Cynthia Fantoni Alves Ferreira

Avaliação da biodegradabilidade anaeróbia de lixiviados de aterro sanitários

The objectives of this article were to investigate the favorable environment and operational conditions to the development of the anaerobic biodegradability test for landfill leachate. The evaluated conditions were the relation food/microrganismo (A/M), seed acclimatization, and toxicity due to high ammonia concentration. The results indicated that A/M relation equivalent to 0,45 was presented as most favorable to the accomplishment of the test, and that the seed used presented good capacity of adaptation to the leachate, not demanding previous acclimatization. The leachate in question presented relatively low anaerobic biodegradability, and associated to the results of previous studies of aerobic biodegradability suggest that a significant fraction of organic substance is refractory to the aerobic and anaerobic metabolism, indicating that the physical-chemical treatment must be used as form of pre or post-treatment.

Characterization of landfill leachates by molecular size distribution, biodegradability, and inert chemical oxygen demand.

This work presents results from a detailed characterization of landfill leachates of different ages from a landfill in a major Brazilian city. This characterization consists of determining the molecular size distribution and the inert chemical oxygen demand (COD) and the biodegradability of both aerobic and anaerobic processes. Results show that leachate with a high COD concentration leachate has low biodegradability. A significant fraction of the COD is not characterized as protein, carbohydrate, or lipids, which reinforces the hypothesis that the remaining fraction was present in all leachate fractions (less than 1 kDa; between 1 and 10 kDa; between 10 and 100 kDa; and greater than 100 kDa) and is refractory. These results suggest that leachates with such characteristics require treatment systems that use physical-chemical processes as a pre- or post-treatment step to biological processes.