed and the results showed approximately 95% of adsorbed metal ions were desorbed.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2586
Author(s):  
Inas A. Ahmed ◽  
Ahmed H. Ragab ◽  
Mohamed A. Habila ◽  
Taghrid S. Alomar ◽  
Enas H. Aljuhani

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.


Author(s):  
Mohamed Nasser Sahmoune ◽  
Krim Louhab ◽  
Aissa Boukhiar

Dead streptomyces rimosus was found to be an effective biosorbent for the removal of chromium from industrial tanning effluents. A sorption level of 65 mg/g was observed at pH 4.8 while the precipitation effect augmented this value at a higher pH range. Chromium desorption increased with decreasing desorption agents pH (including HCl and H2SO4) to a maximum value of 95% at approximately zero pH. The biosorption data of trivalent chromium by streptomyces rimosus has been used for kinetic studies based on fractional power, Elovich, pseudo-first order and pseudo-second order rate expressions. The time-dependent Cr (III) biosorption data were well-described by a pseudo-second-order kinetic model. The intraparticle diffusion is not the rate-limiting step for the whole reaction. It was found that the biosorption equilibrium data fit well with the Langmuir model.


2013 ◽  
Vol 78 (6) ◽  
pp. 811-826 ◽  
Author(s):  
M.H. Morcali ◽  
B. Zeytuncu ◽  
O. Yucel

Rice hull, a biomass waste product, and Lewatit TP 214, a thiosemicarbazide sorbent, were investigated as adsorbents for the adsorption of platinum (IV) ions from synthetically prepared dilute chloroplatinic acid solutions. The rice hull was characterized by Attenuated Total Reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The effects of the different adsorption parameters, sorbent dosage, contact time, temperature and pH of solution on adsorption percentage were studied in detail on a batch sorption. The adsorption equilibrium data were best fitted with the Langmuir isotherm model. The maximum monolayer adsorption capacities, Qmax, at 25?C were found to be 42.02 and 33.22 mg g-1 for the rice hull and Lewatit TP 214, respectively. Thermodynamic calculations using the measured ?H?, ?S? and ?G? values indicate that the adsorption process was spontaneous and exothermic. The pseudo-first-order and pseudo-second-order rate equations were investigated; the adsorption of platinum ions for both sorbents was found to be described by the pseudo-second-order kinetic model. The kinetic rate, k2, using 30 mg sorbent at 25?C was found to be 0.0289 and 0.0039 g min-1 mg-1 for the rice hull and Lewatit TP 214, respectively. The results indicated that the rice hull can be effectively used for the removal of platinum from aqueous solution.


2016 ◽  
Vol 62 (4) ◽  
pp. 329-337 ◽  
Author(s):  
Yuan Jiang ◽  
Ruixia Hao ◽  
Shiqin Yang

In this work, we studied the natural bioaccumulation and biosorption of Pb(II) in several common edible macrofungi. The macrofungi include the following species: Lentinus edodes, Pleurotus eryngii, Flammulina velutipes, Hypsizygus marmoreus, and Agrocybe cylindracea. The present analysis of Pb(II) revealed distinct capabilities of metal accumulation among individual species. Moreover, the natural concentrations of lead did not reach a health risk level when cultivated in uncontaminated soil. In the biosorption experiment by edible macrofungi, we found that the equilibrium data of living sporocarp (P. eryngii and H. marmoreus) and the homogenate of L. edodes and F. velutipes fit the Freundlich model well. Other data samples exhibited a better fit to the Langmuir model. The edible macrofungi showed a higher lead removal capacity than did other biosorbents. Furthermore, the pseudo-second-order kinetics model exhibited the best fit to the biosorption processes. The effectiveness of edible macrofungi as biosorbents for Pb(II) was confirmed.


2015 ◽  
Vol 6 (2) ◽  
pp. 310-324 ◽  
Author(s):  
Selvaraj Dinesh Kirupha ◽  
Selvaraj Kalaivani ◽  
Thangaraj Vidhyadevi ◽  
Periyaraman Premkumar ◽  
Palanithamy Baskaralingam ◽  
...  

