scholarly journals Adsorption of phenol onto unactivated Moringa oleifera Seed Shells residue by UV -visible spectrophotometer

2020 ◽  
Vol 13 (2) ◽  
pp. 080-090
Author(s):  
Daniel Eneji Sani ◽  
John O. Idoko ◽  
Enyojo Samson Okwute ◽  
Matthew Chijioke Apeh
Keyword(s):  
Moringa Oleifera ◽  
Maximum Adsorption Capacity ◽  
Operational Parameters ◽  
Order Model ◽  
Solution Ph ◽  
Phenol Adsorption ◽  
Aqueous Effluents ◽  
Pseudo Second Order ◽  
Uv Visible ◽  
Moringa Oleifera Seed

Unactivated adsorbent was prepared from Moringa oleifera seed shells precursor, characterized and evaluated for aqueous phase removal of phenol. The effects of operational parameters such as initial phenolic solution pH and adsorbent dosage on equilibrium sorption were studied. Adsorption isotherms and kinetic experiments performed at (25 oC) furnished some equilibrium and kinetic parameters, respectively. UAMSS shows favorable attributes on (pH, bulk density, attrition, iodine number/surface area, surface charge/functional groups and Fourier transform infrared FTIR). Phenol uptake decreases with increase in solution pH for the adsorbent. Maximum adsorption capacity Qmax (mg/g) was (6.95). The optimal pH for phenol adsorption was attained at pH 3, adsorption kinetics obeyed closely pseudo-second-order model. Adsorption of phenol was well described by Langmuir isotherm. The adsorbent shows a promise of applicability in dephenolation of aqueous effluents/wastewater.

scholarly journals Kinetic, sorption isotherms, pseudo-first-order model and pseudo-second-order model studies of Cu(II) and Pb(II) using defatted Moringa oleifera seed powder

2016 ◽  
Vol 5 (2) ◽  
pp. 71-78
Author(s):  
Keno David Kowanga ◽  
◽  
Erastus Gatebe ◽  
Godfrey Omare Mauti ◽  
Eliakim Mbaka Mauti ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Contact Time ◽  
Moringa Oleifera ◽  
Second Order ◽  
Isotherm Model ◽  
Order Kinetic ◽  
Order Model ◽  
Pseudo Second Order ◽  
Moringa Oleifera Seed

In the recent decades, there has been a concern on heavy metals in waste water and high cost of conventional methods of removing heavy metals, for this reason search on adsorbents of biological origin which is low cost and efficient is necessary. In this work defatted Moringa oleifera seed powder was studied as a potential alternative adsorbent for removal of Cu(II) and Pb(II) from aqueous solution. Physicochemical parameters such as pH, contact time, adsorption kinetics and initial ions concentration adsorption capacity using sorption models were evaluated. The results showed that the optimum pH for biosorption of Cu(II) was 6.5 while that of Pb(II) was 5.5. Contact time for Cu(II) was observed to occur after 30 min while that of Pb(II) occurred after 40 min. FTIR analysis revealed that defatted Moringa oleifera seed biomass had presence of amino, carboxyl, hydroxyl and carbonyl groups, these groups were responsible for biosorption of Cu(II) and Pb(II) from aqueous solution. Biosorption kinetic data fitted well with pseudo-second-order kinetic model (r2 ≤ 0.9997) giving equilibrium rate constant (k2) of 0.0350±0.0275 g mg−1 min−1 for Cu (II) loaded biomass and 0.0206±0.0114 g mg−1 min−1 for Pb (II) loaded biomass; the biosorption isotherms for the biosorbent fitted well with Freundlich isotherm model than with Langmuir isotherm model. However, the separation factor RL of Langmuir model was between 0 and 1 indicating favourable sorption process and the low value of mean sorption energy of 9.19×10-2 kJ from D-R model showed that the forces of attraction involved were Van der Waal forces indicating the process of adsorption was physical adsorption. In conclusion, the study revealed that defatted Moringa oleifera seed is an efficient biosorbent for removal of Cu(II) and Pb(II) from aqueous solution.

