Investigation of the aqueous adsorption capacity of a 6-connected Zr-MOF for anionic and cationic dyes in comparison with other traditional porous materials

Abstract A 6-connected Zr-MOF (MOF-808) was successfully synthesized via the solvothermal method with the assistance of formic acid (HCOOH). The resulting MOF showed high crystallinity and thermal stability, which was verified by powder X-ray diffraction (PXRD) measurement, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). As can be expected, the obtained material possessed high porosity with an extremely high specific BET surface area (SABet) of 2372 m2/g. The adsorption capacity of MOF-808 for anionic dyes (i.e. sunset yellow, quinoline yellow, and methyl orange) and cationic ones (i.e. methylene blue and malachite green) in aqueous solutions was respectively investigated. For comparison purpose, the adsorption experiments were also carried out using other traditional porous materials, including commercial microporous activated carbon and synthesized mesoporous SBA-15 with BET surface areas of 1030 m2/g and approximately 800 m2/g, respectively. It was demonstrated that the efficiency of MOF-808 in trapping anionic dyes in water was significantly higher while carbon and silica materials exhibited better performances for the case of cationic dyes.

Download Full-text

Adsorption of strontium on different sodium-enriched bentonites

Journal of the Serbian Chemical Society ◽

10.2298/jsc161010008m ◽

2017 ◽

Vol 82 (4) ◽

pp. 449-463 ◽

Cited By ~ 6

Author(s):

Sanja Marinovic ◽

Marija Ajdukovic ◽

Natasa Jovic-Jovicic ◽

Tihana Mudrinic ◽

Bojana Nedic-Vasiljevic ◽

...

Keyword(s):

Cation Exchange ◽

Adsorption Capacity ◽

Textural Properties ◽

X Ray Diffraction ◽

Order Model ◽

Surface Areas ◽

Alkaline Conditions ◽

Langmuir Isotherm Model ◽

Pseudo Second Order ◽

Ph Range

Bentonites from three different deposits (Wyoming, TX, USA and Bogovina, Serbia) with similar cation exchange capacities were sodium enriched and tested as adsorbents for Sr2+ in aqueous solutions. X-Ray diffraction analysis confirmed successful Na-exchange. The textural properties of the bentonite samples were determined using low-temperature the nitrogen physisorption method. Significant differences in the textural properties between the different sodium enriched bentonites were found. Adsorption was investigated with respect to adsorbent dosage, pH, contact time and the initial concentration of Sr2+. The adsorption capacity increased with pH. In the pH range from 4.0?8.5, the amount of adsorbed Sr2+ was almost constant but 2?3 times smaller than at pH ?11. Further experiments were performed at the unadjusted pH since extreme alkaline conditions are environmentally hostile and inapplicable in real systems. The adsorption capacity of all the investigated adsorbents toward Sr2+ was similar under the investigated conditions, regardless of significant differences in the specific surface areas. It was shown and confirmed by the Dubinin?Radushkevich model that the cation exchange mechanism was the dominant mechanism of Sr2+ adsorption. Their developed microporous structures contributed to the Sr2+ adsorption process. The adsorption kinetics obeyed the pseudo-second-order model. The isotherm data were best fitted with the Langmuir isotherm model.

Download Full-text

Correlations Between Alkali and Crystallinity in lyocell-Based ACF Probed with X-Ray Diffraction

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2020.58.7.495 ◽

2020 ◽

Vol 58 (7) ◽

pp. 495-500

Author(s):

Young Min Jin ◽

Joon Hyuk Lee ◽

Sang Sun Choi

Keyword(s):

Thermo Gravimetric Analysis ◽

Thermal Characteristics ◽

Degree Of Crystallinity ◽

Bet Surface Area ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Surface Areas ◽

Potential Applications ◽

Activated Carbon Fibres

This study examined the effect of alkalis on lyocell-based activated carbon fibres (ACFs) with high Brunauer-Emmett-Teller (BET) surface areas, using X-ray diffraction (XRD). Here, alkali treatments were conducted using 10 ~ 25 % NaOH and KOH on lyocell samples for 3 h at ambient room temperature. A secondary treatment with 4 % each of KOH and H3PO4 for an additional 3 h followed. An activated form of the samples was prepared by oxidation (stabilisation), carbonisation, and activation. The final ACF form of the samples showed a porous structure with high BET surface areas (> 1,000 m<sup>2</sup> g<sup>-1</sup>). A 25 % dosage of NaOH produced the highest BET surface area compared to other samples. In terms of crystallinity, a 15 % dosage of KOH was found to be the optimum dosage to secure the highest degree of crystallinity among all samples. Meanwhile, the NaOH was successfully shifted the samples into the most distinct form of cellulose II. 15 % NaOH was found to secure the most stable thermal characteristics, as determined via thermo-gravimetric analysis. The present work demonstrates the various physio-chemistries of ACFs prepared with different proportions and types of alkalis, leading to intriguing potential applications.

