scholarly journals Enhanced Removal of Soluble and Insoluble Dyes over Hierarchical Zeolites: Effect of Synthesis Condition

Inorganics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 52
Author(s):  
Ani Iryani ◽  
Ahmad Masudi ◽  
Ade I. Rozafia ◽  
Djoko Hartanto ◽  
Mardi Santoso ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Dye Adsorption ◽  
Nitrogen Adsorption ◽  
Langmuir Model ◽  
Order Kinetic ◽  
Hierarchical Zeolites ◽  
Hierarchical Zeolite ◽  
First Order ◽  
Adsorption Desorption

A hierarchical zeolite ZSM-5 with micro and meso-pore was prepared by optimising the most affecting parameter in sequence of desilication and dealumination. The physicochemical properties of zeolite were characterised with XRD, nitrogen adsorption–desorption, FTIR and SEM. The potential of this zeolite for decolorisation of CR, RY, MB, RhB, DB-1 and DB-14 was evaluated with adsorption isotherm, thermodynamics, kinetics, and influencing parameter for adsorption. The unique modification of ZSM-5 resulted in lower crystallinity, easier porosity control, rich terminal silanol and unbridged silanol groups which assisted in higher adsorption capacity. The adsorption capacity of the optimum ZSM-5 was 323, 435, 589, 625, 61 and 244 mg/g for CR, RY, MB, RhB, DB-1 and DB-14, respectively. The dye adsorption progressed through pseudo-first-order kinetic and close to the Langmuir model. The adsorption mechanism is proposed mainly through interaction between deprotonated silanol site and the electron-rich dye site.

scholarly journals Efficient Removal 17-Estradiol by Graphene-Like Magnetic Sawdust Biochar: Preparation Condition and Adsorption Mechanism

2020 ◽  
Vol 17 (22) ◽  
pp. 8377
Author(s):  
Yahui Zhou ◽  
Shaobo Liu ◽  
Yunguo Liu ◽  
Xiaofei Tan ◽  
Ni Liu ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
First Order ◽  
Micropore Filling ◽  
Order Kinetic Model ◽  
Pseudo First Order

The occurrence of environmental endocrine disrupting chemicals (EDCs) in aquatic environments has caused extensive concern. Graphene-like magnetic sawdust biochar was synthesized using potassium ferrate (K2FeO4) to make activated sawdust biochar and applied for the removal of 17-estradiol (E2). The characterization showed that the surface morphology of five graphene-like magnetic sawdust biochars prepared with different preparation conditions were quite different. The specific surface area and pore structure increased with the increment of K2FeO4 addition. The results have shown that graphene-like magnetic sawdust biochar (1:1/900 °C) had the best removal on E2. The experimental results indicated that pseudo-first-order kinetic model and the Langmuir model could describe the adsorption process well, in which the equilibrium adsorption capacity (qe,1) of 1:1/900 °C were 59.18 mg·g−1 obtained from pseudo-first-order kinetic model and the maximum adsorption capacity (qmax) of 1:1/900 °C were 133.45 mg·g−1 obtained from Langmuir model at 298K. At the same time, lower temperatures, the presence of humic acid (HA), and the presence of NaCl could be regulated to change the adsorption reaction in order to remove E2. Adsorption capacity was decreased with the increase of solution pH because pH value not only changed the surface charge of graphene-like magnetic sawdust biochar, but also affected the E2 in the water. The possible adsorption mechanism for E2 adsorption on graphene-like magnetic sawdust biochar was multifaceted, involving chemical adsorption and physical absorption, such as H-bonding, π-π interactions, micropore filling effects, and electrostatic interaction. To sum up, graphene-like magnetic sawdust biochar was found to be a promising absorbent for E2 removal from water.

scholarly journals Preparation of GO/MIL-101(Fe,Cu) composite and its adsorption mechanisms for phosphate in aqueous solution

2021 ◽  
Author(s):  
You Wu ◽  
Zuannian Liu ◽  
Bakhtari Mohammad Fahim ◽  
Junnan Luo
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Adsorption Mechanism ◽  
Nitrogen Adsorption ◽  
Adsorption Properties ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Mechanisms ◽  
Adsorption Desorption

