Effectiveness and Mechanism of the In Situ Formed Iron Hydroxide (FeOxHy) towards the Removal of Phosphate by Coagulation and Adsorption

2013 ◽  
Vol 807-809 ◽  
pp. 1251-1257 ◽  
Author(s):  
Li Hua Sun ◽  
Xiao Lu Qi ◽  
Ya Jun Zhang
Keyword(s):  
Iron Hydroxide ◽  
Iron Phosphate ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Molar Ratios ◽  
Beneficial Effects ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Hydrolysis Of

This study prepares the in situ formed iron hydroxide (In situ FeOxHy) by the interactions between Fe3+ and OH- at different molar ratios of 1:0,1:1,1:2,and 1:3, and investigates the performance and mechanism involved in the removal of phosphate. The removal efficiency increases with elevated doses of FeOxHy and the maximum removal is observed to be in neutral pH ranges. The elevated ratios of OH- to Fe3+ inhibit the removal of phosphate whereas at low alkalinity,the introduction of OH- shows beneficial effects. The abovementioned four kinds of FeOxHy can rapidly adsorb most phosphate within 15 s, and the adsorption process can be well described by the Pseudo-second-order kinetic model. Freundlich model can well describe the adsorption of phosphorus onto these four FeOxHy. The adsorption of phosphate significantly decreases the zeta potential of these in situ FeOxHy. The MINITEQ software can indicate the species distribution of phosphate and iron salts, and the theoretical calculation indicates that the introduced OH- can promote the hydrolysis of Fe3+ especially in low alkalinity system,which can easily adsorb H2PO4- and HPO42- and form the multinuclear hydroxy iron phosphate complexes thereafter.

scholarly journals Removal of Lead(II) from Synthetic Wastewater by Lavandula pubescens Decne Biosorbent: Insight into Composition–Adsorption Relationship

2020 ◽  
Vol 10 (21) ◽  
pp. 7450
Author(s):  
Ali Q. Alorabi ◽  
Fahad A. Alharthi ◽  
Mohamed Azizi ◽  
Nabil Al-Zaqri ◽  
Adel El-Marghany ◽  
...  
Keyword(s):  
Ion Concentration ◽  
Wild Plant ◽  
Synthetic Wastewater ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Liquid Chromatography ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Best Fit

In this work, the widely-abundant, cheap, wild plant Lavandula pubescens Decne was evaluated as an adsorbent for removing Pb(II) ions from wastewater. The chemical composition of the plant was partially isolated and characterized by the corresponding techniques, including gas chromatography–mass spectrometry, gas liquid chromatography, and FTIR spectroscopy. The adsorption capacity of the dried plant material for Pb(II) ions increased with increasing contact time, initial ion concentration, and temperature, while it decreased with increasing adsorbent dosage. The optimum condition for Pb(II) adsorption was determined as 550 mg/L initial metal concentration, pH ≤ 7, and 90 min of contact. The best fit for Pb(II) adsorption isotherms was the linear form of the Freundlich model; however, the maximum capacity indicated by Langmuir was 91.32 mg/g. The experimental data fit better the pseudo-second-order kinetic model (R2 = 0.969), suggesting chemisorption process. Thermodynamic data revealed an endothermic, nonspontaneous, and adsorption process favored at higher concentrations.

scholarly journals Preparation and Adsorption Properties of Biochar/g-C3N4 Composites for Methylene Blue in Aqueous Solution

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Li
Keyword(s):  
Methylene Blue ◽  
Thermodynamic Parameters ◽  
Raw Materials ◽  
Order Kinetic ◽  
Adsorption Effect ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Doping Ratio