Download Full-text

Understanding the physicochemical properties of Zn–Fe LDH nanostructure as sorbent material for removing of anionic and cationic dyes mixture

Scientific Reports ◽

10.1038/s41598-021-00437-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Rehab K. Mahmoud ◽

Mohamed Taha ◽

Amal Zaher ◽

Rafat M. Amin

Keyword(s):

Adsorption Capacity ◽

Photoelectron Spectroscopy ◽

Adsorption Process ◽

Dye Adsorption ◽

Chemical Properties ◽

Cationic Dyes ◽

Anionic Dyes ◽

Visible Radiation ◽

X Ray ◽

Before And After

AbstractIn our work, the removal of cationic and anionic dyes from water was estimated both experimentally and computationally. We check the selectivity of the adsorbent, Zn–Fe layered double hydroxide (LDH) toward three dyes. The physical and chemical properties of the synthesis adsorbent before and after the adsorption process were investigated using X-ray photoelectron spectroscopy, energy dispersive X-ray, X-ray diffraction, FT-IR, HRTEM, and FESEM analysis, particle size, zeta potential, optical and electric properties were estimated. The effect of pH on the adsorption process was estimated. The chemical stability was investigated at pH 4. Monte Carlo simulations were achieved to understand the mechanism of the adsorption process and calculate the adsorption energies. Single dye adsorption tests revealed that Zn–Fe LDH effectively takes up anionic methyl orange (MO) more than the cationic dyes methylene blue (MB) and malachite green (MG). From MO/MB/MG mixture experiments, LDH selectively adsorbed in the following order: MO > MB > MG. The adsorption capacity of a single dye solution was 230.68, 133.29, and 57.34 mg/g for MO, MB, and MG, respectively; for the ternary solution, the adsorption capacity was 217.97, 93.122, and 49.57 mg/g for MO, MB, and MG, respectively. Zn–Fe LDH was also used as a photocatalyst, giving 92.2% and 84.7% degradation at concentrations of 10 and 20 mg/L, respectively. For visible radiation, the Zn–Fe LDH showed no activity.

Download Full-text

Adsorptive removal of phosphate from aqueous solutions using different types of red mud

Water Science & Technology ◽

10.2166/wst.2018.182 ◽

2018 ◽

Vol 2017 (2) ◽

pp. 570-577 ◽

Cited By ~ 13

Author(s):

Tengfei Guo ◽

Haiquan Yang ◽

Qingyou Liu ◽

Hannian Gu ◽

Ning Wang ◽

...

Keyword(s):

Adsorption Capacity ◽

Red Mud ◽

Inductively Coupled Plasma ◽

Atomic Emission ◽

Sintering Process ◽

X Ray Diffraction ◽

Inductively Coupled ◽

Surface Areas ◽

Plasma Mass Spectrometry ◽

Pseudo Second Order

Abstract Red mud (RM) is an industrial waste generated during production of alumina from using the Bayer process or the sintering process. Four types of red mud from China were characterized for their diverse chemical and mineral compositions using inductively coupled plasma–atomic emission spectroscopy (ICP-AES), inductively coupled plasma–mass spectrometry (ICP-MS) and X-ray diffraction (XRD). Acid treatment was employed to obtain activated red mud (ARM), posing increased surface areas from 10–28 m2/g to 220–350 m2/g. RMs and ARMs were used to adsorb phosphate in solution to compare the adsorption capacity. Sample GZ3, a red mud from the sintering process, presented the highest adsorption capacity among the four raw RMs, posing an adsorption capacity of 0.37 mg P/g in the solution of 1 mg P/L with a solid/solution ratio of 0.5 g: 1 L. Whereas, activated GX (AGX), a high iron Bayer red mud from diaspore bauxite, showed the highest adsorption capacity of all the ARMs, with an adsorption capacity of 1.92 mg P/g in the same condition. The dynamic studies indicate that the adsorption mainly followed the pseudo second-order model. The models of Freundlich and Langmuir were used to simulate the sorption equilibrium on GZ3 and AGX. It suggests that the Freundlich model had a better correlation with GZ3 while the Langmuir model fitted well with AGX.

