Atenuação da Contaminação de Nitrato em Aqüíferos com Uso de Serragem como Material Reativo: Ensaios de Colunas com Solos

The attenuation of contaminants in soil and water can be promoted using reactive media that, through physical, chemical or biological reactions, transform harmful forms into environmentally accepted ones. It is important that the study of reactive materials efficiency precede the implementation of permeable reactive barriers at field scale. This paper shows the results of column experiments in which the efficiency of sawdust was tested in the degradation of nitrate, a very common contaminant in aquifers, from in situ sanitation systems. Three columns were set up: one with sediments from the area (C1) and the other two with sediments from the area and 10 cm (C2) and 20 cm (C3) thickness of sand mixed with sawdust. The removal efficiency of nitrate solution in the columns with reactive material was initially quite high: C3 worked for 460 h with an efficiency above 90% and C2, for only 35 h. C3 was on average 2.5 times more efficient in reducing nitrate concentrations than C2