Mesosilica materials and organic pollutant adsorption: part B removal from aqueous solution

This tutorial review focuses on the application of mesoporous silica materials, primarily MCM-41 and SBA-15, for the removal of organic pollutants in the vapour phase.

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Valorization of Green Clay from Bouaflé (Ivory Coast) in the Simultaneous Elimination of Organic Pollutants and Metallic Trace Elements by Adsorption: Case of Methylene Blue and Cadmium Ions

Chemical Science International Journal ◽

10.9734/csji/2020/v29i830200 ◽

2020 ◽

pp. 37-51

Author(s):

Bintou Coulibaly ◽

Lemeyonouin Aliou Guillaume Pohan ◽

Ollo Kambiré ◽

Lébé Prisca Sandrine Kouakou ◽

Hervé Goure-Doubi ◽

...

Keyword(s):

Aqueous Solution ◽

Methylene Blue ◽

Specific Surface ◽

Organic Pollutants ◽

Adsorption Kinetics ◽

Organic Pollutant ◽

Positive Sign ◽

Basic Medium ◽

Order Kinetic ◽

Cadmium Ions

The objective of this work was to valorize the clays of Côte d'Ivoire in the treatment of wastewater. The study focused on the ability of raw clays from Bouaflé city to adsorb methylene blue and cadmium ions, in aqueous solution. The physicochemical characteristics of the clay were determined using the measurement of its specific surface area, chemical analysis and mineralogical analysis. It emerges from these characterizations that clay is essentially composed of type 2/1 minerals such as illite (32.94%), type 1/1 kaolinite (8.47%), quartz (40.23 %) and approximately iron oxy-hydroxides (18.36%). Its specific surface is 37.58 m2 / g. The kinetics, thermodynamics and isotherms of adsorption have been used to understand the mechanism of adsorption. The results obtained show that the organic pollutant alone in solution (methylene blue (MB)) is adsorbed quite quickly. We obtained a decoloration yield greater than 90% after 40 min of adsorbate-adsorbent contact. The elimination of methylene blue is greater in a basic medium. The BM adsorption kinetics were modeled. The comparison of the correlation factors of the different kinetic models used has shown that the adsorption kinetics of the organic pollutant (MB) better match the pseudo second order kinetic model. Thermodynamics predicted a spontaneous endothermic surface reaction, due to the positive sign of and the negative sign of , obtained ( = 31.398; = -12.635). Analysis of adsorption isotherms allowed us to show that the adsorption of methylene blue on clay is physisorption type and in monolayer. The experiments were also performed with an aqueous solution containing both methylene blue and cadmium ions. After a contact time of 120 min, 60% of the cadmium ions are adsorbed on the clay against only 20% of methylene blue. Thus, clay preferentially eliminates trace metal elements (Cd2+) compared to organic pollutants (methylene blue).

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Heterogeneous Fenton Catalytic Removal of Organic Pollutant in Aqueous Solution by using Coal Gangue as a Catalyst

Recent Innovations in Chemical Engineering (Formerly Recent Patents on Chemical Engineering) ◽

10.2174/2405520412666190806120033 ◽

2019 ◽

Vol 12 (4) ◽

pp. 312-325

Author(s):

Jiwei Zhang ◽

Jingjing Xu ◽

Shuaixia Liu ◽

Baoxiang Gu ◽

Feng Chen ◽

...

Keyword(s):

Aqueous Solution ◽

Hydrogen Peroxide ◽

Hydroxyl Radical ◽

Removal Rate ◽

Organic Pollutant ◽

Coal Gangue ◽

Ion Leakage ◽

Heterogeneous Fenton ◽

Solution Ph ◽

X Ray

Background: Coal gangue was used as a catalyst in heterogeneous Fenton process for the degradation of azo dye and phenol. The influencing factors, such as solution pH gangue concentration and hydrogen peroxide dosage were investigated, and the reaction mechanism between coal gangue and hydrogen peroxide was also discussed. Methods: Experimental results showed that coal gangue has the ability to activate hydrogen peroxide to degrade environmental pollutants in aqueous solution. Under optimal conditions, after 60 minutes of treatment, more than 90.57% of reactive red dye was removed, and the removal efficiency of Chemical Oxygen Demand (COD) up to 72.83%. Results: Both hydroxyl radical and superoxide radical anion participated in the degradation of organic pollutant but hydroxyl radical predominated. Stability tests for coal gangue were also carried out via the continuous degradation experiment and ion leakage analysis. After five times continuous degradation, dye removal rate decreased slightly and the leached Fe was still at very low level (2.24-3.02 mg L-1). The results of Scanning Electron Microscope (SEM), energy dispersive X-Ray Spectrometer (EDS) and X-Ray Powder Diffraction (XRD) indicated that coal gangue catalyst is stable after five times continuous reuse. Conclusion: The progress in this research suggested that coal gangue is a potential nature catalyst for the efficient degradation of organic pollutant in water and wastewater via the Fenton reaction.

