scholarly journals Adsorptive Removal of Fe (II) By NaOH Treated Rice Husk: Adsorption Equilibrium And Kinetics

2021 ◽  
Vol 14 (14) ◽  
pp. 75-82
Author(s):  
Sunita Shrestha ◽  
Anita Kumari Dhami ◽  
Armila Rajbhandari Nyachhyon

The low cost adsorbents were prepared from raw rice husk (RRH) and NaOH treated rice husk (NRH). Then prepared materials were characterized by XRD, FTIR and surface area of rice husk adsorbent were determined by methylene blue adsorption method. XRD showed amorphous nature with low crystallinity of the material. The FTIR spectra showed the presence of oxygenated functional groups such as ester, phenol, carbonyl and silica on the material. The surface area of RRH and NRH were found to be 387 and 417 m2/g respectively. Thus, prepared adsorbents were used for the removal of Fe(II) ion from aqueous solution. The influence of various parameters like pH, adsorbent doge, and contact time were studied for the better adsorption of Fe(II) on rice husk adsorbents. Results revealed that the maximum efficiency was achieved at pH 3 for Fe(II). The adsorption process was found to be best fitted to Langmuir adsorption isotherm model controlled by pseudo-second–order kinetics with the rate constant value i.e. 0.0218 and 0.0235 g/(mg·min) for RRH and NRH respectively.  The χ2 values of pseudo second order was found to be lower which confirmed chemisorption, involving ion exchange and valence forces through sharing or exchange of electrons between adsorbent and adsorbate. The maximum adsorption capacity for Fe(II) on RRH and NRH was found to be 2.9 mg/g and 5.6 mg/g respectively. The positive ∆G value represents the randomness of the system during adsorption process. The slope of the linear plot of Qt vs t0.5 was linear but not passed through the origin, which indicates that, the intraparticle diffusion was not only rate controlling step. Temkin value showed the maximum binding energy (KT) for NRH was 16.4 L/g and for RRH it was 12.2 L/g. 

2021 ◽  
pp. 1-12
Author(s):  
Raafia Najam ◽  
Syed Muzaffar Ali Andrabi

Sawdust of willow has been investigated as an adsorbent for the removal of Ni(II), and Cd(II) ions from aqueous solution. Since willow tree is widely grown in almost all parts of Kashmir, it can be a common most easily available, sustainable, low cost adsorbent for the treatment of wastewaters in this part of the world where growing industrialization is affecting water quality like elsewhere in the world. Therefore, it is worthwhile to investigate the potential of sawdust of willow tree as an adsorbent for the removal of Ni(II) and Cd(II) ions from aqueous solution as a first step. Batch experiments were conducted to study the effect of some parameters such as contact time, initial concentration of metal ions, solution pH and temperature. Langmuir and Freundlich models were employed for the mechanistic analysis of experimental data obtained. Results reveal that in our system adsorption follows the Langmuir isotherm. The maximum adsorption capacity of Ni(II) and Cd(II) were found to be 7.98 and 7.11 mg/g respectively at optimum conditions. The pseudo-first-order and pseudo-second-order models were employed for kinetic analysis of adsorption process. The adsorption process follows pseudo-second-order kinetics. The efficacy of the adsorbent in the treatment of effluent from fertilizer factory has been investigated and the results have been found encouraging.


2017 ◽  
Vol 36 (1-2) ◽  
pp. 80-94 ◽  
Author(s):  
Nezam Mirzaei ◽  
Amir Hossein Mahvi ◽  
Hooshyar Hossini

This study deals with the application of Iranian zeolite as a low cost adsorbent for the removal of the Direct blue 71 (DB 71) from colored solution. Important parameters including equilibrium and contact time, initial dye concentration, effect of pH, and zeolite dosage were evaluated. Maximum dye removal was obtained at about 99.8% for 25 mg/L at 120 min of equilibrium. Higher adsorption efficiency of direct dye was obtained at higher dose and acidic pH. To analyze the adsorption equilibrium and kinetic, Langmuir, Freundlich, and Temkin isotherms as well as four kinetic models encompassing pseudo first-order, pseudo second-order, intraparticle diffusion, and Elovich were evaluated. The Langmuir isotherm ( R2 = 0.995) and pseudo second-order models, gave the best fit to equilibrium experimental data. In Langmuir analysis, the maximum adsorption capacity (qm) by 13.66 mg/g was determined. Finally, the characteristics of zeolite including both natural and modified, such as compositions, surface morphology by X-ray diffraction technique (XRD), X-ray fluorescence (XRF), and scanning electron microscopy (SEM) were obtained. According to XRF analysis, it was demonstrated that Al2O3 and SiO2 are the most part of natural and modified zeolite. Furthermore, the clinoptilolite was determined as the significant crystalloid phase by XRD pattern.


