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18The production of chitosan nanofiber mats by electrospinning presents serious 19 difficulties due to the lack of suitable solvents and the strong influence of processing were the parameters considered in this study.

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This work aims at the reutilization of a Cr-loaded NaY zeolite obtained by biorecovery of chromium from water as catalyst in the oxidation of volatile organic compounds (VOC). Cr-NaY catalysts were obtained after biosorption of Cr(VI) using a bacterium, Arthrobacter viscosus, supported on the zeolite. The biosorption experiments were conducted at different pH values in the range 1-4. The catalysts were characterized by several techniques, namely ICP-AES, SEM-EDS, XRD, XPS, Raman, H(2)-TPR and N(2) adsorption. The zeolite obtained at pH 4 has the highest content of chromium, 0.9%, and was selected as the best catalyst for the oxidation of different VOC, namely ethyl acetate, ethanol and toluene. For all VOC tested, the catalyst with chromium showed higher activity and selectivity to CO(2), in comparison with the starting zeolite NaY. The presence of chromium shifted also the reaction pathways. In terms of selectivity to CO(2), the following sequence was observed: ethyl acetate>toluene>ethanol.

The reduction of bromate to bromide was successfully catalyzed by mono and bimetallic catalysts based on ZSM5 zeolites. This reaction is important since the presence of bromate in water is potentially carcinogenic to humans. The catalysts were prepared by ion-exchange and incipient wetness methods with different metals (copper, palladium, rhodium and thorium) using ZSM5. Several analytical techniques (N 2 adsorption, TPR experiments, NH 3 -TPD, FTIR, XRD, SEM/EDX and TEM/EDX) were used to characterize the mono and bimetallic catalysts prepared by the two methods. The catalytic tests were carried out in a semi-batch reactor under hydrogen, working at room temperature and pressure. All catalysts prepared are undeniably effective in achieving the complete conversion of bromate into bromide. The most promising among the catalysts tested in this work are the palladium bimetallic catalysts.