scholarly journals Evaluation of the Adsorption Efficiency on the Removal of Lead(II) Ions from Aqueous Solutions Using Azadirachta indica Leaves as an Adsorbent

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 559
Author(s):  
Abubakr Elkhaleefa ◽  
Ismat H. Ali ◽  
Eid I. Brima ◽  
Ihab Shigidi ◽  
Ahmed. B. Elhag ◽  
...  
Keyword(s):  
Surface Area ◽  
Azadirachta Indica ◽  
Standard Free Energy ◽  
Solution Concentration ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Neem Leaves ◽  
Pseudo Second Order ◽  
Adsorbent Dose

The efficiency of Azadirachta indica (neem leaves) on the removal of Pb(II) ions by adsorption from aqueous solution was investigated in this study. The efficiency of these leaves (without chemical or thermal treatment) for the adsorption of Pb(II) ions has not previously been reported. Batch experiments were performed to study the effect of the particle size, pH, adsorbent dose, contact time, initial Pb(II) ion concentration, and temperature. The maximum removal of 93.5% was achieved from an original Pb(II) ion solution concentration of 50 mg/L after 40 min, at pH 7, with 0.60 g of an adsorbent dose. The maximum adsorption capacity recorded was 39.7 mg/g. The adsorption process was also studied by examining Langmuir, Freundlich, Temkin isotherm, and Dubinin–Radushkevich (D-R) isotherm models. The results revealed that the adsorption system follows the pseudo-second-order model and fitted the Freundlich model. Several thermodynamic factors, namely, the standard free energy (∆G°), enthalpy (∆H°), and entropy (∆S°) changes, were also calculated. The results demonstrated that the adsorption is a spontaneous, physical, and exothermic process. The surface area, pore size, and volume of adsorbent particles were measured and presented using a surface area analyzer (BET); the morphology was scanned and presented with the scanning electron microscope technique (SEM); and the functional groups were investigated using μ-FTIR.

Adsorption of heavy metals from aqueous solutions by Mg–Al–Zn mingled oxides adsorbent

2016 ◽  
Vol 74 (7) ◽  
pp. 1644-1657 ◽  
Author(s):  
Mona El-Sayed ◽  
Gh. Eshaq ◽  
A. E. ElMetwally
Keyword(s):  
Heavy Metals ◽  
Metal Ion ◽  
Second Order ◽  
Ion Concentration ◽  
Precipitation Method ◽  
Isotherm Models ◽  
Infrared Spectrometry ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Pseudo Second Order

In our study, Mg–Al–Zn mingled oxides were prepared by the co-precipitation method. The structure, composition, morphology and thermal stability of the synthesized Mg–Al–Zn mingled oxides were analyzed by powder X-ray diffraction, Fourier transform infrared spectrometry, N2 physisorption, scanning electron microscopy, differential scanning calorimetry and thermogravimetry. Batch experiments were performed to study the adsorption behavior of cobalt(II) and nickel(II) as a function of pH, contact time, initial metal ion concentration, and adsorbent dose. The maximum adsorption capacity of Mg–Al–Zn mingled oxides for cobalt and nickel metal ions was 116.7 mg g−1, and 70.4 mg g−1, respectively. The experimental data were analyzed using pseudo-first- and pseudo-second-order kinetic models in linear and nonlinear regression analysis. The kinetic studies showed that the adsorption process could be described by the pseudo-second-order kinetic model. Experimental equilibrium data were well represented by Langmuir and Freundlich isotherm models. Also, the maximum monolayer capacity, qmax, obtained was 113.8 mg g−1, and 79.4 mg g−1 for Co(II), and Ni(II), respectively. Our results showed that Mg–Al–Zn mingled oxides can be used as an efficient adsorbent material for removal of heavy metals from industrial wastewater samples.

Removal of Mercury (II) from Aqueous Solution by using Rice Residues

2013 ◽  
Vol 63 (1) ◽  
Author(s):  
S. T. Song ◽  
N. Saman ◽  
K. Johari ◽  
H. B. Mat
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
Second Order ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Adsorption Mechanisms ◽  
Pseudo Second Order ◽  
Rice Residues

