Disposal of plastics into the environment has been one of the major problems for the environment. The accumulation of polystyrene (PS) occurs in an accelerated way and, therefore, its reuse is challenging. Polystyrene nanocomposites impregnated with Ag nanoparticles (PS/AgNP) are generated from polystyrene residues and can be applied in the catalytic and plasmonic photo-catalytic reduction of phenolic compounds such as p-nitrophenol (PNP) to p-aminophenol (PAP). The AgNP were synthesized by a reverse micelle method resulting in nanoparticles with sizes in a range of 31.1-34.0 nm. The organocolloid was characterized by UV Vis and dynamic light scattering (DLS), demonstrating the preparation of spherical nanoparticles. The preparation of the PS/AgNP, obtained using a thermally induced phase separation method (TIPS), was confirmed by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), laser-induced breakdown spectroscopy (LIBS), and Fourier transform visible infrared spectroscopy (FTIR). Nanocomposites showed impressive performance in the catalytic and plasmonic photocatalytic reduction under blue light irradiation, reaching up to 98% conversion, being a promising material for wastewater treatment as well as other various environmental issues. We used blue light to observe the plasmonic effect of silver nanoparticles, and no previous reports of this composite for PNP reduction using blue light photocatalysis were found.

RESUMO O lançamento de águas residuárias industriais em corpos aquáticos, sem o devido tratamento, pode causar danos severos ao meio ambiente e à saúde humana. O objetivo deste estudo foi realizar a secagem da casca de laranja cultivar Pêra (Citrus sinensis L. Osbeck) e avaliar a viabilidade do seu uso como biossorvente para remoção de um corante direto. A secagem foi realizada em estufa com circulação de ar nas temperaturas de 60 e 80 ºC. Os dados de umidade em função do tempo foram ajustados aos modelos matemáticos de Page, Henderson e Pabis, Logarítmico, Midilli e exponencial de dois termos. A caracterização do material foi realizada a partir da microscopia eletrônica de varredura, do ponto de carga zero, e da espectroscopia na região do infravermelho. No estudo da adsorção realizou-se um planejamento fatorial 24 completo, analisando-se a influência da massa, concentração inicial, pH da solução e tempo de contato, na quantidade adsorvida (qt) e no percentual de remoção do corante (R%). Na secagem, o modelo exponencial de dois termos apresentou melhor ajuste aos dados experimentais. A caracterização do material apontou que o adsorvente apresenta ponto de carga zero de 3,5 e estrutura porosa, e as análises de infravermelho indicaram a presença de grupos carboxílicos e hidroxilas. Na adsorção, a quantidade adsorvida do corante aumentou em condições de menor pH e massa de biossorvente, maior concentração inicial e tempo de contato. O percentual de remoção do corante aumenta com maior massa de biossorvente. O biossorvente utilizado é um resíduo promissor para a adsorção do corante bordô-16.

ABSTRACT The disposal of industrial wastewater into aquatic bodies without proper treatment can cause severe damage to the environment and human health. The objective of this study was to perform the drying of the sweet orange (Citrus sinensis L. Osbeck) peel cultivar Pêra and evaluate the viability of its use as biosorbent in the removal of a direct dye. Drying was carried out in an oven with air circulation at temperatures of 60 and 80 ºC. The mathematical models of Page, Henderson and Pabis, Logarithmic, Midilli and Two-term exponential were fitted to the moisture data as a function of time. The material was characterized by scanning electron microscopy, point of zero charge, and infrared spectroscopy. In the adsorption study, a complete 24 factorial design was used to analyze the influence of mass, initial concentration, solution pH and contact time on adsorbed quantity (qt) and removal percentage of the dye (R%). In the drying, the two-term exponential model fitted best to the experimental data. The characterization of the material indicated that the adsorbent has zero charge point of 3.5 and porous structure, and the infrared analysis indicated the presence of carboxylic and hydroxyl groups. In the adsorption, the adsorbed quantity of the dye increased under conditions of lower pH and biosorbent mass and higher initial concentration and contact time. The removal percentage of dye increases with higher biosorbent mass. The biosorbent used is a promising waste for the adsorption of the burgundy-16 dye.

Inflammatory and genetic alterations are related to the development of chronic diseases such as cancer. Schinus terebinthifolius Raddi, Anacardiaceae, is used in folk medicine to treat inflammation, wounds and tumors. This study evaluated the anti-inflammatory, immunomodulatory, chemopreventive, and wound healing potentials of the methanolic extract from the leaves of Schinus terebinthifolius. The chemical composition of the extract was characterized using preliminary analytical LC methods. The results showed that the anti-inflammatory activity of the methanolic extract was similar to that of dexamethasone for edema reduction. Also, it inhibited the leukocyte migration into the air pouch and decreased plasma extravasation. In addition, the methanolic extract showed a healing action similar to that observed with collagenase. The methanolic extract is not genotoxic nor mutagenic, and in contrast it has chemopreventive activity, which elicits a high percentage of damage reduction by comet and micronucleus assay, preferably by bioantimutagenic action. The methanolic extract induced apoptosis and enhanced splenic phagocytosis in animals treated with cyclophosphamide. The methanolic extract contents, resolved by LC, include phenolic acid and flavonoids. Our results suggest a therapeutic potential for the methanolic extract.