Avaliação da combinação da coagulação/floculação e processo de separação por membrana, em escala real, como pós-tratamento do lixiviado de aterro sanitário

Abstract

The treatment of leachate from landfills is of paramount importance to combat the environmental impacts generated through the disposal of waste. The leachate has a very complex composition and is difficult to treat, thus requiring a series of treatment processes, combining physical-chemical and biological methods. Generally, biological processes start the process through anaerobic and aerobic lagoons, followed by physical-chemical post-treatment. In view of this, the study aims to determine the physicochemical characteristics of the pretreated leachate, as well as to evaluate the efficiency, both globally and at each stage, of the combination of coagulation-flocculation-decantation, filtration and membrane separation processes. used as post-treatment of leachate from the Central de Tratamento de Resíduos de Maceió. Thus, samples from 4 collection points of the post-treatment system were analyzed in 4 different months, in October and November 2022 and January and February 2023, thus obtaining the values of each parameter analyzed for all stages of physical-chemical treatment. During the analysis period, it was observed that the removal of color, turbidity, COD and phosphorus showed global efficiency above 90% in all months, and that there was a reduction of alkalinity in the treated effluent. The removal of nitrate and volatile acids showed global efficiency ranging from 34% to 93% and from 52% to 96% respectively. As for the concentration of ammoniacal nitrogen, a global efficiency above 97% was observed, except for the month of November, with only 75% that also presented a value above the resolution nº 430 of CONAMA of 2011, being the only parameter that did not met release standards. Finally, it was noted that filtration did not show relevant results in the removal of any of the parameters, coagulation-flocculation-decantation had a significant influence on the removal of color and turbidity, while reverse osmosis showed expressive results in the removal of all parameters, except for volatile acids.