Modified Grape Seeds: A Promising Alternative for Nitrate Removal from Water

The aim of this work was to investigate grape seeds as a potential adsorbent for nitrate removal from water. Grape seeds were modified by quaternization and the applicability of the modified grape seeds (MGS) was evaluated in batch adsorption experiments. Fixed bed adsorption and regeneration studies were carried out to determine the regeneration capacity of MGS. The maximum adsorption capacity of 25.626 mg g−1 at native pH (6.3) for nitrate removal by MSG was comparable to that of the commercial anion exchange resin Relite A490 under similar conditions. The percent removal of nitrate from model nitrate solution was 86.47% and 93.25% for MGS, and Relite A490, respectively, and in synthetic wastewater 57.54% and 78.37%. Analysis of the batch adsorption data using isotherm models revealed that the Freundlich model provided a better fit to the data obtained than the Langmuir model, indicating multilayer adsorption. In kinetic terms, the results showed that the adsorption followed the pseudo-first order model. By investigating the adsorption mechanism, the results suggest that the intraparticle diffusion model was not the only process controlling the adsorption of nitrate on MGS. In column experiments (adsorption/desorption studies), three adsorption cycles were tested with minimal decrease in adsorption capacities, implying that this alternative adsorbent can be successfully regenerated and reused.

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Fly Ash Coated with Magnetic Materials: Improved Adsorbent for Cu (II) Removal from Wastewater

Materials ◽

10.3390/ma14010063 ◽

2020 ◽

Vol 14 (1) ◽

pp. 63

Author(s):

Maria Harja ◽

Gabriela Buema ◽

Nicoleta Lupu ◽

Horia Chiriac ◽

Dumitru Daniel Herea ◽

...

Keyword(s):

Fly Ash ◽

Adsorption Capacity ◽

Copper Ions ◽

Synthetic Wastewater ◽

Bet Surface Area ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Copper Adsorption ◽

X Ray

Fly ash/magnetite material was used for the adsorption of copper ions from synthetic wastewater. The obtained material was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area, and vibrating sample magnetometer (VSM). Batch adsorption experiments were employed in order to investigate the effects of adsorbent dose, initial Cu (II) concentration and contact time over adsorption efficiency. The experimental isotherms were modeled using Langmuir (four types of its linearization), Freundlich, Temkin, and Harkins–Jura isotherm models. The fits of the results are estimated according to the Langmuir isotherm, with a maximum adsorption capacity of 17.39 mg/g. The pseudo-second-order model was able to describe kinetic results. The data obtained throughout the study prove that this novel material represents a potential low-cost adsorbent for copper adsorption with improved adsorption capacity and magnetic separation capability compared with raw fly ash.

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Granular activated carbon (GAC) adsorption in tertiary wastewater treatment: experiments and models

Water Science & Technology ◽

10.2166/wst.2003.0030 ◽

2003 ◽

Vol 47 (1) ◽

pp. 113-120 ◽

Cited By ~ 14

Author(s):

D.S. Chaudhary ◽

S. Vigneswaran ◽

V. Jegatheesan ◽

H.H. Ngo ◽

H. Moon ◽

...

Keyword(s):

