Exfoliated Clay Decorated with Magnetic Iron Nanoparticles for Crystal Violet Adsorption: Modeling and Physicochemical Interpretation

Surfactant–modified exfoliated Fayum clay (CTAB–EC) obtained after chemical treatment with a CTAB/H2O2 solution was further decorated with magnetic Fe3O4 nanoparticles (MNP). The final nanocomposite (MNP/CTAB–EC) was characterized by XRD, SEM, FTIR, TEM and its adsorptive capability against a model cationic dye, crystal violet (CV), was evaluated. A comparison of the adsorption performance of the raw clay and its modified counterparts using H2O2, CTAB, CTAB/H2O2 or MNP indicated that the adsorption capacity of MNP/CTAB–EC was the highest for CV removal at pH 8.0. The pseudo‒second order for the kinetics and Freundlich model for adsorption equilibrium fitted well the CV removal experimental data at all tested temperatures (25, 40 and 55 °C). The enhancement of the Langmuir adsorption capacity from 447.1 to 499.4 mg g−1 with increasing the temperature from 25 to 55 °C revealed an endothermic nature of the removal process. The interactions between CV and MNP/CTAB–EC were interpreted using advanced statistical physics models (ASPM) in order to elucidate the adsorption mechanism. Multilayer model fitted the adsorption process and therefore, the steric and energetic factors that impacted the CV adsorption were also interpreted using this model. The aggregated number of CV molecules per MNP/CTAB–EC active site ( n ) was more than unity at all temperatures, representing thus a vertical adsorption orientation and a multi‒interactions mechanism. It was determined that the increase of CV uptake with temperature was mainly controlled by the increase of the number of active sites (NM). Calculated adsorption energies (ΔE) revealed that CV removal was an endothermic and a physisorption process (ΔE < 40 kJ mol −1). MNP/CTAB–EC was magnetically separated, regenerated by NaOH, and reused without significant decrease in its adsorption efficiency, supporting a prosperity of its utilization as an effective adsorbent against hazardous dyes from wastewaters.

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Adsorptive removal of Ni2+ and Cd2+ from wastewater using a green longan hull adsorbent

Adsorption Science & Technology ◽

10.1177/0263617417722254 ◽

2017 ◽

Vol 36 (1-2) ◽

pp. 762-773 ◽

Cited By ~ 4

Author(s):

Xingmei Guo ◽

Sihan Tang ◽

Yan Song ◽

Junmin Nan

Keyword(s):

Metal Ions ◽

Adsorption Capacity ◽

Adsorption Mechanism ◽

Maximum Adsorption Capacity ◽

Adsorptive Removal ◽

Langmuir Adsorption ◽

Monolayer Adsorption ◽

Pseudo Second Order ◽

Adsorptive Mechanism ◽

Optimized Conditions

The adsorptive removal of Ni2+ and Cd2+ at concentrations of approximately 50 mg L−1 in wastewater is investigated using an agricultural adsorbent, longan hull, and the adsorptive mechanism is characterized. The maximum adsorption capacity of approximately 4.19 mg g−1 Cd2+ was obtained under the optimized conditions of room temperature, pH 5.0, and a solid-to-liquid ratio of 1:30 in approximately 15 min. For Ni2+, the maximum adsorption capacity of approximately 3.96 mg g−1 was obtained at pH 4.7 in approximately 20 min. The adsorption kinetics for both metal ions on the longan hull can be described by a pseudo second-order rate model and are well fitted to the Langmuir adsorption isotherm. The adsorption mechanism of the longan hull to Ni2+ and Cd2+ ions is shown to be a monolayer adsorption of metal ions onto the absorbent surface. Thereinto, the longan hull adsorbent contains N–H, C–H, C=O, and C=C functional groups that can form ligands when loaded with Ni2+ and Cd2+, which reduces the fluorescence of the dried longan hull material.

