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The textile industry generates huge volumes of dye-contaminated wastewater. Discharging these effluents into the environment causes many diseases that can be detrimental to human health. Therefore, adsorption of these types of dyes such as methylene blue onto mineral matrices offers an efficient method for pollution remediation. The present investigation is undertaken to test the use of Tunisian clay in raw and sodium form to remove methylene blue from aqueous solution. The experimental data were analysed using the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. The equilibrium data fit well to the Langmuir model, and the monolayer adsorption capacity for methylene blue dye is 312.5 and 208.33 mg/g, respectively with sodium clay (MS002-1) and raw clay (MS001-2). [ABSTRACT FROM AUTHOR] more...

Graphical abstract Highlights • Mesoporous activated carbon was prepared from date palm petiole. • Activated carbon was used for the removal of IC in batch and fixed bed columns. • A pseudo-second-order model described the kinetics of the adsorption process. • The isotherms were found to be best described by the Langmuir model in batch mode. • Breakthrough curves of Bohart-Adams, Thomas, Yoon-Nelson and Yan models were used. Abstract In this work, the date palm petiole was transformed into activated carbon implying sodium hydroxide as the activating agent. The carbon obtained was exerted for the adsorption of indigo carmine in batch and continuous mode. The properties of activated carbon were established. The effects of pH, adsorbent mass, contact time, initial concentration and temperature on the adsorption of indigo carmine were examined in batch mode. The models of Langmuir, Freundlich, Temkin and Dubinin-Radushkevich were used for modeling adsorption isotherms. The Langmuir model appears to be the most appropriate for describing the adsorption of indigo carmine. The adsorption mechanism was governed by the pseudo-second order model and can be explained by physisorption accompanied by chemisorption. From the thermodynamic point of view, the adsorption was spontaneous and exothermic. In continuous adsorption, The Bohart-Adams model fit perfectly to the initial part of the breakthrough curve ((C t /C 0)<0.5), and the hole curve was well fit by the Yoon-Nelson and Thomas models. [ABSTRACT FROM AUTHOR] more...

Sunflower oil (SFO) and Flaxseed oil (FSO) were microencapsulated using simple and complex coacervation techniques with Opuntia (Cactaceae) mucilage (Mu) and with a combination of Mu with chitosan (Chit). The encapsulation efficiency (EE) of SFO and FSO in emulsions using Mu/Chit shells was 96.7% and 97.4%, respectively. Morphological studies indicated successful entrapment of oils in core shells with particle sizes ranging from 1396 ± 42.4 to 399.8 ± 42.3 nm. The thermogravimetric analyses demonstrated enhanced core protection with thermal stability noted for microcapsules regardless of encapsulation method. The stability of the microcapsules, during in vitro digestion was studied. The obtained results revealed that the microcapsules are intact in oral conditions and have a slow release of oil over stomach digestion and rapid release in the small intestine. The results showed that Mu and Mu/Chit coacervates can be used as effective carrier systems to encapsulate sensitive ingredients and functional oils. [Display omitted] • Simple and complex microencapsulations are used to encapsulate oils. • Coacervates are produced from Opuntia (Cactaceae) mucilage and chitosan. • Mucilage-based microcapsules are thermally stable. • Produced microcapsules can deliver the oils to the intestinal phase. [ABSTRACT FROM AUTHOR] more...

Submicron-in-size silica particles with controllable morphology, particle size and mesoporosity, have been prepared under basic conditions making use of cationic alkyltrimethylammonium surfactants (C n TAB, n = 12,16,18) as porogens. Gaseous nitrogen adsorption, XRD and TEM experiments revealed quasi-spherical homodispersed objects possessing regular mesopores of the MCM-41 type; lengthening of the hydrophobic tail of the template resulted in smaller particles with greater intraparticle pores. The aggregation and sintering of individual silica particles during the calcination step led to the formation of particle clusters comprising interparticle voids, as evidenced by the 129 Xe NMR and TEM studies. The calcined particles were subsequently loaded with metallic silver. The measurements of iodine adsorption onto Ag-functionalized materials from the gas phase were supplemented by XRD, SEM/EDX, and TGA/DTA studies. It was demonstrated that the functionalized silica retained much gaseous iodine in an irreversible manner, mainly as an 'interfacial' AgI. The best compromise between the textural parameters and the post-synthesis functionalization was obtained for the large-pore silica templated with C 18 TAB. Indications about the presence of silver metal nanoparticles, displaying certain heterogeneity in size and shape, within the pores of this sample were given based on the analysis of 129 Xe NMR spectra supplemented by UV-Visible absorption spectra and powder XRD patterns in the wide-angle region. The material can be recommended for the entrapment and immobilization of radioactive iodine in the nuclear industry since it guarantees that the adsorbed pollutant is primarily localized within the material pores and is thermally stable up to 800 K in air. [ABSTRACT FROM AUTHOR] more...