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Pollution of water from a wide range of organic pollutants is a serious environmental problem. Conventional water treatment technologies are not very effective for reducing the concentration of these pollutants to a desirable level. The aim of this work was to evaluate the efficiency of two technologies in reducing the pollutant concentration of two wastewater samples. Therefore, cross-linked cyclodextrin (CD) polymers were synthesized and their adsorption capacities were evaluated. An emerging oxidation process using doped TiO 2 was also evaluated. For both technologies, we observed a decrease in the total organic carbon (TOC) content due either to the adsorption of pollutants by CD polymers or to the mineralization of pollutants by photocatalysis.

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Water contamination by pharmaceutical compounds has become one of the most serious problem for environment. The use of solar illumination as a renewable energy associated to nanomaterials is an alternative solution for disinfection of wastewater. Therefore, there is a great challenge in green chemistry research to synthesize robust and efficient catalysts for the degradation of organic pollutant under visible light. In this study, we describe new ways to decorated mesoporous TiO 2 with cerium (Ce) and silver (Ag) nanoparticles. Indeed, mesoporous TiO 2 was co-doped with Ag and Ce using two different methods: co-impregnation (Co-IMP) and co-deposition precipitation with urea (Co-DPU). The prepared catalysts were characterized using different analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), diffuse reflectance spectroscopy (DR/UV-vis) and N 2 adsorption/desorption. The effect of the preparation method has been evaluated in the photodegradation of ibuprofen (IBP) under visible light irradiation. The obtained results underlined the improvement of photocatalytic activity of mesoporous TiO 2 by metals under visible light. A mineralization of IBP up to 98 % was achieved after 4 h irradiation for the catalyst prepared by co-deposition precipitation with urea. Therefore, this catalyst could be suitable for the treatment of pharmaceuticals in aqueous media using solar light as the energy source.

The development of novel polymeric composites, especially those based on conductive polymers has attracted a consider-able attention due to their applications in a wide range of fields. This study focuses on one of these biocomposites based on polyaniline Pani and a biopolymer (microcrystalline cellulose MCC), synthesized by in-situ polymerization of aniline using ammonium persulfate (APS) as oxidant at room temperature. Firstly, different amounts of MCC were dispersed in HCl solu-tion with aniline monomer under stirring. Then a mixture of APS/HCl solution was introduced into the first aniline-MCC-HCl mixture. The obtained materials as well as Pani and MCC were characterized using powder X-ray diffraction (XRD), Argon adsorption-desorption (BET/DFT), thermal analysis, fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thus, a correlation between interesting structural/textural/morphological data of these materials will be established. The results confirm the formation of Polyaniline-MCC composite under well determined conditions which has a more compact homogeneous morphology and a higher thermal stability than those of Pani and MCC. Furthermore, these materials are used for the catalytic degradation of toxic anionic dye namely Methyl Orange (MO) from aqueous media under UV light irradiation. The optimum values were 0.1 g L − 1 of photocatalyst, 30 ppm of MO solution, and pH solution of 5.6, which allowed reaching 97% within 70 min with high stability after four continuous runs. The photodegradation kinetics of MO onto composite followed the pseudo-first order model.

Silver nanoparticles (AgNPs) at different amounts have successfully been deposited, by simple impregnation on the titanium dioxide (TiO 2) developed by the hydrothermal method. A textural and structural study of prepared materials was conducted using different analysis techniques, namely X-Ray Diffraction (XRD), Diffuse Reflectance UV-Vis (DR/UV-Vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, in addition to the Brunauer-Emmett-Teller (BET) method. The nanostructured prepared materials were tested for their antibacterial activity on four strains, i. e. two Gram-negative (GÀ) bacteria, namely Escherichia coli ATCC 8739 and A. baumanni ATCC 19606, and two Gram positive (G +) bacteria, i. e. S.aureus ATCC 6538 and E.cloacae ATCC 13047. The antioxidant effect was also tested on the reference radical DPPH°(2,2-diphenyl-1-picrylhydrazyle). AgNPs supported on TiO2 showed good antibacterial activity against the four selected strains. In addition, the minimum inhibitory concentration (MIC) was observed in the case of the low-grade silverdoped catalyst (0.1 % Ag/TiO2). Differently from the antibacterial activity, the antioxidant effect of the prepared materials was found to be pronounced in the cases of materials with high silver contents for which there was degradation of the radical in comparison with the one of the reference acid.

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