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Karekterisasi, Kinetika, dan Isoterm Adsorpsi Limbah Ampas Kelapa sebagai Adsorben Ion Cu(II)

SAINTIFIK ◽

10.31605/saintifik.v6i2.265 ◽

2020 ◽

Vol 6 (2) ◽

pp. 104-115

Author(s):

Agusriyadin Agusriyadin

Keyword(s):

Adsorption Capacity ◽

Ph Effect ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Optimum Conditions ◽

Langmuir Adsorption ◽

Adsorbent Surface ◽

Adsorption Data ◽

Order Kinetic Model ◽

Pseudo Second Order

Penelitian ini bertujuan untuk menguji kemampuan AK dan AKPM dalam mengadsorpsi ion Cu (II), pengaruh parameter adsorpsi dan mekanisme adsorpsi. AK dan AKP Madsorben dibuat dari residu ampas kelapa. Adsorben dikarakterisasi dengan FTIR, SEM dan EDS. Pengaruh parameter adsorpsi seperti pH awal, dosis adsorben, waktu kontak dan konsentrasi ion Cu (II) awal diperiksa untuk menentukan kondisi optimum serapan tembaga (II). Ion Cu (II) yang teradsorpsi diukur berdasarkan pada konsentrasi Ion Cu (II) sebelum dan sesudah adsorpsi menggunakan metode AAS. Hasil karakterisasi menunjukkan bahwa struktur pori dan gugus fungsi tersedia pada permukaan adsorben. Menurut percobaan efek pH, kapasitas adsorpsi maksimum dicapai pada pH 7. Waktu kontak optimal dan konsentrasi tembaga awal (II) ditemukan masing-masing pada 120 menit dan 100 mg L-1. Data eksperimental sesuai dengan model kinetik orde dua orde dua, dan Langmuir isoterm adsorpsi yang diperoleh paling sesuai dengan data adsorpsi. Kapasitas adsorpsi maksimum adsorben ditemukan menjadi 4,73 dan 6,46 mg g-1 pada kondisi optimal. The results of characterization showed that the pore structure and the functional groups were available on adsorbent surface. According to the pH effect experiments, the maximum adsorption capacity was achieved at pH 7. Optimum contact time and initial copper(II) concentration were found at 120 min and 100 mg L-1, respectively. The experimental data were comply with the pseudo-second-order kinetic model, and Langmuir adsorption isotherm obtained best fitted the adsorption data. The maximum adsorption capacity of the adsorbents was found to be 4.73 and 6.46 mg g-1 at optimum conditions.

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Selective Removal of Hg2+ Ions from Water Using New Functionalized Silica Resin: Equilibrium, Thermodynamics and Kinetic Modeling Studies

Journal of the chemical society of pakistan ◽

10.52568/000588 ◽

2021 ◽

Vol 43 (4) ◽

pp. 436-436

Author(s):

Nida Shams Jalbani Nida Shams Jalbani ◽

Amber R Solangi Amber R Solangi ◽

Shahabuddin Memon Shahabuddin Memon ◽

Ranjhan Junejo Ranjhan Junejo ◽

Asif Ali Bhatti Asif Ali Bhatti

Keyword(s):

Adsorption Capacity ◽

Adsorption Mechanism ◽

Solid Phase ◽

Maximum Adsorption Capacity ◽

Adsorption Phenomenon ◽

Column Adsorption ◽

Pseudo Second Order ◽

Ft Ir ◽

Wastewater Samples ◽

Ft Ir Spectroscopy

In current study, the diphenylaminomethylcalix[4]arene (3) was synthesized and immobilized onto silica surface to prepare a selective, regenerable and stable resin-4. The synthesized resin-4 has been characterized by FT-IR spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and Brunauer-Emmett-Teller (BET) techniques. To check the adsorption capacity of resin-4, the batch and column adsorption methodology were applied and it has observed that the resin-4 was selectively removed Hg2+ ions under the optimized parameters. The maximum adsorption capacity was obtained at pH 9 using 25 mg/L of resin-4. Under the optimal conditions, different equilibrium, kinetic and thermodynamic models were applied to experimental data. The results show that adsorption mechanism is chemical in nature following Langmuir model with good correlation coefficient (R2=0.999) and having 712.098 (mmol/g) adsorption capacity. The energy of calculated from D-R model suggests the ion exchange nature of the adsorption phenomenon. Dynamic adsorption experiments were conducted using Thomas model. The maximum solid phase concentration (qo) was 7.5 and rate constant was found to be 0.176 with (R2=0.938) for Hg2+ ions. The kinetic study describes that the adsorption mechanism follows pseudo second order (R2=0.999). The thermodynamic parameters such as ∆H (0.032 KJ/mol) and ∆S (0.127 KJ/mol /K) and ∆G (-5.747,-6.306, -7.027 KJ/mol) shows that the adsorption of Hg2+ ion is endothermic and spontaneous. The reusability of resin-4 was also checked and it has observed that the after 15 cycle only 1.2 % adsorption reduces. Moreover, the resin-4 was applied on real wastewater samples obtained from local industrial zone of Karachi, Sindh-Pakistan.

