Reduction and Biosorption of Cr(VI) from Aqueous Solutions by Acid-Modified Guava Seeds: Kinetic and Equilibrium Studies

AbstractThe use of guava seeds (GS) and acid-modified guava seeds (MGS) for the removal of Cr(VI) from aqueous solutions was investigated. Batch-type experiments were performed with Cr(VI) aqueous solutions and biosorbents to determine the kinetic and equilibrium sorption parameters. Results indicated that GS and MGS were capable of reducing and remove Cr(VI) from solutions, but the reduction was only observed at some experimental conditions. Infrared analysis showed that several functional groups were involved in the reduction, and biosorption of Cr(VI), particularly alcohol, phenolic, carboxylic, and methoxymethyl structures. The mechanisms of reduction and biosorption depended upon the type of biosorbent, pH, and temperature of the system. The pseudo-second-order kinetic model describes the kinetic sorption data, and the Langmuir-Freundlich (L-F) model describes the isotherm data in most cases. Significantly high total chromium biosorption capacities were obtained. Acid modification of guava seeds improves chromium biosorption performance.

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Sorption of cationic dyes from aqueous solutions by moss Rhytidiadelphus squarrosus: Kinetics and equilibrium studies

Nova Biotechnologica et Chimica ◽

10.36547/nbc.1287 ◽

2021 ◽

Vol 9 (1) ◽

pp. 53-62

Author(s):

Lucia Remenárová ◽

Martin Pipíška ◽

Miroslav Horník ◽

Jozef Augustín

Keyword(s):

Aqueous Solutions ◽

Low Cost ◽

Freundlich Isotherm ◽

Cationic Dyes ◽

Order Kinetic ◽

Natural Sorbent ◽

Equilibrium Studies ◽

Sorption Data ◽

Maximum Sorption ◽

Rhytidiadelphus Squarrosus

With the aim to investigate sorption properties of natural sorbent prepared from moss Rhytidiadelphus squarrosus we elucidated biosorption of cationic dyes Malachite green (BG4), Auramine O (BY2) and Thioflavine T (BY1) from aqueous solutions. The removal of dyes by moss biosorbent was found to be rapid at an initial stage and the equilibrium was reached within 1-2 hours. The pseudo-n-order kinetic model was successfully applied to the kinetic data and the order of adsorption reaction was calculated in the range from 1.7 to 2.6. The value of rate constant kn' ranged from 0.001 to 0.039 [min-1]/[μmol/g]1-n. The equilibrium data were fitted to the adsorption isotherms. The Freundlich isotherm was found to represent the measured sorption data of BG4, BY1 and BY2 well. The maximum sorption capacities of moss biomass from single dye solutions calculated by Langmuir equation were 354 μmol/g for BG4, 310 μmol/g for BY1 and 382 μmol/g for BY2. These results showed that the prepared biomass presents low-cost, natural and easy available sorbent which may be potentially used for removal of dyes from environment and also may be an alternative to more costly materials such as activated carbon.

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Synthesis and Characterization of Chitosan templated Mesoporous Silica: Efficient use of Mesoporous Silica in the removal of Cu(II) from Aqueous Solutions

Science & Technology Journal ◽

10.22232/stj.2016.04.02.04 ◽

2016 ◽

Vol 4 (2) ◽

pp. 105-112

Author(s):

Lalchhing puii ◽

◽

Seung-Mok Lee ◽

Diwakar Tiwari ◽

◽

...

Keyword(s):

