Tratamento de lixiviado de aterro sanitário do semiárido brasileiro por meio de air stripping.

Abstract

The landfill leachate is a by-product that results from the decomposition of solid waste deposited in this type of undertaking. This effluent has a complex composition, and due to its difficult degradation, the treatment is expensive. Thus, one of the compounds present in landfill leachate, that is difficult to remove, is ammoniacal nitrogen, which, in addition, is a substance that confers toxicity to the leachate. One of the treatments proposed by the technical-scientific literature is the removal of this type of nitrogen by air stripping. In view of this, this work analyzed the removal of total ammonia nitrogen in the leachate from the Sanitary Landfill in Campina Grande - PB, using the treatment of air stripping on a pilot scale. Experiments were carried out for different operating conditions: pH (10 ± 1 and 12 ± 1) and the type of alkalizing agent (hydrated lime and NaOH). For all experiments carried out, the system under study achieved values of total ammonia nitrogen removal greater than 98%, indicating high treatment efficiency. One of the most important factors during the treatment was the addition of alkaline agents, which with an increase in pH, made it possible to reach the desired NAT concentration in less than half of the hours of operation. From phytotoxicity tests, using onion and cabbage seeds, it was also possible to verify that air stripping removed the toxicity of the leachate, from the verification of the results of Germination Index, Relative Root Growth and Relative Germination.