scholarly journals Comparison of adsorption models for the removal of fluorides, nitrates and sulfates by adsorption onto AFN membrane

2016 ◽  
Vol 51 (2) ◽  
pp. 106-116
Author(s):  
Fatma Guesmi ◽  
Islem Louati ◽  
Chiraz Hannachi ◽  
Béchir Hamrouni
Keyword(s):  
Langmuir Isotherm ◽  
Surface Adsorption ◽  
Sorption Isotherms ◽  
Adsorption Parameters ◽  
Sulfate Ions ◽  
Adsorption Models ◽  
Monovalent Ions ◽  
Equilibrium Data ◽  
Sorption Parameters ◽  
Best Fit

The main purpose of this work was to determine adsorption characteristics of fluoride, nitrate and sulfate ions on the AFN membrane. The sorption isotherms for , and ions on the AFN membrane were investigated in the range of 0.05–1 mol.L–1 at 298 K. The suitability of the Langmuir, Dubinin–Astakhov (D-A) and Redlich–Peterson adsorption models to the equilibrium data was investigated. The sorption parameters of the studied models were determined by non-linear regression and discussed. Equilibrium data obtained in this study were found to best fit the Langmuir isotherm. The ΔG° values deduced from the Langmuir isotherm suggest that the affinity order of the AFN membrane for the studied anions is: . In order to improve their selectivity towards monovalent ions, the AFN membrane was modified by adsorption of polyethyleneimine on its surface. Adsorption parameters values of the studied models were determined for the modified AFN membrane. The D-A model provides the best fit to the experimental points. In fact, removal of fluoride and nitrate ions by adsorption on the modified AFN membrane was more effective than the adsorption on the unmodified one. Desorption of fluoride from the modified AFN membrane by nitrate and sulfate ions was investigated.

scholarly journals POTASSIUM ADSORPTION IN CALCAREOUS SOILS OF KURDISTAN REGION OF IRAQ

2020 ◽  
Vol 51 (Special) ◽  
Author(s):  
Gh. A. Mam-Rasul
Keyword(s):  
Soil Solution ◽  
Langmuir Isotherm ◽  
Calcareous Soils ◽  
Sorption Isotherms ◽  
Sufficient Information ◽  
Kurdistan Region ◽  
Langmuir Isotherm Model ◽  
Nutrients Availability ◽  
The Difference ◽  
Sorption Parameters

Sorption is one of the most chemical important processes, which determine nutrients availability in soil. Sorption isotherms provide sufficient information about soils sorption’s capacity, and it’s data can be used to determine thermodynamic sorption parameters. The aim of this studyis to evaluate the sorption of potassium onto some soils. An experiment was conducted with four calcareous soils of the Sulaimani province Kurdistan Region of Iraq by using the batch methods. 5g soil samples were equilibrated at 298±1 Kelvin with 50 ml of 0.01M CaCl2 containing 0 to 250 mg L-1 K as KCl. Suspensions were centrifuged, filtered, and concentration of K+ in the clear extract solution was determined. Amount of K+ sorbed by the soil was calculated from the difference between the initial and final concentration of K+ in the equilibrium solution. Sorption of K+ was evaluated using adsorption isotherms. The results showed that K+ sorption was described by linear, Langmuir, Freundlich, and Temkin equations. Langmuir equation gave a better fit of equilibrium K adsorption when it has a higher R2 and lowers SE.  The data indicated that the maximum monolayer coverage capacity (b) from the Langmuir isotherm model ranged between (-113.63 to 2500) mg kg-1. The negative values of (b) for studied locations soils indicated to potassium release instead of adsorption. The Langmuir isotherm constant (KL) ranged from (-0.01 to 0.01) L mg-1. Maximum buffering capacity (MBC) is a capacity factor, which measures the ability of the soil to replenish K ion to soil solution that the ability of a soil to supply K to the soil solution. The value of MBC of the studied soils ranged from 0.453 to 23.75 mg kg-1.The sorption processes for the forth locations are favorable and spontaneous because the value of RL was an equal one.

scholarly journals Decontamination of cadmium(II) from synthetic wastewater onto shea fruit shell biomass

2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Jonas Bayuo
Keyword(s):  
Negative Charge ◽  
Agricultural Waste ◽  
Freundlich Isotherm ◽  
Synthetic Wastewater ◽  
Batch Method ◽  
Adsorption Parameters ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
The Impact ◽  
Best Fit