Mesoporous Silica ◽

Aqueous Solutions ◽

Background Electrolyte ◽

Second Order ◽

Order Kinetic ◽

Sorption Data ◽

Column Reactor ◽

Wide Ph Range ◽

Freundlich Adsorption Isotherm ◽

Pseudo Second Order

A mesoporous silica was synthesized by annealing (3-Aminopropyl) triethoxysilane grafted chitosan at 800˚C. The mesoporous silica was characterized by the XRD (X-ray diffraction) analysis. The BET specific surface area and pore size of silica was found to be 178.42 m2/g and 4.13 nm. The mesoporous silica was then employed for the efficient remediation of aqueous solutions contaminated with Cu(II) under batch and column reactor operations. The mesoporous silica showed extremely high per cent removal of Cu(II) at wide pH range i.e., pH ~2.0 to 7.0. Relatively a fast uptake of Cu(II) was occurred and high percentage removal was obtained at initial concentrations studied from 1.0 to 15.0 mg/L. The equilibrium state sorption data were utilized for the Langmuir and Freundlich adsorption isotherm studies. Moreover, the effect of an increase in background electrolyte concentrations from 0.0001 to 0.1 mol/L NaNO3 was assessed for the uptake of Cu(II) by mesoporous silica. The equilibrium sorption was achieved within 240 min of contact and the kinetic data is best fitted to the pseudo-second-order and fractal like pseudo-second-order kinetic models. In addition, the mesoporous silica was used for dynamic studies under column reactor operations. The breakthrough curve was then used for the non-linear fitting of the Thomas equation and the loading capacity of the column for Cu(II) was estimated.

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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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Novel Adsorbent Used for Cesium Removal from Aqueous Solutions

Revista de Chimie ◽

10.37358/rc.17.3.5480 ◽

2017 ◽

Vol 68 (3) ◽

pp. 470-473

Author(s):

Corneliu Mircea Davidescu ◽

Andreea Gabor ◽

Adina Negrea ◽

Mihaela Ciopec ◽

Petru Negrea ◽

...

Keyword(s):

Aqueous Solutions ◽

Metal Ion ◽

Nuclear Power ◽

Adsorption Process ◽

Magnesium Silicate ◽

Polluted Water ◽

Order Kinetic ◽

Equilibrium Studies ◽

Removal Process ◽

Geological Formation

Cesium (Cs) removal from wastewater becomes an emerging issue after the Fukushima Daiichi Nuclear Power Plant disaster. Cs(I) is an metal ion present in high level radioactive waste and has to be removed for a better disposal in geological formation. The present study investigates the adsorption process of Cs(I) from aqueous solutions on an novel adsorbent material. The novelty of this material is that the solid support, magnesium silicate, is doped with a new extractant, thiourea dissolved in ethyl alcohol. In order to establish the adsorption capacities of the adsorbent material, it was used in the removal process of metal ions. Kinetically, the adsorption process of this metal ion has the best fit for the pseudo-second-order kinetic model. The removal process through adsorption is endothermic and spontaneous due to the thermodynamic studies. Equilibrium studies were also carried out for the Langmuir, Freundlich and Sips model. The new doped material proves to be favourable as adsorbent material in the removal of Cs(I) from polluted water.

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Studies on the Treatment of Wastewaters Containing Cr6+ with Iron Oxide-Silica Composite Materials Prepared by Different Methods

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.353.33 ◽

2014 ◽

Vol 353 ◽

pp. 33-38

Author(s):

Rafique Ullah ◽

Biplob Kumer Deb ◽

Mohammad Yousuf Ali Mollah

Keyword(s):

Aqueous Solution ◽

Iron Oxide ◽

Adsorption Isotherm ◽

Aqueous Solutions ◽

Order Kinetic ◽

Efficient Technology ◽

Experimental Conditions ◽

Initial Concentration ◽

Oxide Composite ◽

Chromium Vi

Chromium (VI) is known to be carcinogenic to humans and thus it is important to ensure the removal of Chromium (VI) from aqueous solutions and industrial effluents. The present study introduces a good alternative method for Cr (VI) removal from aqueous solutions at ambient temperature by adsorption, allowing the development of newer, lower operational cost, and more efficient technology than other processes already in use. Adsorption was found to be dependent on pH and initial concentration of Cr (VI) solution. Results of adsorption studies suggest that pristine iron oxide and silicon (IV) oxide removes 72.10% and 24.73%, respectively. The iron oxide – silicon (IV) oxide composite, prepared in this work, removes 93.88% Cr (VI) in 20 minutes from aqueous solution at an initial concentration of 50 mgL-1at pH 4.8 ± 0.2. The effect of concentration, contact time, adsorbent dose and solution pH on the adsorption of Cr (VI) were studied in detail in batch experiments. Studies of the sorption kinetics shows that equilibrium adsorption was attained in 20 minutes depending on other experimental conditions. The kinetic data justified Lagergren’s first-order kinetic equation. Adsorption isotherm study showed that the results fulfilled the Langmuir Model of adsorption isotherm. The maximum adsorption (98.28%) was recorded at pH 3 in 90 minutes for the initial Cr (VI) concentration of 50 mg L-1. Therefore, it can be concluded that iron oxide – silicon (IV) oxide composite is a potential adsorbent for adsorption of Cr (VI) from aqueous solution.

