Sulfate reduction in bioreactor in sequencing batch and fed-batch containing granulated biomass with mechanical stirring and draft-tube

Abstract

This present work evaluate an anaerobic sequencing batch reactor (ASBR), fed in batch and fed-batch, and cycles of 8 hours, using granulated biomass and mechanical stirring in a draft-tube, fed with synthetic wastewater (500 mgCOD/L), enriched with sulfate in some COD/['SO IND.4'POT.2-'] relations. In all operations the reactor showed a stable operation, producing alkalinity and maintaining the volatile acids in adequate levels. Considering the fed periods of 10 min, 3 h and 6 h, respectively, the removal efficiencies of the sulfate was 30, 72 e 72%, in the operations when the reactor was fed with a COD/['SO IND.4'POT.2-'] relation of 1,34. In the essays when the reactor was fed in COD/['SO IND.4'POT.2-'] relation of 0,67, the efficiencies of the sulfate reduction was 25, 58 e 55%, respectively. When the reactor was operated with COD/['SO IND.4'POT.2-'] relation of 0,34, the efficiencies of sulfate reduction 23, 37 e 27%, respectively. Thus, is possible to conclude that the operations in fed-batch increased the efficiency of sulfate removal, at what time was observed that in batch operations the organic matter removal attained improved efficiencies.