Influence of pH, layer charge location and crystal thickness distribution on U(VI) sorption onto heterogeneous dioctahedral smectite

Guimarães, Vanessa; Rodríguez‐Castellón, Enrique; Algarra, Manuel; Rocha, Fernando; Boboş, Iuliu

doi:10.1016/j.jhazmat.2016.05.060

Cited by 31 publications

(8 citation statements)

References 54 publications

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“…The LF isotherm is reduced to the Langmuir form for n = 1, and a homogeneous surface is considered. The greater the difference from this value, the greater the clay surface heterogeneity [28].…”

Section: Tbz Adsorption Studiesmentioning

confidence: 95%

“…The fact that n increased when Cu 2+ was incorporated in the adsorbent structure (Table 1) was related to the development of surface heterogeneity, which indicated the existence of energetically different adsorption sites [28]. It is important to notice the presence of inner and edge sites in Mt and different functional groups in OMt and BMt where Cu 2+ could be loaded, which reveals the chemical complexity of the surface adsorbents.…”

Section: Adsorption Isothermsmentioning

confidence: 96%

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Thiabendazole adsorption on montmorillonite, octadecyltrimethylammonium- and Acremonium sp.-loaded products and their copper complexes

Gamba

Olivelli

Martinez

et al. 2017

Chemical Engineering Journal

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Section: Tbz Adsorption Studiesmentioning

confidence: 95%

Section: Adsorption Isothermsmentioning

confidence: 96%

Thiabendazole adsorption on montmorillonite, octadecyltrimethylammonium- and Acremonium sp.-loaded products and their copper complexes

Gamba

Olivelli

Martinez

et al. 2017

Chemical Engineering Journal

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“…After the adsorption runs, the samples were centrifuged and the TOC content of the supernatant solution was measured. The percentage of organic carbon removed through adsorption was calculated according to Equation (2) [47,48]:…”

Section: Adsorption Testsmentioning

confidence: 99%

Effect of Zr Impregnation on Clay-Based Materials for H2O2-Assisted Photocatalytic Wet Oxidation of Winery Wastewater

Guimarães¹,

Teixeira²,

Lucas³

et al. 2020

Water

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UV-activated Zr-doped composites were successfully produced through the impregnation of Zr on the crystal lattice of different clay materials by a one-step route. Fixing the amount of Zr available for dopage (4%), the influence of different supports, submitted to different chemical treatments, on the photocatalytic activity of the resulting Zr-doped pillared clay materials (PILC) was assessed. Both chemical characterization and structural characterization suggest that the immobilization of Zr on montmorillonite and PILC structures occurred through isomorphic substitution between Si and Zr in the tetrahedral sheet of the clay material. This structural change was demonstrated by significant modifications on Si-OH stretching vibrations (1016 cm−1, 1100 cm−1 and 1150 cm−1), and resulted in improved textural properties, with an increase in surface area from 8 m2/g (natural montmorillonite) to 107 m2/g after the pillaring process, and to 118 m2/g after the pillaring and Zr-doping processes ((Zr)Al-Cu-PILC). These materials were tested in the UV-photodegradation of agro-industrial wastewater (AIW), characterized by high concentrations of recalcitrant contaminants. After Zr-dopage on AlCu-PILC heterogeneous catalyst, the total organic carbon (TOC) removals of 8.9% and 10.4% were obtained through adsorption and 77% and 86% by photocatalytic oxidation, at pH 4 and 7, respectively. These results suggest a synergetic effect deriving from the combination of Zr and Cu on the photocatalytic degradation process.

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“…The variable charge of clays is affected by the pH, due to the ionization of its external hydroxyl groups. Therefore, the external sites may acquire positive (OH + 2 ) or negative charge ( − O − ), whether the pH is lower or higher than its isoelectric point (pH at the point of zero charge) [69,70]. In the work of Guimarães et al [69], when the clay was mixed with WW at pH 4.0, a mechanism of adsorption occurred, in which a high concentration of amphoteric flavylium species were adsorbed by the clay.…”

Section: Simplex Lattice Design-model Optimizationmentioning

confidence: 99%

Combination of Coagulation–Flocculation–Decantation and Ozonation Processes for Winery Wastewater Treatment

Jorge

Teixeira

Matos

et al. 2021

IJERPH

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This research assessed a novel treatment process of winery wastewater, through the application of a chemical-based process aiming to decrease the high organic carbon content, which represents a difficulty for wastewater treatment plants and a public health problem. Firstly, a coagulation–flocculation–decantation process (CFD process) was optimized by a simplex lattice design. Afterwards, the efficiency of a UV-C/ferrous iron/ozone system was assessed for organic carbon removal in winery wastewater. This system was applied alone and in combination with the CFD process (as a pre- and post-treatment). The coagulation–flocculation–decantation process, with a mixture of 0.48 g/L potassium caseinate and 0.52 g/L bentonite at pH 4.0, achieved 98.3, 97.6, and 87.8% removals of turbidity, total suspended solids, and total polyphenols, respectively. For the ozonation process, the required pH and ferrous iron concentration (Fe2+) were crucial variables in treatment optimization. With the application of the best operational conditions (pH = 4.0, [Fe2+] = 1.0 mM), the UV-C/ferrous iron/ozone system achieved 63.2% total organic carbon (TOC) removal and an energy consumption of 1843 kWh∙m−3∙order−1. The combination of CFD and ozonation processes increased the TOC removal to 66.1 and 65.5%, respectively, for the ozone/ferrous iron/UV-C/CFD and CFD/ozone/ferrous iron/UV-C systems. In addition, the germination index of several seeds was assessed and excellent values (>80%) were observed, which revealed the reduction in phytotoxicity. In conclusion, the combination of CFD and UV-C/ferrous iron/ozone processes is efficient for WW treatment.

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Influence of pH, layer charge location and crystal thickness distribution on U(VI) sorption onto heterogeneous dioctahedral smectite

Cited by 31 publications

References 54 publications

Thiabendazole adsorption on montmorillonite, octadecyltrimethylammonium- and Acremonium sp.-loaded products and their copper complexes

Thiabendazole adsorption on montmorillonite, octadecyltrimethylammonium- and Acremonium sp.-loaded products and their copper complexes

Effect of Zr Impregnation on Clay-Based Materials for H2O2-Assisted Photocatalytic Wet Oxidation of Winery Wastewater

Combination of Coagulation–Flocculation–Decantation and Ozonation Processes for Winery Wastewater Treatment

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