Effect of thermal treatment on the catalytic activity of a Fe-rich bentonite for the photo-Fenton reaction

Abstract

The objective of this work was to evaluate the degradation of rhodamine B dye from aqueous solution by photo-Fenton reaction under visible irradiation using a Fe-rich bentonite as a catalyst. The material was thermally treated at a low temperature (200 °C) and characterized by XRD, N 2 adsorption-desorption isotherms, FTIR, SEM-EDS and XRF. Iron leaching in aqueous solution after the photo-Fenton reaction was evaluated by atomic absorption spectroscopy. The material exhibited a mesoporous structure, containing a specific surface area of 99 m 2 .g -1 . The catalytic results showed significant dye degradation, reaching 95% of decolorization and 72% of mineralization at 300 min of reaction. The catalyst showed high chemical stability in four reaction cycles. Therefore, this thermally treated Fe-rich bentonite can be considered as a promising catalyst in the heterogeneous photo-Fenton reaction for the degradation of rhodamine B from aqueous solution. ResumoO objetivo deste trabalho foi avaliar a degradação do corante rodamina B em solução aquosa por reação foto-Fenton sob irradiação visível utilizando uma bentonita rica em ferro como catalisador. O material foi tratado termicamente a baixa temperatura (200 ºC) e caracterizado por DRX, isotermas de adsorção-dessorção de N 2 , FTIR, MEV-EDS e FRX. A lixiviação do ferro na solução aquosa após a reação foto-Fenton foi avaliada por espectroscopia de absorção atômica. O material exibiu uma estrutura mesoporosa, apresentando uma área de superfície específica de 99 m 2 .g -1 . Os resultados catalíticos mostraram alta eficiência na degradação do corante, atingindo 95% de descoloração e 72% de mineralização em 300 min de reação. O catalisador apresentou alta estabilidade química em quatro ciclos de reação. Portanto, esta bentonita rica em Fe tratada termicamente pode ser considerada como um promissor catalisador na reação foto-Fenton heterogênea para a degradação da rodamina B em solução aquosa.

Swelling Characteristics of Clay Minerals According to the Ionic Strength in Pore Water

“…3. 팽창 실험 장비 및 방법 , 2006;POSIVA, 2007;Egirani et al, 2018;Zimmermann et al, 2019). XRD 분석 결과 카올리나이트와 일라이트는 Muscovite와 Alpha-SiO 2 로 구성되어 있음을 확인하였다.…”

Heterogeneous Fenton-like catalytic degradation of phenazine dye over CeO2 (CP-2) nanoscale powder

“…Amongst them, iron minerals are relatively less priced and can be separated magnetically from the reaction medium [43]. Applications o f Fe-rich bentonite [44], fly ash-based catalysts [45], and molybdenum carbide doped with nanostructured nickel [46] have been reviewed in detail.…”

Decolorization and degradation of methylene blue by photo-Fenton reaction under visible light using an iron-rich clay as catalyst: CCD-RSM design and LC-MS technique

“…This clay can exhibit excellent properties, as large specific surface area, high cation exchange capacity (CEC) and low permeability, which gives it a wide application as adsorbents and catalysts (BELBACHIR and MAKHOUKHI, 2017;ZONG et al, 2015). The work of Zimmermann et al (2019) showed an increase of the specific surface area of these clays when subjected to thermal treatment at 200 °C. Morphological characteristics of the sample were examined using scanning electron microscopy (SEM; Jeol, JSM 6010LV).…”

“…The photodegradation was determined by Liquid Chromatography coupled to Mass Spectrometry (LC−MS) using an electrospray ionization mass spectrometer (Agilent Technologies − 6460 Triple Quadrupole LC/MS) in order to verify the fragmentation of dye molecules. The methodology of equipment operation and analytical conditions are described byZimmermann et al (2019).…”