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Sodium hydroxide modified rice husk for enhanced removal of copper ions

Water Science & Technology ◽

10.2166/wst.2018.395 ◽

2018 ◽

Vol 78 (7) ◽

pp. 1615-1623 ◽

Cited By ~ 1

Author(s):

N. Priyantha ◽

H. K. W. Sandamali ◽

T. P. K. Kulasooriya

Keyword(s):

Heavy Metal ◽

Adsorption Capacity ◽

Rice Husk ◽

Copper Ions ◽

Maximum Adsorption Capacity ◽

Adsorption Model ◽

Natural Form ◽

Langmuir Adsorption ◽

Pseudo Second Order ◽

Heavy Metal Adsorbent

Abstract Although rice husk (RH) is a readily available, natural, heavy metal adsorbent, adsorption capacity in its natural form is insufficient for certain heavy metal ions. In this context, the study is based on enhancement of the adsorption capacity of RH for Cu(II). NaOH modified rice husk (SRH) shows higher extent of removal for Cu(II) ions than that of heated rice husk (HRH) and HNO3 modified rice husk (NRH). The extent of removal of SRH is increased with the concentration of NaOH, and the optimum NaOH concentration is 0.2 mol dm−3, used to modify rice husk for further studies. The surface area of SRH is 215 m2 g−1, which is twice as much as that of HRH according to previous studies. The sorption of Cu(II) on SRH obeys the Langmuir adsorption model, leading to the maximum adsorption capacity of 1.19 × 104 mg kg−1. Kinetics studies show that the interaction of Cu(II) with SRH obeys pseudo second order kinetics. The X-ray fluorescence spectroscopy confirms the adsorption of Cu(II) on SRH, while desorption studies confirm that Cu(II) adsorbed on SRH does not leach it back to water under normal conditions.

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Chitosan Grafted with Biobased 5-Hydroxymethyl-Furfural as Adsorbent for Copper and Cadmium Ions Removal

Polymers ◽

10.3390/polym12051173 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1173 ◽

Cited By ~ 1

Author(s):

Mariza Mone ◽

Dimitra A. Lambropoulou ◽

Dimitrios N. Bikiaris ◽

George Kyzas

Keyword(s):

Adsorption Capacity ◽

Significant Loss ◽

X Ray Diffraction ◽

Freundlich Model ◽

Hydroxymethyl Furfural ◽

Before And After ◽

Equilibrium Data ◽

Best Fitting ◽

Pseudo Second Order ◽

Grafting From

This work investigates the application of 5-hydroxymethyl-furfural (HMF) as a grafting agent to chitosan (CS). The material produced was further modified by cross-linking. Three different derivatives were tested with molecular ratios CS/HMF of 1:1 (CS-HMF1), 2:1 (CS-HMF2) and 10:1 mol/mol (CS-HMF3)) to remove Cu2+ and Cd2+ from aqueous solutions. CS-HMF derivatives were characterized both before, and after, metal ions adsorption by using scanning electron microscopy (SEM), as well as Fourier-transform infrared (FTIR) spectroscopy thermogravimetric analysis (TGA), and X-Ray diffraction analysis (XRD). The CS-HMF derivatives were tested at pH = 5 and showed higher adsorption capacity with the increase of temperature. Also, the equilibrium data were fitted to Langmuir (best fitting) and Freundlich model, while the kinetic data to pseudo-first (best fitting) and pseudo-second order equations. The Langmuir model fitted better (higher R2) the equilibrium data than the Freundlich equation. By increasing the HMF grafting from 130% (CS-HMF1) to 310% (CS-HMF3), an increase of 24% (26 m/g) was observed for Cu2+ adsorption and 19% (20 mg/g) for Cd2+. By increasing from T = 25 to 65 °C, an increase of the adsorption capacity (metal uptake) was observed. Ten reuse cycles were successfully carried out without significant loss of adsorption ability. The reuse potential was higher of Cd2+, but more stable desorption reuse ability during all cycles for Cu2+.

