Chitosan/Zeolite Composite Aerogels for a Fast and Effective Removal of Both Anionic and Cationic Dyes from Water

Organic dyes are extensively used in many industrial sectors, and their uncontrolled disposal into wastewaters raises serious concerns for environmental and human health. Due to the large variety of such pollutants, an effective remediation strategy should be characterized by a broad-spectrum efficacy. A promising strategy is represented by the combination of different adsorbent materials with complementary functionalities to develop composite materials that are expected to remove different contaminants. In the present work, a broad-spectrum adsorbent was developed by embedding zeolite 13X powder (ZX) in a chitosan (CS) aerogel (1:1 by weight). The CS–ZX composite adsorbent removes both anionic (indigo carmine, IC) and cationic (methylene blue, MB) dyes effectively, with a maximum uptake capacity of 221 mg/g and 108 mg/g, respectively. In addition, the adsorption kinetics are rather fast, with equilibrium conditions attained in less than 2 h. The composite exhibits good mechanical properties in both dry and wet state, which enables its handling for reusability purposes. In this regard, preliminary tests show that the full restoration of the IC removal ability over three adsorption–desorption cycles is achieved using a 0.1 M NaOH aqueous solution, while a 1 M NaCl aqueous solution allows one to preserve >60% of the MB removal ability.

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Photocatalytic Degradation of Indigo Carmine Dye Using Hydrothermally Synthesized Anatase TiO2 Nanotubes under Ultraviolet Light Emitting Diode Irradiation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.855.45 ◽

2016 ◽

Vol 855 ◽

pp. 45-57 ◽

Cited By ~ 2

Author(s):

Kalithasan Natarajan ◽

Rukshana I. Kureshy ◽

Hari C. Bajaj ◽

Rajesh J. Tayade

Keyword(s):

Photocatalytic Degradation ◽

Band Gap ◽

Organic Dyes ◽

Light Emitting Diode ◽

Indigo Carmine ◽

Order Kinetic ◽

Light Emitting ◽

Order Kinetic Model ◽

Different Temperatures ◽

Adsorption Desorption

Anatase TiO2 nanotubes (ATNT) was synthesised by hydrothermal method using anatase TiO2 nanoparticles (AT) as precursor and calcined at two different temperatures (250 & 450 °C) for 2 h. The AT and synthesized ATNT photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurements, UV-vis diffuse reflectance and Fourier Transform Infra-red spectroscopy techniques for their structural, textural and electronic properties. The photocatalytic degradation of Indigo carmine (IC) dye aqueous solution has carried out using ATNT-250 and ATNT-450 photocatalysts under UVLED irradiation. The kinetic analysis has also revealed that the degradation of IC dye solution follows first order kinetic model. The overall study demonstrates the appropriate band gap of the photocatalysts used and the suitable irradiation source which could accelerate the rate of photocatalytic degradation. The band gap of the synthesised ATNT is not much affected due to the change in morphology from nanoparticle to nanotube. The results demonstrated that the irradiation of UV-LED could be utilised for the degradation of organic dyes

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Surface-functionalized silica gel adsorbents for efficient remediation of cationic dyes

Pure and Applied Chemistry ◽

10.1515/pac-2014-0105 ◽

2014 ◽

Vol 86 (7) ◽

pp. 1177-1188 ◽

Cited By ~ 9

Author(s):

Aleeza Farrukh ◽

Attia Akram ◽

Abdul Ghaffar ◽

Eylül Tuncel ◽

Zehra Oluz ◽

...

Keyword(s):

Electron Microscopy ◽

Silica Gel ◽

Photoelectron Spectroscopy ◽

Organic Dyes ◽

Water Soluble ◽

Cationic Dyes ◽

Functionalized Silica ◽

Design And Synthesis ◽

Effective Removal ◽

Adsorption Desorption

AbstractThe toxic and non-biodegradable nature of organic dyes necessitates the design and synthesis of novel adsorbents for their effective removal from the environment. This study reports an effective remediation behavior of surface-functionalized silica gel against water-soluble cationic dyes (up to 98 % removal). Thiol groups were functionalized at the surface of silica gel (SiO2–SH). The surface-tethered –SH groups were further oxidized to sulfonic acid groups to generate the negatively charged moieties at the surface of silica gel (SiO2–SO3 H). The morphology of the developed adsorbents and the surface modifications were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Uptake study of three cationic dyes, namely, rhodamine B (Rh B), rhodamine 6G (Rh 6G), and crystal violet (CV) with SiO2–SH and SiO2–SO3 H adsorbents was performed by varying the adsorbent amount, contact time, pH of solution, and temperature. The presence of negatively charged species at the surface of SiO2–SO3 H results in an increased electrostatic interaction with the cationic dyes, which leads to better remediation characteristics for SiO2–SO3 H as compared to SiO2–SH. The reusability of the developed adsorbents was also assessed by investigating adsorption/desorption of dyes. The simple fabrication process provides a facile avenue to the adsorbents with efficient remediation towards cationic dyes.

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Effective Removal of Penicillin from Aqueous Solution Using Zinc Oxide/Natural-Zeolite Composite Nano-Powders Prepared Via Ball Milling Technique

Recent Patents on Nanotechnology ◽

10.2174/1872210511666170105141550 ◽

2017 ◽

Vol 11 (2) ◽

Cited By ~ 6

Author(s):

Peyman Khosravian ◽

Majid Ghashang ◽

Hamid Ghayoor

Keyword(s):

Aqueous Solution ◽

Zinc Oxide ◽

Ball Milling ◽

Natural Zeolite ◽

Effective Removal ◽

Ball Milling Technique ◽

Zeolite Composite

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Adsorption of Cadmium Ions from an Aqueous Solution on a Highly Stable Dopamine-Modified Magnetic Nano-Adsorbent

Nanoscale Research Letters ◽

10.1186/s11671-019-3154-0 ◽

2019 ◽

Vol 14 (1) ◽

Cited By ~ 9

Author(s):

Ting Lei ◽

Sheng-Jian Li ◽

Fang Jiang ◽

Zi-Xuan Ren ◽

Li-Lian Wang ◽

...

