Kinetics and Adsorption Equilibrium in the Removal of Azo-Anionic Dyes by Modified Cellulose

Villabona-Ortíz, Ángel; Figueroa-López, Kelly J.; Ortega-Toro, Rodrigo

doi:10.3390/su14063640

Cited by 52 publications

(34 citation statements)

References 56 publications

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“…Nevertheless, for longer contact times, a decrease in the removal of all metals was evidenced, as shown in Figure 5 . Other authors reported similar results for equilibrium times between adsorbent and adsorbate, which varied between 5 and 40 min, using solutions contaminated with different heavy metals and biosorbents of crambe [ 41 ], cashew-nut shell [ 56 ], cassava peel [ 57 ] and pinus bark [ 58 ]; likewise, it was observed that the adsorption kinetics is influenced by chemical modifications to the biomass [ 59 , 60 ], so the removal rates of biosorbents T2, T3 and T4 were higher than biosorbent T1.…”

Section: Resultsmentioning

confidence: 71%

Modified Polymeric Biosorbents from Rumex acetosella for the Removal of Heavy Metals in Wastewater

et al. 2022

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The contamination of water resources by effluents from various industries often contains heavy metals, which cause irreversible damage to the environment and health. The objective was to evaluate different biosorbents from the weed Rumex acetosella to remove metal cations in wastewater. Drying, grinding and sieving of the stems was carried out to obtain the biomass, retaining the fractions of 250 to 500 µm and 500 to 750 µm, which served to obtain the biosorbents in natura (unmodified), acidic, alkaline, and mixed. Proximal analysis, PZC, TOC, removal capacity, influence of pH, functional groups, thermal analysis, structural characteristics, adsorption isotherms, and kinetic study were evaluated. The 250 µm mixed treatment was the one that presented the highest removal percentages, mainly due to the OH, NH, -C-H, COOH, and C-O functional groups achieving the removal of up to 96.14% of lead, 36.30% of zinc, 34.10% of cadmium and 32.50% of arsenic. For contact times of 120 min and an optimum pH of 5.0, a loss of cellulose mass of 59% at 328 °C and a change in the surface of the material were also observed, which allowed for obtaining a topography with greater chelating capacity, and the Langmuir and pseudo-second order models were better fitted to the adsorption data. The new biosorbents could be used in wastewater treatment economically and efficiently.

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Section: Resultsmentioning

confidence: 71%

Modified Polymeric Biosorbents from Rumex acetosella for the Removal of Heavy Metals in Wastewater

et al. 2022

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“…From the parameters in Table 2 , it can be said that the Freundlich model best fits the experimental adsorption equilibrium data of As(III) on Ag@PDMAEMA-g-PET and PDMAEMA-g-PET TeMs, indicating that the adsorption process occurs in the form of multilayers with different adsorption energies and non-uniform heat distribution, due to the heterogeneity of the active centers of the adsorbents. The ions first occupied active adsorption sites that present strong interactions, thereby decreasing the interactions [ 93 ]. The

value was higher when As(III) adsorption took place on Ag@PDMAEMA-g-PET, indicating a higher selectivity than DMAEMA-g-PET.…”

Section: Resultsmentioning

confidence: 99%

Hybrid PET Track-Etched Membranes Grafted by Well-Defined Poly(2-(dimethylamino)ethyl methacrylate) Brushes and Loaded with Silver Nanoparticles for the Removal of As(III)

et al. 2022

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Nanoporous track-etched membranes (TeM) are promising materials as adsorbents to remove toxic pollutants, but control over the pore diameter and density in addition to precise functionalization of nanochannels is crucial for controlling the surface area and efficiency of TeMs. This study reported the synthesis of functionalized PET TeMs as high-capacity sorbents for the removal of trivalent arsenic, As(III), which is more mobile and about 60 times more toxic than As(V). Nanochannels of PET-TeMs were functionalized by UV-initiated reversible addition fragmentation chain transfer (RAFT)-mediated grafting of 2-(dimethyamino)ethyl methacrylate (DMAEMA), allowing precise control of the degree of grafting and graft lengths within the nanochannels. Ag NPs were then loaded onto PDMAEMA-g-PET to provide a hybrid sorbent for As(III) removal. The As(III) removal efficiency of Ag@PDMAEMA-g-PET, PDMAEMA-g-PET, and pristine PET TeM was compared by adsorption kinetics studies at various pH and sorption times. The adsorption of As(III) by Ag@DMAEMA-g-PET and DMAEMA-g-PET TeMs was found to follow the Freundlich mechanism and a pseudo-second-order kinetic model. After 10 h, As(III) removal efficiencies were 85.6% and 56% for Ag@PDMAEMA-g-PET and PDMAEMA-g-PET, respectively, while PET template had a very low arsenic sorption capacity of 17.5% at optimal pH of 4.0, indicating that both PDMAEMA grafting and Ag-NPs loading significantly increased the As(III) removal capacity of PET-TeMs.