Abstract In this study, MIL-101(Fe), MIL-101(Fe,Cu), and Graphene Oxide (GO) /MIL-101(Fe,Cu) were synthesized to compose a novel sorbent. The adsorption properties of these three MOFs-based composites were compared toward the removal of phosphate. Furthermore, the influencing factors including reaction time, pH, temperature and initial concentration on the adsorption capacity of phosphate on these materials as well as the reusability of the material were discussed. The structure of fabricated materials and the removal mechanism of phosphate on the composite material were analyzed by Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption analysis and zeta potential. The results show that the maximum adsorption capacity of phosphate by the composite GO/MIL-101(Fe,Cu)-2% was 204.60 mg·g− 1, which is higher than that of MIL-101(Fe,Cu) and MIL-101(Fe). likewise the specific surface area of GO/MIL-101(Fe,Cu)-2% is 778.11 m2/g is higher than that of MIL-101(Fe,Cu) and MIL-101(Fe),which are 747.75 and 510.66m2/g respectively. The adsorption mechanism of phosphate is electrostatic attraction, form coordination bonds and hydrogen bonds. The fabricated material is a promising adsorbent for the removal of phosphate with good reusability.

Adsorption and photocatalytic degradation of malachite green by vanadium doped zinc oxide nanoparticles

2015 ◽  
Vol 73 (4) ◽  
pp. 881-889 ◽  
Author(s):  
L. Khezami ◽  
Kamal K. Taha ◽  
Imed Ghiloufi ◽  
Lassaad El Mir
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Degradation ◽  
Malachite Green ◽  
Dye Adsorption ◽  
Nitrogen Adsorption ◽  
Order Kinetic ◽  
Adsorption Method ◽  
First Order ◽  
Degradation Data ◽  
Pseudo First Order

Herein the degradation of malachite green (MG) dye from aqueous medium by vanadium doped zinc oxide (ZnO:V3%) nanopowder was investigated. The specific surface area and pore volume of the nanopowder was characterized by nitrogen adsorption method. Batch experimental procedures were conducted to investigate the adsorption and photocatalytic degradation of MG dye. Adsorption kinetics investigations were performed by varying the amount of the catalyst and the initial dye concentrations. Adsorption and photocatalytic degradation data were modeled using the Lagergren pseudo-first-order and second-order kinetic equation. The results showed that the ZnO:V3% nanopowder was particularly effective for the removal of MG and data were found to comply with Lagergreen pseudo-first-order kinetic model.

scholarly journals Use of Zeolite ZSM-5 for Loading and Release of 5-Fluorouracil

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ruba A. Al-Thawabeia ◽  
Hamdallah A. Hodali
Keyword(s):  
Nitrogen Adsorption ◽  
Order Rate Constant ◽  
Slight Variation ◽  
Gravimetric Analysis ◽  
Order Kinetic ◽  
Acid Form ◽  
X Ray ◽  
First Order ◽  
Adsorption Desorption ◽  
Sodium Form

Samples of zeolite ZSM-5 have been synthesized in both the sodium form (ZSM-5) and the acid activated form (H-ZSM-5). In addition, each of these two forms was prepared in the two molar SiO2/Al2O3ratios of 169 and 15. All samples of these ZSM-5 derivatives were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, thermal gravimetric analysis (TGA), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). The samples were successfully loaded with the anticancer drug 5-fluorouracil (5-FU) with loading capacities varying from 22% (for the sodium form having the lower molar SiO2/Al2O3ratio of 15, ZSM-5-(15)) to 43% (for the corresponding acid form, H-ZSM-5-(15)). Percent release of the drug-loaded ZSM-5 samples into simulated body fluid (SBF) was measured at pH 7.4 and 37°C. The results showed a slight variation in the % release within the range 84–93%, while the first-order rate constant (k) varied from 2.2 h−1for ZSM-5-(15) to 3.9 h−1for H-ZSM-5-(15). It was interesting to note that at the higher molar SiO2/Al2O3ratios of 169, both the sodium form, ZSM-5-(169), and the acid form, H-ZSM-5-(169), exhibit an intermediate efficiency in either % loading (38%) or first-order kinetic release constant (k= 2.9 h−1).

scholarly journals Attapulgite Nanofiber-Cellulose Nanocomposite with Core-Shell Structure for Dye Adsorption