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Electrospun-based TiO2 nanofibers for organic pollutant photodegradation: a comprehensive review

Reviews in Chemical Engineering ◽

10.1515/revce-2020-0022 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Khee Chung Hui ◽

Hazwani Suhaimi ◽

Nonni Soraya Sambudi

Keyword(s):

Visible Light ◽

Organic Pollutants ◽

Organic Pollutant ◽

Hollow Fibers ◽

Promising Alternative ◽

Tio2 Nanofibers ◽

As Doping ◽

Secondary Pollutants ◽

Photocatalytic Reactors ◽

Light Area

Abstract Titanium dioxide (TiO2) is commonly used as a photocatalyst in the removal of organic pollutants. However, weaknesses of TiO2 such as fast charge recombination and low visible light usage limit its industrial application. Furthermore, photocatalysts that are lost during the treatment of pollutants create the problem of secondary pollutants. Electrospun-based TiO2 fiber is a promising alternative to immobilize TiO2 and to improve its performance in photodegradation. Some strategies have been employed in fabricating the photocatalytic fibers by producing hollow fibers, porous fibers, composite TiO2 with magnetic materials, graphene oxide, as well as doping TiO2 with metal. The modification of TiO2 can improve the absorption of TiO2 to the visible light area, act as an electron acceptor, provide large surface area, and promote the phase transformation of TiO2. The improvement of TiO2 properties can enhance carrier transfer rate which reduces the recombination and promotes the generation of radicals that potentially degrade organic pollutants. The recyclability of fibers, calcination effect, photocatalytic reactors used, operation parameters involved in photodegradation as well as the commercialization potential of TiO2 fibers are also discussed in this review.

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Fabrication of TiO2/Fe2O3/CdS systems: effects of Fe2O3 and CdS content on superior photocatalytic activity

RSC Advances ◽

10.1039/d1ra00195g ◽

2021 ◽

Vol 11 (17) ◽

pp. 10300-10308

Author(s):

Hui Feng ◽

Siqi Feng ◽

Niu Tang ◽

Songbai Zhang ◽

Xiangyang Zhang ◽

...

Keyword(s):

Aqueous Solution ◽

Photocatalytic Activity ◽

Organic Pollutants ◽

High Performance ◽

Low Cost

New idea for the low cost synthesis of high performance photocatalysts for the photodegradation of organic pollutants in aqueous solution.

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Magnetic Field-Assisted Photocatalytic Degradation of Organic Pollutants over Bi1−xRxFeO3 (R = Ce, Tb; x = 0.00, 0.05, 0.10 and 0.15) Nanostructures

Materials ◽

10.3390/ma14154079 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4079

Author(s):

Radhalayam Dhanalakshmi ◽

Nambi Venkatesan Giridharan ◽

Juliano C. Denardin

Keyword(s):

Magnetic Field ◽

Rare Earth ◽

Visible Light ◽

Photocatalytic Degradation ◽

Organic Pollutants ◽

Visible Light Irradiation ◽

Organic Pollutant ◽

Hydrothermal Process ◽

Phenol Red ◽

Magnetic Features

Magnetic-field-accelerated photocatalytic degradation of the phenol red (PR) as a model organic pollutant was studied using rare-earth elements modified BiFeO3 (Bi1−xRxFeO3 (R = Ce, Tb; x = 0.0, 0.05, 0.10 and 0.15); BFO: RE) nanostructures. The nanostructures were prepared via the hydrothermal process and their morphological, structural, functional, optical and magnetic features were investigated in detail. The effect of magnetic fields (MFs) on photocatalysis were examined by applying the different MFs under visible light irradiation. The enhanced photodegradation efficiencies were achieved by increasing the MF up to 0.5T and reduced at 0.7T for the compositions x = 0.10 in both Ce and Tb substituted BFO. Further, mineralization efficiencies of PR, reproducibility of MF-assisted photocatalysis, stability and recyclability of BFO: RE nanostructures were also tested.

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