Caracterização físico-química de lodo proveniente de duas estações de tratamento de esgoto da região oeste do Paraná

Abstract

The progressive increase in urbanization is resulting the generation of large volumes of wastewater that can’t be reused and when disposed of improperly, pollute the environment generating ecological imbalances as the acceleration of eutrophication processes and render the use of natural resources. These effluents called sewage, should receive treatment to fit the specific power of dilution of each water body. The treatments concentrate and remove organic matter and other pollutants and so is the sewage sludge. This research was conducted in order to characterize the physical and chemical parameters of the sludge generated in in sewage treatment plants from the municipalities of Santa Helena and Medianeira, that one operates stabilization ponds and the other with Reactor Anaerobic Fluidized Bed (RALF) respectively. The sludge samples were collected in February and March, and evaluated the parameters pH, moisture, organic matter, total carbon, total phosphorus, total potassium, total, fixed and volatile solids. The results showed that the sludge samples from the stabilizations ponds of Santa Helena and the point 1 (ETE Medianeira) have neutral pH and only the point 2 showed relatively acidic pH (pH = 4,49). It was also seen high humidity in point 1 with values greater than 90%. This same point was low concentration of Total Solids (average 6,53%) with 51.43% ST Volatile solids and 47.76% ST Fixed Solid. The sludge samples from the ponds of Santa Helena ETE have low values for nutrients (3.12 g.kg-1 for Total Phosphorus and 0.423 g.kg-1 for Total Potassium) and that if they were intended for agricultural use would be necessary one mineral supplementation thereof. While the other parameters showed satisfactory values for agricultural use. Point 2 concerning the ETE of Medianeira drying bed also showed satisfactory values for the parameters analyzed with a view to agriculture, and only the supplementation of nutrients and pH correction would be necessary. Since the sludge from the reactor proved to be a more crude sludge characteristics where the retention time is low. For your final destination would be necessary to go through a process of stabilization. Also worth mentioning at this point, the Phosphorus values present in the sludge that may indicate high concentration of this element in the effluent due to characteristic of this type of system has low efficiency in the removal of this compound, and is intended for receiving body without post reactor treatment can cause eutrophication. The realization of this characterization should serve as a basis for comparison studies and contribute in research aimed at the treatment and agricultural reuse of sewage sludge produced by these types of system.