AbstractShea fruit shells being an agricultural waste material was utilized to test its novelty as an inexpensive biosorbent for the elimination of Cd(II) from synthetic wastewater using the batch method. A batch study was employed to probe the impact of pH of the solution, contact time, temperature and initial concentration on the depollution of Cd(II) ions using unmodified Shea fruit shells biomass. The decontamination of Cd(II) by the unmodified Shea fruit shells biomass was found to be dependent on these adsorption parameters. The equilibrium data best represented Freundlich isotherm by a correlation coefficient (R2) of 0.9691. The kinetic models analyzed suggest pseudo-second-order ($${R}^{2} = 0.9515$$ R 2 = 0.9515 ) as the best fit model signifying that the removal of Cd(II) ions was on account of chemisorption. The positive values of the thermodynamic parameters, ΔH° and ΔS° reveal endothermic and increase of disorder of the process while the negative charge of ΔG° shows spontaneity of the system.

scholarly journals Investigation of Seeds and Peels of Citrullus colocynthis as Efficient Natural Adsorbent for Methylene Blue Dye

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1279
Author(s):  
Wafa Mohammed Alghamdi ◽  
Ines El Mannoubi
Keyword(s):  
Methylene Blue ◽  
Kinetic Model ◽  
Langmuir Isotherm ◽  
Order Kinetic ◽  
Citrullus Colocynthis ◽  
Natural Adsorbent ◽  
Spontaneous Process ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Mb Adsorption

Natural adsorbents as low-cost materials have been proved efficient for water remediation and have significant capacity for the removal of certain chemicals from wastewater. The present investigation aimed to use Citrullus colocynthis seeds (CCSs) and peels (CCPs) as an efficient natural adsorbent for methylene blue (MB) dye in an aqueous solution. The examined biosorbents were characterized using surface area analyzer (BET), scanning electron microscope (SEM), thermogravimetric analyzer (TGA) and Fourier transform infra-red (FT-IR) spectroscopy. Batch adsorption experiments were conducted to optimize the main factors influencing the biosorption process. The equilibrium data for the adsorption of MB by CCSs were best described by the Langmuir isotherm followed by the Freundlich adsorption isotherms, while the equilibrium data for MB adsorption by CCPs were well fitted by the Langmuir isotherm followed by the Temkin isotherm. Under optimum conditions, the maximum biosorption capacity and removal efficiency were 18.832 mg g−1 and 98.00% for MB-CCSs and 4.480 mg g−1 and 91.43% for MB-CCPs. Kinetic studies revealed that MB adsorption onto CCSs obeys pseudo-first order kinetic model (K1 = 0.0274 min−1), while MB adsorption onto CCPs follows the pseudo-second order kinetic model (K2 = 0.0177 g mg−1 min−1). Thermodynamic studies revealed that the MB biosorption by CCSs was endothermic and a spontaneous process in nature associated with a rise in randomness, but the MB adsorption by CCPs was exothermic and a spontaneous process only at room temperature with a decline in disorder. Based on the obtained results, CCSs and CCPSs can be utilized as efficient, natural biosorbents, and CCSs is promising since it showed the highest removal percentage and adsorption capacity of MB dye.

scholarly journals Preparation and Characterization of Cationized Cellulose for the Removal of Anionic Dyes

2001 ◽  
Vol 19 (3) ◽  
pp. 197-210 ◽  
Author(s):  
A. Hashem ◽  
Reda M. El-Shishtawy
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Structural Features ◽  
Isotherm Models ◽  
Acid Orange 7 ◽  
Anionic Dyes ◽  
Adsorption Parameters ◽  
Direct Blue ◽  
Equilibrium Data

The factors influencing the cationization of microcrystalline cellulose with 3-chloro-2-hydroxypropyl triethylammonium chloride in the presence of NaOH were investigated. The course of the reaction was followed by estimating the nitrogen content of the cationized product while its structural features were confirmed by IR analysis. The ability of cationized cellulose to adsorb anionic dyes, viz. Acid Orange 7, Direct Blue 75 and Direct Violet 31, was investigated at 25°C and 50°C. The equilibrium data obtained were fitted by the Langmuir and Freundlich isotherm models, allowing the corresponding adsorption parameters to be determined. The results showed that the adsorption capacity was dependent on the adsorbent, temperature, the nature of the dye and (to some extent) on van der Waals and hydrogen bonding. Cationized cellulose exhibited a much better adsorption capacity towards anionic dyes than cellulose.

scholarly journals Comparison of adsorptions by rice hull and Lewatit TP 214 of platinum in chloride solution

2013 ◽  
Vol 78 (6) ◽  
pp. 811-826 ◽  
Author(s):  
M.H. Morcali ◽  
B. Zeytuncu ◽  
O. Yucel
Keyword(s):  
Waste Product ◽  
Second Order ◽  
Attenuated Total Reflection ◽  
Rate Equations ◽  
Rice Hull ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Biomass Waste ◽  
Equilibrium Data ◽  
Pseudo Second Order

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.