Wastewater Treatment ◽

Activated Carbon ◽

Fixed Bed ◽

Granular Activated Carbon ◽

Developed Countries ◽

Synthetic Wastewater ◽

Batch Adsorption ◽

Model Parameters ◽

Wide Range ◽

Gac Adsorption

Wastewater treatment has always been a major concern in the developed countries. Over the last few decades, activated carbon adsorption has gained importance as an alternative tertiary wastewater treatment and purification process. In this study, granular activated carbon (GAC) adsorption was evaluated in terms of total organic carbon (TOC) removal from low strength synthetic wastewater. This paper provides details on adsorption experiments conducted on synthetic wastewater to develop suitable adsorption isotherms. Although the inorganics used in the synthetic wastewater solution had an overall unfavourable effect on adsorption of organics, the GAC adsorption system was found to be effective in removing TOC from the wastewater. This study showed that equation of state (EOS) theory was able to fit the adsorption isotherm results more precisely than the most commonly used Freundlich isotherm. Biodegradation of the organics with time was the most crucial and important aspect of the system and it was taken into account in determining the isotherm parameters. Initial organic concentration of the wastewater was the determining factor of the model parameters, and hence the isotherm parameters were determined covering a wide range of initial organic concentrations of the wastewater. As such, the isotherm parameters derived using the EOS theory could predict the batch adsorption and fixed bed adsorption results of the multi-component system successfully. The isotherm parameters showed a significant effect on the determination of the mass transfer coefficients in batch and fixed bed systems.

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Phosphorylated cellulose nanofibers exhibit exceptional capacity for uranium capture

Cellulose ◽

10.1007/s10570-020-02971-8 ◽

2020 ◽

Vol 27 (18) ◽

pp. 10719-10732

Author(s):

Janika Lehtonen ◽

Jukka Hassinen ◽

Avula Anil Kumar ◽

Leena-Sisko Johansson ◽

Roni Mäenpää ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Structural Changes ◽

Cellulose Nanofibers ◽

Aqueous Media ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Electron Microscopies ◽

Network Scanning ◽

Aqueous Matrices

AbstractWe investigate the adsorption of hexavalent uranium, U(VI), on phosphorylated cellulose nanofibers (PHO-CNF) and compare the results with those for native and TEMPO-oxidized nanocelluloses. Batch adsorption experiments in aqueous media show that PHO-CNF is highly efficient in removing U(VI) in the pH range between 3 and 6. Gelling of nanofiber hydrogels is observed at U(VI) concentration of 500 mg/L. Structural changes in the nanofiber network (scanning and transmission electron microscopies) and the surface chemical composition (X-ray photoelectron spectroscopy) gave insights on the mechanism of adsorption. The results from batch adsorption experiments are fitted to Langmuir, Freundlich, and Sips isotherm models, which indicate a maximum adsorption capacity of 1550 mg/g, the highest value reported so far for any bioadsorbent. Compared to other metals (Zn, Mn, and Cu) and typical ions present in natural aqueous matrices the phosphorylated nanofibers are shown to be remarkably selective to U(VI). The results suggest a solution for the capture of uranium, which is of interest given its health and toxic impacts when present in aqueous matrices.

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Removal of Cu(II) from Aqueous Solutions Using Amine-Doped Polyacrylonitrile Fibers

Applied Sciences ◽

10.3390/app10051738 ◽

2020 ◽

Vol 10 (5) ◽

pp. 1738

Author(s):

Kay Thwe Aung ◽

Seung-Hee Hong ◽

Seong-Jik Park ◽

Chang-Gu Lee

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Equilibrium Studies ◽

Naoh Solution ◽

Surface Modified ◽

Pan Fibers

Polyacrylonitrile (PAN) fibers were prepared via electrospinning and were modified with diethylenetriamine (DETA) to fabricate surface-modified PAN fibers. The surface-modified PAN fibers were used to evaluate their adsorption capacity for the removal of Cu(II) from aqueous solutions. Batch adsorption experiments were performed to examine the effects of the modification process, initial concentration, initial pH, and adsorbent dose on the adsorption of Cu(II). Kinetic analysis revealed that the experimental data fitted the pseudo-second-order kinetic model better than the pseudo-first-order model. Adsorption equilibrium studies were conducted using the Freundlich and Langmuir isotherm models, and the findings indicated that the PAN fibers modified with 85% DETA presented the highest adsorption capacity for Cu(II) of all analyzed samples. Moreover, the results revealed that the Freundlich model was more appropriate than the Langmuir one for describing the adsorption of Cu(II) onto the modified fibers at various initial Cu(II) concentrations. The maximum adsorption capacity was determined to be 87.77 mg/g at pH 4, and the percent removal of Cu(II) increased as the amount of adsorbent increased. Furthermore, the surface-modified PAN fibers could be easily regenerated using NaOH solution. Therefore, surface-modified PAN fibers could be used as adsorbents for the removal of Cu(II) from aqueous solutions.

