Influence of Nitric Acid Concentration on Characteristics of Olive Stone Based Activated Carbon

Soudani, Nouha; Souissi-Najar, Souad; Ouederni, Abdelmottaleb

doi:10.1016/s1004-9541(13)60638-2

Cited by 39 publications

(23 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, since the values of the enthalpy of immersion in cyclohexane were greater than in hexane, the slope of the line presented for the immersion in this solvent was greater. It was also observed that for CAN the difference in the enthalpy of immersion was lower than for the other activated carbons, which indicates that as the volume of micropore decreased, the liquid−solid interaction became similar [34][35][36]. The linear trend described by the experimental data was in agreement with Equation 3, which represented the relationship between ∆H im and W o for microporous activated carbons [16].…”

Section: Resultssupporting

confidence: 71%

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

2019

View full text Add to dashboard Cite

The enthalpy of immersion for five activated carbons (with different surface chemistry) in cyclohexane and hexane was determined in order to observe the intensity of the solid–liquid interaction. The enthalpy of immersion was related to the properties of activated carbons, such as micropore volume, total basic groups content, and the EoWo product, that characterized each solid-liquid system. The values for the immersion enthalpy were between −21.2 and −91.7 J g−1 for cyclohexane and between −16.4 and −66.1 J g−1 for hexane. It showed greater interaction between the cyclohexane and the activated carbons and it was related to the properties of this adsorbate, such as molecular size and molecular arrangement. The difference in the enthalpy of immersion between the solvents per unit of micropore volume for the set of activated carbons was calculated obtaining a value of −487 J cm−3.

show abstract

Section: Resultssupporting

confidence: 71%

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

2019

View full text Add to dashboard Cite

show abstract

“…The surface chemistry of carbon materials is basically determined by the acidic and basic character of their surface [17] and can be changed by treating them with alkaline solution or with oxidizing agents either in the gas phase such as air [18], ozone [19,20] or in solution such as sulfuric acid [21], nitric acid [22] hydrogen peroxide [23,24], chlorine water [25]. A given treatment will modify the pore structure and the chemical nature of the activated carbon surface.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Adsorption of Phenol Using Alkaline Modified Activated Carbon Prepared From Olive Stones

Soudani

Najar-Souissi

Ouederni

2019

J. Chil. Chem. Soc.

View full text Add to dashboard Cite

Activated carbon (AC) prepared from olive stone (OSAC) was modified separately by ammoniac (OSAC/AM) and sodium hydroxide (OSAC/H) aqueous solutions impregnation in order to improve their adsorption properties toward phenol. The raw and modified activated carbons were characterized. The porous structure was characterized using N 2 adsorption at 77 K. The surface functional group characteristics were examined by Fourier transform infrared (FTIR) spectroscopy, Boehm titration, the point of zero charge (pH pzc) measurement and X-ray photoelectron spectroscopy (XPS) method. The isotherms of phenol adsorption on the original and modified ACs were measured. After modification, the activated carbon showed enhanced adsorption capacity for phenol. The effect of alkaline solution concentration on adsorption process was investigated. Results showed a decrease of the microporosity of AC after alkalin treatment especially for higher solution concentration. The amounts of the surface basic groups of the modified ACs increased, in comparison with the original AC, with the increase of the alkaline concentration; however the acidic surface groups decreased. The equilibrium adsorption data were best described by Langmuir model. The maximum adsorption capacity of phenol enhanced for ammonia and sodium hydroxide, respectively, compared with the original AC. We noted that the higher alkaline concentration the higher the adsorption capacity of AC for phenol.

show abstract

“…These results are corroborated by those reported in the literature. In fact, many studies reported that nitric acid treatment reduces the specific surface area (Soudani et al 2013, Bernal et al 2018, Rehman et al 2019. Soudani et al 2013 reported that this reduction depends on the concentration of HNO 3 .…”

Section: Surface Morphology and Surface Areamentioning

confidence: 99%

Selective oxidation of cumene into 2-phenyl-2-propanol and acetophenone over activated carbon supported Co_1.5PW₁₂O₄₀ material

Abduh

AlGarni

Kahtani

et al. 2020

Mater. Res. Express

View full text Add to dashboard Cite

This article reports the oxidation of cumene by H 2 O 2 in the presence of CO 2 . It describes the role played by carbon dioxide on the course of the reaction. The reaction was catalyzed by unsupported Co 1.5 PW 12 O 40 and supported on activated carbon. The prepared materials were characterized by ICP, IR, XRD and UV. Analysis of the reaction products by gas chromatography coupled with mass spectrometry and gas chromatography showed that 2-phenyl-2-propanol and acetophenone were the main products of the reaction. Activated carbon significantly increases conversion by increasing Co 1.5 PW 12 O 40 accessibility to cumene molecules. The improvement in the conversion and selectivities of 2-phenyl-2-propanol and acetophenone by the use of the oxidizing system H 2 O 2 /CO 2 compared to the use of H 2 O 2 alone or CO 2 alone is due to the role of the percarbonate entity -HCO 4 formed by reaction between H 2 O 2 and CO 2 . Oxidation by large amounts of H 2 O 2 decreases the conversion by decreasing the solubility of cumene in the resulting aqueous medium. An increase in the reaction time resulting in a decrease in the concentration of H 2 O 2 and leaving the effect of the predominant CO 2 accentuates the cracking reactions.

show abstract

Influence of Nitric Acid Concentration on Characteristics of Olive Stone Based Activated Carbon

Cited by 39 publications

References 42 publications

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

Enhanced Adsorption of Phenol Using Alkaline Modified Activated Carbon Prepared From Olive Stones

Selective oxidation of cumene into 2-phenyl-2-propanol and acetophenone over activated carbon supported Co_1.5PW₁₂O₄₀ material

Contact Info

Product

Resources

About

Influence of Nitric Acid Concentration on Characteristics of Olive Stone Based Activated Carbon

Cited by 39 publications

References 42 publications

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

Enhanced Adsorption of Phenol Using Alkaline Modified Activated Carbon Prepared From Olive Stones

Selective oxidation of cumene into 2-phenyl-2-propanol and acetophenone over activated carbon supported Co1.5PW12O40 material

Contact Info

Product

Resources

About

Selective oxidation of cumene into 2-phenyl-2-propanol and acetophenone over activated carbon supported Co_1.5PW₁₂O₄₀ material