scholarly journals Functionalized coconut husks for rhodamine-B dye sequestration

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Olugbenga Solomon Bello ◽  
Kayode Adesina Adegoke ◽  
Samuel Oluwaseun Fagbenro ◽  
Olasunkanmi Seun Lameed
Keyword(s):  
Rhodamine B ◽  
Dye Removal ◽  
Dye Adsorption ◽  
Isotherm Models ◽  
Acid Activation ◽  
Order Kinetic ◽  
Operational Parameters ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract This study investigates the efficacy of acid activated coconut husk (CHA) for the removal of rhodamine-B (Rh-B) dye from aqueous solutions. The CHA prepared was characterized using various techniques: SEM, FTIR EDX, Boehm titration and pHpzc, respectively. The effects of different operational parameters including initial concentration, contact time and solution temperatures were examined. Kinetic data for Rh-B dye adsorption onto CHA fitted best to pseudo-second-order kinetic model considering the correlation regression (R2) and the sum of squares of error values. Adsorption data were fitted to Langmuir, Freundlich, Dubinin–Radushkevich and Temkin isotherm models. Langmuir isotherm was the most fitted among all the models used with maximum monolayer sorption capacity of 1666.67 mg g−1 and the highest regression value of 0.99 indicating that CHA has greater affinity for Rh-B dye adsorption due to increased pore development via acid activation. Thermodynamic studies revealed an endothermic adsorption process with the ΔH0 value of 62.77 kJ mol−1. Spontaneity was ascertained based on the negative values of ΔGo (ranging from − 26.38 kJ mol−1 to − 20.93 kJ mol−1). The positive value of ΔS0 (0.276 kJ mol−1 K−1) suggests increased randomness that exists between CHA and Rh-B dye. Cost analysis results revealed that CHA is six times cheaper than commercial activated carbon (CAC), providing a savings of 217 US$ kg−1. CHA adsorbent was found to be suitable for Rh-B dye removal from aqueous solution.

scholarly journals Removal of Rhodamine B from aqueous solution by ZnFe2O4 nanocomposite with magnetic separation performance

2017 ◽  
Vol 19 (4) ◽  
pp. 65-74 ◽  
Author(s):  
Wojciech Konicki ◽  
Daniel Siber ◽  
Urszula Narkiewicz
Keyword(s):  
Aqueous Solution ◽  
Kinetic Model ◽  
Adsorption Capacity ◽  
Rhodamine B ◽  
Second Order ◽  
Isotherm Models ◽  
Separation Performance ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Magnetic ZnFe2O4 nanocomposite (ZnFe-NC) was used as an adsorbent for the removal of Rhodamine B (RB) from aqueous solution. The synthesized nanocomposite was characterized by XRD, SEM, HRTEM, BET and FTIR. The effects of various parameters such as initial RB concentration (5–25 mg L−1), pH (3.4–11.1) and temperature (20–60°C) were investigated. The adsorption capacity at equilibrium increased from 5.02 to 9.83 mg g−1, with the increase in the initial concentration of RB from 5 to 25 mg L−1 at pH 7.0 and at 20°C. The experimental results indicated that the maximum RB removal could be attained at a solution pH of 4.4 and the adsorption capacity obtained was 6.02 mg g−1. Kinetic adsorption data were analyzed using the pseudo-first-order kinetic model, the pseudo-second-order model and the intraparticle diffusion model. The adsorption kinetics well fitted using a pseudo-second-order kinetic model. The experimental isotherm data were analyzed using two isotherm models, namely, Langmuir and Freundlich. The results revealed that the adsorption behavior of the RB onto ZnFe-NC fitted well with the Langmuir isotherm model. In addition, various thermodynamic parameters, such as standard Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) have been calculated.

scholarly journals Equilibrium and Isotherm Modeling of Toxic dye Adsorption onto Modified Apricot Stone

2018 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Dye Adsorption ◽  
Acid Activation ◽  
Order Kinetic ◽  
Bet Analysis ◽  
Effects Of Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

In the present study, adsorption of toxic dye Diret red 28 (acid benzidinediazo-bis-1- naphtylamine - 4- sulfonique) from aqueous solution was investigated using activated carbon synthesized with Phosphoric Acid activation. The synthesized adsorbent was analyzed using BET, FT-IR and SEM techniques. The BET analysis showed that the area provided by the synthesized activated carbon was 88.01 m2 g-1. The adsorption isotherms of Toxic dye onto ASAC are determined and correlated with common isotherms equations. The smaller RMSE values obtained for the Langmuir and Dubinin-R models indicate the better curves fitting, the monolayer adsorption capacity of toxic dye is found to be 32.85 mg.g-1 at temperature 25 o C and 23.42 mg.g-1 at temperature 65 o C at pH 13. The adsorption of toxic dye was carried out using a batch system and the effects of pH, contact time, adsorbent dosage, initial concentration and temperature on the adsorption capacity of synthesized adsorbent were investigated. Kinetics studies proved that for both metals, the kinetic data follows the pseudo second order kinetic model. In addition, the thermodynamics studies proved that the adsorption process of toxic dye could be considered spontaneous and endothermic.

