RESUMO
In the present work the degradation of the lignin and its derivatives in the residual water of a paper industry by simple ozonation was investigated. The remediation of lignin was realized using the combination of the pre-treatment with chemical precipitation, using concentrated sulfuric acid (97.1%) at the pH 1 and 3, and of the simple ozonation of the filtered residual water at the pH 1, 3, 8 and 12. Since the high residues content (the initial chemical oxygen demand (COD) is 70,000 mg/L) in the experiments the diluted samples (1:10) were used. The previous precipitation has showed a significant effect on the reduction of the COD (77%) and color (96.1%). The sludge precipitated contents sulfolignin, which in the reaction with sulfuric acid was formed. In ozonation of the filtered residual water during 25 min at the pH 1, 3, 8 and 12 the follows by-products were formed: fumaric, maleic, malonic and formic acids. The biodegradability of the treated water in ozonation increases up 0.067-0.29. The effect of the precipitation and the ozonation conditions on the decolorization kinetics was evaluated.
Assuntos
Recuperação e Remediação Ambiental/métodos , Resíduos Industriais , Lignina , Papel , Biodegradação Ambiental , Fracionamento Químico , Concentração de Íons de Hidrogênio , Cinética , Esgotos , Ácidos SulfúricosRESUMO
The antioxidant and antiradical activities of 5,7,3'-trihydroxy-3,6,4'-trimethoxyflavone or centaureidin isolated and characterized from Brickellia veronicaefolia were elucidated by heat-induced oxidation in a beta-carotene and linoleic acid system and by the 1,1-diphenyl-2-picrylhydrazyl decoloration test. The centaureidin (32.1%) exhibited antioxidative activity less than that of BHT (95.5%) and alpha-tocopherol (95.9%) on oxidation in a beta-carotene and linoleic acid system. A moderate antiradical effect (47.6%) compared with BHT (96.7%) and alpha-tocopherol (94.6%) in DPPH decoloration test was found.