scholarly journals Synthesis of Reusable Cyclodextrin Polymers for Removal of Naphthol and Naphthylamine from Water

2021 ◽  
Author(s):  
Weifeng Xu ◽  
Xiang Liu ◽  
Jianzhe Cai ◽  
Tiemeng Xue ◽  
Kewen Tang
Keyword(s):  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Naphthalene Derivatives ◽  
Initial Concentration ◽  
Low Concentration ◽  
Adsorption Temperature ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Cyclodextrin Polymers ◽  
The Impact

Abstract As one group of important naphthalene derivatives, naphthol and naphthylamine, are diffusely employed as dye intermediates. The presence of naphthol and naphthylamine in water systems may pose risks to the environment and public health due to their carcinogenicity. In this study, four mesoporous polymers prepared by β-cyclodextrin derivatives and tetrafluoroterephthalonitrile were obtained, and applied to deal with 1-naphthylamine, 2-naphthylamine, 1-naphthol, and 2-naphthol from water. The impact of adsorption time, initial concentration of naphthol and naphthylamine, and temperature on the adsorption efficiency of the four polymers were explored separately. The four polymers present fast adsorption kinetics towards naphthol and naphthylamine, attaining 93%~100% of adsorption equilibrium uptake for 1-naphthol, 1-naphthylamine, 2-naphthylamine in 15 min, and 87%~90% of equilibrium uptake for 2-naphthol in 15 min. The kinetics could be depicted well by the pseudo-second-order kinetic model. The adsorption isotherms of the four polymers towards naphthol and naphthylamine accord with Redlich-Peterson or Sips model. The adsorption ratio increases fast with reducing the initial concentration of naphthol and naphthylamine, which suggest that these polymers are applicable to removing low concentration of naphthol and naphthylamine from water. The adsorption ratio of naphthol and naphthylamine in 5 mg/L, can achieve over 95% in 25 oC. In addition, the four polymers can be effortlessly recovered by a gentle and simple washing procedure with little reduction in performance. The adsorption performance of the four polymers towards the four naphthalene derivatives can be improved by increasing the adsorption temperature. In conclusion, the prepared β-cyclodextrin polymers exhibit rapid water treatment in removing the four low-concentration naphthalene derivatives with convenient regeneration and good reusability.

MODIFIED AMORPHOUS SiO2 FROM Zr-CONTAINING SILICA RESIDUE: A PROMISING WAY OF RECYCLING USEFUL MATERIALS AS WELL AS REMOVING Cr(VI) FROM WATER

2021 ◽  
pp. 2150022
Author(s):  
YU LIANG ◽  
WANTING CHEN ◽  
HAN ZHANG ◽  
JIMO WANG ◽  
HAO DING ◽  
...  
Keyword(s):  
Ph Value ◽  
Waste Water Treatment ◽  
Order Kinetic ◽  
Solution Ph ◽  
Amorphous Sio2 ◽  
Adsorption Temperature ◽  
Effective Option ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
The Impact

The amorphous SiO2, which is purified from Zr-containing silica residue, was modified by CTAB before the adsorption of Cr(VI). The impact of different variables, such as solution pH value, adsorption time, adsorption temperature, and adsorbent dosage were investigated on the Cr(VI) removal from solution. The results show that the optimal pH value for Cr(VI) adsorption is 3. And 60 min is needed for the adsorption with 10 g/L of modified amorphous SiO2 at [Formula: see text]C. The acquired adsorption isotherm and the adsorption process can be interpreted by Langmuir model and pseudo-second-order kinetic model, respectively. This paper provides an effective option for waste water treatment as well as a way of recycling useful materials from the discarded Zr-containing silica residue.

scholarly journals Preparation of chitosan/MCM-41-PAA nanocomposites and the adsorption behaviour of Hg(II) ions

2018 ◽  
Vol 5 (3) ◽  
pp. 171927 ◽  
Author(s):  
Yong Fu ◽  
Yue Huang ◽  
Jianshe Hu
Keyword(s):  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Behaviour ◽  
X Ray Diffraction ◽  
Mesoporous Composite ◽  
Adsorption Temperature ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Enthalpy And Entropy ◽  
Mcm 41

