scholarly journals Kinetic and thermodynamic adsorption of nickel (II) onto hydroxyapatite prepared from Snakehead (Channa striata) fish bone

2019 ◽  
Vol 9 (2) ◽  
pp. 85-94
Author(s):  
Poedji Loekitowati Hariani ◽  
Muryati Muryati ◽  
Muhammad Said Said

Biomaterial exploration base on solid waste has been an attractive issue, particularly regarding economic and environmental demand. This work aimed to extract hydroxyapatite from snakehead fishbone through precipitation method and used to remove Ni(II). The hydroxyapatite product was characterized by using X-ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) and Brunauer Emmett Teller (BET) method. Batch adsorption experiment includes pH solution, contact time and Ni(II) concentration. Pseudo-first order and pseudo-second-order were used to investigate the reaction mechanism and kinetic model, while adsorption equilibrium was evaluated according to Langmuir and Freundlich isotherm. XRD and FTIR spectra confirmed that hydroxyapatite was successfully extracted. The molar ratio (Ca/P) of hydroxyapatite was found at 1.70. The particle size of the hydroxyapatite was 48.77 nm. The pseudo-second-order is appropriate to describe the kinetic model while the adsorption mechanism follows Langmuir isotherm, which has an adsorption capacity of 5.359mg/g. The thermodynamic evaluation suggested the adsorption of Ni(II) is spontaneous in the endothermic process.

2010 ◽  
Vol 113-116 ◽  
pp. 632-638
Author(s):  
Feng Yu Li ◽  
Xiao Mei Sun ◽  
Bu Hai Li

Batch adsorption experiments were carried out to remove heavy metals Cu(II)and Ni(II) by pyromellitic dianhydride (PMDA) grafted β-Cyclodextrin (β-CD). The effects concerning the pH of the solution, contact time and initial heavy metal concentration were studied and discussed. The adsorption values increased significantly after a large number of carboxyl groups were gragfted on the microspheres surface. In order to investigate the mechanism of sorption, adsorption data were modeled using the pseudo-first-order and pseudo-second-order kinetic equation. It was found that kinetic studies showed good correlation coefficients for a pseudo-second-order kinetic model, confirming that the sorption rate was controlled by chemical adsorption. The equilibrium process was better described by the Langmuir isotherm than the Freundlich isotherm. XPS analysis further confirmed that the carboxyl group which grafted on the surface of the β-CD microspheres play a very important role in the removal of heavy metals.


2016 ◽  
Vol 7 (3) ◽  
pp. 307-318 ◽  
Author(s):  
F. Z. Mahjoubi ◽  
A. Khalidi ◽  
O. Cherkaoui ◽  
R. Elmoubarki ◽  
M. Abdennouri ◽  
...  

This work involved the preparation, characterization and dyes removal ability of Zn-Al, Mg-Al and Ni-Al layered double hydroxide (LDH) minerals intercalated by chloride ions. The materials were synthetized by the co-precipitation method. X-ray diffraction, Fourier transform infrared, thermogravimetric-differential thermal analysis and transmission electron microscopy characterization exhibited a typical hydrotalcite structure for all the samples. Adsorption experiments for methyl orange were performed in terms of solution pH, contact time and initial dye concentration. Experimental results indicate that the capacity of dye uptake augmented rapidly within the first 60 min and then stayed practically the same regardless of the concentration. Maximum adsorption occurred with acidic pH medium. Kinetic data were studied using pseudo-first-order and pseudo-second-order kinetic models. Suitable correlation was acquired with the pseudo-second-order kinetic model. Equilibrium data were fitted to Langmuir and Freundlich isotherm models. The maximum Langmuir monolayer adsorption capacities were 2,758, 1,622 and 800 mg/g, respectively, for Zn-Al-Cl, Mg-Al-Cl and Ni-Al-Cl. The materials were later examined for the elimination of color and chemical oxygen demand (COD) from a real textile effluent wastewater. The results indicated that the suitable conditions for color and COD removal were acquired at pH of 5. The maximum COD removal efficiency from the effluent was noted as 92.84% for Zn-Al-Cl LDH.