2018 ◽  
Vol 77 (5) ◽  
pp. 1313-1323 ◽  
Author(s):  
Jianjun Zhou ◽  
Xionghui Ji ◽  
Xiaohui Zhou ◽  
Jialin Ren ◽  
Yaochi Liu

Abstract A novel magnetic bio-adsorbent (MCIA) was developed, characterized and tested for its Cd(II) removal from aqueous solution. MCIA could be easily separated from the solution after equilibrium adsorption due to its super-paramagnetic property. The functional and magnetic bio-material was an attractive adsorbent for the removal of Cd(II) from aqueous solution owing to the abundant adsorption sites, amino-group and oxygen-containing groups on the surface of Cyclosorus interruptus. The experimental results indicated that the MCIA exhibited excellent adsorption ability and the adsorption process was spontaneous and endothermic. The adsorption isotherm was consistent with the Langmuir model. The adsorption kinetic fitted the pseudo-second-order model very well. The maximum adsorption capacity of Cd(II) onto MCIA was 40.8, 49.4, 54.6 and 56.6 mg/g at 293, 303, 313 and 323 K, respectively. And the MCIA exhibited an excellent reusability and impressive regeneration. Therefore, MCIA could serve as a sustainable, efficient and low-cost magnetic adsorbent for Cd(II) removal from aqueous solution.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joshua N. Edokpayi ◽  
Samson O. Alayande ◽  
Ahmed Adetoro ◽  
John O. Odiyo

In this study, the potential for pulverized raw macadamia nut shell (MNS) for the sequestration of methylene blue from aqueous media was assessed. The sorbent was characterized using scanning electron microscopy for surface morphology, functional group analysis was performed with a Fourier-transform infrared spectrometer (FT-IR), and Brunauer–Emmett–Teller (BET) isotherm was used for surface area elucidation. The effects of contact time, sorbent dosage, particle size, pH, and change in a solution matrix were studied. Equilibrium data were fitted using Temkin, Langmuir, and Freundlich adsorption isotherm models. The sorption kinetics was studied using the Lagergren pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The feasibility of the study was established from the thermodynamic studies. A surface area of 2.763 m2/g was obtained. The equilibrium and kinetics of sorption was best described by the Langmuir and the pseudo-second-order models, respectively. The sorption process was spontaneous (−ΔG0=28.72−31.77 kJ/mol) and endothermic in nature (ΔH0=17.45 kJ/mol). The positive value of ΔS0 (0.15 kJ/molK) implies increased randomness of the sorbate molecules at the surface of the sorbent. This study presents sustainable management of wastewater using MNS as a potential low-cost sorbent for dye decontamination from aqueous solution.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Ankur Gupta ◽  
Chandrajit Balomajumder

Fe modified rice husk was prepared as a low cost biosorbent for the removal of Cr(VI) and phenol both singly and in combination from single and binary simulated synthetic waste water. Rice husk was modified by treating with FeSO4·7H2O. The results showed that impregnation of iron onto the surface of rice husk improved the adsorption capability of both Cr(VI) and phenol. The effects of process parameters for multicomponent system such as pH, adsorbent dose, and contact time onto the percentage removal of both Cr(VI) and phenol were investigated. The experimental data for the adsorption of both Cr(VI) and phenol onto the surface of Fe modified rice husk applied to various kinetic and adsorption isotherm models. Multicomponent isotherm models such as Nonmodified Langmuir, Modified Langmuir, Extended Langmuir, Extended Freundlich, Competitive Nonmodified Redlich Peterson, Competitive Modified Redlich Peterson were applied. The results show that Extended Freundlich model best described the experimental data for both Cr(VI) and phenol from binary solution. Pseudo second-order model agreed well with Cr(VI) while pseudo first-order model agreed well with phenol. Maximum adsorption capacity in synthetic binary solution of Cr(VI) and phenol was found to be 36.3817 mg g−1for Cr(VI) and 6.569 mg g−1for phenol, respectively.


2012 ◽  
Vol 65 (8) ◽  
pp. 1341-1349 ◽  
Author(s):  
Shokooh Sadat Khaloo ◽  
Amir Hossein Matin ◽  
Sahar Sharifi ◽  
Masoumeh Fadaeinia ◽  
Narges Kazempour ◽  
...  

The application of almond shell as a low cost natural adsorbent to remove Hg2+ from aqueous solution was investigated. Batch experiments were carried out to evaluate the adsorption capacity of the material. The chemical and physical parameters such as pH, sorbent amount, initial ion concentration, and contact time were optimized for the maximum uptake of mercury onto the solid surface. Adsorption isotherms were expressed by Langmuir and Freundlich adsorption models, and the experimental data were found to fit the Langmuir model rather than the Freundlich. The maximum adsorption capacity obtained from the Langmuir isotherm was 135.13 mg/g. A kinetic study was carried out with pseudo-first-order and pseudo-second-order reaction equations and it was found that the Hg2+ uptake process followed the pseudo-second-order rate expression. The thermodynamic values, ΔG0, ΔH0 and ΔS0, indicated that adsorption was an endothermic and spontaneous process. The potential of this material for mercury elimination was demonstrated by efficient Hg2+ removal from a synthetic effluent.