Using straw and urea as raw materials, biochar (BC) and g-C3N4 were prepared by oxygen-free pyrolysis at 300°C and 550°C. BC/g-C3N4 was prepared by loading different amounts of g-C3N4 onto the surface of biochar and characterized by SEM and FT-IR. The adsorption effect on methylene blue (MB) was investigated from the aspects of dosage and pH. The studies of adsorption equilibrium isotherms and the kinetic and the thermodynamic parameters on the BC/g-C3N4 adsorbents are discussed. The results showed that BC/g-C3N4 0.16 g/L with a doping ratio of 1 : 3 was added to the MB solution with an initial concentration of 50 mg/L and pH=11. The adsorption rate and adsorption amount were 96.72% and 302.25 mg/g, respectively. The adsorption process included surface adsorption and intraparticle diffusion, which conformed to the pseudo-second-order kinetic model and Langmuir-Freundlich model. Thermodynamic parameters (ΔG0<0, ΔH0>0, and ΔS0>0) showed that the adsorption reaction is spontaneous, which positively correlated with temperature.

scholarly journals Construction of Novel Polymerizable Ionic Liquid Microemulsions and the In Situ Synthesis of Poly(Ionic Liquid) Adsorbents

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 454 ◽  
Author(s):  
Aili Wang ◽  
Shuhui Li ◽  
Hou Chen ◽  
Ying Liu ◽  
Xiong Peng
Keyword(s):  
Ionic Liquid ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
In Situ Synthesis ◽  
Scattering Data ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Poly Ionic Liquid

This paper reports the successful construction of novel polymerizable ionic liquid microemulsions and the in situ synthesis of poly(ionic liquid) adsorbents for the removal of Zn2+ from aqueous solution. Dynamic light-scattering data were used to confirm the polymerization media and to illustrate the effect of the crosslinker dosage on the droplet size of the microemulsion. FTIR and thermal analysis were employed to confirm the successful preparation of the designed polymers and characterize their thermostability and glass transition-temperature value. The optimization of the adsorption process indicates that the initial concentration of Zn2+, pH, adsorbent dosage and contact time affected the adsorption performance of poly(ionic liquid)s toward Zn2+. Furthermore, our research revealed that the adsorption process can be effectively described by the pseudo second-order kinetic model and the Freundlich isotherm model.

Adsorption kinetics and isotherm of vanadium with melamine

2017 ◽  
Vol 75 (10) ◽  
pp. 2316-2321 ◽  
Author(s):  
Hao Peng ◽  
Zuohua Liu ◽  
Changyuan Tao
Keyword(s):  
Adsorption Kinetics ◽  
Impact Factors ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Initial Ph ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm ◽  
Langmuir And Freundlich Models

Melamine, possessing three free amino groups and three aromatic nitrogen atoms in its molecule, has great potential as an adsorbent for metal ions. We investigated three impact factors of the adsorption process: the initial pH of the vanadium solution, contact time and reaction temperature. The adsorption kinetics could be accurately described by the pseudo-second-order kinetic model. Langmuir and Freundlich models fitted well with the experimental equilibrium data, and the maximal adsorption capacity was found to be 1,428.57 mg vanadium/g melamine, and the Freundlich model showed the adsorption is privilege type.

The Bentonite Copolymer Composite for Removing Lead Ions

2013 ◽  
Vol 750-752 ◽  
pp. 47-50
Author(s):  
Wen Juan He ◽  
Yu Feng He ◽  
Zhen Hua Zhang ◽  
Ju Hua Guo ◽  
Rong Min Wang
Keyword(s):  
Kinetic Model ◽  
Maleic Anhydride ◽  
In Situ Polymerization ◽  
Removal Rate ◽  
Order Kinetic ◽  
Adsorption Dynamics ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Polymer Adsorbent

In this paper, a new kind of clay copolymer adsorbent, bentonite compositing with maleic anhydride (MAH)-acrylic acid (AA)-vinyl acetate (VAc) copolymer (NaB/PMAV) was prepared by in-situ polymerization. It was used as polymer adsorbent for removing Pb (II) ions in wastewater.. Under the optimal condition of adsorption, the removal rate reached to 94.4% and the adsorption capacity got to 235.9 mg/g. Adsorption dynamics were consistent with pseudo-second-order kinetic model and isotherm model can meet the Langmuir isotherm.

scholarly journals In situ synthesis of layered double hydroxides on γ-Al2O3 and its application in chromium(VI) removal

