Does Continuous Bioaugmentation of Aerated Stabilization Basins Improve Performance? A Field Scale Trial With a Control

Continuous bioaugmentation is widely employed across the pulp and paper industry in attempts to improve the resilience of wastewater treatment systems or the performance of undersized (in terms of volume, aeration, or nutrient supply) systems. Bench and field scale research into bioaugmentation has shown that success is often unpredictable. A field scale trial at an aerated lagoon system treating pulp and paper mill wastewater was completed over a 6-month period. The system consisted of two nearly identical trains of aerated stabilization basins (ASBs), one operated as a control and the other treated with a commercially available bioaugmentation product. The control and treated basins were then switched to minimize train-specific effects. Throughout the trial, changes in soluble or total biochemical oxygen demand (sBOD5 and TBOD5, respectively) or total suspended solids (TSS) at the first of the two ponds in series were not associated with bioaugmentation. In the second set of ponds, bioaugmentation was associated with 6.0 ± 2.6 mg/L higher TBOD5 and 12.4 ± 5.2 mg/L higher TSS. Further, 16S rRNA gene sequencing identified high levels of Thiothrix in the bioaugmented train, whereas TSS data between the trains diverged. This provided evidence that the significant difference in BOD and TSS was likely due to a microbial community dominated by a filamentous bacterial bloom rather than bioaugmentation.