Bifurcaria bifurcata activated carbon for the adsorption enhancement of Acid Orange 7 and Basic Red 5 dyes: Kinetics, equilibrium and thermodynamics investigations

Bouzikri, Said; Ouasfi, Nadia; Khamliche, Layachi

doi:10.1016/j.nexus.2022.100138

Cited by 9 publications

(10 citation statements)

References 67 publications

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“…The positive ∆S • value indicates that the AO7 adsorption process is characterized by increased disorder in the interaction between dye molecules and the AC surface. A similar result has been reported for AO7 adsorption on AC from algae [18]. Adsorption is generally considered to decrease the number of degrees of freedom by reducing the adsorbate movement, resulting in a negative ∆S • value.…”

Section: Adsorption Thermodynamicssupporting

confidence: 84%

“…Table 12 compares the efficiency of the different adsorbents used to remove AO7 dye from aqueous solution reported in the literature [18,43,58,[60][61][62][63]. As shown in this survey, the AC obtained from the SCGs had an excellent affinity for AO7 dye removal (in terms of adsorption capacity and kinetics) and compared favorably with the other low-cost activated carbon and bio-adsorbents.…”

Section: Comparative Studymentioning

confidence: 87%

“…Under these operating conditions, the predominant electrical interactions are repulsive, making adsorption unfavorable or limited even if a number of positive charges are present. This means that electrostatic interactions cannot be the main mechanism of AO7 adsorption and suggests the involvement of other types of interactions [18]. One possible mechanism is hydrogen bonding, as shown by the analysis of the FTIR spectra (Figure 1).…”

Section: Adsorption Mechanismmentioning

confidence: 99%

“…The experimental results fit better with the Langmuir model based on homogeneous monolayer sorption (R 2 = 0.9877) than with the Freundlich model based on heterogeneous multilayer sorption at all temperatures. As a result, AO7 molecules are assumed to disperse into monolayers on adsorption sites that are identical in terms of energy and without electrostatic interactions between them [18]. The parameter R L is a measure of the separation factor between the adsorbate and adsorbent in a system.…”

Section: Adsorption Isothermsmentioning

confidence: 99%

“…Azo dyes, characterized by an azo chromophore group (-N=N-) and an electronreceiving sulfonate group (-SO 3 − ), are difficult to degrade by conventional processing methods [18][19][20]. In fact, textile dyes are not easily biodegradable, requiring the development of specific microbial strains and immobilized enzymes [21].…”

Section: Introductionmentioning

confidence: 99%

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Activated Carbon Prepared from Waste Coffee Grounds: Characterization and Adsorption Properties of Dyes

Aouay,

Attia,

Dammak

et al. 2024

Materials

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Spent coffee grounds (SCGs) have great potential as a useful, value-added biological material. In this context, activated carbon (AC) was prepared from SCGs by an activation process using H3PO4 at 600 °C in the air and used as an adsorbent for the azo dye AO7, a model molecule for dye colorants found in textile industry effluents. X-ray diffraction, SEM and BET revealed that the AC was predominantly amorphous, consisting of a powder of 20–100 µm particles with mesopores averaging 5.5 nm in pore size. Adsorption kinetics followed a pseudo-second-order law, while the Langmuir model best fitted the experimental isotherm data (maximum capacity of 119.5 mg AO7 per AC g). The thermodynamic parameters revealed that adsorption was endothermic and spontaneous. All the characterizations indicated that adsorption occurred by physisorption via mainly π–π interactions. The best experimental removal efficiency optimized by means of a Box–Behnken design and response surface methodology was 98% for an initial AO7 concentration of 20 mg·L−1 at pH 7.5 with a dose of 0.285 g·L−1 of AC and a contact time of 40 min. These results clearly show that activated carbon prepared from SCGs can be a useful material for efficiently removing organic matter from aqueous solutions.

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Section: Adsorption Thermodynamicssupporting

confidence: 84%