Influência do fármaco paracetamol no processo de digestão anaeróbia de efluentes

Abstract

Among the drugs most consumed in Brazil, there is paracetamol, it is the analgesic-antipyretic currently more consumed. The objectives of this study were to evaluate the polluter degree of paracetamol-based drugs and check the degree of interference of these drugs in the production of methane by anaerobic reactors in Waste Water Treatment Plants (WWTP). Three drugs, paracetamol base (750 mg), manufactured by different laboratories, were selected authentic replicas of each laboratory were prepared by diluting one tablet in one liter of deionized water, a total of 3 samples for each laboratory forming surface 9 samples. These samples were analyzed for determination of pH, conductivity, color, turbidity, chemical oxygen demand and biochemical (DBO and DQO), chloride, sulphate, nitrogen and serious series of solids. Borosilicate reactor bottles with a volume of 480 ml and 10% of headspace were used as anaerobic batch reactors. In these reactors were added biomass (2 gVSS / l), nutrient solution, substrate solution (3 g DQO / L) and different concentrations of paracetamol (0, 80, 160, 240 and 320 mg / L). Methane production was determined by liquid displacement technique every 12 hours for about 100 days. The results in the characterization of drugs, showed a significant difference between the drugs manufactured by different laboratories for the parameters pH, conductivity, turbidity and color. For the parameters DQO, nitrogen, solids and sulfate values were similar between laboratories. Because of its acidic character and high organic load, medicines paracetamol base can cause serious environmental problems and affect the operation of anaerobic reactors. A significant decrease in methane production, independently of the type of biomass and despite the high DQO removal. Increasing the concentration of paracetamol in the inhibition caused an increase in methane production rate and microbial anaerobic digestion. The paracetamol-based medications can cause great environmental impact and affect the operation of anaerobic reactors in wastewater treatment plants.