scholarly journals Isotherm models and kinetics of copper adsorption by using hydrochar produced from hydrothermal carbonization of faecal sludge

2017 ◽  
Vol 7 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Thammarat Koottatep ◽  
Krailak Fakkaew ◽  
Nutnicha Tajai ◽  
Chongrak Polprasert
Keyword(s):  
Functional Groups ◽  
Low Cost ◽  
Hydrothermal Carbonization ◽  
Pollutant Removal ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Surface Functional Groups ◽  
Water And Wastewater Treatment ◽  
Copper Adsorption ◽  
Faecal Sludge

Low cost adsorbents have been extensively reported for use as a promising substitution for commercial adsorbents for pollutant removal in water and wastewater treatment. In this study, hydrochar produced from the hydrothermal carbonization (HTC) of faecal sludge (FS) (called HTC-hydrochar) was further chemically modified with KOH (called KOH-hydrochar) to improve its surface functional groups, which were suitable for copper (Cu) removal. The adsorption of Cu was conducted using the produced HTC-hydrochar and KOH-hydrochar as absorbents. Experimental results showed the KOH-hydrochar could adsorb Cu at the maximum adsorption capacity of 18.6 mg-Cu/g-hydrochar with Cu removal efficiency of 93%, relatively higher than the HTC-hydrochar and a commercial powdered activated carbon. The quantity of the surface functional groups of the adsorbents was more effective in Cu removal than the surface area. The Cu adsorption mechanism was found to follow the pseudo-second order and intra-particle diffusion models and fit well with Freundlich and Langmuir isotherms. Application of hydrothermal carbonization could be a novel candidate to convert FS into hydrochar which is pathogen free, and to employ the produced hydrochar as an adsorbent to remove Cu from industrial wastewaters.

scholarly journals Efficient Removal of Cd (II) From Aqueous Solution By Chitosan Modified Kiwi Branch Biochar

2021 ◽  
Author(s):  
Yuehui Tan ◽  
Xirui Wan ◽  
Xue Ni ◽  
Le Wang ◽  
Ting Zhou ◽  
...  
Keyword(s):  
Functional Groups ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
Surface Functional Groups ◽  
Order Model ◽  
Efficient Removal ◽  
Adsorption Ability ◽  
Modified Biochar ◽  
Pseudo Second Order ◽  
Interaction Surface

Abstract A novel chitosan-modified kiwi branch biochar (CHKB) was successfully fabricated as cut-price modified biochar to remove Cd (II) from wastewater. Characterization experiments with SEM-EDS, FTIR and XPS suggested that CHKB had more cations and surface functional groups compared with the original kiwi biochar (KB). The adsorption experiment results of Cd (II) on CHKB showed that the adsorption isotherms can be described best by the Langmuir model and that the pseudo-second-order model fits the Cd (II) adsorption kinetics well, indicating that the process was monolayer and controlled by chemisorption. CHKB exhibited the Langmuir maximum adsorption capacity of Cd (II) (126.58 mg g-1), however, that of KB is only 4.26 mg g-1. The adsorption ability of CHKB was improved by the increase of the surface area and abundant surface functional groups (-OH, -NH, C=O and so on). And the cation exchange, electrostatic interaction, surface complexation and precipitation were main mechanisms in the sorption of Cd (II) on CHKB. In addition, CHKB can be regenerated and reused for Cd (II) sorption by the eluent of EDTA-2Na. Excellent adsorption performance, low-cost, and environmental-friendly made CHKB become the fantastic adsorbent to remove Cd (II) in wastewater.

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

Materials ◽  
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.

Biosorption of Cadmium onto Pseudomonas fluorescens: Application of Isotherm and Kinetic Models

2010 ◽  
Vol 171-172 ◽  
pp. 49-52 ◽  
Author(s):  
Chang Li Yu ◽  
Zhi Peng Lu ◽  
Fa Zhi Ge ◽  
Er Li Zhao
Keyword(s):  
Pseudomonas Fluorescens ◽  
Functional Groups ◽  
Metal Ion ◽  
Freundlich Isotherm ◽  
Industrial Effluents ◽  
Rate Equations ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Kinetics Of Adsorption ◽  
Isotherm And Kinetic Models

The present study was undertaken to evaluate the feasibility of Pseudomonas fluorescens biomass for the removal of cadmium ions from aqueous solutions. Batch experiments were performed to study the adsorption of cadmium on pH, Pseudomonas fluorescens biomass adsorbent with respect to initial Cd(II) concentration, contact time and biomass dose. The experimental data were modeled by Langmuir and Freundlich isotherm models. Langmuir model resulted in the best fit of the adsorption data. The maximum adsorption capacity for Cd(II) was 66.25 mg/g (pH 5.0 and 5 g/L biomass dose). Kinetics of adsorption followed second-order rate equations. The FTIR results of Pseudomonas fluorescens biomass showed that biomass has different functional groups and these functional groups are able to react with metal ion in aqueous solution. The results of the present study suggest that Pseudomonas fluorescens biomass can be used beneficially in treating industrial effluents containing heavy metal ions.