Download Full-text

Polyethylenimine-Silica Mesoporous Hybrid: A Novel Adsorbent for CO2 Capture

Advanced Composites Letters ◽

10.1177/096369351202100201 ◽

2012 ◽

Vol 21 (2) ◽

pp. 096369351202100

Author(s):

Xin Fu

Keyword(s):

Adsorption Capacity ◽

High Porosity ◽

In Situ Ftir ◽

High Adsorption ◽

Surface Areas ◽

Polycondensation Process ◽

Cyclic Adsorption ◽

Adsorption Desorption ◽

Hydrolysis And Polycondensation

A facile pathway has been developed to synthesize polyethylenimine-modified mesoporous hybrid materials with highly efficient CO2 capturer. It is the special feature of this pathway that there are no surfactants introduced and the amine guest can be dispersed within the channels of the silica materials during the hydrolysis and polycondensation process. The obtained materials exhibit high specific surface areas, high porosity and high CO2 uptake. The amount of polyethylenimine (PEI) has important effect on the surface area, pore size and CO2 adsorption capacity of the adsorbents. For the sample containing 50 wt% PEI, the adsorbent exhibits a high adsorption capacity of 186.6 mg/g-PEI, and in situ FTIR show that CO2 is sorbed on amine sites through the formation of alkylammonium carbamates. The adsorbed CO2 could be desorbed completely from the sample at 150 °C. Moreover, the adsorbents show a stable cyclic adsorption-desorption performance.

Download Full-text

Microscopic Structure and Adsorption Properties of the Terpenoids-Based Adsorption Material

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.723.667 ◽

2016 ◽

Vol 723 ◽

pp. 667-672 ◽

Cited By ~ 2

Author(s):

Ling Zhang ◽

Zhao Lin Zhan ◽

Chun Lin Li ◽

Tian Dong Zhang ◽

Rui Gao ◽

...

Keyword(s):

Decomposition Temperature ◽

Adsorption Properties ◽

Infrared Analysis ◽

High Porosity ◽

X Ray Diffraction ◽

Surface Areas ◽

Preparation Conditions ◽

New Type ◽

Adsorption Desorption ◽

Spray Granulation

In this paper, a new type of natural adsorption materials were prepared by spray granulation. The structure and properties of the product were characterized by scanning electron microscope analysis, N2 adsorption desorption analysis, infrared analysis, X ray diffraction analysis, the rmogravimetric analysis. The results showed that: the best preparation conditions of the adsorption materials were as follows: the temperature was 59.21°C, the pressure was 0.28 Bar, and the rate was 14.15 ml/min. In addition, the natural materials had high porosity and specific surface areas , which was better for adsorption. The pore size was mainly concentrated between 13 ~ 28nm. Moreover, these materials had more functional groups. The decomposition temperature was 250°C,which resulted in better thermal stability. Consequently, the materials had better adsorption properties, and the materials will have better application prospect.

Download Full-text

Zn-Cr Layered Double Hydroxides Composites for Methyl Orange (MO) Absorption

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.281.836 ◽

2018 ◽

Vol 281 ◽

pp. 836-841

Author(s):

Tao Zhou ◽

Jian Ping Ai ◽

Wei Xiu Liao ◽

Li Hong Cheng ◽

Yue Zhang ◽

...

Keyword(s):

Methyl Orange ◽

Layered Double Hydroxides ◽

Adsorption Property ◽

Bet Surface Area ◽

Molar Ratio ◽

Light Illumination ◽

X Ray Diffraction ◽

Anionic Dyes ◽

Molar Ratios ◽

Double Hydroxides

In this study, The Zn-Cr nanocomposite was synthesized using the hydrothermal method show good adsorption property. The as-prepared LDHs absorbent were characterized by Powder X-ray Diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier Transform Infrared (FT-IR), BET surface area, and simultaneously UV-visible spectrophotometer. The nanocomposites of Zn-Cr layered double hydroxides, the strong adsorptive adsorbents for anions. Zn-Cr LDHs with various Zn/Cr molar ratios for 2, 3, 4. The nanocomposites quickly adsorbed the anionic dyes such as methyl orange (MO) without the light illumination. The effects of Zn/Cr molar ratio on the adsorption performance of Zn-Cr LDHs were investigated.