2020 ◽  
Vol 15 (2) ◽  
pp. 525-537 ◽  
Author(s):  
Neza Rahayu Palapa ◽  
Tarmizi Taher ◽  
Bakri Rio Rahayu ◽  
Risfidian Mohadi ◽  
Addy Rachmat ◽  
...  

The preparation of CuAl LDH and biochar (BC) composite derived from rice husk and its application as a low-cost adsorbent for enhanced adsorptive removal of malachite green has been studied. The composite was prepared by a one-step coprecipitation method and characterized by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Brunauer-Emmett-Teller (BET), and Scanning Electron Microscopy - Energy Dispersive X-ray (SEM−EDX). The result indicated that CuAl LDH was successfully incorporated with the biochar that evidenced by the broadening of XRD peak at 2θ = 24° and the appearance of a new peak at 1095 cm−1 on the FTIR spectra. The BET surface area analysis revealed that CuAl/BC composite exhibited a larger surface area (200.9 m2/g) that the original CuAl LDH (46.2 m2/g). Surface morphological changes also confirmed by SEM image, which showed more aggregated particles. The result of the adsorption study indicated the composite material was efficient in removing malachite green with Langmuir maximum adsorption capacity of CuAl/BC reaching 470.96 mg/g, which is higher than the original CuAl LDH 59.523 mg/g. The thermodynamic analysis suggested that the adsorption of malachite green occurs spontaneously (ΔG < 0 at all tested temperature) and endothermic nature. Moreover, the CuAl/BC composite showed strong potential as a low-cost adsorbent for cationic dye removal since it showed not only a high adsorption capacity but also good reusability. Copyright © 2020 BCREC Group. All rights reserved


2014 ◽  
Vol 625 ◽  
pp. 498-502
Author(s):  
Samah B. Daffalla ◽  
Hilmi Mukhtar ◽  
Maizatul S. Shaharun

In this research, the development of three (3) low-cost adsorbent materials from abundant waste rice husk was achieved via thermal treatment. The physiochemical properties of the developed adsorbents were evaluated. Their adsorption behaviours in batch system were evaluated for the removal of phenol from aqueous solutions by varying the pH (2 to 10). It was found that, the rice husk ash burned a 400oC for 1hr ‘RHA400,1’ has the highest surface area (201.36 m2.g-1) followed by RHA300,4(87.08 m2.g-1) and RHA600,1(43.22 m2.g-1), respectively. RHA400,1had shown the highest removal efficiency followed by RHA300,4and RHA600,1, towards phenol due to high surface area and porosity. The maximum uptake of phenol was found at pH 4. The adsorption kinetics was well described by both pseudo-second order and the Elovich models.


2011 ◽  
Vol 356-360 ◽  
pp. 1289-1292
Author(s):  
Dan Fu ◽  
Yi He Zhang ◽  
He Li Wang ◽  
Feng Zhu Lv

In this paper, the adsorption properties of TNT on Rice husk active carbon (RHAC) were investigated. The effects of contact time was examined. Kinetic data obtained at different concentrations were conducted using Lagergren’s pseudo first-order, pseudo second-order and diffusion models. The regression results showed that the adsorption kinetics was more accurately represented by pseudo second-order model. The study indicates that there is significant potential for RHAC as an adsorbent material for TNT removal from wastewater.


2019 ◽  
Vol 233 (5) ◽  
pp. 669-690
Author(s):  
Khalida Naseem ◽  
Zahoor H. Farooqi ◽  
Robina Begum ◽  
Muhammad Zia Ur Rehman ◽  
Aiman Shahbaz ◽  
...  

Abstract In the present study, a novel biosorbent Vigna radiata leaves biomass (L. biomass) was utilized for cadmium (II) extraction from aqueous medium. Cadmium (II) free and cadmium (II) loaded L. biomass was analyzed by Fourier transform infrared (FTIR) spectroscopy. Adsorption of cadmium (II) from aqueous medium was studied under various conditions such as adsorbent dose, agitation time, pH and temperature of the medium to optimize the process variables. Different models including Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (DR) were used to elaborate the insight of adsorption process. Best interpretation of biosorption process was given by Langmuir model. Value of maximum adsorption capacity (qm) calculated from Langmuir isotherm model was found to be 13.44 mg/g. Results indicated the establishment of physical interaction between cadmium (II) ions and functional groups of L. biomass. Kinetic study for adsorption of cadmium (II) ions on L. biomass was done by applying pseudo first order, pseudo second order, elovich and intra-particles diffusion models. Biosorption process best followed the pseudo second order kinetics. Value of standard Gibbs energy (ΔG°) and standard enthalpy change (ΔH°) showed the feasibility, spontaneity and endothermic nature of adsorption process. Percentage removal efficiency of L. biomass for cadmium (II) was successfully maintained for four cycles. Biomass has a potential to be used as an efficient adsorbent for the removal of cadmium (II) from different polluted water samples.


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