2019 ◽  
Vol 59 (3) ◽  
pp. 260-271 ◽  
Author(s):  
Eddy Heraldy ◽  
Fitria Rahmawati ◽  
Dwi Ardiyanti ◽  
Ika Nurmawanti

The fabrication of Mg-Zn-Al Hydrotalcite (HT) was carried out by the co-precipitation method at various molar ratios. The Mg-Zn-Al HT compound at the optimum molar ratio was then calcined to determine the effect of calcination on the Pb2+ adsorption. The kinetics of the adsorption type was determined by applying pseudo first order and pseudo second order kinetics models. Meanwhile, to investigate the adsorption process, the Freundlich and Langmuir equations were applied to determine the adsorption isotherm. The results showed that the optimum Mg-Zn-Al HT was at a molar ratio of 3 : 1 : 1 with an adsorption efficiency of 73.16 %, while Mg-Zn-Al HT oxide increased the adsorption efficiency to 98.12 %. The optimum condition of Pb2+ removal using Mg-Zn-Al HT oxide was reached at pH 5 and a contact time of 30 minutes. The adsorption kinetics follows the pseudo second order kinetics model with a rate constant of 0.544 g/mg·min. The isotherm adsorption follows the Langmuir isotherm model with a maximum capacity of 3.916 mg/g and adsorption energy of 28.756 kJ/mol.


Author(s):  
I. R. Ilaboya ◽  
O. C. Izinyon

Time dependent adsorption study on the sorption of Cr(III) and Mn(II) ions onto acid activated shale was conducted using batch adsorption techniques to investigate the effect of initial metal ion concentration on the process of adsorption. Experimental data obtained were fitted into different kinetic models to analyze the mechanism of adsorption in terms of reaction controlled and transport controlled mechanism. Some of the selected kinetic models include; Pseudo-first order, Pseudo-second order, Elovich, Film diffusion, Parabolic diffusion and Intra-particle diffusion model. From the result, it was observed based on the linear coefficient of determination (r2) that the experimental data fitted well into the various kinetic model tested. Application of non-linear error function such as error sum of square (SSE), root mean square error (RMSE) and residual average (RA) revealed that the rate limiting step for the adsorption of Cr3+ and Mn2+ ions on acid activated shale was chemical attachment (chemisorption) and the reaction mechanism follows the Pseudo-second order kinetic model.


2021 ◽  
Vol 46 (2) ◽  
Author(s):  
C. M. Ngwu ◽  
O. K. Amadi ◽  
M. O. Mac-Kalunta ◽  
J. Onyeuwaoma

This study investigated the potential of iron filings as low cost and environmentally friendly adsorbent for removing Naphthol AS dye from aqueous solutions. The batch-adsorption experiments were performed as a function of pH, temperature, concentration, contact time as well as dynamics of the process. The Langmuir, Freundlich and Dubinin-Raduskevich isotherm models for the adsorption processes were tested but Freundlich isotherm provided the best description for adsorption of the dye solution onto the iron filings, suggesting a physisorption controlled adsorption. The adsorption process was highly pH-dependent and the result indicates that the optimum pH for adsorption of Naphthol AS onto the adsorbent occurred at 4.0 having a maximum removal efficiency of 88 % respectively. Pseudo first-order and second-order as well as the intra-particle diffusivity kinetic models were applied to the experimental data and results showed that the pseudo second-order provided best fit for the experimental data. Kinetic studies also showed that the adsorption transport mechanism was particle-diffusion controlled.


2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç

The biosorption of lead ions (Pb2+) onto lyophilized fungus Aspergillus niveus was investigated in aqueous solutions in a batch system with respect to pH, contact time and initial concentration of the ions at 30 °C. The maximum adsorption capacity of lyophilized A. niveus was found to be 92.6 mg g−1 at pH 5.1 and the biosorption equilibrium was established about in 30 min. The adsorption capacity obtained is one of the highest value among those reported in the literature. The kinetic data were analyzed using the pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion equations. Kinetic parameters, such as rate constants, equilibrium adsorption capacities, and related correlation coefficients for the kinetic models were calculated and discussed. It was found that the adsorption of lead ions onto lyophilized A. niveus biomass fit the pseudo-second-order kinetic model well. The Langmuir and Freundlich isotherm parameters for the lead ion adsorption were applied and the Langmuir model agreed better with the adsorption of lead ions onto lyophilized A. niveus.


Author(s):  
Tasrina R. Choudhury ◽  
Snahasish Bhowmik ◽  
M. S. Rahman ◽  
Mithun R. Nath ◽  
F. N. Jahan ◽  
...  

Sawdust supported nano-zerovalent (NZVI/SD) iron was synthesized by treating sawdust with ferrous sulphate followed by reduction with NaBH4. The NZVI/SD was characterized by SEM, XRD, FTIR and Chemical method. Adsorption of As (III) by NZVI/SD was investigated and the maximum uptake of As (III) was found at pH value of 7.74 and equilibrium time of 3 hrs. The adsorption isotherm modelling revealed that the equilibrium adsorption data were better fitted with the Langmuir isotherm model compared with the Freundlich Isotherm model. This study revealed that the maximum As (III) ions adsorption capacity was found to be 12.66 mg/g for using NZVI/SD adsorbent. However, the kinetics data were tested by pseudo-first-order and pseudo-second-order kinetic models; and it was observed that the adsorption data could be well fitted with pseudo-second-order kinetics for As (III) adsorption onto NZVI/SD depending on both adsorbate concentration and adsorption sites. The result of this study suggested that NZVI/SD could be developed as a prominent environment-friendly adsorbent for the removal of As (III) ions from aqueous systems.