Absorption Equilibrium and Thermodynamics of Fenugreek Yellow Pigment on Macroporous Resins

2011 ◽  
Vol 233-235 ◽  
pp. 91-94
Author(s):  
Feng Han ◽  
Wen Hong Li ◽  
Xuan Tang ◽  
Dong Li
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Adsorption Equilibrium ◽  
Yellow Pigment ◽  
Adsorption Models ◽  
Freundlich Model ◽  
Langmuir Adsorption ◽  
Macroporous Resins ◽  
Equilibrium Data

The adsorption equilibrium and thermodynamics of pigment extracted from Fenugreek after degumming on macroporous resins was investigated under differentinitial concentrations. The suitability of the Freundlich and Langmuir adsorption models to the equilibrium data was investigated. The model fitness was determined by R2 . Thermodynamic parameters were calculated by the Van’t Hof equation.The results showed that Freundlich model gave a better fit of adsorption isotherms than Langmuir models. The positive value of enthalpy(∆H) indicated that the adsorption was endothermic, the negative value of Gibbs free energy (∆G) showed the spontaneous and favoured nature of adsorption, and the entropy(∆S) was positive.The resins LS-46 showed an effective adsorbtion for Fenugreek yellow pigment.

Preparation of Al2O3 Whiskers from AACH Using Hydrothermal Method and its Use for the Removal of Lead Ions by Adsorption

2021 ◽  
Vol 875 ◽  
pp. 177-183
Author(s):  
Asma Ameer ◽  
Syed Mujtaba Ul Hassan ◽  
Syed M. Husnain ◽  
Jamil Ahmad ◽  
Faisal Shahzad ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Heavy Ion ◽  
Lead Ions ◽  
Hydrothermal Route ◽  
Adsorption Parameters ◽  
Ion Removal ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Adsorption Equilibrium Data

This work explores the potential of adsorption of Pb2+ by hydrothermally synthesized alumina. In comparison to other heavy ion removal techniques, adsorption is preferred in the current study as it has the edge of ease of operation and environment friendly characteristics. Synthesis of high surface area alumina whiskers was achieved by hydrothermal route which were subsequently employed for the active adsorption of lead ions. AACH (Ammonium Aluminum Carbonate Hydroxide), used as precursor for alumina, was calcined at three different temperatures i.e. 700, 900 and 1100 °C to form alumina whiskers. These whiskers were characterized by XRD, SEM, BET and FTIR. Various adsorption parameters such as contact time, pH, initial metal concentration were studied for lead ions. Maximal removal efficiency was obtained for the specimen having pH 4 and calcined at 700 °C for 60 minutes. Kinetic data was best described by pseudo second order model, whereas the adsorption equilibrium data obeyed the Langmuir adsorption isotherm model.

scholarly journals Adsorption isotherm and thermodynamic studies of As(III) removal from aqueous solutions using used cigarette filter ash

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Pezhman Zein Al-Salehin ◽  
Farid Moeinpour ◽  
Fatemeh S. Mohseni-Shahri
Keyword(s):  
Aqueous Solutions ◽  
Langmuir Isotherm ◽  
Adsorption Equilibrium ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Cigarette Filter ◽  
Electron Microscopy Analysis ◽  
Equilibrium Data ◽  
Thermodynamic Variables ◽  
Adsorption Equilibrium Data

Abstract In the present paper, used cigarette filter ash was prepared and used as an active adsorbent to remove As(III) ions from aqueous solutions. The prepared adsorbent structure was identified by scanning electron microscopy analysis, Brunauer–Emmett–Teller method and energy-dispersive X-ray spectroscopy analysis. The influence of contact time, pH, adsorbent dose and initial concentration of As(III) on the removal of As(III) was assessed. Several isotherm models were checked to illustrate the adsorption equilibrium. The adsorption equilibrium data adapted well with the Langmuir isotherm model. The maximum adsorption capacity of 33.33 mg/g was acquired from the Langmuir isotherm. The calculated thermodynamic variables verified that the adsorption process is spontaneous and endothermic.