scholarly journals Comparative Biosorption Studies of Hexavalent Chromium Ion onto Raw and Modified Palm Branches

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Mona A. Shouman ◽  
Nady A. Fathy ◽  
Soheir A. Khedr ◽  
Amina A. Attia
Keyword(s):  
Adsorption Process ◽  
Isotherm Models ◽  
Ammonium Bromide ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Chemically Modified ◽  
Chromium Vi ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The waste of palm branches (PB) was tested for its ability to remove chromium (VI) from aqueous solution by batch and column experiments. Palm branches chemically modified with an oxidizing agent (sulphuric acid) then coated with chitosan and surfactant (hexadecyl trimethyl ammonium bromide surfactant, HDTMA), respectively, were carried out to improve the removal performance of PB. The results of their Cr (VI) removal performances are pH dependent. The adsorption data could be well interpreted by the Langmuir, Freundlich, and Flory-Huggins isotherm models. The maximum adsorption capacity obtained from the Langmuir model for the chitosan coated oxidized palm branches is 55 mg/mg. The adsorption process could be described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that film diffusion might be involved. The biosorbents were successfully regenerated using 1 M HCL solution.

scholarly journals Synergistic modification of bentonite by acid activation and hydroxyl iron pillaring for enhanced dye adsorption capacity

2020 ◽  
Vol 81 (7) ◽  
pp. 1518-1529
Author(s):  
Huan Xi ◽  
Qingqing Li ◽  
Yan Yang ◽  
Jianfeng Zhang ◽  
Feng Guo ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Dye Adsorption ◽  
Interlayer Spacing ◽  
Acid Activation ◽  
Order Kinetic ◽  
Environmental Friendliness ◽  
Dye Pollutants ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract Despite the fact of natural abundance, low cost and environmental friendliness, the far-from-sufficient adsorption capacity of natural bentonite (BT) has limited such a promising application to remove dye pollutants. In this paper, we proposed a facile modification strategy to enhance adsorption performance of bentonite utilizing synergistic acid activation and hydroxyl iron pillaring, by which the adsorbent (abbreviated as S-Fe-BT) exhibited the highest adsorption capacity (246.06 mg/g) and a high rapid adsorption rate for a typical organic dye, Rhodamine B (RhB). This could be ascribed to the increased interlayer spacing, the increased specific surface area, and the optimized OH/Fe ratio after the synthetic modification of the pristine BT. The adsorption behavior of RhB onto S-Fe-BT was well described by the pseudo-second-order kinetic model, indicating a chemical-adsorption-controlled process. Furthermore, its adsorption isotherm matched well with the Langmuir model due to a monolayer adsorption process. This paper opens a promising direction to remove the dye pollution using low cost bentonite adsorbents treated by such a convenient modification strategy.

Adsorption Characteristics of Phenol in Aqueous Solution by Pinus massoniana Biochar

2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Pinus Massoniana ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Salt Ions ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The objective of this paper is to investigate the feasibility of phenol adsorption from aqueous solution by Pinus massoniana biochar. Adsorption conditions, including contact time, initial phenol concentration, adsorbent dosage, strength of salt ions and pH, have been investigated by batch experiments. Equilibrium can be reached in 24 h for phenol from 50 to 250 mg• L-1. The optimum pH value for this kind of biochar is 5.0. The amount of phenol adsorbed per unit decreases with the increase in adsorbent dosage. The existence of salt ions makes negligible influence on the equilibrium adsorption capacity. The experimental data is analyzed by the Freundlich and Langmuir isotherm models. Equilibrium data fits well to the Freundlich model. Adsorption kinetics models are deduced and the pseudo-second-order kinetic model provides a good correlation for the adsorbent process. The results show that the Pinus massoniana biochar can be utilized as an effective adsorption material for the removal of phenol from aqueous solution.

