Removal of ciprofloxacin from aqueous solutions using pillared clays

Emerging contaminants in the environment have caused enormous concern in the last few decades, and among them, antibiotics have received special attention. On the other hand, adsorption has shown to be a useful, low-cost, and eco-friendly method for the removal of this type of contaminants from water. This work is focused on the study of ciprofloxacin (CPX) removal from water by adsorption on pillared clays (PILC) under basic pH conditions, where CPX is in its anionic form (CPX-). Four different materials were synthetized, characterized, and studied as adsorbents of CPX (Al-, Fe-, Si-, and Zr-PILC). The highest CPX adsorption capacities of 100.6 and 122.1 mg g-1 were obtained for the Si- and Fe-PILC (respectively), and can be related to the porous structure of the PILCs. The suggested adsorption mechanism involves inner-sphere complexes formation as well as van der Waals interactions between CPX- and the available adsorption sites on the PILC surfaces.Fil: Roca Jalil, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Baschini, Miria Teresita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Sapag, Manuel Karim. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

Effect of Aluminium Content in Aluminium Pillared Montmorillonite on Its Surface Acidity Properties

Aluminium pillared montmorillonites from Indonesian natural montmorillonite has been prepared using Al13 Keggin ion pillaring precursor in varied concentrations. Herein we studied their characterization and catalysis application for esterification reaction. X-ray diffraction (XRD), energy dispersive x-ray analysis (EDX), and BET gas sorption analysis were employed to characterize the prepared materials besides the characterization on surface acidity by pyridine and n-butylammine adsorptions and FTIR analysis. The result showed that significant improvement on physicochemical character data was obtained by a pillarization process. Such a process also provided improvements on catalytic activities in esterification reactions. The effect of aluminium content on material characters was discussed in this paper. It was observed from the catalytic activity tests that pillared montmorillonite samples demonstrated higher activity in esterification reaction relative to the raw montmorillonite. It was found that surface profile of materials consist of specific surface area, pore volume and Lewis acidity were significantly affect the catalyst activity

Microwave-Assisted Pillaring of a Montmorillonite with Al-Polycations in Concentrated Media

[EN]A montmorillonite has been intercalated with Al3+ polycations, using concentrated solutions and clay mineral dispersions. The reaction has been assisted by microwave radiation, yielding new intercalated solids and leading to Al-pillared solids after their calcination at 500 C. The solids were characterized by elemental chemical analysis, X-ray diffraction, FTIR spectroscopy, thermal analyses, and nitrogen adsorption. The evolution of the properties of the materials was discussed as a function of the preparation conditions. Microwave treatment for 2.5 min provided correctly pillared solids

Concentration of 2-phenylphenol by organoclays from aqueous sucrose solution

The adsorption of 2-phenylphenol, which is an antifungal agent, onto organically modified clay from aqueous sucrose solution was investigated. 2-Phenylphenol was effectively adsorbed on neostigmine-modified smectites and octadecyltrimethylammoniurh modified smectites even in the presence of sucrose in the starting aqueous solution. Two smectites (a natural montmorillonite, Kunipia F, and a synthetic saponite, Sumecton SA) were used to find clay minerals with lower layer charge density gave larger adsorption capacity for 2-phenylphenol. The result showed the potential application of the organically modified clays to remove 2-phenylphenol from orange extracts. (C) 2014 Published by Elsevier B.V.ArticleAPPLIED CLAY SCIENCE. 109: 64-67 (2015)journal articl

High Temperature Structural Modifications of Intercalated Montmorillonite Clay Mineral with OH-Al Polymers

AbstractTwo montmorillonitic clays were put into contact with a solution containing inorganic OH-Al polymers and subsequently washed and dried. The obtained solid (i.e.the clays with the OH -Al species in the montmorillonite interlayer) which was called the precursor, was subjected to a thermal treatment up to 1000 ¡ C using DTA-TG for analysis at low temperature. Additionally, the structural changes of the precursor by heating at 1030, 1100 and 1200 ¡ C for 2hours and that of the natural clays were examined. The crystallinity and formation of new phases was followed by x-ray diffraction analysis. Mullite and cordierite were originated depending on the different contents of aluminium and magnesium in the structure of natural montmorillonite, respectively, accompanied with other phases. The intercalated OH-Al species in both clays favored the increase in the mullite content in the final products. However, the transformation to this phase was directly related to the octahedral aluminium of the natural clay and thus mullite was found to be the dominant phase from montmorillomite containing higher octahedral Al