A novel functional hybrid mesoporous composite material (CMP) based on chitosan and MCM-41-PAA was reported and its application as an excellent adsorbent for Hg(II) ions was also investigated. Innovatively, MCM-41-PAA was prepared by using diatomite and polyacrylic acid (PAA) with integrated polymer–silica hybrid frameworks, and then CMP was fabricated by introducing MCM-41-PAA to chitosan using glutaraldehyde as a cross-linking agent. The structure and morphology of CMP were characterized by X-ray diffraction, Fourier transform infrared spectra, thermogravimetric analysis, scanning electron microscopy and Brunauer–Emmett–Teller measurements. The results showed that the CMP possessed multifunctional groups such as –OH, –COOH and –NH 2 with large specific surface area. Adsorption behaviour of Hg(II) ions onto CMP was fitted better by the pseudo-second-order kinetic model and the Langmuir model when the initial Hg(II) concentration, pH, adsorption temperature and time were 200 mg l −1 , 4, 298 K and 120 min, respectively, as the optimum conditions. The corresponding maximum adsorption capacity could reach 164 mg g −1 . According to the thermodynamic parameters determined such as free energy, enthalpy and entropy, the adsorption process of Hg(II) ions was spontaneous endothermic adsorption.

Adsorption mechanism of As(V) and As(III) on Fe–Mn binary oxides in synthetic and real water matrices

2016 ◽  
Vol 16 (4) ◽  
pp. 992-1001 ◽  
Author(s):  
Jasmina Nikić ◽  
Jasmina Agbaba ◽  
Malcolm Watson ◽  
Snežana Maletić ◽  
Jelena Molnar Jazić ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Binary Oxides ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
The Eu

A series of Fe–Mn binary oxides with different Fe:Mn ratios (1:1, 3:1, 6:1, 9:1) were synthesized to investigate the optimal Fe:Mn ratio for the removal of As(III) and As(V). Batch experiments were performed to determine the rate of adsorption and equilibrium isotherms. Adsorption kinetics were well described by the pseudo-second-order kinetic model for both As(III) and As(V). The adsorption equilibrium data fitted well to Langmuir and Freundlich isotherms. The maximum As(V) sorption capacity was observed at an Fe:Mn ratio of 6:1 (65.0 mg/g), whereas maximum As(III) uptake was at Fe:Mn ratio 3:1 (46.9 mg/g). Arsenic levels in real water samples were reduced from 37 μg/l to below the EU Water Framework Directive limit (10 μg/L) after treatment with Fe–Mn adsorbents.

scholarly journals Comparison of Adsorptive Removal of Total Nitrogen (T-N) and Total Phosphorous (T-P) in Aqueous Solution using Granular Activated Charcoal (GAC)

2013 ◽  
Vol 9 (1) ◽  
pp. 1822-1836
Author(s):  
Keon Sang Ryoo ◽  
Jong-Ha Choi ◽  
Yong Pyo Hong
Keyword(s):  
Aqueous Solution ◽  
Kinetic Model ◽  
Adsorption Capacity ◽  
Total Nitrogen ◽  
Activated Charcoal ◽  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Total Phosphorous ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The present study is to explore the possibility of utilizing granular activated charcoal (GAC) for the removal of total phosphorous (T-P) and total nitrogen (T-N) in aqueous solution. Batch adsorption studies were carried out to determine the influences of various factors like initial concentration, contact time and temperature. The adsorption data showed that GAC has a similar adsorption capacity for both T-N and T-P. The adsorption degree of T-N and T-P on GAC was highly concentration dependent. It was found that the adsorption capacity of GAC is quite favorable at a low concentration. At concentrations of 1.0 mg L-1 of T-P and 2.0 mg L-1 of T-N, approximately 97 % of adsorption was achieved by GAC. The equilibrium data were fitted well to the Langmuir isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher R2 compared with the pseudo-first-order and intra-particle kinetic model. The theoretical adsorption equilibrium qe,cal from pseudo-second-order kinetic model were relatively similar to the experimental adsorption equilibrium qe,exp. To evaluate the effect of thermodynamic parameters at different temperatures, the change in free energy ΔG, the enthalpy ΔH and the entropy ΔS were estimated. Except for adsorption of T-P at 278 K, the ΔG values obtained were all negative at the investigated temperatures. It indicates that the present adsorption system occurs spontaneously. The adsorption process of T-N by GAC was exothermic in nature, whereas T-P showed endothermic behavior. In addition, the positive values of ΔS imply that there was the increase in the randomness of adsorption of T-N and T-P at GAC-solution interface.  

