scholarly journals Preparation of a novel CeO2/SiO2 adsorbent and its adsorption behavior for fluoride ion

2017 ◽  
Vol 36 (1-2) ◽  
pp. 743-761 ◽  
Author(s):  
Jin Lin ◽  
Yan Wu ◽  
Afshin Khayambashi ◽  
Xiaolong Wang ◽  
Yuezhou Wei
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Fluoride Concentration ◽  
Energy Dispersive Spectrum ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Potential Measurement ◽  
Fluoride Adsorption ◽  
Kinetics And Isotherms

The silica-based CeO2 adsorbent (CeO2/SiO2) was prepared for removing fluoride from the aqueous solution. The synthesized adsorbent was characterized by scanning electron microscope, energy dispersive spectrum, X-ray diffractometer, Fourier transform infrared spectrometer, and zeta potential measurement analyses. The adsorption batch experiments in the various experimental conditions including solution pH, contact time, initial fluoride concentration, and adsorption temperature were performed and investigated. The maximum adsorption capacity of fluoride into CeO2/SiO2 was 2.441 mmol/g at pH 3 and 298 K. The adsorption kinetics and isotherms were well described by the pseudo-second-order model and the Langmuir model, respectively. The fluoride adsorption reached the equilibrium in 15 min from the aqueous solution with the initial fluoride concentration of 400 mg/l at 298 K. In the temperature range of 298–338 K, the maximum adsorption capacity of fluoride decreased from 2.441 mmol/g to 2.109 mmol/l at pH 3. The adsorption thermodynamics study revealed that this process was a spontaneous, exothermic, and entropy-driving adsorption. Furthermore, the mechanism of adsorption was identified as the anion exchange and the electrostatic interaction. The desorption efficiency of fluoride-loaded CeO2/SiO2 adsorbent could reach about 95% by 0.1 mol/l NaOH.

scholarly journals Efficient Removal of Diclofenac from Aqueous Solution by Potassium Ferrate-Activated Porous Graphitic Biochar: Ambient Condition Influences and Adsorption Mechanism

2019 ◽  
Vol 17 (1) ◽  
pp. 291 ◽  
Author(s):  
Nguyen Thi Minh Tam ◽  
Yunguo Liu ◽  
Hassan Bashir ◽  
Zhihong Yin ◽  
Yuan He ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Diclofenac Sodium ◽  
Maximum Adsorption Capacity ◽  
Potassium Ferrate ◽  
Solution Ph ◽  
Modified Biochar ◽  
Prepared Material ◽  
Endothermic Process ◽  
One Step

Porous graphitic biochar was synthesized by one-step treatment biomass using potassium ferrate (K2FeO4) as activator for both carbonization and graphitization processes. The modified biochar (Fe@BC) was applied for the removal of diclofenac sodium (DCF) in an aqueous solution. The as-prepared material possesses a well-developed micro/mesoporous and graphitic structure, which can strengthen its adsorption capacity towards DCF. The experimental results indicated that the maximum adsorption capacity (qmax) of Fe@BC for DCF obtained from Langmuir isotherm simulation was 123.45 mg·L−1 and it was a remarkable value of DCF adsorption in comparison with that of other biomass-based adsorbents previously reported. Thermodynamic quality and effect of ionic strength studies demonstrated that the adsorption was a endothermic process, and higher environmental temperatures may be more favorable for the uptake of DCF onto Fe@BC surface; however, the presence of NaCl in the solution slightly obstructed DCF adsorption. Adsorption capacity was found to be decreased with the increase of solution pH. Additionally, the possible mechanism of the DCF adsorption process on Fe@BC may involve chemical adsorption with the presence of H-bonding and π–π interaction. With high adsorption capacity and reusability, Fe@BC was found to be a promising absorbent for DCF removal from water as well as for water purification applications.

scholarly journals Adsorption and removal of bisphenol A from aqueous solution by p-phenylenediamine modified magnetic graphene oxide

2017 ◽  
Vol 82 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Xiaosheng Tang ◽  
Ping Tang ◽  
Shihui Si ◽  
Liangliang Liu
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Bisphenol A ◽  
Adsorption Capacity ◽  
Infrared Spectrometry ◽  
Maximum Adsorption Capacity ◽  
Adsorption Ability ◽  
Magnetic Graphene Oxide ◽  
Magnetic Graphene ◽  
Kinetics And Isotherms

p-Phenylenediamine functionalized magnetic graphene oxide nanocomposites (PPD-MGO) were prepared and utilized in the adsorption and removal of bisphenol A in aqueous solution. The novel nanomaterials were characterized by transmission electron microscopy (TEM), Fourier infrared spectrometry (FT-IR) and vibrating sample magnetometer (VSM). The factors affected the adsorption of bisphenol A including adsorption time, temperature and pH of solution, adsorption kinetics and isotherms were all investigated. The results showed that PPD-MGO nanomaterial exhibited good adsorption ability for bisphenol A and good resuability. The maximum adsorption capacity reached 155.0 mg g-1 at 45?C and pH 7. The removal rate was 99.2 % after three times of adsorption with new nanomaterials. After five cycles adsorption, the adsorption capacity of PPD-MGO remained at 94.0 %. The adsorption of bisphenol A was found that fitted pseudo second order kinetics equations and the Freundlich adsorption model. The experimental results showed the PPD-MGO nanomaterial had a good adsorption ability to remove organic compounds in aqueous solution.