2021 ◽  
Vol 348 ◽  
pp. 01016
Author(s):  
Rajaa Bassam ◽  
Marouane El Alouani ◽  
Nabila Jarmouni ◽  
Jabrane Maissara ◽  
Mohammed El Mahi Chbihi ◽  
...  

Heavy metals are the most dangerous inorganic pollutants Due to their bioaccumulation and their nonbiodegradability, for this, several studies have focused on the recovery of these metals from water using different techniques. In this context, our study consists of evaluating an efficient and eco-friendly pathway of competitive recovery of heavy metals (Cd, Cr and As) from aqueous solutions by adsorption using raw rock. This adsorbent was characterized before and after the adsorption process by several techniques. The multi-metals adsorption process in the batch mode was undertaken to evaluate the effect of adsorbent mass, contact time, pH, Temperature, and initial heavy metals concentration. The kinetic data were analyzed using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic models. According to the modeling of the experimental results, the adsorption kinetics of heavy metals were adapted to the pseudo-second-order model. The adsorption isotherms were evaluated by the Langmuir and Freundlich isotherm models. The experimental isotherm data of heavy metals were better fitted with the Langmuir model rather than Freundlich isotherm models. The maximum experimental adsorption capacities (Qmax) predicted by the Langmuir model are 15.23 mg/g for Cd (II), 17.54 mg/g for Cr (VI) and 16.36 mg/g for As (III). The values of thermodynamic parameters revealed that the heavy metals adsorption was exothermic, favorable, and spontaneous in nature. The desorption process of heavy metals showed that this raw rock had excellent recycling capacity. Based on the results, these untreated clays can be used as inexpensive and environmentally friendly adsorbents to treat water contaminated by heavy metals.


2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic

The aim of this study was to determine adsorptive properties of acid activated bentonite clay for the removal of Direct Red 173 (DR 173) and Reactive Red 22 (RR 22) dyes from aqueous solutions. Raw and modified clay were characterized by the following methods: Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The efficiency of activated clay adsorption was investigated depending on process parameters: the adsorbent dose, pH, temperature, initial dye concentration, and contact time. Experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm as well as kinetic models of pseudo-first order, pseudo-second order and intra-particle diffusion. The process of dye adsorption was best described by Langmuir, Temkin, and Dubinin-Radushkevich isotherm (R2 > 0.97). Pseudo-second order model (R2 > 0.99) had the highest correlation with the obtained kinetic results. The positive value of ?H? indicated that adsorption of dyes by activated bentonite clay is endothermic process. The activated bentonite exhibited good regenerative ability in the 0.1 M NaOH solution. Maximum adsorption capacities of acid activated bentonite clay at 25?C for DR 173 and RR 22 dyes were 356.65 and 109.58 ?mol g-1, respectively.


Author(s):  
Jurgita Seniūnaitė ◽  
Rasa Vaiškūnaitė ◽  
Kristina Bazienė

Research studies on the adsorption kinetics are conducted in order to determine the absorption time of heavy metals on coffee grounds from liquid. The models of adsorption kinetics and adsorption diffusion are based on mathe-matical models (Cho et al. 2005). The adsorption kinetics can provide information on the mechanisms occurring be-tween adsorbates and adsorbents and give an understanding of the adsorption process. In the mathematical modelling of processes, Lagergren’s pseudo-first- and pseudo-second-order kinetics and the intra-particle diffusion models are usually applied. The mathematical modelling has shown that the kinetics of the adsorption process of heavy metals (copper (Cu) and lead (Pb)) is more appropriately described by the Lagergren’s pseudo-second-order kinetic model. The kinetic constants (k2Cu = 0.117; k2Pb = 0,037 min−1) and the sorption process speed (k2qeCu = 0.0058–0.4975; k2qePb = 0.021–0.1661 mg/g per min) were calculated. After completing the mathematical modelling it was calculated that the Langmuir isotherm better reflects the sorption processes of copper (Cu) (R2 = 0.950), whilst the Freundlich isotherm – the sorption processes of lead (Pb) (R2 = 0.925). The difference between the mathematically modelled and experimen-tally obtained sorption capacities for removal of heavy metals on coffee grounds from aqueous solutions is 0.059–0.164 mg/l for copper and 0.004–0.285 mg/l for lead. Residual concentrations of metals in a solution showed difference of 1.01 and 0.96 mg/l, respectively.


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