2017 ◽  
Vol 75 (6) ◽  
pp. 1466-1473 ◽  
Author(s):  
Shifeng Li ◽  
Fang Qi ◽  
Min Xiao ◽  
Hongtao Fan ◽  
Yanming Shen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxides ◽  
Adsorptive Capacity ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Chromium Vi ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Double Hydroxides

Mg-Al layered double hydroxides (LDHs) adsorbent was synthesized in situ on γ-Al2O3 for the removal of Cr(VI) from aqueous solution. The material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electronic microscopy and thermogravimetry and differential thermal analysis. Compared to the LDHs powder, the calcined LDHs sorbent prepared in situ on γ-Al2O3 had higher specific surface area and was easy to recover and reuse. The adsorptive capacity for removing Cr(VI) from aqueous solution was resulting from the memory effect of LDHs based on the XRD results. Both the pseudo-second-order kinetic model and the Langmuir model fit the experimental data well. Furthermore, the adsorbent exhibits excellent sorption–regeneration performances.

scholarly journals Chromium and nickel metal ions removal from contaminated water using Nigerian bentonite clay

2021 ◽  
Author(s):  
Jock Asanja Alexander ◽  
Oboh Oseribo Innocent ◽  
Uwem Ekwere Inyang ◽  
Ganchok Lawrence ◽  
Adeku Ojo
Keyword(s):  
Metal Ions ◽  
Bentonite Clay ◽  
Textural Properties ◽  
Order Kinetic ◽  
Nickel Metal ◽  
Batch Mode ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Maximum Removal

Abstract In this work bentonite clay was characterized and investigated for the adsorption of chromium and nickel metal ions from aqueous solution. The clay calcined at 650 °C was characterized for physical, chemical and textural properties. Nickel sulphate hexahydrate (NiSO4.6H2O) and chromium tri oxide (Cr2O3) solutions were used as metal model compounds to evaluate the adsorption efficiency of the clay in a batch mode. The initial metal ions concentration range from 10 to 50 mg/L and the maximum removal efficiency was 99.40% for Cr (III) and 71.50% for Ni (II) metal ions. Langmuir and Freundlich models were utilized for the analysis of adsorption equilibrium isotherm. The experimental data fitted well into Freundlich model for Cr (III) with regression coefficient (R2) of 0.996 and the Langmuir model for Ni (II) having R2 value 0.994. The Pseudo second order kinetic model fitted well for both chromium and nickel and their adsorption from single metal solutions followed the order Cr &gt; Ni. Highlight The local clay has not been reported in any scholarly journal or publication. Theremoval of nickel and chromium using this clay has been found effective. The dataobtained will form a baseline for references and learning purposes.

scholarly journals Synthesis, Characterization and Application of a Diatomite-Based Composite for the Adsorption of Anionic Dyes in Aqueous Solutions

2021 ◽  
Vol 15 (3) ◽  
pp. 377-388
Author(s):  
Sadek Chentouf ◽  
◽  
Smail Kacha ◽  
Réda Marouf ◽  
Fouad Mekhalef Benhafsa ◽  
...  
Keyword(s):  
Adsorption Isotherm ◽  
In Situ Polymerization ◽  
Order Kinetic ◽  
Anionic Dyes ◽  
Bet Model ◽  
Freundlich Adsorption Isotherm ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Acid Blue

Synthesis, characterization and application of the polyaniline-diatomite (PAD) composite in the adsorption of Reactive Red 120 (RR 120) and Acid Blue (AB) dyes were carried out. The composite was prepared by the in situ polymerization of aniline. Mass of purified diatomite was mixed with a solution containing aniline dissolved in 2M hydrochloric acid at room temperature. The solid obtained was characterized using the SEM, XRD and FTIR analyses. The kinetic adsorption of dyes was described using the pseudo-second order kinetic model. The adsorption isotherm of the RR 120 dye can be fitted by the Freundlich adsorption isotherm model. However, the adsorption isotherm of the AB dye can be better fitted by the BET model.

