ABSTRACT
RESUMO Os processos de adsorção podem ser empregados no tratamento de efluentes líquidos contendo metais pesados visando a reduzir os danos ambientais. Porém, o alto custo dos materiais adsorventes justifica a aplicação de adsorventes alternativos, como a fibra de coco (FC) e a quitosana (Q). Assim, este trabalho teve como objetivo desenvolver compósitos porosos adsorventes a partir da mistura de polietileno graftizado com anidrido maleico/FC/Q/NaCl, como agente porogênico (PE-g-MA/FC/Q/NaCl), e avaliar estatisticamente a capacidade de adsorção do cromo (III) em solução, com auxílio do software Statistica 5.0®. Os resultados mostraram que a eficiência do processo sofreu influência das dimensões da FC, do teor de Q e do pH da solução contendo Cr (III). A capacidade máxima de remoção de Cr (III) por unidade de massa do compósito foi de 42,28 mg.g-1.
ABSTRACT Adsorption processes can be employed in the treatment of wastewater containing heavy metals to reduce environmental damage. However, the high cost of adsorbent materials justifies the application of alternative adsorbents, such as coconut fiber (CF) and chitosan (C). Thus, this study aimed to develop porous composite adsorbents from the mixture of grafted maleic anhydride polyethylene/CF/C/NaCl, as porogen agent (PE-g-MA/CF/C/NaCl), and evaluate statistically adsorption capacity of chromium (III) solution, with the aid of software Statistica 5.0®. The results showed that the process efficiency was influenced by the size of the CF, the content of C and the pH of the solution containing Cr (III). The maximum removal capacity of Cr (III) per unit mass of the composite was 42.28 mg.g-1.
ABSTRACT
Guided tissue regeneration is a technique used for periodontium reconstruction. This technique uses barrier membranes, which prevent epithelial growth in the wound site and may also be used to release antibiotics, to protect the wound against opportunistic infections. Periodontal poly(3-hydroxybutyrate) membranes containing metronidazole (a drug used to help in infection control) were produced and characterized. The kinetic mechanism of the metronidazole delivery of leached and nonleached membrane as well as its cytotoxicity and structural integrity were evaluated. Poly(3-hydroxybutyrate) membranes containing 0.5-2 wt % of the drug and 20 wt % of the plasticizer were manufactured via compression molding. Based on morphological analysis, membranes loaded with 2% metronidazole were considered for detailed studies. The results revealed that metronidazole delivery by the leached membranes seemed to follow the Fick's law. Membranes were noncytotoxic. The amount of metronidazole delivered was in the range of the minimal inhibitory concentration for Porphyromonas gingivalis, and the membranes inhibited the proliferation of these bacteria. Besides, they maintained their mechanical resistance after 30 days of immersion in phosphate buffer at pH 7.4.