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

2017 ◽  
Vol 75 (6) ◽  
pp. 1399-1409 ◽  
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.

Magnetic nanopowder as effective adsorbent for the removal of Congo Red from aqueous solution

2013 ◽  
Vol 69 (6) ◽  
pp. 1234-1240 ◽  
Author(s):  
O. Paşka ◽  
R. Ianoş ◽  
C. Păcurariu ◽  
A. Brădeanu
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Congo Red ◽  
Polluted Water ◽  
Maximum Adsorption Capacity ◽  
Anionic Dyes ◽  
Solution Ph ◽  
Efficient Combustion ◽  
Equilibrium Data ◽  
Pseudo Second Order

A magnetic iron oxide nanopowder (MnP), prepared by a simple and efficient combustion synthesis technique, was tested for the removal of the anionic dye Congo Red (CR) from aqueous solution. The influence of solution pH, adsorbent dose, temperature, contact time and initial dye concentration on the adsorption of CR onto MnP were investigated. It was shown that the CR adsorption was pH dependent and the adsorption mechanism was governed by electrostatic forces. The adsorption kinetic was best described by the pseudo-second-order model and the equilibrium data were well fitted to the Langmuir isotherm, yielding maximum adsorption capacity of 54.46 mg g−1. The undeniable advantages of the MnP adsorbent such as inexpensive preparation method, good adsorption capacity and easy separation using an external magnetic field, recommend it as a promising candidate for the removal of anionic dyes from polluted water.

scholarly journals The nature and kinetics of 2,4-dimethylphenol adsorption in aqueous solution on biochar derived from Sargassum boveanum macroalgae

2020 ◽  
Vol 69 (5) ◽  
pp. 438-452 ◽  
Author(s):  
Mazen K. Nazal ◽  
Durga Rao ◽  
Nabeel Abuzaid
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Freundlich Model ◽  
Adsorptive Removal ◽  
Adsorbate Concentration ◽  
Pseudo Second Order ◽  
Kinetics Of

Abstract Many industries produce 2,4-dimethylphenol (DMP) compound in the wastewater which is persistent, toxic, and carcinogenic. Therefore, an adsorbent was prepared by carbonizing a dried Sargassum boveanum macroalgae. The prepared biosorbent was investigated for adsorptive removal of DMP from aqueous solution. After carbonization, the biochar derived from S. boveanum macroalgae (BCM) removed almost 100% of DMP adsorbate. Effects of contact time, solution pH, adsorbate concentration, adsorbent mass, and temperature have been studied. It has been found that, within the experimental conditions, the maximum adsorption capacity is 17 mg/g, rate of adsorption follows pseudo-second order kinetics and the adsorption isotherm experimental data fit the Freundlich model. The thermodynamic parameters were calculated and it has been found that the adsorption of DMP on BCM is endothermic and thermodynamically favorable, and in addition the surface of BCM adsorbent shows affinity to the DMP molecules. The BCM adsorbent has the capability to remove around 65% of DMP from high saline seawater contaminated with DMP. Moreover, the prepared BCM adsorbent was reusable for at least four times in seawater for removal of DMP contaminant.

Removing Cd(II) from Aqueous Solution by Inverse Opal Hybrid SiO2

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050047
Author(s):  
Yanhong Wang ◽  
Xiuli Wang ◽  
Cuihong Wu ◽  
Xiaomei Wang ◽  
Xu Zhang
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Pore Wall ◽  
Ionic Concentration ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Inverse Opal ◽  
Solution Ph ◽  
Adsorption Desorption

A hybrid adsorbent with inverse opal (IO) structure was prepared for removing Cd(II) from aqueous solution. The functional polymeric chains were grafted from the pore wall of IO silica to prepare the porous hybrid material by surface-initiated atom-transfer radical polymerization. Furthermore, the amidation reaction was carried out to obtain diethylenetriamine-modified hybrid adsorbent (IO SiO2-g-PAA-DETA). Batch adsorption of removing Cd(II) onto IO SiO2-g-PAA-DETA was studied as the effect of solution pH, adsorbent doses, contact time, ionic concentration, and temperature. When the grafted amount was 73%, the maximum adsorption capacity was obtained. The optimum adsorbent dose and pH value for adsorbing Cd(II) were found to be 5[Formula: see text]g/L and 0.5[Formula: see text]g/L, respectively. The adsorption capacity was almost unaffected by Na[Formula: see text] at low concentrations. The adsorption data was depicted by the corresponding models and the results displayed that adsorbing Cd(II) on IO SiO2-g-PAA-DETA followed the Freundlich and pseudo-first-order model. In addition, after six adsorption–desorption cycles, IO adsorbent could remain above 80% of the first adsorption ability while it was washed using 0.025[Formula: see text]M EDTA.