Pore Structure of Surfactant Modified Montmorillonites

A series of organoclays with different surfactant arrangements were prepared by ion exchange. The resulting organoclays were investigated using a combination of characterization techniques, including XRD, FTIR, TG and N2 adsorption-desorption. In the present study, the pores within the organoclays were discussed on the basis of the microstructural parameters, including BET-N2 surface area, pore volume, pore size, surfactant loading and distribution. The results show that both BET-N2 surface area and pore volume decrease from low to high packing density of the surfactant as the average pore size increases. Two basic organoclay models were proposed for hexadecyltrimethylammonium bromide (HDTMAB) modified montmorillonites: 1) the surfactant mainly occupied the clay interlayer and 2) both the clay interlayer space and external surface were modified by surfactant. This study demonstrates that the pore structure of the resulting organoclays has a significant influence on the sorption efficiency and mechanism of p-nitrophenol onto the organoclays

Influence of Operational Parameters on Photocatalytic Degradation of Linuron in Aqueous TiO2 Pillared Montmorillonite Suspension

TiO2 pillared clay was prepared by intercalation of titan polyoxocation into interlamelar space of an Algerian montmorillonite and used for the photocatalytic degradation of the linuron herbicide as a target pollutant in aqueous solution. The TiO2 pillared montmorillonite (Mont-TiO2) was characterized by X-ray photoelectron spectroscopy (XPS), X-Ray diffraction (XRD), X-Ray fluorescence (XRF), scanning electronic microscopy (SEM), thermogravimetry and differential thermal analysis (TG-DTA), Fourier transformed infra-red (FT-IR), specific area and porosity determinations. This physicochemical characterization pointed to successful TiO2 pillaring of the clay. The prepared material has porous structure and exhibit a good thermal stability as indicated by its surface area after calcination by microwave. The effects of operating parameters such as catalyst loading, initial pH of the solution and the pollutant concentration on the photocatalytic efficiency and COD removal  were evaluated. Under initial pH of the solution around seven, pollutant concentration of 10 mg/L and 2.5 g/L of catalyst at room temperature, the degradation efficiency and COD removal of linuron was best then the other operating conditions. It was observed that operational parameters play a major role in the photocatalytic degradation process. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Crecimiento in-situ de nanoclusters metálicos de fe o mn intercalados en una bentonita previamente pilarizada con Al

Dado que la preparación de nanoclusters metálicos es termodinámicamente inestable, debido principalmente al crecimiento ilimitado durante la síntesis, se ha explorado la formación in-situ de clusters de MnS o FeS confinados en el espacio interlaminar de una bentonita en un proceso rápido de reacción de aproximadamente 12 horas. Los clusters sulfidizados polinucleares interlaminares fueron preparados por intercambio catiónico de Mn2+ o Fe2+ en la bentonita, como también sobre el aluminosilicato previamente intercalado/pilarizado con diferentes cargas de aluminio: 10, 20 o 30 meq Al3+/g arcilla en forma de (Al13)7+, seguido por sulfidización con H2S(g). Durante el proceso de sulfidización se evaluaron los siguientes parámetros: (i) Relación H2S(g)/Mn2+ o entre 5 y 500; (ii) Temperatura de sulfidización entre 50 y 400 °C; (iii) Temperatura y atmósfera de tratamiento térmico entre 200 y 400 °C en atmósfera inerte (N2) u oxidante (aire) y (iv) Efecto de la neutralización básica antes del tratamiento térmico. Los materiales fueron caracterizados por análisis elemental (EAA/FRX), capacidad de intercambio catiónico (CIC), difracción de rayos-X (DRX), espectroscopia fotoelectrónica de rayos X (XPS), análisis textural (adsorción N2) y térmico (DTA/TGA). La pilarización más eficiente se consiguió con una carga de pilares de 20 meq Al3+/g arcilla (Al13)7+, en términos de mayor expansión del espaciado basal (desplazamiento hacia menores ángulos 2θ de la señal d001) y distribución más homogénea de los pilares (menores hhpw). La relación más apropiada H2S(g)/Mn2+ o fue de 50 con la cual se alcanzó el mejor balance entre la cantidad de sulfuro de hidrógeno alimentado para el crecimiento de los nanoclusters de Mn, pero sin afectar la estructura laminar del aluminosilicato por el ataque ácido, bajo temperatura de sulfidización de 100 °C y temperatura de tratamiento térmico de 200 °C. Con estas condiciones se logró promover el crecimiento y estabilización de los nanoclusters de Mn o Fe preservando la estructura laminar de la bentonita. Por su parte, el tipo de atmósfera empleado en el tratamiento térmico no mostró un efecto significativo sobre la estructura final de los sólidos. Los materiales modificados con Fe resultaron menos estables que los modificados con Mn, probablemente por las propiedades intrínsecas fuertemente ácidas del primero. Se estudió el efecto de las principales variables de preparación que afectan la estabilidad de los nanoclusters finales de Mn o Fe y se demostró que la pilarización del mineral arcilloso es una estrategia novedosa y muy útil para controlar el crecimiento y el tamaño final promedio de los agregados polinucleares de MnS y FeS