Aplicação de processo eletro-fenton da remoção de compostos aromáticos (absorbância 254nm) contidos em lixiviado de aterro sanitário

Abstract

The leachate is one of the by-products of waste degradation in landfills and consists of an effluent highly contaminated by a large variety of pollutants, many of them with toxic, recalcitrant and low degradability characteristics. Within this context, this work aimed to evaluate the application of the electro-Fenton advanced oxidation process to remove pollutants from landfill leachate. The experiments were performed in a batch reactor, having as electrodes four iron plates, with cathodes and anodes arranged in an interleaved way. In electrolysis times 0 to 120 min, the removals of aromatic compounds (absorbance in 254 nm), color and turbidity were investigated as a function of current intensity (0.5 a 4.5 A) and H 2 O 2 added concentration (400 to 1800 mg L -1 ). In order to determine the best experimental conditions of the process, a response surface methodology was applied. The best results were observed in current intensity 0,5 A and H 2 O 2 added concentration of 700 mg L -1 , pH 4 and 60-minutes electrolysis time, achieving a maximal removal near 90% of aromatic compounds (absorbance in 254 nm). This process showed to be efficient in landfill leachate treatment, with its use being suggested as a final polishing treatment, minimizing the environmental impacts of its inadequate disposal of this wastewater into water bodies.