Study of the effect of an acid treatment of a natural Moroccan bentonite on its physicochemical and adsorption properties

2016 ◽  
Vol 75 (5) ◽  
pp. 1098-1117 ◽  
Author(s):  
Ikram Daou ◽  
Omar Zegaoui ◽  
Ali Amachrouq
Keyword(s):  
Acid Treatment ◽  
Physicochemical Characterization ◽  
Weight Ratio ◽  
Exchange Capacity ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
The Impact

In this study, a natural bentonite taken from a deposit in the Northeast of Morocco has been purified (PB) and treated with various HCl molarities (xHPB) in order to obtain an HCl/Bentonite weight ratio equal to 0.2, 0.4 and 0.6. The obtained physicochemical characterization results indicated that the PB sample is composed mainly of the montmorillonite phase. The impact of acid treatment was investigated by identifying changes in the chemical composition, cation exchange capacity, infrared absorption bands, crystalline structure, morphology of the particles and specific surface area. The adsorption behavior of methylene blue (MB) and methyl orange (MO) in aqueous solution onto PB and xHPB samples was investigated by varying the initial concentration of dyes, the contact time and the temperature. The obtained results showed that the experimental data best fit the Langmuir model and the pseudo-second-order kinetic model. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) studies carried out after MB and MO adsorption onto PB samples indicated that MB cations were intercalated, in the form of monomers and dimers, with a large amount of monomers, slightly tilted against the plane of the clay surface. While MO molecules adsorb, with a near perpendicular alignment, with their SO3− group and O− atoms facing the mineral surface plane.

Use of Natural Kaolinite Clay as an Adsorbent to Remove PB(II), CD(II), and CU(II) from Aqueous Solution

2014 ◽  
Vol 805 ◽  
pp. 581-584 ◽  
Author(s):  
Débora Martins Aragão ◽  
Maria de Lara P.M. Arguelho ◽  
Carolina Mangieri Oliveira Prado ◽  
José do Patrocinio Hora Alves
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Northeast Brazil ◽  
Order Kinetic ◽  
Kaolinite Clay ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Natural kaolinite clay collected in the State of Sergipe (northeast Brazil) was used as an adsorbent for the ions Pb2+, Cd2+, and Cu2+present in aqueous solution. Adsorption equilibrium was reached rapidly, enabling use of a contact time of 30 minutes, and maximum adsorption was achieved at pH 7.0. For all three metal ions, the adsorption data could be fitted using the Langmuir isotherm and the adsorption process obeyed a pseudo-second order kinetic model.

scholarly journals A novel activated carbon prepared from grapefruit peel and its application in removal of phenolic compounds

2018 ◽  
Vol 77 (10) ◽  
pp. 2517-2527 ◽  
Author(s):  
Xiao Liu ◽  
Yibei Wan ◽  
Penglei Liu ◽  
Yanzhen Fu ◽  
Weihua Zou
Keyword(s):  
Activated Carbon ◽  
Phenolic Compounds ◽  
Contact Time ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Bet Analysis ◽  
Order Kinetic Model ◽  
Grapefruit Peel ◽  
Pseudo Second Order ◽  
Activating Agent

Abstract The most ideal conditions for preparing activated carbon from grapefruit peel (GPAC) were studied using NH4H2PO4 as a chemical activating agent and the obtained material was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) analysis. The adsorption capacity of the resulting material has been checked using three phenolic compounds (pyrocatechol (CA), 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP)). The adsorption characteristics of phenolic compounds from aqueous solution by GPAC have been investigated as a function of contact time, pH, initial concentration and temperature. The equilibrium experimental data fitted well with Freundlich and Koble–Corrigan isotherms. The adsorption of the three phenolic compounds on GPAC fitted well with pseudo-second-order kinetic model. Different thermodynamic parameters were also evaluated and it was found that the adsorption was spontaneous, feasible and endothermic in nature. Adsorbents were regenerated by 0.1 mol/L NaOH and GPAC could be reused in phenolic compounds removal.