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoyu Chen ◽  
Xiaoxue Song ◽  
Yihe Sun
Keyword(s):  
Adsorption Capacity ◽  
Dye Adsorption ◽  
Langmuir Equation ◽  
Order Equation ◽  
Adsorption Kinetic ◽  
Adsorption Effect ◽  
First Order ◽  
Nanocomposite Particle ◽  
Pseudo First Order ◽  
Adsorption Desorption

Nanocomposite particle used for adsorption has attracted continuous attention because of large specific surface area and adjustable properties from nanocomponent. Herein nanocomposite particle with cellulose core and attapulgite nanofibers shell was prepared. The size of cellulose core was about 2 mm and the thickness of nanofibers shell is about 300 μm. Adsorption capacity of nanocomposite particle to methylene blue can reach up to 11.07 mg L−1and the best adsorption effect occurs at pH = 8; pseudo-first-order equation and the Langmuir equation best describe the adsorption kinetic and isotherm, respectively; repeated adsorption-desorption experimental results show that 94.64% of the original adsorption capacity can be retained after being reused three times.

MODELLING NITROGEN PROCESSES IN SOIL: MATHEMATICAL DEVELOPMENT AND RELATIONSHIPS

1976 ◽  
Vol 56 (2) ◽  
pp. 71-78 ◽  
Author(s):  
D. R. CAMERON ◽  
C. G. KOWALENKO
Keyword(s):  
Time Dependent ◽  
Rate Coefficients ◽  
Nitrification Rate ◽  
Order Kinetic ◽  
Nitrogen Flow ◽  
First Order ◽  
Interaction Term ◽  
Flow Pathways ◽  
Adsorption Desorption ◽  
Temperature Water

A small subsystem model was developed to simulate the major nitrogen flow pathways in an unsaturated soil treated with ammonium sulphate. A nonlinear Freundlich equilibrium model and a Langmuir kinetic model were used to describe mathematically the adsorption–desorption of soluble NH4+ to the exchangeable and clay-fixed phases, respectively. Time dependent, microbial mediated first-order kinetic models were used to quantify the ammonification and nitrification processes. The subsystem model was then used as a research tool to derive ammonification and nitrification rate coefficients for a preceding incubation experiment conducted using different soil moisture contents and temperatures. The model yields reasonably good fits to the observed data. A subsequent regression analysis relating the coefficients to temperature and moisture pointed out the importance of the temperature–water content interaction term in quantifying microbial mediated processes.

Application of raw and modified Uruguayan clays to phosphate adsorption for water remediation

MRS Advances ◽  
2018 ◽  
Vol 3 (61) ◽  
pp. 3543-3549
Author(s):  
Pablo González ◽  
Andrea C. De Los Santos ◽  
Jorge R. Castiglioni ◽  
María A. De León
Keyword(s):  
Nitrogen Adsorption ◽  
Pillared Clay ◽  
Water Remediation ◽  
Phosphate Adsorption ◽  
X Ray Diffraction ◽  
Order Model ◽  
Freundlich Model ◽  
X Ray ◽  
First Order ◽  
Adsorption Desorption

ABSTRACTA raw clay from Uruguay was modified with aluminium to obtain an aluminium pillared clay (Al-PILC). The solids were characterized by scanning electron microscopy, X-ray diffraction and nitrogen adsorption-desorption isotherms. The Al-PILC retained the typical laminar structure of montmorillonite. The specific surface area and the microporous volume of the Al-PILC, 235 m2 g-1 and 0.096 cm3 g-1, respectively, were much higher than those of the clay. The phosphate adsorption capacity of the Al-PILC was higher than those of the clay. The phosphate adsorption kinetic followed the pseudo-first-order model for both, the clay and the Al-PILC, and the phosphate adsorption isotherm for the Al-PILC fit the Freundlich model.

scholarly journals Study on the adsorption of methylene blue from aqueous solution using hydrogel glucomannan/graphene oxide