Synthesis, Characterization and Adsorption Studies of a Graphene Oxide/Polyacrylic Acid Nanocomposite Hydrogel

2021 ◽  
Vol 19 (9) ◽  
pp. 46-54
Author(s):  
Makarim A. Mahdi ◽  
Aymen A.R. Jawad ◽  
Aseel M. Aljeboree ◽  
Layth S. Jasim ◽  
Ayad F. Alkaim
Keyword(s):  
Industrial Effluents ◽  
Langmuir Model ◽  
Isotherm Models ◽  
Nanocomposite Hydrogel ◽  
Adsorption System ◽  
Order Model ◽  
Solution Ph ◽  
Freundlich Model ◽  
Dye Sorption ◽  
Pseudo Second Order

The AAc/GO nanocomposite hydrogel was successfully employed as a polymeric Nano sorbent of the removal efficiency of M G dye from the model. The complication of the mechanism of the adsorption system was completely exposed by examining how solution pH affects adsorption, Ionic strength isotherm models, kinetic models, and thermodynamics. The adsorption of the MG dye was greatly dependent on the solution pH. The Freundlich model has been demonstrated to be the most accurate in describing the MG dye sorption, whilst the Langmuir model was shown to be the least accurate. Additionally, these integrated mechanisms fit nicely within the framework of a pseudo-second-order model. Additionally, the contact time at equilibrium short (ten minutes) required to MG removes demonstrates the AAc/GO nanocomposite hydrogel can be considered an efficient and potentially useful adsorbent for MG removal from industrial effluents.

scholarly journals Equilibrium and Kinetic Study of Lead and Copper Ion Adsorption on Chitosan-Grafted-Polyacrylic Acid Synthesized by Surface Initiated Atomic Transfer Polymerization

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2218 ◽  
Author(s):  
Carlos Grande-Tovar ◽  
William Vallejo ◽  
Fabio Zuluaga
Keyword(s):  
Adsorption Capacity ◽  
Polyacrylic Acid ◽  
Adsorption Process ◽  
Kinetic Constant ◽  
Copper Ion ◽  
Toxic Metal ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Equilibrium Studies ◽  
Pseudo Second Order

In this work, we synthesized chitosan grafted-polyacrylic acid (CS-g-PA) through surface-initiated atom transfer radical polymerization (SI-ATRP). We also studied the adsorption process of copper and lead ions onto the CS-g-PA surface. Adsorption equilibrium studies indicated that pH 4.0 was the best pH for the adsorption process and the maximum adsorption capacity over CS-g-PA for Pb2+ ions was 98 mg·g−1 and for Cu2+ it was 164 mg·g−1, while for chitosan alone (CS), the Pb2+ adsorption capacity was only 14.8 mg·g−1 and for Cu2+ it was 140 mg·g−1. Furthermore, the adsorption studies indicated that Langmuir model describes all the experimental data and besides, pseudo-second-order model was suitable to describe kinetic results for the adsorption process, demonstrating a larger kinetic constant of the process was larger for Pb2+ than Cu2+. Compared to other adsorbents reported, CS-g-PA had comparable or even superior adsorbent capacity and besides, all these results suggest that the new CS-g-PA polymers had potential as an adsorbent for hazardous and toxic metal ions produced by different industries.

scholarly journals Adsorption of Tea Polyphenols using Microporous Starch: A Study of Kinetics, Equilibrium and Thermodynamics

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1449 ◽  
Author(s):  
Xianchun Hu ◽  
Xianfeng Du
Keyword(s):  
Physical Adsorption ◽  
Tea Polyphenols ◽  
Adsorptive Capacity ◽  
Partial Hydrolysis ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Long Term Storage ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir

Microporous starch (MPS) granules were formed by the partial hydrolysis of starch using α–amylase and glucoamylase. Due to its biodegradability and safety, MPS was employed to adsorb tea polyphenols (TPS) based on their microporous characteristics. The influences of solution pH, time, initial concentration and temperature on the adsorptive capacity were investigated. The adsorption kinetics data conformed to the pseudo second–order kinetics model, and the equilibrium adsorption data were well described by the Langmuir isotherm model. According to the fitting of the adsorption isotherm formula, the maximum adsorption capacity of TPS onto MPS at pH 6.7 and T = 293 K was approximately 63.1 mg/g. The thermodynamic parameters suggested that the adsorption of TPS onto MPS was spontaneous and exothermic. Fourier transform infrared (FT–IR) analysis and the thermodynamics data were consistent with a physical adsorption mechanism. In addition, MPS-loaded TPS had better stability during long-term storage at ambient temperature.