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Compressive Alginate Sponge Derived from Seaweed Biomass Resources for Methylene Blue Removal from Wastewater

Polymers ◽

10.3390/polym11060961 ◽

2019 ◽

Vol 11 (6) ◽

pp. 961 ◽

Cited By ~ 2

Author(s):

Xiaojun Shen ◽

Panli Huang ◽

Fengfeng Li ◽

Xiluan Wang ◽

Tongqi Yuan ◽

...

Keyword(s):

Methylene Blue ◽

Water Treatment ◽

Low Cost ◽

Fixed Bed ◽

Polymer Materials ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Seaweed Biomass ◽

Biomass Resources ◽

The Impact

Low cost fabrication of water treatment polymer materials directly from biomass resources is urgently needed in recent days. Herein, a compressive alginate sponge (AS) is prepared from seaweed biomass resources through a green two-step lyophilization method. This material is much different from conventional oven-, air-, vacuum-dried alginate-based adsorbents, which show limitations of shrinkage, rigidness, tight nonporous structure and restricted ions diffusion, hindering its practical applications, and was used to efficiently remove methylene blue (MB), a main colorful contaminant in dye manufacturing, from wastewater. The batch adsorption studies are carried out to determine the impact of pH, contact time and concentration of dye on the adsorption process. The maximum adsorption capacity can be obtained at 1279 mg g−1, and the shape-moldable AS can be facilely utilized as a fixed-bed absorption column, providing an efficient approach for continuous removal of MB within a short time. It is also important that such a compressive AS can be regenerated by a simple squeezing method while retaining about 70% capacity for more than ten cycles, which is convenient to be reused in practical water treatment. Compressive AS demonstrates its merits of high capability, large efficiency and easy to recycle as well as low cost resources, indicating widespread potentials for application in dye contaminant control regarding environmental protection.

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Phosphorus recovery from sewage with a sustainable and low-cost treatment system

Water Science & Technology ◽

10.2166/wst.2019.332 ◽

2019 ◽

Vol 80 (5) ◽

pp. 846-854

Author(s):

Vitor Tonzar Chaves ◽

Dione Mari Morita ◽

Iara Regina Soares Chao ◽

Ronan Cleber Contrera

Keyword(s):

Constructed Wetland ◽

Phosphorus Removal ◽

Phosphorus Recovery ◽

Maximum Efficiency ◽

Integrative Approach ◽

Isotherm Models ◽

Phosphorus Concentration ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Initial Ph

Abstract This study proposes a technology conceived based on an integrative approach that aims to promote phosphorus recovery and to recycle ferric water treatment sludge (FWTS), using it as a phosphorus adsorbent which may be applied as a soil ameliorant after reaching saturation. The assessed pilot plant operated with a daily influent flow of 360 litres and presented a removal efficiency of 94.4% ± 3.2% for chemical oxygen demand (COD) and of 91.2% ± 7.8% for suspended solids. It also presented promising results for phosphorus removal. The maximum efficiency of dissolved reactive phosphorus removal was 95% on the first day and it decreased until reaching adsorbent saturation. The estimated breakthrough time was one year in the condition in which the filling medium of a second constructed wetland was only FWTS. In this situation, the effluent phosphorus concentration was 0.2 mg·L−1. The authors concluded that the application of FWTS in a constructed wetland bed is an interesting alternative. Batch adsorption experiments were run using phosphorus stock solution. Langmuir and Freundlich adsorption isotherm models were obtained for different initial pH values. The maximum adsorption capacity decreased as the initial pH was increased; values ranged from 4.76 mg P·g−1 (pH = 3.9) to 1.44 mg P·g−1 (pH = 9.0).