2021 ◽  
Vol 10 (1) ◽  
pp. 59-66
Author(s):  
Son Le Lam ◽  
Phu Nguyen Vinh ◽  
Hieu Le Trung ◽  
Tan Le Thua ◽  
Nhan Dang Thi Thanh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Glucomannan/graphene oxide (GM/GO) hydrogel was synthesized by using calcium hydroxide as the crosslinker. The synthesized material was characterized by using IR, XRD, SEM, EDX and RAMAN technology. The composite hydrogel was used for removal of organic dyes from aqueous solution. The results showed that the GM/GO hydrogel had a porous structure and a high adsorption capacity toward methylene blue (MB). The pseudo-second-order kinetic model could fit the rate equation of MB adsorption onto the GM/GO hydrogel. The adsorption of MB onto GM/GO hydrogel was a spontaneous process. In addition, the equilibrium adsorption isotherm data indicated that equilibrium data were fitted to the Langmuir isotherm and the maximum dye adsorption capacity was 198,69 mg.g-1. Moreover, the hydrogel was stable and easily recovered and adsorption capacity was around 97% of the initial saturation adsorption capacity after being used five times.

scholarly journals Preparation of bio-absorbents by modifying licorice residue via chemical methods and removal of copper ions from wastewater

2021 ◽  
Author(s):  
Xiaochun Yin ◽  
Nadi Zhang ◽  
Meixia Du ◽  
Hai Zhu ◽  
Ting Ke
Keyword(s):  
Adsorption Capacity ◽  
Copper Ions ◽  
Order Kinetic ◽  
Solution Ph ◽  
Chemical Methods ◽  
Simple Strategy ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Surface Active ◽  
Adsorption Desorption

Abstract In this paper, a series of bio-adsorbents (LR-NaOH, LR-Na2CO3 and LR-CA) were successfully prepared by modifying Licorice Residue with NaOH, Na2CO3 and citric acid, which were used as the adsorbents to remove Cu2+ from wastewater. The morphology and structure of bio-adsorbents were characterized by Fourier Transform Infrared, SEM, TG and XRD. Using static adsorption experiments, the effects of the adsorbent dosage, the solution pH, the adsorption time, and the initial Cu2+ concentration on the adsorption performance of the adsorbents were investigated. The results showed that the adsorption process of Cu2+ by the bio-adsorbents can be described by pseudo-second order kinetic model and the Langmuir model. The surface structure of the LR-NaOH, LR-Na2CO3 and LR-CA changed obviously, and the surface-active groups increased. The adsorption capacity of raw LR was 21.56 mg/g, LR-NaOH, LR- Na2CO3 significantly enhanced this value up to 43.65 mg/g, 43.55 mg/g, respectively. After four adsorption-desorption processes, the adsorption capacity of LR-NaOH also maintained about 73%. Therefore, LR-NaOH would be a promising adsorbent for removing Cu2+ from wastewater, and the simple strategy towards preparation of adsorbent from the waste residue can be as a potential approach using in the water treatment.

scholarly journals Enhanced adsorptive removal of Indigo carmine dye performance by functionalized carbon nanotubes based adsorbents from aqueous solution: equilibrium, kinetic, and DFT study

2019 ◽  
Vol 9 (4) ◽  
pp. 323-334 ◽  
Author(s):  
Zeinab Hoseini Dastgerdi ◽  
Seyyed Salar Meshkat ◽  
Mehdi D. Esrafili
Keyword(s):  
Density Functional ◽  
Indigo Carmine ◽  
Dye Adsorption ◽  
Chemical Vapor ◽  
Density Functional Theory Calculations ◽  
Nitrogen Adsorption ◽  
Adsorptive Removal ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption

AbstractThe present work considers an adsorptive removal of Indigo carmine (IC) dye onto nanotube carbon (CNTs). The pure CNTs were prepared via chemical vapor deposition (CVD) method utilizing methane gas as a carbon source at 1000 °C in a quartz tube. The morphology and surface chemical structure of the adsorbents were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption/desorption technique, and thermal gravity analysis (TGA). The parameters of the IC dye adsorption, such as initial concentration, contact time, pH, and mass-loaded adsorbent, were evaluated. The kinetic study confirmed that a pseudo-second-order model was best fitted to the adsorption data. The removal efficiency of adsorption onto pure and COOH-functionalized CNTs was 84% and 98.7% at 15 min, respectively. The equilibrium results were fitted well to the Langmuir isotherm model. The adsorption capacity of the CNT and COOH–CNT was 88.5 and 136 mg/g, respectively. The reusability of the adsorbents was studied, and after eight cycles, the efficiency decreased to 70%. Moreover, the density functional theory calculations confirmed that the functionalization of CNTs with COOH groups improves the adsorption properties of IC due to the formation of hydrogen-bonding interactions.

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