Kinetics and adsorption equilibrium of some radionuclides on polyaniline/SiO2 composite

2021 ◽  
Vol 109 (2) ◽  
pp. 85-97
Author(s):  
Abeer E. Kasem ◽  
Ezzat A. Abdel-Galil ◽  
Nabil Belacy ◽  
Nagwa A. Badawy
Keyword(s):  
Adsorption Equilibrium ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Sorption Behavior ◽  
Order Kinetic ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Abstract The sorption kinetics and equilibrium isotherms of zirconium, uranium, and molybdenum ions onto synthetic polyaniline/SiO2 composite (PAn/SiO2) have been studied using batch-sorption techniques. This study was carried out to examine the sorption behavior of the PAn/SiO2 for the removal of Zr(IV), U(VI), and Mo(VI) ions from an aqueous solution. The influence of some parameters on the sorption process was also studied. The maximum sorption for Zr(IV), U(VI), and Mo(VI) ions was achieved at 60 min shaking time. Langmuir isotherm model is the most representative for discussing the sorption process with a maximum sorption capacity of 24.26, 21.82, and 13.01 mg/g for Zr(IV), U(VI), and Mo(VI) ions, respectively. Kinetic modeling revealed that the sorption of all ions follows the pseudo-second-order kinetic model. The results demonstrated that both the external and intra-particular diffusion are taken into account in determining the sorption rate. Thermodynamic parameters like ΔG°, ΔH°, and ΔS° for the sorption process were evaluated. The synthetic composite has been successfully applied for the removal and recovery of U(VI) ions from real solution (monazite leachate) using a chromatographic column packed with PAn/SiO2 composite with a breakthrough capacity equal to 239.70 mg/g.

scholarly journals EFFICIENT ADSORPTION OF Ce (III) ONTO POROUS CELLULOSE/GRAPHENE OXIDE COMPOSITE MICROSPHERES PREPARED IN IONIC LIQUID

2021 ◽  
Vol 55 (9-10) ◽  
pp. 1163-1175
Author(s):  
YAN HAO ◽  
◽  
JING QU ◽  
ZUNYI LIU ◽  
SONGBO LI ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Graphene Oxide ◽  
Adsorption Equilibrium ◽  
Rare Earth Ions ◽  
Order Kinetic ◽  
Oxide Composite ◽  
Composite Microspheres ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

A novel adsorbent made of porous cellulose/graphene oxide composite microspheres (PCGCM) was synthesized in [Bmim]Cl ionic liquid. The as-prepared PCGCM was evaluated for the removal of Ce (III) via static adsorption experiments. The results showed that the adsorption equilibrium of Ce (III) onto PCGCM was achieved within 50 min and the adsorption was highly pH dependent. An excellent adsorption capacity as high as 415.1 mg•g-1 was obtained at a pH of 4.9, which was much higher than most adsorbents reported in the literature. The pseudo-second order kinetic model and Langmuir isotherm model were found to fit the adsorption behavior of PCGCM well. The XPS analysis confirmed that the adsorption was based on the ion exchange mechanism. Meanwhile, PCGCM could be regenerated with 1 mol•L-1 HCl for repetitious adsorption of Ce (III). This work provides an attractive approach for the removal of rare earth ions as pollutants.

scholarly journals Investigation on the use of aluminium rich sandy soil as natural adsorbent in the removal of lead from water

2021 ◽  
Vol 1195 (1) ◽  
pp. 012003
Author(s):  
Y S Ng ◽  
Y J Tan ◽  
K J Heng ◽  
Y H Ong
Keyword(s):  
Response Surface Methodology ◽  
Sandy Soil ◽  
Order Kinetic ◽  
Adsorption Efficiency ◽  
Solution Ph ◽  
Initial Concentration ◽  
Adsorption Sites ◽  
Natural Adsorbent ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract The feasibility of aluminium rich sandy soil collected from Jeram as natural adsorbent in removing lead (Pb) from water was investigated without any surface modification. The investigation on the effect of initial concentration, solution pH, and soil:solution ratio was carried out using response surface methodology. The adsorption efficiency was increased at higher pH and soil:solution ratio, as well as lower initial concentration, as a result of higher availability of adsorption sites and less adsorbate competition. The adsorption followed Langmuir isotherm and monolayer chemisorption with an adsorption capacity of 10.64 mg g−1. The process followed pseudo-second order kinetic model, with a rate constant of 0.011 g mg−1 min−1 at optimum adsorption pH of 4-5.

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