scholarly journals Cr(VI) adsorption from aqueous streams on eggshell membranes of different birds used as biosorbents

2020 ◽  
Vol 38 (9-10) ◽  
pp. 413-434
Author(s):  
Jessica Badillo-Camacho ◽  
Eulogio Orozco-Guareño ◽  
Gregorio G Carbajal-Arizaga ◽  
Ricardo Manríquez-Gonzalez ◽  
Icela D Barcelo-Quintal ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Membrane Surfaces ◽  
Adsorption Isotherm Models ◽  
Before And After ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Efficient Option

The discharges enriched with heavy metals, particularly Cr(VI), are a serious environmental problem. In this work, it is presented the use of biosorbents from eggshells membranes of ostrich, quail, duck and chicken; the membranes were easily prepared and studied for the removal of Cr(VI) from aqueous solutions. Maximum uptake of 1.41 mmol g−1 membrane permitted the identification of ostrich membrane as the material with the highest Cr(VI) uptake. N2 adsorption experiments permitted to classify ostrich membranes as mesoporous materials, since they had pore size of 14.8 nm. This represented an advantage on the nature of these membranes to be used as biosorbents with respect to other membranes. The adsorption isotherm models such as Langmuir and Freundlich were verified using experimental data. Langmuir model described the adsorption process satisfactorily at pH 1 and 2 whereas Freundlich model fitted data better at pH 3 and 5. The adsorption kinetic data were adjusted to a pseudo-second order kinetic model. TGA results permitted demonstrating a low thermal stability of ostrich membrane, since it starts decomposing at around 50°C due to the fact that membranes have about 60% protein. Through SEM microscopy was possible to observe the morphology of the membrane surfaces before and after Cr(VI) uptake which reflects the textural characteristics of the biosorbent. FTIR and XPS analyses suggested that Cr was adsorbed on ostrich membranes through the amine groups of proteins conforming the fibers of membranes. Despite the oxygen shows higher electronegativity than N, Cr shows more preference toward N due to fact that pH conditions favor the positive charges on the surface of the membrane. Our results make evident that this waste material is a novel and efficient option for the removal of Cr(VI) from aqueous solutions.

scholarly journals Kinetics and Isotherm Modeling for the Treatment of Rubber Processing Effluent Using Iron (II) Sulphate Waste as a Coagulant

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1747 ◽  
Author(s):  
Rahmat Ngteni ◽  
Md. Sohrab Hossain ◽  
Mohd Omar Ab Kadir ◽  
Ahmad Jaril Asis ◽  
Zulhafiz Tajudin
Keyword(s):  
Iron Hydroxide ◽  
Industrial Effluent ◽  
Oxygen Demand ◽  
Industrial Effluents ◽  
Suspended Solid ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Minimal Environmental Impact ◽  
Multilayer Formation

There is increasing concern to determine an alternative coagulant for treating industrial effluent with minimal environmental impact and operational cost. In this study, iron (II) sulphate heptahydrate (FeSO4·7H2O) waste, an industrial byproduct from a titanium oxide processing industry, was used as a coagulant for the removal of ammonia (NH3), chemical oxygen demand (COD), biochemical oxygen demand (BOD), and suspended solid (SS) from secondary rubber processing effluent (SRPE). The highest percentage removal of BOD, COD, SS, and NH3 achieved was approximately 97%, 99%, 98%, and 95%, respectively, at pH 5.0, coagulant dose of 1 g/L, coagulation time of 60 min, sedimentation time of 60 min, and at an elevated temperature of 70 °C. The best described adsorption isotherm model was found to be the Brunauer–Emmett–Teller (BET) model, indicated that the FeSO4·7H2O adsorption took placed on the surface of iron hydroxide precipitates with multilayer formation and random distribution. The kinetics analysis showed that the adsorption mechanism was well fitted with the pseudo-second-order kinetic model. The findings of the present study show that the FeSO4·7H2O waste has the potential to be used as a coagulant for the treatment of industrial effluents, including the secondary rubber processing effluent.

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