This work evaluates the performance of activated carbon obtained from sugarcane straw (SCAC) as an adsorbent for polyaromatic hydrocarbons (PAHs) present in model wastewater. Two commercial samples of activated carbons with different textural properties were also studied for comparison. The activated carbon prepared from sugarcane straw presents a well-developed porosity with a high surface area, which was comparable to that of one of the commercial samples studied. For all the studied carbons, adsorption followed pseudo-second-order kinetics, and the higher rate constants were found for the SCAC sample for the four PAHs. Sips and Hill isotherms best fitted the adsorption equilibrium data of the PAHs on all activated carbons investigated. The activated carbon obtained from sugarcane straw (SCAC) presented a higher adsorption capacity (2.08 mmol g^-1 for naphthalene, 1.26 mmol g^-1 for fluorene, 1.14 mmol g^-1 for phenanthrene, and 0.98 mmol g^-1 for fluoranthene) when compared to the commercial carbon samples studied in this work as well as for those related in the literature. It confirms that its use of SCAC as an adsorbent for PAHs is a promising application for the valorization of this biomass waste.

The effect of ammonium bicarbonate (AB) and polyethylene wax (PW) on the physicochemical properties of macroporous biphasic calcium phosphate bioceramics (BCPs) processed by space-holder technique was investigated. BCP powder was mixed with AB and PW and, then, uniaxially cold-pressed at 300 MPa. AB and PW were eliminated by heat treatment at 170°C for 2 hours or 550°C for 4 hours, respectively. Subsequently, the samples were air-sintered at 1070ºC for 2 hours. The results revealed that AB is more attractive than PW due to its lower degradation temperature, which has avoided the formation of undesirable phases. In addition, it favored an adequate consolidation of the particles with the formation of sintering necks that provided a better mechanical resistance to handling. The samples with AB also presented the formation of uniformly distributed macro and microporosity in great extension, which is shown by literature as a fundamental combination to stimulate cells/scaffold interaction.

The biomimetic method can be used to coat scaffolds with calcium phosphate to improve bioactivity. This method presents the advantages of low cost, reproducibility, and applicability to complex surface and porous structures. This study aimed to manufacture alumina scaffolds coated with calcium phosphate by a biomimetic method for use as a biomaterial. The scaffolds were compacted at 200 MPa with 40 wt.% ammonium bicarbonate and 60 wt.% alumina, subjected to heat treatment at 270 °C for 120 min, and sintered at 1500 °C for 120 min. The samples were biomimetically coated by immersing them in a simplified solution of calcium chloride dihydrate (CaCl2.2H2O) and sodium hydrogen phosphate dihydrate (Na2HPO4.2H2O) for 7, 14, and 21 days. The samples were characterized by Archimedes' principle for density and porosity determination, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR). The scaffolds showed a porosity of 55%, with homogeneous distribution, interconnection, and pore sizes. Calcium phosphate formation was observed on the scaffold surfaces after 21 days of biomimetic coating. The samples presented promising results for use as biocompatible scaffolds.