Adsorption Thermodynamics of Cr(VI) Removal by using Agro-Industrial Waste of Oil Palm Bagasse and Plantain Peels

The effect of temperature on the adsorption of Cr (VI) was determined with waste materials from the agroindustry, such as palm bagasse and plantain peels, by determining the thermodynamic parameters which allow to establish the mechanisms that control the process. The methodology included an initial preparation of the biomass, its characterization, and subsequent adsorption tests by setting the initial concentration of the metal to 100 ppm, a particle size of 0,5 mm, a biomass amount of 0,325 g, pH 2, and a volume of 100 mL. The process temperature varied between 303,15, and 352,15 K. The concentration of the remaining metal in the solution was performed using the diphenyl carbazide colorimetric method through a UVVis spectroscopy at a wavelength of 540 nm. The results show that the effect of temperature does not present a defined trend for palm bagasse, whereas it is linear for adsorption using plantain peels. Furthermore, the process of adsorption of Cr (VI) with palm bagasse is more favorable at higher temperatures, since it is a spontaneous process with a physical adsorption mechanism. On the other hand, the adsorption process with plantain peels is thermodynamically feasible at temperatures from 40 to 55 °C and not spontaneous at higher temperatures. Also, a physicochemical adsorption mechanism was evinced. It is concluded that the use of the studied materials is possible in the removal of the Cr (VI) ion in aqueous solutions.

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Adsorption of Cyanide from Cassava Wastewater Using Calcined and Activated Oyster Shell Ash

Journal of Engineering Research and Reports ◽

10.9734/jerr/2019/v6i116938 ◽

2019 ◽

pp. 1-9

Author(s):

Oto-Obong P. Akpan ◽

B. R. Etuk

Keyword(s):

Contact Time ◽

Adsorption Process ◽

Physical Adsorption ◽

Chemical Properties ◽

Oyster Shell ◽

Effect Of Temperature ◽

Cyanide Concentration ◽

Adsorbent Dosage ◽

Cyanide Removal ◽

Cassava Wastewater

Calcined ash and activated ash adsorbents were prepared from oyster shell. The physico-chemical properties of the prepared calcined oyster shell ash (COSA) and activated oyster shell ash (AOSA) were obtained using ASTM standards and Sears method. The results show that AOSA is a better adsorbent for removal of cyanide from cassava wastewater than COSA. The adsorption of cyanide from cassava wastewater onto adsorbents (COSA and AOSA) was investigated as a function of pH, adsorbent dosage, contact time, temperature and initial cyanide concentration. The batch study reveals that the adsorption process is strongly pH dependent and maximum cyanide removal is found to occur at pH of 10. The highest percent removal of cyanide from cassava wastewater was found at contact time of 80 minutes and 30oC. The effect of temperature on the adsorption process shows a small increase in the percent cyanide removal followed by a large decrease which suggests physical adsorption as the adsorption mechanism. The percent cyanide removal efficiency decreases with increase in initial cyanide concentration and increases with increase in adsorbent dosage.

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New Cyanoacetamide Derivatives as Corrosion Inhibitors for Carbon Steel in Acidic Media

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v4i1.962 ◽

2008 ◽

Vol 4 (1) ◽

pp. 323-350 ◽

Cited By ~ 3

Author(s):

Abdel Aziz Fouda ◽

A. M. El-desoky ◽

M. M. Muhtar

Keyword(s):

Carbon Steel ◽

Benzoic Acid ◽

Adsorption Mechanism ◽

Electrochemical Impedance ◽

Physical Adsorption ◽

Effect Of Temperature ◽

Active Centers ◽

Carbon Steel Surface ◽

Freundlich Adsorption Isotherm ◽

Inhibitive Action

The corrosion behavior of carbon steel in 1 M HCl solution in the absence and presence of 4-(2-Cyano-7- hydroxy-4-methylene-hepta-2,5-dienoylamino)-benzoic acid (a), 4-[2-Cyano-3-(4-methoxy -phenyl)-acryloylamino]-benzoicacid.(b), 4-(2-Cyano-3-phenyl acryloylamino)-benzoic acid (c) ,4-[3-(4-Chloro-phenyl)-2-cyano-acryloylamino]-benzoic acid(d), was investigated using weight loss , potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The inhibitive action of the investigated compounds was discussed in terms of blocking the electrode surface by adsorption of the molecules through the active centers contained in their structures. The adsorption of these derivatives on carbon steel surface is consistent with Freundlich adsorption isotherm. The effect of temperature on the rate of corrosion in the absence and presence of these compounds were also studied. Physical adsorption mechanism is proposed from the calculated thermodynamic parameters for all investigated compounds.

