ZnAl 2 O 4 spinel was synthesized by co-precipitation using ammonia as precipitating agent, followed by thermal treatment at 750 °C. The structural properties of particles were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), differential thermal analysis (DTA), and N 2 adsorption/desorption isotherms (BET) techniques. The photocatalytic activity was evaluated in the degradation of organic pollutant in aqueous solution under sunlight. The results showed that the ZnAl 2 O 4 particles exhibited a mesoporous structure, and a promising photocatalytic activity for the degradation of pollutant molecules.

No abstract

ZnWO 4 particles were synthesized as a single-phase by a simple and easy solvo-hydrothermal technique using water-ethylene glycol mixture as solvent, without using surfactant. Physical properties of produced particles were analyzed by X-ray diffraction (XRD), infrared spectroscopy (FTIR), surface area (BET), particles size distribution and atomic force microscopy (AFM). This material was used as support for inulinase immobilization by physical adsorption and the influence of temperature (30 and 50 o C) was evaluated. Material with mesoporous characteristic and with a surface area of 35.5 m 2 .g -1 was obtained. According to the findings, ZnWO 4 present a satisfactory inulinase adsorption, and the better result was 605 U.g -1 support at 30 o C. Therefore, ZnWO 4 particles prepared by one-step solvo/ hydrothermal route provide a new potential support for inulinase immobilization.

FeWO4 particles were synthesized by a simple, rapid and facile microwave technique and their catalytic properties in heterogeneous photo-Fenton reaction were evaluated. This material was employed in the degradation of Amaranth azo dye. Individual and interactive effects of operational parameters such as pH, dye concentration and H2O2 dosage on the decolorization efficiency of Amaranth dye were evaluated by 2(3) central composite design. According to characterization techniques, a porous material and a well-crystallized phase of FeWO4 oxide were obtained. Regarding the photo-Fenton reaction assays, up to 97% color and 58% organic carbon removal were achieved in the best experimental conditions. In addition, the photo-Fenton process maintained treatment efficiency over five catalyst reuse cycles to indicate the durability of the FeWO4 catalyst. In summary, the results reveal that the synthesized FeWO4 material is a promising catalyst for wastewater treatment by heterogeneous photo-Fenton process.

No abstract