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Granules of brick waste (GBW) as low-cost sorbent for removal of Pb+2 ions from aqueous solutions

Association of Arab Universities Journal of Engineering Sciences ◽

10.33261/jaaru.2020.27.3.001 ◽

2020 ◽

Vol 27 (3) ◽

pp. 1-8

Author(s):

Teba H. Mhawesh ◽

Ziad T. Abd Ali

Keyword(s):

Aqueous Solutions ◽

Low Cost ◽

Isotherm Models ◽

Order Kinetic ◽

Sorption Data ◽

X Ray ◽

Batch Tests ◽

Order Kinetic Model ◽

Langmuir Isotherm Model ◽

Pseudo Second Order

The potential application of granules of Granular brick waste as a low-cost sorbent for removal of Pb+2 ions from aqueous solutions has been studied. The properties of Granular brick waste were determined through several tests such as X-Ray diffraction , Energy dispersive X-ray, Scanning electron microscopy , and surface area. In batch tests, the influence of several operating parameters including contact time, initial concentration, agitation speed, and the dose of GBW was investigated. The best values of these parameters that provided maximum removal efficiency of lead (89.5 %) were 2.5 hr, 50 mg/L, 250 rpm, and 1.8 g/100mL, respectively. The sorption data obtained by batch experiments subjected to the three isotherm models called Langmuir, Freundlich and Elovich. The results showed that the Langmuir isotherm model described well the sorption data (R2= 0.9866) in comparison with other models. The kinetic data were analyzed using two kinetic models called pseudo_first_order and pseudo_second_order. The pseudo-second-order kinetic model was found to agree well with the experimental data.

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Synthesis of Kit-6 magnetite silica nanocomposite functionalized by amine group for removal of Carmoisine dye from aqueous solutions

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207323666201007153747 ◽

2020 ◽

Vol 23 ◽

Author(s):

Seyedeh Mahsa Seyed Danesh ◽

Shahab Shariati ◽

Hossein Faghihian

Keyword(s):

Aqueous Solutions ◽

Second Order ◽

Isotherm Models ◽

Infrared Spectrometry ◽

Order Kinetic ◽

Experimental Conditions ◽

X Ray ◽

Food Dye ◽

Pseudo Second Order ◽

Silica Nanocomposite

Objective: In this study, amine functionalized magnetite Kit-6 silica nanocomposite (Fe3O4@SiO2@Kit-6-NH2) was synthesized as an adsorbent for removing Carmoisine food dye from aqueous solutions. Method: The nanocomposite was chemically synthesized and was characterized by X-ray diffraction analysis (XRD), vi-brating sample magnetometer (VSM), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FT-IR). Taguchi orthogonal array experimental design method was used to op-timize the experimental conditions including adsorbent amount, pH of solution, amount of salt, the volume of sample and contact time. Pseudo first-order, pseudo second-order, intra-particle diffusion and Elovich kinetic models were investigated to study the kinetic parameters of sorption process. Results: The kinetic data corresponded to the pseudo second-order kinetic model with R2 = 0.9999. Also, adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherm models. The results indicated that the data were well fitted to the Freundlich isotherm model (R2 = 0.9984, n=1.0786). The reusability tests showed the proposed nanocomposite can be used more than 8 cycles with removal efficiency higher than 90%. Conclusion: The applicability study of proposed nanocomposite proved its ability for efficient removal of Carmoisine dye from real aqueous samples.

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Enhanced adsorption removal of anionic dyes via a facile preparation of amino-functionalized magnetic silica

Water Science & Technology ◽

10.2166/wst.2017.009 ◽

2017 ◽

Vol 75 (6) ◽

pp. 1399-1409 ◽

Cited By ~ 2

Author(s):

Xiao-Shui Li ◽

Yu-Han Fan ◽

Shou-Wen Zhang ◽

Shi-Hua Qi

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Maximum Adsorption Capacity ◽