Keyword(s):

Aqueous Solution ◽

Adsorption Capacity ◽

Magnetic Nanomaterials ◽

Maximum Adsorption Capacity ◽

Cadmium Ions ◽

Effective Removal ◽

Dopamine Hydrochloride ◽

Pseudo Second Order ◽

Adsorption Desorption ◽

Nano Adsorbent

Abstract Magnetic nanomaterials were functionalized with dopamine hydrochloride as the functional reagent to afford a core–shell-type Fe3O4 modified with polydopamine (Fe3O4@PDA) composite, which was used for the adsorption of cadmium ions from an aqueous solution. In addition, the effects of environmental factors on the adsorption capacity were investigated. Furthermore, the adsorption kinetics, isotherm, and thermodynamics of the adsorbents were discussed. Results revealed that the adsorption of cadmium by Fe3O4@PDA reaches equilibrium within 120 min, and kinetic fitting data are consistent with the pseudo-second-order kinetics (R2 > 0.999). The adsorption isotherm of Cd2+ on Fe3O4@PDA was in agreement with the Freundlich model, with the maximum adsorption capacity of 21.58 mg/g. The thermodynamic parameters revealed that adsorption is inherently endothermic and spontaneous. Results obtained from the adsorption–desorption cycles revealed that Fe3O4@PDA exhibits ultra-high adsorption stability and reusability. Furthermore, the adsorbents were easily separated from water under an enhanced external magnetic field after adsorption due to the introduction of an iron-based core. Hence, this study demonstrates a promising magnetic nano-adsorbent for the effective removal of cadmium from cadmium-containing wastewater. Graphical Abstract

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A green synthesis of nanocatalysts based on reduced graphene oxide/magnetic nanoparticles for the degradation of Acid Red 1

RSC Advances ◽

10.1039/d0ra06311h ◽

2020 ◽

Vol 10 (64) ◽

pp. 38805-38817

Author(s):

Fatemeh Sadegh ◽

Nikolaos Politakos ◽

Estibaliz González de San Román ◽

Oihane Sanz ◽

Iñigo Perez-Miqueo ◽

...

Keyword(s):

Aqueous Solution ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Fenton Reaction ◽

Magnetic Nanoparticle ◽

Organic Dyes ◽

Reduced Graphene ◽

Composite Aerogels ◽

Acid Red 1 ◽

3D Composite

Fenton reaction nanocatalysts made of reduced graphene oxide–magnetic nanoparticle 3D composite aerogels for the elimination of organic dyes from aqueous solution.

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Utilization of chitosan–zeolite composite in the removal of Cu(II) from aqueous solution: Adsorption, desorption and fixed bed column studies

Chemical Engineering Journal ◽

10.1016/j.cej.2012.07.116 ◽

2012 ◽

Vol 209 ◽

pp. 46-53 ◽

Cited By ~ 84

Author(s):

W.S. Wan Ngah ◽

L.C. Teong ◽

R.H. Toh ◽

M.A.K.M. Hanafiah

Keyword(s):

Aqueous Solution ◽

Fixed Bed ◽

Column Studies ◽

Fixed Bed Column ◽

Zeolite Composite ◽

Adsorption Desorption

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From Adsorbent to Photocatalyst: The Sensitization Effect of SnO2 Surface towards Dye Photodecomposition

Molecules ◽

10.3390/molecules26237123 ◽

2021 ◽

Vol 26 (23) ◽

pp. 7123

Author(s):

Kinga Michalec ◽

Anna Kusior

Keyword(s):

Structural Changes ◽

Photocatalytic Performance ◽

Organic Dyes ◽

Indigo Carmine ◽

Dye Adsorption ◽

Chemical Conversion ◽

Photocatalytic Properties ◽

Hydrodynamic Diameter ◽

Micro Structure ◽

Adsorption Desorption

Semiconductor photocatalysis is considered one of the most promising technologies for water purification from toxic organic dyes. However, to reliably evaluate the possibility of using a given material as a photocatalyst, it is crucial to investigate not only the photocatalytic activity but also its affinity towards various dyes and reusability. In this work, we studied the adsorptive/photocatalytic properties of hollow-spherical raspberry-like SnO2 and its SnO2/SnS2 heterostructures that were obtained via a chemical conversion method using three different concentrations of a sulfide precursor (thioacetamide). The adsorptive/photocatalytic properties of the samples towards cationic rhodamine B (RhB) and anionic indigo carmine (IC) were analyzed using uncommon wall zeta potential measurements, hydrodynamic diameter studies, and adsorption/photodecomposition tests. Moreover, after conducting cyclic experiments, we investigated the (micro)structural changes of the reused photocatalysts by scanning electron microscopy and Fourier-transform infrared spectroscopy. The obtained results revealed that the sensitization of SnO2 resulted not only in the significantly enhanced photocatalytic performance of the heterostructures, but also completely changed their affinity towards dyes. Furthermore, despite the seemingly best photocatalytic performance, the sample with the highest SnS2 content was unstable due to its (micro)structure. This work demonstrates that dye adsorption/desorption processes may overlap the results of cyclic photodecomposition kinetics.

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