Preparation of bio-based magnetic adsorbent and application for efficient removal of Cd(II) from water

2018 ◽  
Vol 77 (5) ◽  
pp. 1313-1323 ◽  
Author(s):  
Jianjun Zhou ◽  
Xionghui Ji ◽  
Xiaohui Zhou ◽  
Jialin Ren ◽  
Yaochi Liu
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
Magnetic Adsorbent ◽  
Order Model ◽  
Efficient Removal ◽  
Adsorption Ability ◽  
Adsorption Sites ◽  
Pseudo Second Order

Abstract A novel magnetic bio-adsorbent (MCIA) was developed, characterized and tested for its Cd(II) removal from aqueous solution. MCIA could be easily separated from the solution after equilibrium adsorption due to its super-paramagnetic property. The functional and magnetic bio-material was an attractive adsorbent for the removal of Cd(II) from aqueous solution owing to the abundant adsorption sites, amino-group and oxygen-containing groups on the surface of Cyclosorus interruptus. The experimental results indicated that the MCIA exhibited excellent adsorption ability and the adsorption process was spontaneous and endothermic. The adsorption isotherm was consistent with the Langmuir model. The adsorption kinetic fitted the pseudo-second-order model very well. The maximum adsorption capacity of Cd(II) onto MCIA was 40.8, 49.4, 54.6 and 56.6 mg/g at 293, 303, 313 and 323 K, respectively. And the MCIA exhibited an excellent reusability and impressive regeneration. Therefore, MCIA could serve as a sustainable, efficient and low-cost magnetic adsorbent for Cd(II) removal from aqueous solution.

scholarly journals Dysprosium Removal from Water Using Active Carbons Obtained from Spent Coffee Ground

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1372 ◽  
Author(s):  
Lorena Alcaraz ◽  
María Esther Escudero ◽  
Francisco José Alguacil ◽  
Irene Llorente ◽  
Ana Urbieta ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Potassium Hydroxide ◽  
Activated Carbons ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Microporous Material ◽  
Spent Coffee Ground ◽  
Coffee Ground ◽  
Pseudo Second Order

This paper describes the physicochemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. Potassium hydroxide (KOH)-activated carbon is a microporous material with a specific Brunauer–Emmett–Teller (BET) surface area of 2330 m2·g−1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g−1. A significant dependence of the adsorption capacity on the solution pH was found, but it does not significantly depend on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g−1 and 33.52 mg·g−1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better a fit to the Langmuir model and pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous, and favorable process.

Removal of Strontium Ions from Aqueous Solution by Sunflower Straw

2013 ◽  
Vol 726-731 ◽  
pp. 1922-1925 ◽  
Author(s):  
Lian Ai ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Si Zhao Zhang
Keyword(s):  
Aqueous Solution ◽  
Batch Adsorption ◽  
Order Model ◽  
Solution Ph ◽  
Sorption Data ◽  
Freundlich Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Sunflower Straw ◽  
Langmuir And Freundlich Models

The sorptive potential of sunflower straw (≤125 μm) for Sr2+ from aqueous solution was evaluated. Batch adsorption experiments were carried out as a function of solution pH, adsorbent dosage, Sr2+ concentration and contact time. FT-IR spectra and SEM of sunflower straw were employed to explore the functional groups available for the binding of Sr2+ and morphology of the adsorbent. Maximum uptake capacity of sunflower straw was 17.48 mg/g occurred at around pH 3-7. The adsorption equilibrium can be achieved within 5 min and kinetic data were fitted well to pseudo-second-order model. The Langmuir and Freundlich models were applied to describe isotherm sorption data. The Langmuir model gave an acceptable fit than Freundlich model.

scholarly journals Removal of Crystal Violet Dye from Aqueous Solutions onto Date Palm Fiber by Adsorption Technique