Reactive Black 5 ◽

Order Kinetic ◽

Step Method ◽

Anionic Dyes ◽

Solution Ph ◽

Experimental Conditions ◽

Magnetic Silica

A novel amino-functionalized magnetic silica (Fe3O4@SiO2-NH2) was easily prepared via a one-step method integrating the immobilization of 3-aminopropyltriethoxysilane with a sol-gel process of tetraethyl orthosilicate into a single process. This showed significant improvement in the adsorption capacity of anionic dyes. The product (Fe3O4@SiO2-NH2) was characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectrometry, zeta potential and vibrating sample magnetometry. The adsorption performance of Fe3O4@SiO2-NH2 was then tested by removing acid orange 10 (AO10) and reactive black 5 (RB5) from the aqueous solutions under various experimental conditions including initial solution pH, initial dye concentrations, reaction time and temperature. The results indicated that the maximum adsorption capacity of AO10 and RB5 on Fe3O4@SiO2-NH2 was 621.9 and 919.1 mg g−1 at pH 2, respectively. The sorption isotherms fit the Langmuir model nicely. Similarly, the sorption kinetic data were better fitted into the pseudo-second order kinetic model than the pseudo-first order model. In addition, the thermodynamic data demonstrated that the adsorption process was endothermic, spontaneous and physical. Furthermore, Fe3O4@SiO2-NH2 could be easily separated from aqueous solutions by an external magnetic field, and the preparation was reproducible.

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Adsorption characteristics of Cu2+ on NiFe2O4 magnetic nanoparticles

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2014.020 ◽

2014 ◽

Vol 5 (2) ◽

pp. 223-230

Author(s):

Farid Moeinpour ◽

Shohreh Kamyab

Keyword(s):

Experimental Data ◽

Electron Microscope ◽

Magnetic Nanoparticles ◽

Kinetic Model ◽

Aqueous Solutions ◽

Copper Ions ◽

Order Kinetic ◽

Experimental Conditions ◽

Order Kinetic Model ◽

Nife2o4 Nanoparticles

Magnetic NiFe2O4 nanoparticles have been synthesized and used as adsorbents for copper removal from aqueous solution. The NiFe2O4 nanoparticles were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, and Fourier transform infrared spectroscopy. The batch removal of Cu2+ ions from aqueous solutions using NiFe2O4 magnetic nanoparticles under different experimental conditions was investigated. The effects of initial concentration, adsorbent dose, contact time, and pH were investigated. The adsorption process was pH dependent, and the maximum adsorption was observed at a pH of 6.0. Equilibrium was achieved for copper ion after 25 min. Experimental results showed that NiFe2O4 magnetic nanoparticles are effective for the removal of copper ions from aqueous solutions. The pseudo-second-order kinetic model gave a better fit of the experimental data as compared to the pseudo-first-order kinetic model. Experimental data showed a good fit with the Langmuir isotherm model.

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Competitive Sorption of Pb, Cd, and Ni on Chicken Feathers from Binary Aqueous Solutions

International Journal of Chemical Reactor Engineering ◽

10.1515/1542-6580.2724 ◽

2012 ◽

Vol 10 (1) ◽

Cited By ~ 5

Author(s):

Hilda Elizabeth Reynel-Avila ◽

Adrian Bonilla-Petriciolet ◽

Guadalupe de la Rosa

Keyword(s):

Experimental Data ◽

Aqueous Solutions ◽

Metal Ions ◽

Low Cost ◽

Competitive Sorption ◽

Equilibrium Studies ◽

Sorption Data ◽

Competitive Effects ◽

Chicken Feathers ◽

Isotherm Equations

In this paper, we report the competitive removal of Pb, Cd, and Ni ions from binary metal solutions using chicken feathers. These heavy metals are very toxic for human being and are present in wastewaters of several industrial activities. Therefore, multi-component sorption studies are required to identify the capabilities and limitations of chicken feathers as low-cost sorbent for the simultaneous removal of these metal ions from wastewaters. To the best of our knowledge, sorption equilibrium studies involving chicken feathers and Pb, Cd, and Ni in binary aqueous solutions have not been reported. Therefore, the binary sorption data for systems Pb - Cd, Pb â Ni, and Cd - Ni at different pH conditions are reported in this paper. Our experimental data are modeled using multi-component isotherm equations and desorption studies were also performed. In summary, this study provides new experimental data to identify the competitive effects of these metal ions onto the multi-component sorption performance of chicken feathers.

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