Sorption potential of rice residues for Hg(II) removal from aqueous solution was investigated. Rice husk (RH) and rice straw (RS) were selected and treated with sodium hydroxide (NaOH). The raw and modified adsorbents were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and BET surface area measurements. The effects of pH, initial ion concentration, and agitation time on the removal process were studied in batch adsorption experiments. Two simple kinetic models, which are pseudo-first-order and pseudo-second-order, were tested to investigate the adsorption mechanisms. The kinetic data fits to pseudo second order model with correlation coefficients greater than 0.99 for all adsorbents. The equilibrium data fitted well with the Langmuir compared to Freundlich isotherm models. Alkali-treated adsorbent obtained larger surface area and RH-NaOH showed highest adsorption capacity followed by RS-Pure > RH-Pure > RS-NaOH. The maximum removal efficiency obtained by RH-NaOH and RS-Pure was 42 mg/l (80%) at pH 6.5 and with 2 days contact time (for 50 mg/l initial concentration and 25 mg adsorbents). 

scholarly journals Adsorption of Mn2+ from Aqueous Solution Using Manganese Oxide-Coated Hollow Polymethylmethacrylate Microspheres (MHPM)

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Dhiraj Dutta ◽  
Jyoti Prasad Borah ◽  
Amrit Puzari
Keyword(s):  
Aqueous Solution ◽  
Manganese Oxide ◽  
Adsorption Capacity ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Coated Sand

Results of investigation on adsorption of Mn2+ from aqueous solution by manganese oxide-coated hollow polymethylmethacrylate microspheres (MHPM) are reported here. This is the first report on Mn-coated hollow polymer as a substitute for widely used materials like green sand or MN-coated sand. Hollow polymethylmethacrylate (HPM) was prepared by using a literature procedure. Manganese oxide (MnO) was coated on the surface of HPM (MHPM) by using the electroless plating technique. The HPM and MHPM were characterized by using optical microscopy (OM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Optical and scanning micrographs were used to monitor the surface properties of the coated layer which revealed the presence of MnO on the surface of HPM. TGA showed the presence of 4-5% of MnO in MHPM. Adsorption isotherm studies were carried out as a function of pH, initial ion concentration, and contact time, to determine the adsorption efficiency for removal of Mn2+ from contaminated water by the synthesized MHPM. The isotherm results showed that the maximum adsorption capacity of MnO-coated HPM to remove manganese contaminants from water is 8.373 mg/g. The obtained R 2 values of Langmuir isotherm and Freundlich isotherm models were 1 and 0.87, respectively. Therefore, R 2 magnitude confirmed that the Langmuir model is best suited for Mn2+ adsorption by a monolayer of MHPM adsorbent. The material developed shows higher adsorption capacity even at a higher concentration of solute ions, which is not usually observed with similar materials of this kind. Overall findings indicate that MHPM is a very potential lightweight adsorbent for removal of Mn2+ from the aqueous solution because of its low density and high surface area.

scholarly journals Utilization to Remove Pb (II) Ions from Aqueous Environments Using Waste Fish Bones by Ion Exchange

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Bayram Kizilkaya ◽  
A. Adem Tekınay
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Mechanism ◽  
Cost Effective ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Fish Bones ◽  
Adsorption Capacities ◽  
Aqueous Environments ◽  
Equilibrium Data ◽  
Pseudo Second Order

Removal of lead (II) from aqueous solutions was studied by using pretreated fish bones as natural, cost-effective, waste sorbents. The effect of pH, contact time, temperature, and metal concentration on the adsorption capacities of the adsorbent was investigated. The maximum adsorption capacity for Pb (II) was found to be 323 mg/g at optimum conditions. The experiments showed that when pH increased, an increase in the adsorbed amount of metal of the fish bones was observed. The kinetic results of adsorption obeyed a pseudo second-order model. Freundlich and Langmuir isotherm models were applied to experimental equilibrium data of Pb (II) adsorption and the value ofRLfor Pb (II) was found to be 0.906. The thermodynamic parameters related to the adsorption process such asEa,ΔG°,ΔH°, andΔS° were calculated andEa,ΔH°, andΔS° were found to be 7.06, 46.01 kJ mol−1, and 0.141 kJ mol−1K−1for Pb (III), respectively.ΔH° values (46.01 kJmol−1) showed that the adsorption mechanism was endothermic. Weber-Morris and Urano-Tachikawa diffusion models were also applied to the experimental equilibrium data. The fish bones were effectively used as sorbent for the removal of Pb (II) ions from aqueous solutions.