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“…Equilibrium adsorption isotherm study is an important factor that optimizes the application of adsorbents by describing the interactions between the adsorbate and the adsorbent. The isotherm studies are carried out through the ratio of the absorbed quantity to the concentration of adsorption equilibrium or pressure at a constant temperature [18]. The isotherm studies evaluate the relationship between the amount and concentration of a substance removed from a liquid phase per unit mass of adsorbent at a constant temperature.…”

Section: Equilibrium Isotherm Modelingmentioning

confidence: 99%

“…The highest bleaching efficiency observed was 83.2% at 50 minutes using 3 g of AAMC. It was observed that increasing the dosage of activated clay to 7 g using the same quantity of crude palm oil reduced the equilibrium concentration in the medium thereby reducing the adsorption capacity [18]. [6] observed a decrease in the absorbance of the bleached oils following the increase in the adsorbent dosage of acid-activated Kangole clay by up to 4%.…”

Section: Effect Of Adsorbent Dosage On the Bleaching Efficiencymentioning

confidence: 99%

“…The equilibrium rate constant of the pseudo-second order model, K 2 (g/mg min) obtained at 50, 70, 90 and 100 oC were 0.0699, 0.0389, 0.0311 and 0.1233 respectively. The Pseudo-second order model gave high regression coefficients which was an indication that chemisorption was the rate-controlling step in the adsorption process [18,31]. Chemical adsorption or chemisorption is the process where there are chemical forces of attraction due to the pressure of the appeal current between the adsorbent and adsorbate during the formation of a layer of adsorbate on the adsorbent [1].…”

Section: Adsorption Kineticsmentioning

confidence: 99%

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Kinetic and Thermodynamic Studies of Crude Palm Oil Bleaching Using Amansea Clay

Nkeiruka

Elijah

Ositadimma

2023

AJACR

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The effectiveness of the bleaching of crude palm oil was carried out using alkaline-activated Amansea clay. The clay sample was sun-dried, ground, sieved and activated with sodium hydroxide (NaOH) and Potassium hydroxide (KOH). The raw and alkaline-activated clay (AAMC) samples were characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray fluorescence (XRF) analyses. The dosage, temperature and contact time of the process were varied to observe the efficiency of the bleaching process. The results of the characterization indicated that the raw and activated clays were kaolinite and the clay changed significantly after activation. The bleaching efficiency improved with an increase in temperature and an increase in the mass of the adsorbent. The highest bleaching efficiency of 83.2% was obtained. The pseudo-second-order model best described the adsorption process at 100 oC. The Temkin isotherm model best fitted the experimental data when compared to the other isotherm models because it gave the highest R2 values of >0.9 at all temperatures. The thermodynamics studies carried out from the experimental data indicated that the process was endothermic with an increase in randomness at the solid/liquid interface. The values of the enthalpy and entropy were evaluated as 6.193 KJ/mol and 173.50 J/mol respectively. The adsorption of crude palm oil became spontaneous at 363 and 373 K due to the negative values of Gibb’s free energy obtained at those temperatures. The experimental result indicates that 83.2% bleaching efficiency can be from bleaching crude palm oil with alkaline-activated Amansea clay.

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Kinetics and Adsorption Equilibrium in the Removal of Azo-Anionic Dyes by Modified Cellulose

Cited by 52 publications

References 56 publications

Modified Polymeric Biosorbents from Rumex acetosella for the Removal of Heavy Metals in Wastewater

Modified Polymeric Biosorbents from Rumex acetosella for the Removal of Heavy Metals in Wastewater

Hybrid PET Track-Etched Membranes Grafted by Well-Defined Poly(2-(dimethylamino)ethyl methacrylate) Brushes and Loaded with Silver Nanoparticles for the Removal of As(III)

Kinetic and Thermodynamic Studies of Crude Palm Oil Bleaching Using Amansea Clay

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