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mashael Alshabanat ◽  
Ghadah Alsenani ◽  
Rasmiah Almufarij
Keyword(s):  
Crystal Violet ◽  
Date Palm ◽  
Dye Removal ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Date Palm Fibers ◽  
Crystal Violet Dye ◽  
Pseudo Second Order ◽  
Influence Of Ph

The adsorption of crystal violet (CV) onto date palm fibers (DPFs) was examined in aqueous solution at 25°C. The experimental maximum adsorption capacity value was0.66×10−6. Langmuir, Freundlich, Elovich and Temkin models were applied to describe the equilibrium isotherms. The influence of pH and temperature on dye removal was evaluated. The percentage removal of CV dye by adsorption onto DPF at different pH and temperatures showed that these factors play a role in the adsorption process. Thermodynamic analysis was performed, and the Gibbs free energyΔGο, enthalpy changeΔHο, and entropyΔSοwere calculated. The negative values ofΔGοindicate spontaneous adsorption. The negative value ofΔHοindicates that the interaction between CV and DPF is exothermic, and the positive value ofΔSοindicates good affinity between DPF and CV. The kinetic data were fitted to a pseudo-second-order model.

Equilibrium and Kinetics Studies for Adsorption of Cu(II) from Aqueous Solution by Modified Phosphogypusum

2012 ◽  
Vol 518-523 ◽  
pp. 369-375 ◽  
Author(s):  
Yue Hong Yang ◽  
Dun Tao Shu ◽  
Ting Dong Fu ◽  
Huai Yu Zhang
Keyword(s):  
Freundlich Isotherm ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Wet Process ◽  
Removal Capacity ◽  
Adsorbate Concentration ◽  
Equilibrium And Kinetics ◽  
Pseudo Second Order ◽  
Best Fit

The purpose of this study was to investigate the adsorption of Cu(II) on phosphogypsum, a waste material from the manufacture of phosphoric acid by wet process. The removal capacity of phosphogypsum for Cu(II) ions was studied as a function of solution pH, contact time, adsorbent dosage and adsorbate concentration. Before batch adsorption study, phosphogypsum was pre-conditioned by calcine without water. The Langmuir and Freundlich theories were used to describe the Cu(II) adsorption process, and the Freundlich isotherm showed the best fit to the process. The adsorptions of Cu(II) followed pseudo-second-order kinetics. Maximum adsorption capacity of lime-preconditioned phosphogypsum was found to be 2.824 mg/g. The results showed that the phoshogypsum is a suitable adsorbent for the removal of Cu(II) ions from aqueous solutions.

scholarly journals Simultaneous Adsorption of Cr(VI) and Phenol from Binary Mixture Using Iron Incorporated Rice Husk: Insight to Multicomponent Equilibrium Isotherm

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Ankur Gupta ◽  
Chandrajit Balomajumder
Keyword(s):  
Experimental Data ◽  
Rice Husk ◽  
Low Cost ◽  
Binary Solution ◽  
Multicomponent System ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Adsorption Isotherm Models ◽  
Pseudo Second Order

Fe modified rice husk was prepared as a low cost biosorbent for the removal of Cr(VI) and phenol both singly and in combination from single and binary simulated synthetic waste water. Rice husk was modified by treating with FeSO4·7H2O. The results showed that impregnation of iron onto the surface of rice husk improved the adsorption capability of both Cr(VI) and phenol. The effects of process parameters for multicomponent system such as pH, adsorbent dose, and contact time onto the percentage removal of both Cr(VI) and phenol were investigated. The experimental data for the adsorption of both Cr(VI) and phenol onto the surface of Fe modified rice husk applied to various kinetic and adsorption isotherm models. Multicomponent isotherm models such as Nonmodified Langmuir, Modified Langmuir, Extended Langmuir, Extended Freundlich, Competitive Nonmodified Redlich Peterson, Competitive Modified Redlich Peterson were applied. The results show that Extended Freundlich model best described the experimental data for both Cr(VI) and phenol from binary solution. Pseudo second-order model agreed well with Cr(VI) while pseudo first-order model agreed well with phenol. Maximum adsorption capacity in synthetic binary solution of Cr(VI) and phenol was found to be 36.3817 mg g−1for Cr(VI) and 6.569 mg g−1for phenol, respectively.

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