3D Porous Graphene/Polyvinyl Alcohol Composites: The Effect of Modification on the Adsorption Properties

NANO ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. 1650125 ◽  
Author(s):  
Shuang Sun ◽  
Xiaofei Ma
Keyword(s):  
Polyvinyl Alcohol ◽  
Graphene Nanosheets ◽  
Adsorption Properties ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Porous Structures ◽  
Edta Solution ◽  
Pseudo Second Order

Polyvinyl alcohol (PVA) was grafted on graphene nanosheets (GN) in the reduction of graphene oxide with hydrazine hydrate. The obtained GN-PVA (GP) suspension was treated with the freezing–thawing cycle to fabricate 3D porous monolithic GP materials, which were modified with carbon disulfide to introduce xanthan groups on the wall of porous materials, marked as GPCs. The characterization of GPCs confirmed that PVA was attached on the surface of GNs, and xanthan groups were effectively functionalized on the porous structures, which were composed of randomly oriented GNs. The Pb[Formula: see text] adsorption pattern for GPC materials was investigated. The kinetic adsorption and isotherm data fit the pseudo second-order kinetic and the Langmuir isotherm models, respectively. The maximum adsorption capacity of Pb[Formula: see text] reached 242.7[Formula: see text]mg/g. And GPCs for Pb[Formula: see text] adsorption could be regenerated with ethylenediamine tetracetic acid (EDTA) solution for repetitious adsorption.

scholarly journals Application of treated eggplant peel as a low-cost adsorbent for water treatment toward elimination of Pb2+: Kinetic modeling and isotherm study

2018 ◽  
Vol 36 (3-4) ◽  
pp. 1112-1143 ◽  
Author(s):  
Mohammad Hossein Karimi Darvanjooghi ◽  
Seyyed Mohammadreza Davoodi ◽  
Arzu Y Dursun ◽  
Mohammad Reza Ehsani ◽  
Iman Karimpour ◽  
...  
Keyword(s):  
Contact Time ◽  
Low Cost ◽  
Standard Free Energy ◽  
Chemical Properties ◽  
Entropy Change ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Standard Entropy ◽  
Adsorption Parameters ◽  
Adsorbent Dose

In this study, treated eggplant peel was used as an adsorbent to remove Pb2+ from aqueous solution. For this purpose batch adsorption experiments were performed for investigating the effect of contact time, pH, adsorbent dose, solute concentrations, and temperature. In order to assess adsorbent’s physical and chemical properties, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy were used. The results showed that the adsorption parameters for reaching maximum removal were found to be contact time of 110 min, adsorbent dose of 0.01 g/ml, initial lead(II) concentration of 70 ppm, pH of 4, and temperature of 25°C. Moreover, for the experiments carried out at pH > 4 the removal occurred by means of significant precipitation as well as adsorption. Furthermore, these results indicated that the adsorption followed pseudo-second-order kinetics model implying that during the adsorption process strong bond between lead(II) and chemical functional groups of adsorbent surface took place. The process was described by Langmuir model (R2 = 0.99; maximum adsorption capacity 88.33 mg/g). Also thermodynamics of adsorption was studied at various temperatures and the thermodynamic parameters including equilibrium constant (K), standard enthalpy change, standard entropy change, and standard free energy changes were obtained from experimental data.

scholarly journals Investigation on adsorption capacity of TiO2-P25 nanoparticles in the removal of a mono-azo dye from aqueous solution: A comprehensive isotherm analysis

2014 ◽  
Vol 20 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Mohammad Behnajady ◽  
Shahrzad Yavari ◽  
Nasser Modirshahla
Keyword(s):  
Aqueous Solution ◽  
Crystallite Size ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Correlation Coefficients ◽  
Average Crystallite Size ◽  
Isotherm Models ◽  
Equilibrium Data ◽  
Pseudo Second Order

In this work TiO2-P25 nanoparticles with high surface area have been used as adsorbent for the removal of C.I Acid Red 27 (AR27), as an organic contaminant from aqueous solution. Characteristics of phases and crystallite size of TiO2-P25 nanoparticles were achieved from XRD and the surface area and pore size distribution were obtained from BET and BJH techniques. TiO2-P25 nanoparticles with almost 80% anatase and 20% rutile phases, the average crystallite size of 18 nm, have specific surface area of 56.82 m2 g-1. The effect of various parameters like initial AR27 concentration, pH, contact time and adsorbent dosage has been carried out in order to find desired adsorption conditions. The desired pH for adsorption of AR27 onto TiO2-P25 nanoparticles was 3. The equilibrium data were analyzed with various 2-, 3- and 4-parameter isotherm models. Equilibrium data fitted very well by the 4-parameter Fritz-Schluender model. Results of adsorption kinetics study indicated that the pseudo-second order kinetics provided the best fit with correlation coefficients close to unity.

scholarly journals The Equilibrium, Kinetics, and Thermodynamics Studies of the Sorption of Methylene Blue from Aqueous Solution Using Pulverized Raw Macadamia Nut Shells

