Uso de processos oxidativos avançados no tratamento dos resíduos líquidos oriundos da estação de tratamento de esgoto do município de Marmeleiro – PR

Abstract

The conventional treatments employed in the sewage concentrate and remove organic matter and other pollutants, thus constituting the sewage sludge. On the other hand, alternative treatments such as the Oxidative Processes Advanced (POAs) can promote the degradation, total or partial of these pollutants. The present work had as objective to analyze the efficiency of three different POAs, the photocatalysis heterogeneous (TiO2/UV), photolysis of hydrogen peroxide (H2O2/UV) photolysis the direct (UV), in the treatment of the liquid waste from Sewage Treatment Station (ETE) of the city of Marmeleiro – PR. Collected samples of effluent gross ETE after going through the process of railing (EB), as well as samples of the effluent treated by the conventional process of the ETE (ET). For the realization of photocatalytic reactions was used a reactor in sequencing batch reactors with a retention time of 2 hours and, as a source of ultraviolet radiation a mercury vapor lamp. The parameters analyzed before and after each treatment were temperature, pH, turbidity, color, dissolved oxygen, chemical oxygen demand, biochemical oxygen demand, total nitrogen, total phosphorus and coliform organisms. We assessed the efficiency of the processes from the removal of COD and OBD5, as well as assessed the biodegradability of the samples by the ratio of COD/OBD5. In order to verify the toxicity of the samples were used as bioindicators to Artemia salina L. and Allium cepa L. Possession of the results one can observe that the POAs tested, showed good reduction in the physico-chemical parameters for both the EB and the ET, except for the sample ET/H2O2/UV. The highest efficiency in removal of COD was for the sample EB/TiO2/UV, rising to around 58%, which relates to the removal of OBD5, we found a higher efficiency (74%) in the treatment employing EB/H2O2/UV, being that this sample was the only one that decreases the biodegradability of the effluent (ratio COD/OBD5). The ecotoxicological testing have confirmed the toxicity of the effluent, gross (A. cepa and A. salina) and the treaty (A. salina), and the POAs evaluated reduced this toxicity (A. cepa and A. salina), and do not create byproducts lethal when compared to the original samples. In addition, the processes fotocatalíticos if showed efficient in the treatment of liquid wastes of a sewage TREATMENT plant, complying with the relevant laws. However, the processes involving the photocatalysis heterogeneous with TiO2 as catalyst were the most satisfactory, demonstrating that this can either be used as an alternative treatment to the sanitary sewer as a complementary treatment to the processes convencionas employees currently.