A novel poly [2,5-(1,3,4-thiadiazole)-benzalimine] abbreviated as TDPI adsorbent was synthesized using simple polycondensation technique. The synthetic route involves the preparation of 2,5-diamino-1,3,4-thiadiazole from 2,5-dithiourea and subsequent condensation with terephthalaldehyde. The resin was chemically characterized using Fourier transform infrared (FT-IR), 1H-NMR, and 13C-NMR spectroscopic analysis. Surface morphology and thermal stability were analyzed using scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The effect of the pH value of solution, contact time, adsorbent dose, and initial metal ion concentration were investigated by batch equilibrium adsorption experiments. Kinetic studies show that the adsorption of metal ions onto the resin proceeds according to the pseudo-second-order model and the equilibrium data were best interpreted by the Redlich–Peterson isotherm. The experimental values of the adsorption capacities of Pb2+, Cu2+, Ni2+, and Cd2+ on to TDPI could reach up to 437.2, 491.6, 493.7, and 481.9 mg.g−1 respectively. The exothermic nature of the process, the affinity of the adsorbent towards the metal ions and the feasibility of the process are explained in the thermodynamic parameters. The resin stability and re-usability studies suggest that the resin is chemically stable (0.3 N HCl and H2SO4) and could be regenerated without any serious decline in performance.


2014 ◽  
Vol 1043 ◽  
pp. 219-223 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  

Concern about environmental protection has increased over the years and the presence of volatile organic compounds (VOCs) in water poses a threat to the environment. In this study, coconut shell activated carbon (PHAC) was produced by potassium hydroxide activation via microwave for benzene and toluene removal. Equilibrium data were fitted to Langmuir, Freundlich and Tempkin isotherms with all the models having R2 > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238mg/g for benzene and toluene, respectively. The equilibrium parameter (RL) falls between 0 and 1 confirming the favourability of the Langmuir model. Pseudo-second-order kinetic model best fitted the kinetic data. The PHAC produced can be used to remediate water polluted by VOCs.


2014 ◽  
Vol 661 ◽  
pp. 39-44
Author(s):  
Nur Khalida Adibah Md Rodzi ◽  
Senusi Faraziehan ◽  
Alrozi Rasyidah

In this study, biosorption of copper and zinc ions on Baker’s yeast, Saccharomyces Cerevisiae was investigated. The data of batch experiments was used to perform equilibrium and kinetic studies. The experimental results were fitted well to the Langmuir and Freundlich model isotherms. According to the parameters of Langmuir isotherm, the maximum biosorption capacities of copper and zinc ions onto immobilized yeast were 5.408mg/g and 1.479mg/g at 293 Kfor the treated beads. Competitive biosorption of two metal ions was investigated in terms of maximum sorption quantity. The binding capacity for copper ions is more than the zinc ions for both untreated and treated immobilized yeast.While, for the kinetic studies, the pseudo second order model was found the most suitable model for the present systems.


2021 ◽  
Vol 309 ◽  
pp. 01077
Author(s):  
M Tukaram Bai ◽  
Ch. I. A. Raju ◽  
V Sridevi ◽  
Nalluri Chittibabu ◽  
P Venkateswarlu

Biosorption of lead onto Fallen Coffee Plant leaves (FCPL) powder from an aqueous solution was studied in the present study. The characterization of FCPL powder was done by FTIR, XRD, SEM and BET. The equilibrium agitation time for lead biosorption is 60 min. The optimum pH and dosage values are 5.2 and 20 g/L respectively. In the range of variables studied, percentage biosorption is increased from 75.1 to 95.5 %. The maximum uptake capacity of 3.664 mg/g is obtained at 303 K. In the present investigation the equilibrium data was well explained by Langmuir, Redlich-Peterson with a correlation coefficient of 0.99, and followed by Temkin and Freundlich isotherms. The kinetic studies reveal that the biosorption system obeyed the pseudo second order kinetic model by considering the correlation coefficient value as 0.99. From the values of ∆S, ∆H and ∆G it is observed that the biosorption of lead onto Fallen coffee plant leaves(FCPL) powder was irreversible, endothermic and spontaneous.


2021 ◽  
Vol 19 (5) ◽  
pp. 120-131
Author(s):  
Sanaa Tareq ◽  
Masar Ali Awad ◽  
Khawla Kani Jasim ◽  
Shahad Kadhim Taher ◽  
Mustafa M. Kadhim

In the theoretical part, removal of direct yellow 8 (DY8) from water solution was accomplished using Bentonite Clay as an adsorbent. Under batch adsorption, the adsorption was observed as a function of contact time, adsorbent dosage, pH, and temperature. The equilibrium data were fitted with the Langmuir and Freundlich adsorption models, and the linear regression coefficient R2 was used to determine the best fitting isotherm model. thermodynamic parameters of the ongoing adsorption mechanism, such as Gibb's free energy, enthalpy, and entropy, have also been measured. The batch method was also used for the kinetic calculations, and the day's adsorption assumes first-order rate kinetics. The kinetic studies also show that the intraparticle diffusion process was active. Density Functional Theory (DFT) was used to study the dye structure with Gaussian 09 and predict the active site in a molecule using total electron density (TED) and electrostatic surface potential (ESP).


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