Download Full-text

Biosorption of anionic and cationic dyes via raw and chitosan oligosaccharide-modified Huai Flos Chrysanthemum at different temperatures

RSC Advances ◽

10.1039/c9ra00378a ◽

2019 ◽

Vol 9 (20) ◽

pp. 11202-11211 ◽

Cited By ~ 4

Author(s):

Yanzhuo Zhang ◽

Huilin Wan ◽

Jing Zhao ◽

Jun Li

Keyword(s):

Malachite Green ◽

Crystal Violet ◽

Cationic Dyes ◽

Lemon Yellow ◽

Chitosan Oligosaccharide ◽

Sunset Yellow ◽

Anionic Dyes ◽

Different Temperatures ◽

First Time

Raw Huai Flos Chrysanthemum and modified HFC were used for the first time as a biosorbent to remove cationic dyes Malachite green and Crystal violet, and anionic dyes Sunset yellow, Lemon yellow, and Carmine, at different temperatures (5–50 °C).

Download Full-text

Adsorption and reduction of carcinogenic organics by ordered semi-crystalline poly-m-chloroaniline

High Performance Polymers ◽

10.1177/09540083211044391 ◽

2021 ◽

pp. 095400832110443

Author(s):

Pankaj Gupta ◽

Nakshatra Bahadur Singh ◽

Mohit Sahni

Keyword(s):

Oxidative Polymerization ◽

Polymeric Materials ◽

Spectroscopic Studies ◽

Bet Surface Area ◽

Order Kinetic ◽

X Ray Diffraction ◽

Anionic Dyes ◽

Pseudo Second Order ◽

Aromatic Nitro ◽

First Time

Poly-m-chloroaniline has been synthesized by chemical oxidative polymerization of m-chloroaniline and confirmed by spectroscopic studies. Powder X-ray diffraction and FESEM studies confirmed ordered arrangement in poly-m-chloroaniline. The peak at lower angle such as 7.09° having d spacing of 12.53 Å shows ordered structure of PmClA which was further confirmed by layered morphology in the FESEM images. FTIR spectra confirm the stretching and vibration mode of polymeric m-chloroaniline ring. BET surface area and pore diameter of PmClA were found to be 121 m2/g and 15.184 nm. Poly-m-chloroaniline was found to have better adsorption capacity toward anionic dyes over cationic dyes. The anionic dye (IC and EY) was 98 and 99% removed in just 25 min, whereas the cationic dye (MG and Rh6G) was 87 and 83% removed in 30 min. Langmuir adsorption isotherm model and pseudo second-order kinetic equation fitted the data best. Mechanism of adsorption has also been proposed. This is suggested that polymeric materials can be used for purification of water. The reduction of aromatic nitro compounds to amino compounds using organocatalyst has been done for the first time.

Download Full-text

Selective and Highly Efficient Adsorption of a Mixture of Anionic and Cationic Dyes as Synthetic Wastewater Absorbents on Layered Double Hydroxide: Experimental and Computational Studies

10.21203/rs.3.rs-640132/v1 ◽

2021 ◽

Author(s):

Rehab K. Mahmoud ◽

Mohamed Taha ◽

Amal Zaher ◽

Rafat M. Amin

Keyword(s):

Adsorption Capacity ◽

Layered Double Hydroxide ◽

Photoelectron Spectroscopy ◽

Dye Adsorption ◽

Cationic Dyes ◽

Synthetic Wastewater ◽

Anionic Dyes ◽

X Ray ◽

Before And After ◽

Double Hydroxide

Abstract Background: In the current work, the removal of cationic and anionic dyes from water was studied both experimentally and computationally. We examine the selectivity of the adsorbent, Zn–Fe layered double hydroxide (LDH) toward three cationic and anionic dyes. Methods: The chemical and physical properties of the prepared adsorbent before and after adsorption were investigated using FT-IR, X-ray diffraction, zeta potential, energy dispersive X-ray, X-ray photoelectron spectroscopy, particle size, HRTEM, and FESEM analysis; optical and electric properties were estimated. The influence of pH on the adsorption process was estimated. Monte Carlo simulations were performed to understand the adsorption mechanism and compute the adsorption energies.Significant Findings: Single dye adsorption tests revealed that Zn–Fe LDH effectively takes up anionic methyl orange (MO) more than the cationic dyes methylene blue (MB) and malachite green (MG). From MO/MB/MG mixture experiments, LDH selectively adsorbed in the following order: MO>MB>MG. The adsorption capacity of a single dye solution was 230.68, 133.29, and 57.34 mg/g for MO, MB, and MG, respectively; for the ternary solution, the adsorption capacity was 217.97, 93.122, and 49.57 mg/g for MO, MB, and MG, respectively. Zn–Fe LDH was also used as a photocatalyst, giving 92.2% and 84.7% degradation at concentrations of 10 and 20 mg/L, respectively.

Download Full-text