Potential of Cedrella fissilis bark as an adsorbent for the removal of red 97 dye from aqueous effluents

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The palm (Elaeis guineensis), known as dendê, is an important oleaginous Brazilian plant with a high performance of oil production. In this work, a 2 3 full experimental design was performed and the response surface method (RSM) was used to indicate the optimum parameter of caffeine adsorption on Elaeis guineensis endocarp activated carbon, since the endocarp is the main by-product from dendê oil production. It was set the adsorbent point of zero charge (pH pzc), and the material was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The RSM results indicate removal efficiency (%) at the optimal conditions, 0.20 g of adsorbent, and caffeine initial concentration of 20 mg/L, and acidic medium was about 95%. Based on ANOVA and F test (F calculated > F standard), the mathematical/statistical model obtained fits well to the experimental data. The overall kinetic studies showed time was achieved after 5 h and caffeine adsorption followed the pseudo-second-order model suggesting chemisorption is a predominant mechanism. Redlich-Peterson and Sips models best represented the experimental data (0.967 < R 2 < 0.993). Thermodynamic revealed that caffeine adsorption was spontaneous at all temperatures studied, exothermic, and probably with changes in the adsorbate-adsorbent complex during the process. The tests conducted in different water matrixes corroborate the suitability of this adsorbent to be used in caffeine removal even in a complex solution.

Section: Adsorbent Characterizationmentioning

confidence: 99%

Caffeine removal using Elaeis guineensis activated carbon: adsorption and RSM studies

Melo

Ide

Duarte

et al. 2020

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“…This is because at high concentrations there are more molecules occupying the available active sites [57][58][59][60].…”

Section: Kinetic Studymentioning

confidence: 99%

Highly effective adsorption of caffeine by a novel activated carbon prepared from coconut leaf

Oliveira

Meneses

Melo

et al. 2022

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The disposal of coconut wastes is costly and damaging to the environment, but its uses are advantageous activated carbons production. Coconut leaves waste were used for activated carbon production by pyrolysis at 500º C and activation with potassium carbonate.The activated carbon was used for caffeine removal from aqueous solution. The coconut leaves activated carbon showed a predominantly amorphous structure from X-ray diffraction analysis and a pH at the zero charge point of 7.9. From the N2 adsorption/desorption method, the adsorbent showed a predominance of mesopores, with average pore size of 45.48 ηm and a surface area of 678.03 m 2 /g. From kinetic studies the data followed the pseudo-second order, where the intraparticle diffusion can be neglected. The adsorption isotherms were satisfactorily adjusted for the Redlich-Peterson model and a type curve L was identified. The thermodynamic parameters showed that adsorption occurred spontaneously, was exothermic and governed by physical adsorption. The artificial neural networks developed were capable of predicting both kinetics and equilibrium adsorption data under different operating conditions and was comparable to the traditional models available in literature in the training experiments, encouraging its use for data generalization when an efficient dataset is used. In conclusion, coconut leaves waste showed to be a promising feedstock to produce activated carbon aiming caffeine removal from water and wastewater.

“…The signal found at 2922 cm −1 is due to the C-H elongation. The 1650 cm −1 and 1510 cm −1 bands are attributed to the aromatic bond C=C, and the 1052 cm −1 band is related to the C-O elongation of the phenolic compounds found in lignin (Georgin et al 2019). After physical and chemical activation (BCC and BACB), the intensity of the bands at 3444 cm −1 Fig.…”

Section: Characteristics Of Cbs Bcc and Bacbmentioning

confidence: 99%

Adsorption of atrazine and 2,4-D pesticides on alternative biochars from cedar bark sawdust (Cedrella fissilis)

Hernandes

Franco

Georgin

et al. 2021

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Bark residues of the forest species Cedrela fissilis were physically and chemically modified with zinc chloride (ZnCl 2 ) as an activating agent. The two modified materials were analyzed as adsorbents in removing atrazine and 2,4-D herbicides from effluents. Firstly, the precursor material and the modified ones were characterized by different techniques to identify the structural changes that occurred in the surfaces. Through TGA, it was observed that both modified materials have thermal stability close to each other and are highly superior to the precursor. X-ray diffractions proved that the amorphous structure was not altered, the three materials being highly heterogeneous and irregular. The micrographs showed that the treatments brought new spaces and cavities on the surface, especially for the material carbonized with ZnCl 2 . The pH PZC of the modified materials was close to 7.5. The physically modified material had a surface area of 47.31 m 2 g −1 and pore volume of 0.0095 cm 3 g −1 , whereas the carbonized material had a surface area of 98.12 m 2 g −1 and pore volume of 0.0099 cm 3 g −1 . Initial tests indicated that none of the adsorbents were efficient in removing 2,4-D. However, they showed good potential for removing atrazine. The Koble-Corrigan isothermal model best fits the experimental data, with a maximum capacity of 3.44 mg g −1 and 2.70 mg g −1 for physically modified and with ZnCl 2 , respectively. The kinetic studies showed that the system tends to enter into equilibrium after 120 min, presenting good statistical indicators to the linear driving force model (LDF). The surface diffusion coefficients were 2.18×10 −9 and 2.37×10 −9 cm 2 s −1 for atrazine adsorption on the physically and chemically modified materials. These results showed that the application of residues from the processing of cedar bark is promising. However, new future studies must be carried out to improve the porous development of the material and obtain greater adsorption capacities.