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.

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.

Simultaneous sorption of As, B, Cr, Mo and Se from coal fly ash leachates by Al3+-pillared bentonite clay: implication for the construction of activated geo-synthetic clay liner

2017 ◽  
Vol 12 (1) ◽  
pp. 186-201 ◽  
Author(s):  
Vhahangwele Masindi ◽  
W. Mugera Gitari ◽  
Hlanganani Tutu
Keyword(s):  
Fly Ash ◽  
Adsorption Isotherm ◽  
Coal Fly Ash ◽  
Bentonite Clay ◽  
Order Kinetic ◽  
Modified Bentonite ◽  
Adsorption Affinity ◽  
Freundlich Adsorption Isotherm ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The present study reports the optimum conditions for intercalating the Al3+ species to bentonite clay matrices and evaluate the potential of using Al3+-modified bentonite clay (Alum-Bent) for removal of oxyanionic species of As, B, Cr, Mo and Se from coal fly ash (FA) leachates. Removal of oxyanionic species was done in batch experimental procedures. Parameters optimized were: contact time, adsorbent dosage, concentration and pH. The adsorption affinity of Al3+-bentonite clay for oxyanionic species varied as follows: B ≈ Se > Mo > Cr ≈ As respectively. The adsorption data fitted better to Langmuir adsorption isotherm than Freundlich adsorption isotherm hence confirming mono-site adsorption. The adsorption kinetics fitted well pseudo-second-order kinetic model hence confirming chemisorption. The fact that most of the oxyanion were adsorbed at pH ≥ pHpzc indicated that both electrostatic and chemical interactions occurred with the clay surface and interlayers. The Al3+-modified bentonite clay successfully removed oxyanion species from generated coal FA leachates. This study shows that Al3+-modified bentonite clay is an effective adsorbent for oxyanion species in coal FA leachates and could be applied as a reactive barrier in coal FA retention ponds.

Adsorption of Phosphorus by Ce-Modified Lithium Silica Fume

2013 ◽  
Vol 368-370 ◽  
pp. 687-691 ◽  
Author(s):  
Wei Lan Lin ◽  
Jin Chuan Gu ◽  
Wen Yuan Wang ◽  
Yu Heng Wang
Keyword(s):  
Adsorption Isotherm ◽  
Silica Fume ◽  
Adsorption Process ◽  
Ph Value ◽  
Order Kinetic ◽  
Phosphorus Adsorption ◽  
Initial Ph ◽  
Freundlich Adsorption Isotherm ◽  
Order Kinetic Model ◽  
Pseudo Second Order

This is a study about using cerium ions solution to modify lithium silica fume and the phosphorus adsorption by the modified material. The way to modify lithium silica fume and adsorption conditions has been researched. It was found that capacity of adsorption have been improved after modification by the cerium nitrate. In the adsorption test, we studied the effects of the concentration of cerium ions, the calcination temperature, the dosage, initial pH value, reaction temperature and other factors on the adsorption. The results indicated that after modifications by 3% cerium ions , calcinations at 573k, the adsorption of phosphorus can get more than 90% when modified lithium silica fume dosage is 9.6g.l-1 and the concentration of phosphorus solution is 4 mg.l-1. In addition, the Freundlich adsorption isotherm is fit for the description of the phosphorus adsorption. The phosphorus adsorption process was in accord with pseudo-second-order kinetic model.

scholarly journals Simultaneous removal of cationic and anionic dyes from aqueous solution by double functional groups modified bagasse

2020 ◽  
Vol 82 (10) ◽  
pp. 2159-2167
Author(s):  
Ru-yi Zhou ◽  
Jun-xia Yu ◽  
Ru-an Chi
Keyword(s):  
Aqueous Solution ◽  
Functional Groups ◽  
Order Kinetic ◽  
Anionic Dyes ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Amine Groups ◽  
Modified Adsorbents ◽  
Zeta Potential Analysis

