Tratamento Terciário de Esgoto Sanitário Proveniente de Lagoa de Polimento Utilizando Sistema de Coagulação/Precipitação Seguido de Radiação Ultravioleta

Abstract

In this research the process of coagulation/precipitation followed by ultraviolet disinfection was investigated for tertiary treatment of sewage from polish pond. Were done laboratory tests using jart-test to simulate coagulation and in reactor UV to simulate disinfection, varying operational conditions. The process demonstrated a good performance, had been verified moderate removal of turbidity (27%-66%), COD (22%-53%), apparent color (22%-64%), real color (22%-64%), phosphorus (31%-52%), total solids (31%-52%) and suspended solids (10%-30%). To improve the process of coagulation were realized tests with anionic and cationic polymers, and the cationic showed the best results. The dose of coagulant considered optimal was 60 mg.L^-1 of ferric chloride combined with 20 mg.L^-1 of polymer cationic. In the best operational configuration was obtained inactivation of 4,65 log to CT, and 4,60 log to E. coli, obtaining 62,7%  of removal for turbidity, 65,3% and 69,7% of apparent color and real color respectively, 50,3% of COD and 47,3% of suspended solids. In conclusion this process can be considered suitable for the removal of pollutants from a polish pond, but should be observed the quality of the effluent for the presence excessive of algae that can harm the treatment, making the process difficult.