Fotodecomposição e remoção de efluente textil usando fotocatalise com polipirrol

Abstract

A real sample of textile wastewater was successfully decolorized through a simple, fast and efficient photocatalytic treatment using polypyrrole as catalyst. In the optimized operational conditions, the photocatalytic treatment resulted in 95.8% decrease in the units of color and 91.2% photodecomposition. Photocatalysis reduced the COD values from 1111.04 mg L1 to 71.43 mg L1, evidencing 93.6% reduction in the organic matter to be discharged. TOC was also efficiently reduced from 156.75 to 51.74. The efficiency of the photocatalytic process was maintained during repeated use when cycles of photocatalysis were followed by redoping of polypyrrole with 0.1 mol L1 HCl solution. The same photodecomposition efficiency was achieved using sunlight irradiation for 30 min, with values of photodecomposition up to 98%. Tests of toxicity using Artemia saline resulted in 96.7% survival, indicating that the products generated in the photodecomposition are non-toxic. Tests made with an artificial effluent showed the same efficiency in wastewater color removal indicating that the process may be suitable for treating effluents with different colors with same efficiency. In this way, photocatalytic treatment may be applied on photodecomposition of textile effluent, independent of the predominant color present in the effluent.