MICROWAVE ASSISTED K2CO3 PALM SHELL ACTIVATED CARBON AS SORBENT FOR CO2 ADSORPTION APPLICATION

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Usman Dadum Hamza ◽  
Noor Shawal Nasri ◽  
Nor Aishah Saidina Amin ◽  
Jibril Mohammed ◽  
Husna Mohd Zain
Keyword(s):  
Activated Carbon ◽  
Porous Carbon ◽  
Co2 Adsorption ◽  
Co2 Uptake ◽  
Adsorption Method ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Co2 Adsorption Capacity ◽  
Adsorption Equilibrium Data ◽  
Best Fit

Carbon dioxide is believed to be a major greenhouse gas (GHG) that contributes to global warming. In this study, palm shells were used as a precursor to prepare CO2 activated carbon sorbents via carbonization, chemical impregnation with K2CO3 and microwave activation.  Adsorption equilibrium data for CO2 adsorption on the porous carbon were obtained at different temperatures using static volumetric adsorption method. Langmuir, Freundlich, Sips and Toths models were used to correlate the experimental data. The CO2 adsorption capacity at 303.15, 343.15, 378.15 443.15 K and 1 bar on the sorbent was 2.71, 1.5, 0.77, 0.69 mmol/g respectively. Sips isotherm was found to have the best fit. The results indicated that the porous carbon sorbent prepared by carbonization and microwave K2CO3 assisted activation have good CO2 uptake. The porous carbons produced are therefore good candidates for CO2 adsorption applications

Phosphorus sorption capacity of alkaline Manitoba soils and its relationship to soil properties

2005 ◽  
Vol 85 (3) ◽  
pp. 417-426 ◽  
Author(s):  
D V Ige ◽  
O O Akinremi ◽  
D N Flaten ◽  
B. Ajiboye ◽  
M A Kashem
Keyword(s):  
Soil Properties ◽  
Langmuir Isotherm ◽  
Single Point ◽  
Chemical Properties ◽  
Phosphorus Sorption ◽  
Point Index ◽  
Adsorption Parameters ◽  
Retention Capacity ◽  
Phosphorus Adsorption ◽  
P Retention

The establishment of the P retention capacity of soil in Manitoba is essential for effective management of P in the region. However, the methods for determining the P retention capacity for neutral to calcareous soils in the Eastern Prairies are not well developed. The objectives of this study were to determine the P retention capacity of Manitoba soils and to generate equations that relate these capacities to other soil properties. One hundred and fifteen archived surface soils were selected and their physico-chemical properties were measured. These soils were used to generate a single-point P adsorption index by equilibrating 2 g of soil in 20 mL of 0.01 M KCl solution containing either 150 (P150) or 400 (P400) mg P L-1. A subset of 26 of these soils was used for multipoint isotherms with P concentrations in the range of 0–1000 mg P L-1. The data obtained were fitted to the Langmuir isotherm and the adsorption indices were correlated with the various soil properties that were then used to developed predictive equations of the P retention capacity of the soil. The values of the adsorption index, P150, obtained from the single point adsorption study using 150 mg P L-1, ranged between 88 and 891 mg P kg-1, while that of P400 ranged between 100 and 1250 mg P kg-1. A better correlation was obtained between P150 and soil properties compared with P400. For the 26 soil subset, the adsorption indices, Smax1 to Smax 6, obtained from the Langmuir isotherm, ranged from 300 to 1330 mg kg-1. A good correlation was obtained between the single point index and the multipoint isotherm (r = 0.93). Hence, Smax for the 115 soils was estimated from the relationship between P150 and Smax 3 of the 26 soils. The best relationships between the adsorption parameters, P150 and Smax, and the soil properties were obtained with the sum of Mehlich-3 extractable Ca and Mg (R2= 0.66) and the sum of exchangeable Ca and Mg (R2= 0.64). Mehlich-3-Ca and -Mg each explained 56% of the variation, while clay content explained 40% of the variation in the P retention capacity of these soils. Unlike the widely reported influence of Al and Fe in acid soils, our study showed that the retention of P in Manitoba soils was influenced more by Ca and Mg and soil texture. Key words: Phosphorus, phosphorus retention capacity, phosphorus adsorption capacity, phosphorus sorption, single-point index

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