scholarly journals Adsorption of Pb2+ ions from aqueous solutions by gelatin/activated carbon composite bead form

2017 ◽  
Vol 36 (1-2) ◽  
pp. 355-371 ◽  
Author(s):  
Fareeda Hayeeye ◽  
Qiming J Yu ◽  
Memoon Sattar ◽  
Watchanida Chinpa ◽  
Orawan Sirichote
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Carbon Composite ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Composite Bead

Gelatin and activated carbon materials have been combined together to obtain a gelatin/activated carbon composite bead form which is ecofriendly, nontoxic, biocompatible, and inexpensive material. In this paper, gelatin/activated carbon adsorption for Pb2+ ions from aqueous solutions was studied experimentally under various conditions. The experimental conditions such as contact time, solution pH, and gelatin/activated carbon dosage were examined and evaluated by using batch adsorption experiments. The maximum adsorption capacity of gelatin/activated carbon for Pb2+ ions was obtained to be 370.37 mg g−1. This maximum capacity was comparable with that of commercial ion exchange resins and it was much higher than those of natural zeolites. The uptake process for Pb2+ ions was found to be relatively fast with 92.15% of the adsorption completed in about 5 min in batch conditions. The adsorption capacity was also strongly solution pH dependent. Adsorption was observed at pH value as low as 2.0 and maximum adsorption was achieved at a pH of approximately 5. The results indicated that the gelatin/activated carbon was effective to be used as an adsorbent for Pb2+ ions removal in wastewater treatment.

Effect of Oxalic Acid on the Adsorption of Fluoride by Phosphate Rock from Aqueous Solution

2012 ◽  
Vol 610-613 ◽  
pp. 390-393
Author(s):  
Yu Wang ◽  
Xiao Qing Dong ◽  
Bao Hua Zhou ◽  
Zhi Bing Xu
Keyword(s):  
Aqueous Solution ◽  
Oxalic Acid ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Phosphate Rock ◽  
Fluoride Concentration ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Fluoride Uptake ◽  
Adsorbent Dose

The defluoridation capacity of phosphate rock in the presence of oxalic acid was investigated using batch experiments. Defluoridation capacity of phosphate rock was enhanced in the presence of oxalic acid, removing fluoride from 22.46% up to 57.98% with 2.5 mmol/L oxalic acid. The contact time and pH for maximum fluoride uptake were found 2 h and 5, respectively. Maximum adsorption capacity (0.36 mg/g) of fluoride on phosphate rock was observed at 50 mg/L initial fluoride concentration using 2 g adsorbent dose.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

scholarly journals Adsorptive and Coagulative Removal of Trace Metals from Water Using Surface Modified Sawdust-Based Cellulose Nanocrystals

J ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 193-205
Author(s):  
Opeyemi A. Oyewo ◽  
Sam Ramaila ◽  
Lydia Mavuru ◽  
Taile Leswifi ◽  
Maurice S. Onyango
Keyword(s):  
Trace Metals ◽  
Adsorption Capacity ◽  
Cellulose Nanocrystals ◽  
Inductively Coupled Plasma ◽  
Electrostatic Interactions ◽  
Natural Waters ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Major Drawback ◽  
Surface Modified

The presence of toxic metals in surface and natural waters, even at trace levels, poses a great danger to humans and the ecosystem. Although the combination of adsorption and coagulation techniques has the potential to eradicate this problem, the use of inappropriate media remains a major drawback. This study reports on the application of NaNO2/NaHCO3 modified sawdust-based cellulose nanocrystals (MCNC) as both coagulant and adsorbent for the removal of Cu, Fe and Pb from aqueous solution. The surface modified coagulants, prepared by electrostatic interactions, were characterized using Fourier transform infrared, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive spectrometry (SEM/EDS). The amount of coagulated/adsorbed trace metals was then analysed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). SEM analysis revealed the patchy and distributed floccules on Fe-flocs, which was an indication of multiple mechanisms responsible for Fe removal onto MCNC. A shift in the peak position attributed to C2H192N64O16 from 2θ = 30 to 24.5° occurred in the XRD pattern of both Pb- and Cu-flocs. Different process variables, including initial metal ions concentration (10–200 mg/L), solution pH (2–10), and temperature (25–45 °C) were studied in order to investigate how they affect the reaction process. Both Cu and Pb adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 111.1 and 2.82 mg/g, respectively, whereas the adsorption of Fe was suggestive of a multilayer adsorption process; however, Fe Langmuir maximum adsorption capacity was found to be 81.96 mg/g. The sequence of trace metals removal followed the order: Cu > Fe > Pb. The utilization of this product in different water matrices is an effective way to establish their robustness.

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