Tratamento de efluentes oriundo da insdústria de laticínios utilizando os processos fenton e foto-fenton

Abstract

With the constant increase of industrial activity, there is an increase in water consumption and waste generation, so it is necessary to control and treat them, in search of sustainable development. Despite the great economic and social contribution of dairy activity, it also stands out for the generation of liquid waste and the release of effluents into the waters, each liter of processed milk can generate up to 2.5 L of effluents, thus generating more than 80 billion liters of effluents per year in Brazil. Therefore, several studies have been carried out aiming at the treatment of these tailings in an efficient and economically viable way. Among them, the advanced oxidative processes are considered promising technologies to reduce these environmental impacts, especially the Fenton reaction that stands out due to the reactants (H2O2 and Fe2+) presenting low toxicity and low cost and the reaction presenting high efficiency for mineralization of most organic compounds. In this project, the Fenton reaction was used in the treatment of effluents generated in the milk processing process. Initially, the reaction was tested in the treatment of a synthetic effluent using an experimental design 2³, the variables being the concentration of Fenton's reagents and the reaction time. The optimized condition was applied in the treatment of the real effluent and the efficiency of the Photo-Fenton reaction was also evaluated. After the reaction, the toxicity of the treated effluent against the germination of Lactuca sativa and the mortality of Artemia Salina was evaluated. The results indicated the efficiency of the Fenton reaction in the treatment of synthetic and real effluent from the dairy industry, where it was obtained the removal of 100 and 76% of the COD of the synthetic and real effluent, respectively. When the Foto-Fenton process was used, efficiency was even greater, achieving a 92% reduction in COD for the actual effluent, in addition to considerably reducing the toxicity of the treated effluent.