REMOVAL OF STRONTIUM (II) FROM AQUEOUS SOLUTION USING FUNCTIONALIZED CARBON NANOTUBES

2012 ◽  
Vol 11 (02) ◽  
pp. 1250019 ◽  
Author(s):  
RAJESH KUMAR ◽  
S. K. JAIN
Keyword(s):  
Carbon Nanotubes ◽  
Polluted Water ◽  
Order Kinetic ◽  
Environmental Application ◽  
Functionalized Carbon Nanotubes ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

This study was carried out to evaluate the environmental application of functionalized carbon nanotubes through the experimental removal of strontium (II) from water. The aim was to find the optimal condition for the removal of strontium from water under different conditions such as initial concentration of strontium, contact time and neutral pH. The functionalized multi wall carbon nanotubes (f-MWCNT) were characterized by FT-IR and scanning electron microscopy (SEM). The adsorption isotherms were correlated to Freundlich and Langmuir models and it was found that the adsorption data could be fitted better by Langmuir model than Freundlich one. The kinetic data shows that the adsorption describes well with the pseudo-second order kinetic model. Functionalized MWCNT can be used as good adsorbent for the removal of the strontium ions from polluted water according to results.

scholarly journals Study on the adsorption of methylene blue from aqueous solution using hydrogel glucomannan/graphene oxide

2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.

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

SAINTIFIK ◽  
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.

scholarly journals The Presence of Cu Facilitates Adsorption of Tetracycline (TC) onto Water Hyacinth Roots

2018 ◽  
Vol 15 (9) ◽  
pp. 1982 ◽  
Author(s):  
Xin Lu ◽  
Beibei Tang ◽  
Qi Zhang ◽  
Lizhu Liu ◽  
Ruqin Fan ◽  
...  
Keyword(s):  
Water Hyacinth ◽  
Freundlich Isotherm ◽  
Root Surface ◽  
Interactive Effects ◽  
Order Kinetic ◽  
Batch Experiments ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ph Range

Batch experiments were conducted to investigate the adsorption characteristics of tetracycline (TC), and the interactive effects of copper (Cu) on the adsorption of TC onto water hyacinth roots. TC removal efficiency by water hyacinth roots was ranging from 58.9% to 84.6%, for virgin TC, 1:1 TC-Cu and 1:2 TC-Cu. The Freundlich isotherm model and the pseudo-second-order kinetic model fitted the adsorption data well. Thermodynamics parameters ΔG0 for TC were more negative in the TC plus Cu than the TC-only treatments, indicating the spontaneity of TC adsorption increased with increasing of Cu concentrations. An elevated temperature was associated with increasing adsorption of TC by water hyacinth roots. The additions of Cu(II) significantly increased TC adsorption onto water hyacinth roots within the pH range 4 to 6, because copper formed a strong metal bridge between root surface and TC molecule, facilitating the adsorption of TC by roots. However, Cu(II) hindered TC adsorption onto water hyacinth roots on the whole at pH range from 6–10, since the stronger electrostatic repulsion and formation of CuOH+ and Cu(OH)2. Therefore, the interaction between Cu(II) and TC under different environmental conditions should be taken into account to understand the environmental behavior, fate, and ecotoxicity of TC.

scholarly journals Modified Spruce Sawdust for Sorption of Hexavalent Chromium in Batch Systems and Fixed-Bed Columns

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5156
Author(s):  
Dororthea Politi ◽  
Dimitrios Sidiras
Keyword(s):  
Sulfuric Acid ◽  
Adsorption Capacity ◽  
Hexavalent Chromium ◽  
Diethylene Glycol ◽  
Fixed Bed ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order

This study investigated the potential use of spruce sawdust that was pretreated with diethylene glycol and sulfuric acid for the removal of hexavalent chromium from wastewater. The sawdust pretreatment process was conducted at different temperatures and times. The adsorbent was characterized by quantitative saccharification, scanning electron microscopy, and Brunauer–Emmet–Teller surface area analysis. Adsorption capacity was studied for both batch and column processes. The experimental adsorption isotherms were simulated using seven isotherm models, including Freundlich and Langmuir models. By using the Langmuir isotherm model, the maximal Cr(VI) adsorption capacity of organosolv-pretreated spruce sawdust (qm) was 318.3 mg g−1. Furthermore, the kinetic data were fitted to Lagergren, pseudo-second-order, and intraparticle diffusion models, revealing that the adsorption of Cr(VI) onto spruce sawdust pretreated with diethylene glycol and sulfuric acid is best represented by the pseudo-second-order kinetic model. Three kinetic models, namely, the Bohart–Adams model, Thomas model, and modified dose–response (MDR) model, were used to fit the experimental data obtained from the column experiments and to resolve the characteristic parameters. The Thomas adsorption column capacity of the sawdust was increased from 2.44 to 31.1 mg g−1 upon pretreatment, thus, demonstrating that organosolv treatment enhances the adsorption capability of the material.

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