scholarly journals Simultaneous Adsorption of Cr(VI) and Phenol from Binary Mixture Using Iron Incorporated Rice Husk: Insight to Multicomponent Equilibrium Isotherm

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Ankur Gupta ◽  
Chandrajit Balomajumder
Keyword(s):  
Experimental Data ◽  
Rice Husk ◽  
Low Cost ◽  
Binary Solution ◽  
Multicomponent System ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Adsorption Isotherm Models ◽  
Pseudo Second Order

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.

scholarly journals Adsorption of Cu(II) ions from synthetic solution by sunflower seed husks

2019 ◽  
pp. 268-277
Author(s):  
Srdjan Stankovic ◽  
Tatjana Sostaric ◽  
Mladen Bugarcic ◽  
Aleksandra Janicijevic ◽  
Katarina Pantovic-Spajic ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Functional Groups ◽  
Vegetable Oil ◽  
Sunflower Seed ◽  
Active Sites ◽  
Animal Feed ◽  
Added Value ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Synthetic Solution

Annual production of the sunflower seed in Serbia is between 650,000-720,000 tons. Most of this amount is used in vegetable oil industry. Abundant by-products from this processing are sunflower seed husks. Husks are usually incinerated by vegetable oil producers in order to obtain energy, used as an animal feed, or, unfortunately, landed up at some landfills. In order to promote new, added value for this abundant, renewable resource, the investigation presented in this paper was conducted. For that purpose, adsorption of Cu(II) ions from synthetic solution by unmodified sunflower seed husks was examined. ATR-FTIR was used to identify functional groups as potential active sites for Cu(II) sorption. Zeta potential values were determined to reveal the surface charge, while the cation exchange capacity (CEC) was determined to reveal the amount of exchangeable ions on its surface. ATR-FTIR analysis revealed the presence of specific functional groups (hydroxyl, carboxyl, carbonyl, and amine) responsible for removal of Cu(II) ions. The total CEC of sunflower husk is 47.74 meq/100g and Ca(II) and Mg(II) ions are in dominant exchangeable positions. The study of ion-exchange mechanism involvement was done and results confirmed that this mechanism is not the only mechanism which is involved in copper sorption. Also, the results show that the Cu(II) ions have preference for Mg(II) ions substitution. Sorption experiments were conducted in batch system. The effect of operating parameters (pH, contact time, initial concentration of Cu(II) ions and adsorbent dosage) on the adsorption capacity were investigated. The obtained experimental data were fitted by Langmuir and Freundlich isotherm models. The maximum adsorption capacity for Cu(II) ions calculated from Langmuir adsorption isotherm was 34.89 mg/g which is 15 to 35% higher than the capacity that other researchers reported previously for the same material and pollutant. These results are suggesting that sunflower seed husks have a potential to be applied as an effective adsorbent of copper ions from contaminated waters.

Preparation of lignin-based mesoporous biochar nano- and microparticles, and their adsorption properties for hexavalent chromium

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6363-6377
Author(s):  
Yu Hu ◽  
Meng Ling ◽  
Xianfa Li
Keyword(s):  
Adsorption Capacity ◽  
Functional Groups ◽  
Pyrolysis Temperature ◽  
Waste Water Treatment ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Contaminated Waste ◽  
Mesoporous Biochar

The removal performance and mechanism of Cr(VI) from aqueous solution was studied for a novel micro-nano particle kraft lignin biochar (BC) pyrolyzed at 400 to 700 °C. The physicochemical properties of BC were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption-desorption isotherms. The results illustrated that the BC had irregular micro- and nanoparticles with abundant pore structure and high BET surface area (111.1 m2/g). The FT-IR results showed that the lower pyrolysis temperature resulted in more oxygen-containing functional groups. The Cr(VI) adsorption capacity decreased with the pyrolysis temperature increasing from 400 to 700 °C, and the maximum percentage removal of Cr(VI) for BC obtained at 400 °C was 100% at pH 2, which suggested that the removal efficiency was mainly dependent on functional groups. Kinetic analysis demonstrated that Cr(VI) adsorption on BC fit well to the pseudo-second-order kinetic model. The adsorption data was well fitted with the Langmuir isotherm models, and the maximum adsorption capacity was 37.2 mg/g at 298K. The BC could be reused twice with Cr(VI) removal of 63.91% and was suitable for Cr(VI) contaminated waste-water treatment.

scholarly journals The importance of surface functional groups in the adsorption of copper onto walnut shell derived activated carbon

2017 ◽  
Vol 76 (11) ◽  
pp. 3022-3034 ◽  
Author(s):  
Ruzhen Xie ◽  
Yan Jin ◽  
Yao Chen ◽  
Wenju Jiang
Keyword(s):  
Activated Carbon ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Chemical Activation ◽  
Critical Role ◽  
Walnut Shell ◽  
Infrared Spectrometry ◽  
Copper Uptake ◽  
Surface Functional Groups ◽  
Copper Adsorption

