-Metastable-to-stable transformation in oxides is always associated with drastic reduction in surface area and/or porosity. Therefore, all earlier efforts to stabilize the pore structure of oxides undergoing a metastable-to-stable phase transformation are interesting for both scientific and technological concerns. This work presents a new experimental technique for catalytic oxide production through sonication in acid solution for attainment of the anatase-rutile transformation. Mesoporous structure of titania and surface area were stabilized in the rutile phase after calcinations at 430 and 730 o C. Analysis by scanning electron microscopy (SEM) and nitrogen isotherms showed that the mesoporous structure was preserved after calcinations. After the sonication of titania for 32 hours, rutile phase was obtained at 730 o C and still kept a surface area of 28m 2 /g. When sonicated for 64 h, rutile was obtained at 430 o C, still preserving an area of 52m 2 /g.

-This work is related to removal of phenol from wastewaters by adsorption onto polymeric resins, a current alternative to activated carbon. A closed circuit, bench-scale liquid fluidized bed system was developed for this purpose. Phenol aqueous solutions with initial concentrations in the range of 0.084 to 0.451 kg/m 3 were used to fluidize small permeable capsules of stainless steel screen containing a commercial resin at 308 K. Experiments were carried out using a fluidizing velocity 20% above that of the minimum fluidization of the capsules. Typically, 30 passages of the liquid volume circulating through the bed were required to reach a quasi-equilibrium concentration of phenol in the treated effluent. A simple batch adsorption model using the Freundlich isotherm successfully predicted final phenol concentrations. Suspended solids, often present in residual waters and a common cause of fixed bed clogging, were simulated with wood sawdust.

Industrial environmental management includes reutilizing waste by transforming solid bio-waste into a valuable resource, e.g. a bioadsorbent. This study aimed to mitigate two environmental local problems: the disposal of fishing biowaste and the removal of dyes from textile wastewater. For this purpose, fishing industry waste (shrimp exoskeleton – SE and mussel shell-MS) was used as adsorbent material to remove dye from textile wastewaters. Adsorption efficiency was evaluated by general, kinetic and thermodynamic physico-chemical parameters in adsorption isotherms, using Reactive Turquoise Blue 15 (RTB15) and Reactive Red 120 (RR120) dyes as adsorbate models, as these dyes are commonly used in the local textile industry. The isothermal data from the batch experiments were fitted to Langmuir, Freundlich and Langmuir-Freundlich (SIPS) equations, with the best fit shown by the Freundlich isotherm equation. The thermodynamic parameters showed that adsorption of the dyes on the bioadsorbents was an endothermic yet spontaneous processes in the case of SE waste. Both bioadsorbents adsorbed both tested dyes, but the SE showed better results. Due to its abundant availability SE and MS biowaste can be employed as a low-cost alternative adsorbent for dye removal.