Tratabilidade de um lixiviado de aterro sanitário por ozônio combinado com peróxido de hidrogênio

Abstract

Current technologies used to treat leachate from landfills do not always achieve the desired efficiency in the removal of pollutants. This removal is necessary since it has to comply with the parameters of the legislation in force in the country for the release of effluents into the environment. The Advanced Oxidative Processes (POA's) are promising methods for the removal of pollutants from landfill leachates because they either completely oxidize the organic compounds present in the leachates or, through partial oxidation, increase the biodegradability of the leachate making its leachate possible and more feasible post-treatment by biological process, for example. The objective of this work was to study the possibility of treatment of leachate by means of advanced oxidative processes, more precisely by the process of ozonation combined with hydrogen peroxide, aiming the removal of color. The choice of this process was due to the high oxidizing power of the hydroxyl radicals (• OH) generated during the ozonation process. In order to perform the tests, leachate samples were collected from a sanitary landfill in the city of Santa Maria, Rio Grande do Sul. The experiment was carried out in a reactor, responsible for conditioning the sample of leachate with hydrogen peroxide. This reactor was connected through a hose to the ozone generating equipment. The procedure was carried out in a single step, with a constant O3 concentration of 0.54 gO3/hour. The amounts of hydrogen peroxide added to the leachate sample were varied throughout the ozonation process, which lasted for 2 hours and 30 minutes. High rates of color removal were obtained in the four aliquots removed, reaching 90% of removal at aliquot 4. It presented color analysis results of 1420 μC, while the crude leachate sample presented a result of 13530 μC. In this way, it is concluded that the system is effective and should be better studied.