DIXO, N. G. H.; DIXO, Norma Geraldi Hidalgo.
Resumo:
This work evaluated the effluent from an anaerobic upflow digester (DAFA) that treats domestic sewage in the Pedregal neighborhood, located in the city of Campina Brande. The post-treatment was done in a series of pilot scale shallow stabilization ponds, being a facultative (F1), followed by three maturation (M1, M2 and M3), and had as main objective the removal of pathogenic organisms for to the reuse of the final effluent in unrestricted irrigation. The crude sewage had an average concentration of approximately 2.8 x 10 fecal coliforms per 100 ml and 16,800 ae of intestinal helminths per liter. DAFA removed about 67% of fecal Califorms and 90% of helminth eggs, whose final mean concentrations were 9.2 x 10 6/100 ml and 1750/1, respectively. The series of ponds that received the DAFA effluent operated with a total hydraulic detention time of 20 days and produced a final effluent compatible with the microbiological standards recommended by the World Health Organization for its reuse in unrestricted irrigation. High pH values were obtained in the last two lagoons, mainly in M3, whose value reached 10 during the day. An inverse correlation was observed between pH and fecal coliforms. The pond series removed about 85% of the ammoniacal nitrogen present in the DAFA effluent. In terms of the removal of BOD, DQD and suspended solids, the lagoons were not efficient due to the large algae biomass leaving the effluent.