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Crystal Violet Dye Adsorption from Aqueous Solution using Activated Chickpea Husk (Cicer arientum)

Asian Journal of Chemistry ◽

10.14233/ajchem.2022.23444 ◽

2021 ◽

Vol 34 (1) ◽

pp. 104-110

Author(s):

Sonia Rani ◽

Sudesh Chaudhary

Keyword(s):

Crystal Violet ◽

Adsorption Mechanism ◽

Dye Adsorption ◽

Second Order ◽

Order Model ◽

Batch Mode ◽

After Effects ◽

Crystal Violet Dye ◽

Pseudo Second Order ◽

Second Order Model

The chickpea husk (Cicer arientum) were activated by chemical modification with sulphuric acid, for its application as biosorbent for the remediation of crystal violet dye from wastewater. Activated chickpea husk (ACH) was characterized for its chemical structure and morphology using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The after effects of leading affecting parameters like dose of adsorbent, time of contact, pH and concentration were studied by commencing experiments in batch mode. Adsorption mechanism and sorption efficiency of ACH was examined using variety of isotherms (Langmuir & Freundlich) and kinetic models (pseudo first order and pseudo second order). Experimental data for adsorption rate was in good harmony with the results obtained using pseudo second order model. The adsorption capacity determined using Langmuir isotherm and pseudo second order model was found to be 142.85 mg/g.

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Nascent Rice Husk as an Adsorbent for Removing Cationic Dyes from Textile Wastewater

Applied Sciences ◽

10.3390/app10103437 ◽

2020 ◽

Vol 10 (10) ◽

pp. 3437

Author(s):

Jude Ofei Quansah ◽

Thandar Hlaing ◽

Fritz Ndumbe Lyonga ◽

Phyo Phyo Kyi ◽

Seung-Hee Hong ◽

...

Keyword(s):

Adsorption Capacity ◽

Rice Husk ◽

Textile Wastewater ◽

Cationic Dyes ◽

Adsorption Model ◽

Order Model ◽

Solution Ph ◽

Freundlich Model ◽

Langmuir Isotherm Model ◽

Pseudo Second Order

We assessed the applicability of rice husk (RH) to remove cationic dyes, i.e., methylene blue (MB) and crystal violet (CV), from water. RH thermally treated at 75 °C showed a higher adsorption capacity than that at high temperatures (300–700 °C). For a suitable CV-adsorption model, a pseudo-first-order model for MB adsorption was followed by the kinetics adsorption process; however, a pseudo-second-order model was then suggested. In the qt versus t1/2 plot, the MB line passed through the origin, but that of CV did not. The Langmuir isotherm model was better than the Freundlich model for both dye adsorptions; furthermore, the adsorption capacity for MB and CV was 24.48 mg/g and 25.46 mg/g, respectively. Thermodynamically, the adsorption of both MB and CV onto the RH was found to be spontaneous and endothermic. This adsorption increased insignificantly on increasing the solution pH from 4 to 10. With an increasing dosage of the RH, there was an increase in the removal percentages of MB and CV; however, adsorption capacity per unit mass of the RH was observed to decrease. Therefore, we conclude that utilizing RH as an available and affordable adsorbent is feasible to remove MB and CV from wastewater.

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Mass-transfer processes in the adsorption of crystal violet by activated carbon derived from pomegranate peels: Kinetics and thermodynamic studies

Journal of Engineered Fibers and Fabrics ◽

10.1177/1558925020919847 ◽

2020 ◽

Vol 15 ◽

pp. 155892502091984

Author(s):

Moussa Abbas ◽

Zahia Harrache ◽

Mohamed Trari

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Crystal Violet ◽

Agitation Speed ◽

Second Order ◽

Point Of Zero Charge ◽

Order Kinetic ◽

Solution Ph ◽

Pseudo Second Order ◽

Adsorbent Dose

This study investigates the potential use of activated carbon, prepared from pomegranate peels, as an adsorbent activated using H3PO4 and its ability to remove crystal violet from an aqueous solution. The adsorbent was characterized by the Brunauer–Emmett–Teller method (specific surface area: 51.0674 m2 g−1) and point of zero charge (pHPZC = 5.2). However, some examined factors were found to have significant impacts on the adsorption capacity of activated carbon derived from pomegranate peels such as the initial dye concentration (5–15 mg L−1), solution pH (2–14), adsorbent dose (1–8 g L−1), agitation speed (100–700 r/min), and temperature (298–338 K). The best adsorption capacity was found at pH 11 with an adsorbent dose of 1 g L−1, an agitation speed at 400 r/min, and a contact time of 45 min. The adsorption mechanism of crystal violet onto activated carbon derived from pomegranate peels was studied using the pseudo-first-order, pseudo-second-order, Elovich, and Webber–Morris diffusion models. The adsorption kinetics were found to rather follow a pseudo-second order kinetic model with a determination coefficient ( R2) of 0.999. The equilibrium adsorption data for crystal violet adsorbed onto activated carbon derived from pomegranate peels were analyzed by the Langmuir, Freundlich, Elovich, and Temkin models. The results indicate that the Langmuir model provides the best correlation with qmax capacities of 23.26 and 76.92 mg g−1 at 27°C and 32°C, respectively. The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters like the free energy, enthalpy, and entropy to predict the nature of adsorption process. The negative values Δ G0 (−5.221 to −1.571 kJ mol−1) and Δ H0 (−86.141 kJ mol−1) indicate that the overall adsorption is spontaneous and exothermic with a physisorption process. The adsorbent derived from pomegranate peels was found to be very effective and suitable for the removal of reactive dyes from aqueous solutions, due to its availability, low-cost preparation, and good adsorption capacity.

