Avaliação da escória de aciaria (LD) como leito cultivado e leito filtrante no pós-tratamento de efluente de reator UASB compartimentado

Abstract

This research aims to the use of constructed wetlands or not, a simple alternative, with a view to the treatment of wastewater, through a combination of chincanas reactor the constructed wetlands. For both, were built three constructed wetlands from different configuration. CW1 was composed of crushed rock, sand and vegetation and used as controls. CW2 was composed of slag, sand and vegetation, and CW3 was composed only of slag. The analyses carried out in the effluents of the stages of treatment were: BOD5, CODt, solids, phosphorus, nitrogen, hardness, pH value, turbidity and heavy metals, made the second (APHA. 1995). The density of total coliform E. coli was determined by the determination of most probable number (MPN), using chromogenic substrate defined ONPG-MUG (Colilert ®), with quantification through tablet for inscriptionses. The efficiency of removal of organic matter through the analysis of DQOt are 41%, 67%, 66% and 69% respectively for RAC, CW1, CW2, CW3 in the flow of 50mL/se 48%, 73%, 74% and 85% in the flow of 75mL / s. The BOD5 returned efficiency averages around 26%, 53%, 64% and 51% respectively for RAC, CW1, CW2, CW3 in the flow of 50mL/s e 34%, 74%, 84% and 86% in the flow of 75mL/s. The removal of solids was inefficient, presenting accumulation of solids in some points and indicated that most donates solid present, are dissolved. The constructed wetlands 2 and 3 also showed unsatisfactory performance parameters for the hardness and pH due to the presence of slag. In turn, the removal of nutrients has been effective in beds cultivated, with efficiencies of removing nitrogen from 30% to 44% in the flow of 50mL/s e 48% to 61% in the flow of 75mL/s. The removal of phosphorus returned rates of removal of 31% in CW1, 78% and 79% respectively in CW2 and CW3 in the flow of 50mL/s. In the flow of 75mL/s rates were 76% for CW1, 93% and 96% for CW2 to CW3. The efficiency ofCW was also perceived in the removal of microbiological contaminants, as CW3 presented results that met the existing legislation for the launching of effluents tabs on the experimental flow rates, both for total coliform as the parameter for E. coli. Note to be examined in the effluent were not found to indicate metal contamination of effluent by slag from steel plants, indicating that the combination of treatment systems can be an effective alternative in the removal of contaminants.