Abstract Double functional groups modified bagasse (DFMBs), a series of new zwitterionic groups of carboxyl and amine modified adsorbents, were prepared through grafting tetraethylenepentamine (TEPA) onto the pyromellitic dianhydride (PMDA) modified bagasse using the DCC/DMAP method. DFMBs' ability to simultaneously remove basic magenta (BM, cationic dye) and Congo red (CR, anionic dye) from aqueous solution in single and binary dye systems was investigated. FTIR spectra and Zeta potential analysis results showed that PMDA and TEPA were successfully grafted onto the surface of bagasse, and the ratio of the amount of carboxyl groups and amine groups was controlled by the addition of a dosage of TEPA. Adsorption results showed that adsorption capacities of DFMBs for BM decreased while that for CR increased with the increase of the amount of TEPA in both single and binary dye systems, and BM or CR was absorbed on the modified biosorbents was mainly through electrostatic attraction and hydrogen bond. The adsorption for BM and CR could reach equilibrium within 300 min, both processes were fitted well by the pseudo-second-order kinetic model. The cationic and anionic dyes removal experiment in the binary system showed that DMFBs could be chosen as adsorbents to treat wastewater containing different ratios of cationic and anionic dyes.

Adsorption of Pb(II) from Aqueous Solutions on Dithizone-Immobilized Coal Fly Ash

2020 ◽  
Vol 840 ◽  
pp. 57-63
Author(s):  
Dina Fitriana ◽  
Mudasir Mudasir ◽  
Dwi Siswanta
Keyword(s):  
Fly Ash ◽  
Adsorption Isotherm ◽  
Contact Time ◽  
Coal Fly Ash ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Activated Coal ◽  
Concentration Of Ions ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Adsorption of Pb(II) ions onto selective adsorbent of dithizone-immobilized coal fly ash (DCFA) from Holcim, Cilacap, Indonesia has been investigated in batch experiments. Prepared coal fly ash (CFA) modified by immobilization of dithizone previously were characterized by FT-IR and XRD. Several parameters influencing the adsorption of Pb(II) ions such as effect of pH, adsorbent dosage, contact time and initial concentration of ions on the efficiency of the adsorption were studied. The optimum condition of Pb(II) adsorption was found at pH 5, adsorbent dosage 0.1 g, contact time 60 min and initial Pb(II) ions concentration of 60 mg L–1. The adsorption kinetics of Pb(II) ions on DCFA was found to follow a pseudo-second-order kinetic model. The adsorption isotherm data were fitted to the Langmuir model. Kinetics and adsorption isotherm studies suggest that the capacity and affinity of the DCFA in adsorbing Pb(II) ions is significantly improved compared to those of non-immobilized activated coal fly ash (ACFA).

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.

KINETICS AND ISOTHERM STUDIES OF Pb(II) IMPRINTED CARBOXYMETHYL CHITOSAN–PECTIN-PEGDE

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Budi Hastuti ◽  
Dwi Siswanta ◽  
Mudasir Mudasir ◽  
Triyono Triyono
Keyword(s):  
Adsorption Isotherm ◽  
Kinetic Model ◽  
Metal Ion ◽  
Diglycidyl Ether ◽  
Carboxymethyl Chitosan ◽  
Second Order ◽  
Order Kinetic ◽  
Freundlich Adsorption Isotherm ◽  
Order Kinetic Model ◽  
Chelation Reaction

