Solar Photocatalytic Decolorization and Detoxification of Industrial Batik Dye Wastewater Using P(3HB)-TiO_2 Nanocomposite Films

摘要

Solar photocatalytic decolorization and detoxification of batik dye wastewater using titanium dioxide (TiO_2) immobilized on poly-3-hydroxybutyrate (P(3HB)) film was studied. The effects of initial dye concentration, catalyst concentration, P(3HB) film thickness, and fabrication methods of the nanocomposite films were evaluated against methylene blue, a standard organic dye. It was observed that 0.4 g of P(3HB)-40 wt% TiO_2 removed 96% of the color under solar irradiation. P(3HB) and TiO_2, mixed concurrently in chloroform followed by stirring for 24 h showed a more even distribution of the photocatalyst on the polymer surface and yielded almost 100% color removal. The photocatalytic films were able to completely decolorize real industrial batik dye wastewater in 3h and induced a chemical oxygen demand (COD) reduction of 80%. Reusability of the 0.4 g P(3HB)-40 wt% TiO_2 film in decolorizing the batik dye wastewater was also possible as it gave a high consistent value of decolorization percentage (>80%) even after the sixth repeated usage. Recovery step of the photocatalysts was also not required in this simple treatment system. The decolorized batik dye wastewater had lesso toxic effects on mosquito larvae, Aedes aegypti, and microalgae, Scenedesmus quadricauda indicating simultaneous detoxification process along with the decolorization process.