Processo de coagulaçao/floculação com coagulantes naturais para o tratamento de lixiviado de aterro sanitário

Abstract

The population growth, especially combined with high consumption patterns, caused an increase in waste generation and hence more impacts on the environment. Among the most used alternatives for disposal of solid waste are the landfills, in which happens the degradation of organic material, thereby generating slurry, which combined with rainwater, forms the landfill leachate. Leachates are characterized by their varied composition according to the type of waste disposed in the landfill. In this context, the present study aimed to evaluate the effectiveness organic coagulants (Tanfloc SG, Tanfloc SL) and the inorganic coagulant (Aluminum Sulfate) for reduction of color, turbidity and aromatic compounds. In the first part was carried sedimentation of the leached at different pH values. Next were made coagulation/flocculation tests. The following variables were optimized: concentration (C) and optimum pH for different coagulants, using as response variables: color, turbidity, aromatic compounds and sedimentable solids. The sedimentation test showed 40.14% color reduction for the concentrated leached with its original pH (pH=7.8), thus the coagulation/flocculation tests were performed after sedimentation. Among the tested coagulants, Tanfloc SG showed the largest color removal percentage (80.10%) with the combined processes, moreover, it showed turbidity removal of 20.27% and aromatic compounds removal of 85.62%. The operating conditions used to obtain these results were: GMR of 120 rpm and GML of 45 rpm, TML of 20 minutes, TMR of 20 seconds, TS of 1 hour, C of 3050 mg L-1and pH 6.