Pectin and chitosan are biomaterials that capable to act as biosorbent. Pectin has active groups, such as carboxyl, methoxyl, and hydroxyl (OH), while chitosan has amine group (–NH2) and hydroxyl (OH) as the active site metal ion absorber. Integration of two biopolymers is conducted by using a suitable cross-linker agents that are expected to form stable and more organized structure. This structure facilitate metal ions to enter and to form chelation reaction. Thus, it has great capacity for metal adsorption. A modified natural adsorbent pectin-chitosan has been synthesized by reacting of -OH group among pectin (Pec) and chitosan with Poly(ethylene glycol) Diglycidyl Ether (PEGDE) crosslinker agent to form a stable and an acidic medium-resistance adsorbent. Prior to increasing the active group of the adsorbent, chitosan was attached with acetate to form Carboxymethyl Chitosan (CMC). Furthermore, the CMC-Pec-PEGDE adsorbent was imprinted with Pb (II) to afford Pb(II) imprinted-CMC-Pec-PEGDE adsorbent in order to improve the selective sorption of Pb(II) metal ion. All of the functional groups attached on the synthesized adsorbents were characterized by Fourier Transform Infrared (FT-IR) Spectrometry. The kinetics and thermodynamics bath sorption of Pb(II) on Pb(II) imprinted-CMC-Pec-PEGDE film adsorbent have been investigated including the optimal condition for adsorption. The pseudo first-order and second-order kinetic model were investigated in order to determine the adsorption mechanism. The results indicated that all of the three adsorbent, CMC, CMC-Pec-PEGDE, and Pb(II) imprinted-CMC-Pec-PEGDE followed a pseudo-second-order kinetic model. Furthermore, adsorption studies of Pb(II) ion on CMC and CMC–Pec-PEGDE found to follow Langmuir adsorption while on imprinted-CMC-Pec-PEGDE followed Freundlich adsorption isotherm. The adsorption isotherm parameters of CMC and CMC-Pec-PEGDE adsorbents were ΔG° of 24.8 and 23.1 kJ mol-1, respectively. While Pb(II) imprinted-CMC-Pec-PEGDE followedisotherm model with ΔG° of 9.6 kJ mol-1.

scholarly journals Preparation and Characterization of Magadiite–Magnetite Nanocomposite with Its Sorption Performance Analyses on Removal of Methylene Blue from Aqueous Solutions

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 607 ◽  
Author(s):  
Mingliang Ge ◽  
Zhuangzhuang Xi ◽  
Caiping Zhu ◽  
Guodong Liang ◽  
Guoqing Hu ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Isotherm ◽  
Kinetic Model ◽  
Aqueous Solutions ◽  
Langmuir Adsorption Isotherm ◽  
Order Kinetic ◽  
Langmuir Adsorption ◽  
Adsorption Performance ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The magadiite–magnetite (MAG–Fe3O4) nanocomposite has great potential applications in the field of biomaterials research. It has been used as a novel magnetic sorbent, prepared by co-precipitation method. It has the dual advantage of having the magnetism of Fe3O4 and the high adsorption capacity of pure magadiite (MAG). MAG–Fe3O4 was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The results showed that Fe3O4 nanoparticles were deposited on the interlayer and surface of magadiite. MAG–Fe3O4 was treated as an adsorbent for methylene blue (MB) removal from aqueous solutions. The adsorption properties of MAG–Fe3O4 were investigated on methylene blue; however, the results showed that the adsorption performance of MAG–Fe3O4 improved remarkably compared with MA and Fe3O4. The adsorption capacity of MAG–Fe3O4 and the removal ratio of methylene blue were 93.7 mg/g and 96.2%, respectively (at 25 °C for 60 min, pH = 7, methylene blue solution of 100 mg/L, and the adsorbent dosage 1 g/L). In this research, the adsorption experimental data were fitted and well described using a pseudo-second-order kinetic model and a Langmuir adsorption isotherm model. The research results further showed that the adsorption performance of MAG–Fe3O4 was better than that of MAG and Fe3O4. Moreover, the adsorption behavior of MB on MAG–Fe3O4 was investigated to fit well in the pseudo-second-order kinetic model with the adsorption kinetics. The authors also concluded that the isothermal adsorption was followed by the Langmuir adsorption isotherm model; however, it was found that the adsorption of the MAG–Fe3O4 nanocomposite was a monolayer adsorption.

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 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.

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