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Modified xanthan gum for crystal violet uptake: kinetic, isotherm, and thermodynamic behaviors

Water Science & Technology ◽

10.2166/wst.2019.038 ◽

2019 ◽

Vol 79 (1) ◽

pp. 165-174 ◽

Cited By ~ 3

Author(s):

Meixia Zheng ◽

Fengli Lian ◽

Yujing Zhu ◽

Bo Liu ◽

Zheng Chen ◽

...

Keyword(s):

Crystal Violet ◽

Active Sites ◽

Xanthan Gum ◽

Maximum Adsorption Capacity ◽

Hydroxyl Groups ◽

X Ray Diffraction ◽

Uptake Kinetic ◽

Freundlich Isotherms ◽

Pseudo Second Order ◽

Kinetics Of

Abstract Modified xanthan gum (XG-AM-TTE) was employed as an adsorbent to study the adsorption behavior, thermodynamics and kinetics of crystal violet (CV) from an aqueous solution. Fourier transform infrared spectroscopy analysis indicates that the functional groups present in the adsorbent, such as carboxyl, ester and hydroxyl groups, are included on the external surface of the material, and these groups are potential active sites for interaction with CV. According to X-ray diffraction results, the structure of XG-AM-TTE after CV adsorption became more disordered, and the microstructure change is an indication of effective adsorption of CV to the surface, with CV becoming remarkably dispersed in the adsorbent according to the scanning electron microscopy observations. The adsorption kinetics and adsorption equilibrium were best described by the pseudo-second-order model and Freundlich isotherms, respectively. The thermodynamic parameters, as the Gibbs-free energy (ΔG), enthalpy (ΔH) and entropy (ΔS), indicated that the adsorption is a spontaneous, endothermic and entropy increase process. The maximum adsorption capacity of XG-AM-TTE was 183 ± 12 mg/g, suggesting that XG-AM-TTE is an efficient adsorbent.

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Development of Natural Cation Exchanger for the Treatment of Lead ions from Aqueous Solution

Journal of Nepal Chemical Society ◽

10.3126/jncs.v29i0.9235 ◽

2013 ◽

Vol 29 ◽

pp. 34-43

Author(s):

Puspa Lal Homagai

Keyword(s):

Adsorption Capacity ◽

Sugarcane Bagasse ◽

Active Sites ◽

Freundlich Isotherm ◽

Saccharum Officinarum ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Fast Kinetics ◽

Pseudo Second Order

Cellulose, hemicelluloses and lignin are the main constituents found in sugarcane (Saccharum officinarum) bagasse having many surface active sites containing hydroxyl and/or phenolic groups which are effective for chemical modification. The biowaste was first charred with concentrated sulphuric acid and then the charred aminated sugarcane bagasse (CASB) was prepared by reduction followed by oxidation. The developed bio-sorbent was characterized by SEM, TGA/DTA, FTIR and elemental analysis. Batch adsorption methods were carried out to determine Pb+2 sorption capacities at different pH ranges and sorbate concentrations. The maximum adsorption capacity for Pb+2 was found to be 323 mg g-1 with an efficiency of 98% at pH 4.The experimental data showed a good fit to Langmuir isotherm as compared to Freundlich isotherm models. The kinetics was best fitted with the pseudo-second order model. The adsorption equilibrium was attained within 20 min. The high adsorption capacity and fast kinetics results of the charred aminated sugarcane bagasse indicated that it might be potential adsorbent for the removal of lead from contaminated water. DOI: http://dx.doi.org/10.3126/jncs.v29i0.9235Journal of Nepal Chemical SocietyVol. 29, 2012Page: 34-43Uploaded date : 12/3/2013

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