Potencial energético de efluente em estação de tratamento de esgoto

Abstract

Sewage generate in the urban centers grows along with the increase in the urban population and, consequently, leads to an increase in the byproducts formed in the sewage treatment stations (STS), especially sludge. Therefore, there is a need to dispose of these residues. One of the alternatives is the use of this material in the generation of energy. In this context, the objective of this study is the investigated the feasibility of using sludge generated at the Rio Verde STE located in Ponta Grossa is fuel. The samples were collected in two points of the treatment station: in the drying bed (DB) and after the decanter (DEC). The sludge was characterized in relation to the upper energy potential (UEP), composition, water and ash contents. A calorimetric pump was used to obtain the higher heating value (HHV). The HHV mean values obtained were between 13.560 (DEC) and 11.490 (DB) kJ kg-1 depending on the water content, which in turn presented values between 52 %(DB) and 75% (DEC) m/m. To obtain the ash content, sludge pyrolysis was carried out at 600 ° C and 900 ° C, resulting in about 15% ash in mass, regardless of the temperature. The ash majority composition presented silicon, aluminum and iron oxides. The ash composition generated from the DB and DEC burning, at an equal temperature, did not vary significantly. The results obtained lead to the conclusion that the burning of the sludge can be used to generate energy, as well as fuel.