Bacterial diversity in aerated facultative lagoon treating kraft cellulose effluent with bioaugmentation

Abstract

The microbiological diversity was evaluated in an aerated facultative lagoon system with organic loading rates of 0.2 and 0.6 kgCODm-3d-1 treating effluent from the kraft pulp industry for bioaugmentation purposes. Samples were taken from a laboratory-scale lagoon at steady state treating kraft pulp effluent and operated with two different rates for 120 days. The analysis was performed by 16S rDNA sequencing. The autochthonous bacteria were identified through statistical similarity obtained from the NCBI-BLAST database. The lagoon performance was assessed based on the removal efficiency of biochemical oxygen demand (94% and 80%), chemical oxygen demand (51% and 44%), total organic carbon (49% and 41%), lignin-derived compounds (13% and 27%), turbidity (94% and 87%), for the low and high rates used respectively. Color and TPC were not significantly removed during the biological treatment of the industrial matrix. In the biomass samples collected at a steady state, 9 and 12 species of bacteria were identified at the applied rates. The species Bacillus cereus, Bacillus thuringiensis, and Paenibacillus glucanolyticus found in this matrix presented significant removal of the parameters in the kraft effluent. The three referred species show great promise in the removal of specific parameters in an AFL biological treatment system using bioaugmentation.