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Calcium PretreatedHevea brasiliensisSawdust for Copper Removal: Batch and Column Study

Journal of Chemistry ◽

10.1155/2015/495257 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9

Author(s):

Swarup Biswas ◽

Umesh Mishra

Keyword(s):

Adsorption Capacity ◽

Adsorption Process ◽

Copper Ion ◽

Packed Bed ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Packed Bed Column ◽

Pseudo Second Order ◽

Kinetics Of

Calcium pretreatedHevea brasiliensissawdust has been used as an effective and efficient adsorbent for the removal of copper ion from the contaminated water. Batch experiment was conducted to check the effect of pH, initial concentration, contact time, and adsorbent dose. The results conclude that adsorption capacity of adsorbent was influenced by operating parameters. Maximum adsorption capacity found from the batch adsorption process was 37.74 mg/g at pH of 5.6. Various isotherm models like Langmuir, Freundlich, and Temkin were used to compare the theoretical and experimental data, whereas the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied to study the kinetics of the batch adsorption process. Dynamic studies were also conducted in packed-bed column using different bed depths and the maximum adsorption capacity of 34.29 was achieved. Characterizations of the adsorbent were done by Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy.

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Effective and Simple NaOH-Modification Method to Remove Methyl Violet Dye via Ipomoea aquatica Roots

Adsorption Science & Technology ◽

10.1155/2021/5932222 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Yie Chen Lu ◽

Muhammad Raziq Rahimi Kooh ◽

Linda Biaw Leng Lim ◽

Namal Priyantha

Keyword(s):

Adsorption Process ◽

Solution Treatment ◽

Methyl Violet ◽

Coefficient Of Determination ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Methyl Violet 2B ◽

Naoh Solution ◽

Regeneration Experiment

In this study, a simple chemical modification was applied to a sustainable and abundantly available resource, kangkong root (KR), to remove methyl violet 2B (MV) dye. The chemically modified adsorbent (NaOH-KR) was obtained using NaOH solution treatment. Batch adsorption experiments were carried out to investigate the effects of pH, ionic strength, contact time, adsorbent dosage, and initial dye concentration. A regeneration experiment was also carried out to assess the potential of reusability. The adsorption process was modelled using various kinetics and isotherm models, whereby the best-fitting models were evaluated by using the coefficient of determination ( R 2 ) and error functions. The Sips ( R 2 = 0.9714 , χ2 =0.16) and pseudo-second-order ( R 2 = 0.9996 , χ 2 = 0.007 ) models were identified to best represent the adsorption process. The Sips model predicted a maximum adsorption capacity at 551.5 mg g-1 for NaOH-KR, which is 55% improvement in performance when compared to nonmodified KR. Lastly, the regeneration experiment showed that NaOH-KR was able to maintain reasonable dye removal even after five consecutive cycles of regenerating and reusing.

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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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Effective Remediation of Lead Ions from Aqueous Solution by Chemically Carbonized Rubber Wood Sawdust: Equilibrium, Kinetics, and Thermodynamic Study

Journal of Chemistry ◽

10.1155/2015/842707 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Swarup Biswas ◽

Umesh Mishra

Keyword(s):

Aqueous Solution ◽

Ph Effect ◽

Lead Ion ◽

Isotherm Models ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Kinetics Of Adsorption ◽

Wood Sawdust ◽

Rubber Wood ◽

Pseudo Second Order

Rubber wood sawdust was carbonized into charcoal by chemical treatment which was used for removal of lead ion from aqueous solution. The work involves batch experiments to investigate the pH effect, initial concentration of adsorbate, contact time, and adsorbent dose. Experimental data confirmed that the adsorption capacities increased with increasing inlet concentration and bed height and decreased with increasing flow rate. Adsorption results showed a maximum adsorption capacity of 37 mg/g at 308 K. Langmuir, Freundlich, and Temkin model adsorption isotherm models were applied to analyze the process where Temkin was found as a best fitted model for present study. Simultaneously kinetics of adsorption like pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were investigated. Thermodynamic parameters were used to analyze the adsorption experiment. Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy confirmed the batch adsorption of lead ion onto chemically carbonized rubber wood sawdust.

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