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Expanded perlite: potential for removing antibiotics from water

Water SA ◽

10.17159/wsa/2021.v47.i4.3817 ◽

2021 ◽

Vol 47 (4 October) ◽

Author(s):

Bruna Martins Vicentin ◽

Raquel Dalla Costa da Rocha

Keyword(s):

Isoelectric Point ◽

Adsorption Mechanism ◽

Adsorption Process ◽

Physical Adsorption ◽

Expanded Perlite ◽

Adsorption Sites ◽

Low Concentrations ◽

Pseudo Second Order ◽

High Concentrations ◽

Modification Treatment

This work aims to study the potential of expanded perlite (EP) for amoxicillin (AMX) removal in aqueous solution. For this purpose, chemical, morphological, and textural characteristics of the EP were evaluated, in addition to AMX removal by the adsorption process. The kinetic, isothermal, and thermodynamic parameters were also assessed. The EP presented an isoelectric point of 6.5 and a surface with hydroxyl bands, which favour the adsorption process. Air bubbles were sealed and randomly connected with each other, increasing the surface area relative to the adsorption sites. These non-porous or macro-porous sites demonstrate efficiency in the mechanisms of mass transfer. AMX removal was determined to be a pseudo-second-order process since the adsorption velocity was proportional to the square of the available adsorption sites and indicates heterogeneity in the surface interactions between the adsorbed molecules. Also, the interactions were considered multilayer for low concentrations and monolayer for high concentrations (Sips isotherm). The adsorption process was endothermic and utilised a physical adsorption mechanism. Considering that no modification treatment was applied to the EP, and due to its neutral isoelectric point, macropores, amorphous and dipole induction force (physical adsorption) characteristics, favourable affinity between EP and AMX was observed.

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Experimental Study on Adsorption Mechanism of U(VI) by Modified CMC

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.650.231 ◽

2013 ◽

Vol 650 ◽

pp. 231-237

Author(s):

Shu Kui Zhou ◽

Guang Ming Zeng ◽

Ying Jiu Liu ◽

Hai Yang Jiang

Keyword(s):

Adsorption Mechanism ◽

Adsorption Process ◽

Ph Value ◽

Physical Adsorption ◽

Order Kinetic ◽

Freundlich Model ◽

First Order ◽

Batch System ◽

Order Kinetic Model ◽

Pseudo First Order

The modified carboxymethyl cellulose(CMC) was prepared and explored to adsorb uranium(Ⅵ) ions from aqueous solution in a batch system. The experimental results showed that on the condition of reaction temperature 70~80°C, CMC 30%-35% (w/w), CMC to AA (w/w) of 10:2.5 and reaction time 3.5-4 h, the modification effect was the best. High removal efficient of U(Ⅵ) was obtained 97.1% at temperature of 25°C, pH value of 5.0, dosage of modified CMC 0.1 g/L and contact time of 60 min. It was found that the adsorption process was best described by Freundlich model and pseudo-first-order kinetic model (R2=0.9618), indicating that the adsorption is mainly on the surface of the modified CMC. Thermodynamics parameters of negative value of ΔG0 and positive value of ΔH0 revealed the spontaneity and endothermic nature of the adsorption. The adsorption is primarily due to physical adsorption.

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New Cellulose based pH-Sensitive Hydrogel for Highly Efficient Dyes Removal in Water Treatment: Kinetic, Thermodynamic, Theoretical and Computational Studies

10.21203/rs.3.rs-1138998/v1 ◽

2021 ◽

Author(s):

Loubna Jabir ◽

Hayat elhammi ◽

Mohammed Nor ◽

Issam Jilal ◽

Abderrahmane El Idrissi ◽

...

Keyword(s):

Active Sites ◽

Adsorption Process ◽

Physical Adsorption ◽

Reaction System ◽

Ph Sensitive ◽

Acyl Transfer ◽

Effect Of Temperature ◽

Order Kinetic ◽

Experimental Conditions ◽

Crosslinking Degree

Abstract In this paper, a new green pH-sensitive cellulose based hydrogel (swelling rate ~ 1005 %) was successfully elaborated. However, the new EDTA crosslinked HEC was investigated as adsorbent materiel, which it showed high removal efficiency (~2000 mg.g-1) to aquatic micropollutants, especially methylene blue as cationic dyes model. The synthesis of HEC-EDTA at high advanced crosslinking degree (up to 92 %) that confirmed using structural analyzes (FTIR and 13C CP/MAS-NMR), was cried out using DAEDT and DMAP as acyl transfer agent, where the lamellar morphology (2D- microstructure) was highly suggested basing on the average functionality of the reaction system. The kinetic study showed that the adsorption process was better described by pseudo-second-order kinetic, where the thermodynamic parameters exhibited a negative effect of temperature indicating a physical adsorption process. In addition, the adsorption capacity was studied according to the experimental conditions (pH, contact time, concentration, etc.), and the Freundlich model revealed a strong correlation to the experimental results indicating an energetic heterogeneity of the surface active sites. In the other hand, molecular dynamics (MD) simulations were conducted and optimized using COMPASS II, where the results showed a good agreement with the experiment, and that basing on the intermolecular Non-covalent interaction, molecular structure and cluster configurations.