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joshua N. Edokpayi ◽  
Samson O. Alayande ◽  
Ahmed Adetoro ◽  
John O. Odiyo
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Surface Area ◽  
Low Cost ◽  
Aqueous Media ◽  
Group Analysis ◽  
Second Order ◽  
Isotherm Models ◽  
Macadamia Nut ◽  
Pseudo Second Order

In this study, the potential for pulverized raw macadamia nut shell (MNS) for the sequestration of methylene blue from aqueous media was assessed. The sorbent was characterized using scanning electron microscopy for surface morphology, functional group analysis was performed with a Fourier-transform infrared spectrometer (FT-IR), and Brunauer–Emmett–Teller (BET) isotherm was used for surface area elucidation. The effects of contact time, sorbent dosage, particle size, pH, and change in a solution matrix were studied. Equilibrium data were fitted using Temkin, Langmuir, and Freundlich adsorption isotherm models. The sorption kinetics was studied using the Lagergren pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The feasibility of the study was established from the thermodynamic studies. A surface area of 2.763 m2/g was obtained. The equilibrium and kinetics of sorption was best described by the Langmuir and the pseudo-second-order models, respectively. The sorption process was spontaneous (−ΔG0=28.72−31.77 kJ/mol) and endothermic in nature (ΔH0=17.45 kJ/mol). The positive value of ΔS0 (0.15 kJ/molK) implies increased randomness of the sorbate molecules at the surface of the sorbent. This study presents sustainable management of wastewater using MNS as a potential low-cost sorbent for dye decontamination from aqueous solution.

scholarly journals Adsorption Study for the Removal of Nitrate from Water Using Local Clay

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
A. Battas ◽  
A. El Gaidoumi ◽  
A. Ksakas ◽  
A. Kherbeche
Keyword(s):  
Solution Concentration ◽  
Optimal Conditions ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Local Clay ◽  
Initial Concentration ◽  
X Ray ◽  
Rate Of Reaction ◽  
Pseudo Second Order ◽  
Adsorbent Dose

Our research aimed at the removal of nitrate ions through adsorption by local clay. A series of batch experiments were conducted to examine the effects of contact time, adsorbent characteristics, initial concentration of nitrate, pH of the solution, concentration, and granulometry of adsorbent. Adsorption isotherms studies indicated that local clay satisfies Freundlich’s model. The rate of reaction follows pseudo-second-order kinetics. Local clay successfully adsorbs nitrates at pH acid. The adsorption capacity under optimal conditions was found to be 5.1 mg/g. The adsorption yield increases with adsorbent dose and decrease with initial concentration of nitrate. The local clay was characterized by the X-ray fluorescence method (XRF), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), scanning electronics microscopy (SEM), and measurement of specific surface area (BET). The results of the study indicated that local clay is useful materials for the removal of nitrates from aqueous solutions which can be used in water treatment without any chemical modification.

Removal of acetaminophen (ACT) from aqueous solution by using nanosilica adsorbent: experimental study, kinetic and isotherm modeling

2020 ◽  
Vol 49 (1) ◽  
pp. 55-62
Author(s):  
Akbar Eslami ◽  
Zahra Goodarzvand Chegini ◽  
Maryam Khashij ◽  
Mohammad Mehralian ◽  
Marjan Hashemi
Keyword(s):  
Removal Rate ◽  
Synthesis Method ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Content Type ◽  
Bet Analysis ◽  
Pseudo Second Order

Purpose A nanosilica adsorbent was prepared and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET. Design/methodology/approach The optimum conditions for the highest adsorption performance were determined by kinetic modeling. The adsorbent was used for the adsorption of acetaminophen (ACT), and the parameters affecting the adsorption were discussed like pH, initial concentration, contact time and adsorbent dosage. The adsorbent have been characterized by SEM, XRD and BET analysis. The kinetic models including pseudo-first-order and pseudo-second-order with Langmuir and Freundlich isotherm models were applied to investigate the kinetic and isotherms parameters. Findings The adsorption of ACT increased to around 95% with the increase of nanosilica concentration to 30 g/L. Moreover, the adsorption process of ACT follows the pseudo-second-order kinetics and the Langmuir isotherm with the maximum adsorption capacity of 609 mg/g. Practical implications This study provided a simple and effective way to prepare of nanoadsorbents. This way was conductive to protect environmental and subsequent application for removal of emerging pollutants from aqueous solutions. Originality/value The novelty of the study is synthesizing the morphological and structural properties of nanosilica-based adsorbent (specific surface area, pore volume and size, shape and capability) and improving its removal rate through optimizing the synthesis method; and studying the capability of synthesis of nanosilica-based adsorbent for removal of ACT as a main emerging pharmaceutical water contaminant.

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