Abstract In this study, activated carbon (AC) was prepared from walnut shell using chemical activation. The surface chemistry of the prepared AC was modified by introducing or blocking certain functional groups, and the role of the different functional groups involved in the copper uptake was investigated. The structural and chemical heterogeneity of the produced carbons are characterized by Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, Boehm titration method and N2/77 K adsorption isotherm analysis. The equilibrium and the kinetics of copper adsorption onto AC were studied. The results demonstrated that the functional groups on AC played an important role in copper uptake. Among various surface functional groups, the oxygen-containing group was found to play a critical role in the copper uptake, and oxidation is the most effective way to improve Cu (II) adsorption onto AC. Ion-exchange was identified to be the dominant mechanism in the copper uptake by AC. Some other types of interactions, like complexation, were also proven to be involved in the adsorption process, while physical force was found to play a small role in the copper uptake. The regeneration of copper-loaded AC and the recovery of copper were also studied to evaluate the reusability of the oxidized AC.

scholarly journals Regression, kinetics and isotherm models for biosorption of organic pollutants, suspended and dissolved solids by environmentally friendly and economical dried Phragmites australis

RSC Advances ◽  
2018 ◽  
Vol 8 (71) ◽  
pp. 40511-40528
Author(s):  
Abeer El Shahawy ◽  
Ghada Heikal
Keyword(s):  
Functional Groups ◽  
Phragmites Australis ◽  
Organic Pollutants ◽  
Low Cost ◽  
Environmentally Friendly ◽  
Isotherm Models ◽  
Dissolved Solids

Low cost adsorbents such as P. australis have received considerable interest owing to their low cost, large amount of functional groups and easy availability.

scholarly journals Aquatic plant, Ipomoea aquatica, as a potential low-cost adsorbent for the effective removal of toxic methyl violet 2B dye

2020 ◽  
Vol 10 (12) ◽  
Author(s):  
Tze Ling Kua ◽  
Muhammad Raziq Rahimi Kooh ◽  
Muhammad Khairud Dahri ◽  
Nur Afiqah Hazirah Mohamad Zaidi ◽  
YieChen Lu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Low Cost ◽  
Methyl Violet ◽  
Point Of Zero Charge ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Ipomoea Aquatica ◽  
Effective Removal ◽  
Methyl Violet 2B

AbstractIpomoea aquatica (IA) was investigated for its potential as a low-cost adsorbent to remove toxic methyl violet 2B (MV2B) dye in aqueous solutions. Optimising parameters such as the effects of contact time, medium pH and ionic strength (using NaCl, NaNO3, KCl and KNO3) were investigated. The results indicated that 150 min were sufficient for the adsorption to reach an equilibrium state and no adjustment of pH medium was necessary. Batch adsorption experiments such as adsorption isotherm, thermodynamics and kinetics were investigated and the experimental isotherm data were fitted to six isotherm models, namely Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Peterson and Sips, with the latter being the best-fit isotherm model showing maximum adsorption capacity (qmax) of 267.9 mg g−1. Thermodynamics studies indicated adsorption of MV2B to be exothermic in nature, occurring spontaneously. The kinetics was best described by the pseudo-second-order model. Regeneration of IA pointed to its reusability, maintaining high adsorption capacity even up until Cycle 5 when treated with acid (HCl) and base (NaOH). Functional groups such as hydroxyl and amine groups which could be involved in the adsorption of MV2B were determined using FTIR spectroscopy, and the point of zero charge of IA was found to be at pH 6.81.

Effect of the Pore Diameters and Amino-Organo Functional Structures on Mesoporous Silicas for DNA Adsorption

2016 ◽  
Vol 720 ◽  
pp. 31-36 ◽  
Author(s):  
Ryouichi Hikosaka ◽  
Fukue Nagata ◽  
Masahiro Tomita ◽  
Katsuya Kato
Keyword(s):  
Pore Size ◽  
Functional Groups ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Surface Functional Groups ◽  
Dna Adsorption ◽  
Equilibrium Data ◽  
Adsorption Equilibrium Data

Deoxyribonucleic acid (DNA) adsorption onto particles has applications in biosensors, separation methods, and gene delivery. Mesoporous silica (MPS), which exhibits a high surface area and large pore volume, is used in these applications because its pore size is easily controlled and its surface functional groups are easily exchanged. In this study, three types of MPSs with different pore sizes (2.4, 5.6, and 11.8 nm) were functionalized with different aminosilane coupling reagents and the effects of the MPS pore size and surface functional groups on DNA adsorption were evaluated. As the pore size of MPS increased, MPSs with diethylenetriamine (–3NH2) adsorbed higher amounts of DNA, whereas MPSs with hexylenediamine groups (–2HNH2) adsorbed lower amounts of DNA. Moreover, the fitting of DNA adsorption equilibrium data to Langmuir and Freundlich isotherm models was investigated.

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