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Thermodynamic and Kinetic Parameters of Methanolic Extract of Leaves of Cochlospermum Tinctorium as Eco-friendly Inhibitor for Corrosion of Mild Steel in HCL Medium

NIGERIAN ANNALS OF PURE AND APPLIED SCIENCES ◽

10.46912/napas.12 ◽

2015 ◽

Vol 6 ◽

pp. 83-90

Author(s):

G I Adams ◽

S O Adejo ◽

J U Ahile ◽

J A Gbertyo ◽

J O Ogbodo

Keyword(s):

Mild Steel ◽

Adsorption Mechanism ◽

Adsorption Process ◽

Methanolic Extract ◽

Physical Adsorption ◽

Average Value ◽

Extract Concentration ◽

Weight Loss Method ◽

Loss Method ◽

Hcl Medium

Thermodynamic, kinetic and adsorptive parameters of methanolic extract of leaves of Cochlospermum tinctorium as eco-friendly inhibitor for the corrosion of mild steel in HCl medium were evaluated through the weight loss method at 303 K and 311 K. The inhibition efficiency, %IE, increased with increase in extract concentration, but found to be better at 303 K than 311 K. The decrease in %IE with increase in temperature with the average value of 81.88 kJ/mol for activation energy, E a , and the values of free energy, ÄG, for the adsorption process are all supportive of physical adsorption mechanism. The values of heat of adsorption, Q ads,, are all negative, an indication that the adsorption process was exothermal. The half-life, t 1/2 , value increased with increase in inhibitor concentration and low at high higher, implying the inhibitor performance increased with increase in the extract concentration and decreased with rise in temperature. The data best fitted the Langmuir adsorption isotherm.

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Study on Adsorption Properties of Modified Corn Cob Activated Carbon for Mercury Ion

Energies ◽

10.3390/en14154483 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4483

Author(s):

Yuyingnan Liu ◽

Xinrui Xu ◽

Bin Qu ◽

Xiaofeng Liu ◽

Weiming Yi ◽

...

Keyword(s):

Activated Carbon ◽

Photoelectron Spectroscopy ◽

Adsorption Process ◽

Physical Adsorption ◽

Raw Material ◽

Order Kinetic ◽

Mercury Ions ◽

Corn Cob ◽

Adsorption Time ◽

X Ray

In this study, corn cob was used as raw material and modified methods employing KOH and KMnO4 were used to prepare activated carbon with high adsorption capacity for mercury ions. Experiments on the effects of different influencing factors on the adsorption of mercury ions were undertaken. The results showed that when modified with KOH, the optimal adsorption time was 120 min, the optimum pH was 4; when modified with KMnO4, the optimal adsorption time was 60 min, the optimal pH was 3, and the optimal amount of adsorbent and the initial concentration were both 0.40 g/L and 100 mg/L under both modified conditions. The adsorption process conforms to the pseudo-second-order kinetic model and Langmuir model. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Zeta potential characterization results showed that the adsorption process is mainly physical adsorption, surface complexation and ion exchange.

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Development of UHPC Mixtures Utilizing Natural and Industrial Waste Materials as Partial Replacements of Silica Fume and Sand

The Scientific World JOURNAL ◽

10.1155/2014/713531 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Shamsad Ahmad ◽

Ibrahim Hakeem ◽

Mohammed Maslehuddin

Keyword(s):

Silica Fume ◽

Industrial Waste ◽

Steel Slag ◽

Limestone Powder ◽

Waste Materials ◽

Cement Kiln ◽

Test Results ◽

Strength Criteria ◽

Natural Pozzolana ◽

Kiln Dust

In the exploratory study presented in this paper, an attempt was made to develop different mixtures of ultrahigh performance concrete (UHPC) using various locally available natural and industrial waste materials as partial replacements of silica fume and sand. Materials such as natural pozzolana (NP), fly ash (FA), limestone powder (LSP), cement kiln dust (CKD), and pulverized steel slag (PSS), all of which are abundantly available in Saudi Arabia at little or no cost, were employed in the development of the UHPC mixtures. A base mixture of UHPC without replacement of silica fume or sand was selected and a total of 24 trial mixtures of UHPC were prepared using different percentages of NP, FA, LSP, CKD, and PSS, partially replacing the silica fume and sand. Flow and 28-d compressive strength of each UHPC mixture were determined to finally select those mixtures, which satisfied the minimum flow and strength criteria of UHPC. The test results showed that the utilization of NP, FA, LSP, CKD, and PSS in production of UHPC is possible with acceptable flow and strength. A total of 10 UHPC mixtures were identified with flow and strength equal to or more than the minimum required.

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